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Peer-reviewed articles

2024

Al Atrach,M., Phan.C-M., Jones,L. Extended release of ciprofloxacin from commercial contact lenses containing vitamin E diffusion barriers Optometry and Vision Science 2024;Online ahead of print

Arvind,A., Najappa,R., Gupta,K. K., Macedo-De-Araujo,R. J., Fadel,F. Lid wiper epitheliopathy: Topical review of current identification strategies and future perspectives Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Lid Wiper Epitheliopathy (LWE) is a recognized ocular condition affecting visual quality and ocular comfort, characterized by the damage of the marginal conjunctiva of the upper eyelid. This review critically examines the current strategies for LWE identification and explores the multifactorial etiology of LWE and its association with various ocular surface diseases. A literature review conducted on PubMed identified 67 relevant studies, which were analyzed to enhance understanding of LWE’s diagnostic criteria and its clinical implications, offering future perspectives on improving diagnostic accuracy and patient outcomes.

The association between LWE and contact lens-related discomfort is examined, with studies reporting conflicting findings regarding its prevalence and severity among soft contact lens wearers. Moreover, LWE has been linked to tear film abnormalities, altered tear composition, and eyelid margin abnormalities in non-contact lens wearers, further complicating diagnosis and management.

Current LWE grading systems, including subjective methods and semi-objective approaches, are reviewed, highlighting challenges such as subjectivity, complexity, and variability. Recent advances in LWE grading, including semi-automated methods and photographic scales, show promise but face implementation challenges in clinical settings.

The review concludes by proposing areas for further research, including investigating factors contributing to LWE onset and development, developing more sensitive diagnostic tools, and exploring the impact of LWE on ocular surface health and visual function. Standardization, validation, and innovation in grading systems are emphasized to enhance diagnostic accuracy and improve clinical outcomes for patients with LWE. Ongoing research in LWE grading is essential for addressing diagnostic challenges and optimizing assessment methodologies in clinical practice.

Aziz,A., Kuppusamy,R., Mazumder,K., Hui,A., Maulvi,F., Stapleton,F., Willcox,M. Absorption and attachment of atropine to etafilcon A contact lenses Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Purpose: Myopia (short-sightedness) is a growing vision problem worldwide. Currently atropine eye drops are used to control the progression of myopia but these suffer from potential lack of bioavailability and low ocular residence time. Commercially available myopia control contact lenses are also used to limit myopia progression, but neither atropine nor contact lenses individually completely stop progression. Development of myopia control contact lenses which could deliver therapeutic doses of atropine is thus desirable and may provide increased efficacy. This study was designed to explore the feasibility of attaching atropine to etafilcon A contact lenses through an esterification reaction.

Methods: Carboxylic acid groups on etafilcon A contact lenses were quantified using Toluidine Blue O. The carboxylic acid groups in etafilcon A contact lenses were activated using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC-HCl) and N-hydroxysuccinimide (NHS) crosslinkers after which atropine was added to undergo potential binding via esterification. Atropine was released from lenses by alkaline hydrolysis. Reverse phase high performance liquid chromatography (HPLC) was used to detect and quantify the released atropine and its degradation products in solution. Contact lenses that had not been activated by EDC-NHS (controls) were also examined to determine the amount of atropine that could be absorbed rather than chemically bound to lenses.

Results: Each etafilcon A contact lens contained 741.1 ± 5.5 µg carboxylic acid groups which may be available for esterification. HPLC had a limit of detection for atropine of 0.38 µg/mL and for tropic acid, an atropine degradation product, of 0.80 µg/mL. The limits of quantification were 1.16 µg/mL for atropine and 2.41 µg/mL for tropic acid in NH4HCO3. The etafilcon A lenses adsorbed up to 7.69 μg atropine when incubated in a 5 mg/mL atropine solution for 24 h. However, there was no evidence that atropine could be chemically linked to the lenses, as washing in a high concentration of NaCl removed all the atropine from the contact lenses with no atropine being subsequently released from the lenses after incubating in 0.01 N NH4HCO3.

Conclusions: Etafilcon A contact lenses contain free carboxylic acids which may be an appropriate option for attaching drugs such as atropine. Etafilcon A lenses adsorbed up to 7.69 μg atropine, which would be more than enough to deliver atropine to eyes to control myopia. However, atropine could not be chemically bound to the carboxylic acids of the etafilcon A lenses using this methodology.

Bose,S., Phan,C.-M., Rizwan,M., Tse,J. W., Yim,E., Jones,L. Fabrication and Characterization of an Enzyme-Triggered, Therapeutic-Releasing Hydrogel Bandage Contact Lens Material Pharmaceutics 2024;16(1):Article 26 [ Show Abstract ]

Purpose: The purpose of this study was to develop an enzyme-triggered, therapeutic-releasing bandage contact lens material using a unique gelatin methacrylate formulation (GelMA+).

Methods: Two GelMA+ formulations, 20% w/v, and 30% w/v concentrations, were prepared through UV polymerization. The physical properties of the material, including porosity, tensile strain, and swelling ratio, were characterized. The enzymatic degradation of the material was assessed in the presence of matrix metalloproteinase-9 (MMP-9) at concentrations ranging from 0 to 300 µg/mL. Cell viability, cell growth, and cytotoxicity on the GelMA+ gels were evaluated using the AlamarBlueTM assay and the LIVE/DEADTM Viability/Cytotoxicity kit staining with immortalized human corneal epithelial cells over 5 days. For drug release analysis, the 30% w/v gels were loaded with 3 µg of bovine lactoferrin (BLF) as a model drug, and its release was examined over 5 days under various MMP-9 concentrations.

Results: The 30% w/v GelMA+ demonstrated higher crosslinking density, increased tensile strength, smaller pore size, and lower swelling ratio (p < 0.05). In contrast, the 20% w/v GelMA+ degraded at a significantly faster rate (p < 0.001), reaching almost complete degradation within 48 h in the presence of 300 µg/mL of MMP-9. No signs of cytotoxic effects were observed in the live/dead staining assay for either concentration after 5 days. However, the 30% w/v GelMA+ exhibited significantly higher cell viability (p < 0.05). The 30% w/v GelMA+ demonstrated sustained release of the BLF over 5 days. The release rate of BLF increased significantly with higher concentrations of MMP-9 (p < 0.001), corresponding to the degradation rate of the gels.

Discussion: The release of BLF from GelMA+ gels was driven by a combination of diffusion and degradation of the material by MMP-9 enzymes. This work demonstrated that a GelMA+-based material that releases a therapeutic agent can be triggered by enzymes found in the tear fluid.

Chow,A. H. Y., Mungalsingh,M., Thai,D., Selimos,Z., Yan,S. K., Xu,H., Jones,D. A. Suitability of multifunction devices Myah and Myopia Master for monitoring myopia progression in children and adults Ophthalmic and Physiological Optics 2024;44(5):1017-1030 [ Show Abstract ]

Purpose: To assess the feasibility of using multifunction instruments to measure axial length for monitoring myopia progression in children and adults.

Methods: Axial length was measured in 60 children (aged 6–18 years) and 60 adults (aged 19–50 years) with multifunction instruments (Myah and Myopia Master) and stand-alone biometers (Lenstar LS900 and IOLMaster 700). Repeatability (measurements by the same examiner) and reproducibility (measurements by different examiners) were computed as the within-subject standard deviation (Sw) and 95% limits of agreement (LoA). Inter-instrument agreement was computed as intraclass correlation coefficients. The threshold for detecting myopic progression was taken as 0.1 mm. Measures were repeated only in children following the administration of 1% tropicamide to determine the impact of cycloplegia on axial length.

Results: Overall, the IOLMaster 700 had the best repeatability in children (0.014 mm) and adults (0.009 mm). Repeatability Sw values for all devices ranged from 0.005 to 0.021 mm (children) and 0.003 to 0.016 mm (adults). In children, reproducibility fell within 0.1 mm 95% of the time for the Myah, Myopia Master and IOLMaster 700. Agreement among all devices was classified as excellent (ICC 0.999; 95% CI 0.998–0.999), but the 95% LoA among the Myah, Myopia Master and Lenstar LS900 was ≥0.1 mm. Cycloplegia had no statistically significant effect on axial length (all p > 0.13).
Conclusions: The Myah and Myopia Master multifunction instruments demonstrated good repeatability and reproducibility, and their accuracy was comparable to stand-alone biometers. Axial length measurements using different instruments can be considered interchangeable but should be compared with some caution. Accurate axial length measurements can be obtained without cycloplegia. The multifunction instruments Myah and Myopia Master are as well suited for monitoring myopia progression in children as the stand-alone biometers IOLMaster 700 and Lenstar LS900.

Dang,R., Ehrmann,K., Jalbert,I., Hui,A., Kang,P. Refractive power profiles of commercially available soft multifocal contact lenses for myopia control Ophthalmic and Physiological Optics 2024;Online ahead of print [ Show Abstract ]

Purpose: Lens power profiles can provide valuable insights on the imposed optical defocus and visual experience of contact lens wearers, especially in the context of myopia control. This study measured the refractive power profiles of multifocal soft contact lenses (MFCLs) currently used or that have the potential for use in myopia control using high spatial resolution aberrometry. The instrument's repeatability for determining MFCLs power profiles was also assessed.

Method: The power profiles of 10 MFCLs of various designs (centre-distance, centre-near and extended depth of focus) were measured using the Lambda-X NIMOEVO, a phase shifting Schlieren-based device. Power profiles were graphically expressed as measured power at each chord position and the maximum add power was calculated. The repeatability of the NIMOEVO was expressed as the within-subject standard deviation at each chord position for a subset of five MFCLs.

Results: The measured distance powers differed from nominal powers for more than half of the MFCLs with a definable distance zone. There were variations in the chord position of the distance and near correction zones, rate of power transitions and calculated maximum add between the MFCLs which did not depend on lens design. For half of the MFCLs, the power profile shape was inconsistent between different nominal back vertex powers of the same design. The repeatability of the NIMOEVO was dependent on the lens design, with designs featuring faster rates of power change exhibiting worse repeatability.

Conclusions: Significant differences in MFCL power profiles were found which were not adequately represented in labelling. This is likely due to the small number of parameters used to define lens power characteristics. Eye health care practitioners should be aware of potential differences in power profiles between different MFCLs, which will impact the retinal defocus introduced during lens wear and the wearer's visual experience.

Efron,N., Morgan,P., Woods,C. A., Jones,D. A., Jones,L., Nichols,J. International trends in rigid contact lens prescribing (2000–2023): An update Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Purpose: Rigid contact lenses have an important role in contact lens practice. The purpose of this work is to update earlier surveys by describing global trends in rigid lens fitting between 2000-2023.

Method: An annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023. Data relating to 342,500 fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of rigid lens fitting, defined as the fitting of any design of a contact lens manufactured in a rigid material.

Results: Overall, rigid lens prescribing increased slightly over time, from 14.2 % of lens fits in 2000 to 15.2 % in 2023 (p < 0.0001). However, post-hoc analysis shows that the change over time is best described as a decline between 2000 and 2012, followed by a steady increase subsequently. There were significant differences in rigid lens prescribing between countries (p < 0.0001). The difference between the percentage of males fitted with rigid lenses, as a proportion of all contact lenses (12.7 %), and females (12.0 %) is significant (p < 0.0001), although not clinically meaningful. Rigid lens wearers are older at fitting than soft lens wearers (38.7 vs 31.3 years,
respectively) (p < 0.0001). Analysis of 5,994 rigid lens fits prescribed currently (2019–2023) were categorised as: corneal sphere – 30 %; scleral and corneo-scleral – 28 %; corneal myopia control/orthokeratology – 21 %; and corneal complex (including toric, multifocal and monovision) – 16 %.

Conclusion: There has been a slight increase in rigid lens fitting during the second decade of this century. This increase is apparently due to a ‘repurposing’ of rigid lenses, with the growth of scleral/corneo-scleral and myopia control/orthokeratology lens fits essentially replacing conventional spherical corneal lens fits.

Efron,N., Morgan,P., Woods,C. A., Jones,D. A., Jones,L., Nichols,J. International trends in prescribing toric soft contact lenses to correct astigmatism (2000–2023): An update Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Purpose
There have been significant advancements in toric soft contact lens design and manufacturing technology, and increased product availability, over the past half a century. The purpose of this work is to update earlier surveys by describing international trends in toric soft lens fitting between 2000 and 2023, inclusive.

Method
An annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023, inclusive. Data relating to 220,934 standard soft daily wear single vision lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of toric soft lens fitting.

Results
Overall, toric soft lens prescribing almost doubled over the time-course of this survey, from 24.4 % of standard soft daily wear single vision lens fits in 2000 to 46.2 % in 2023 (p < 0.0001). There were significant differences between countries in toric soft lens prescribing (p < 0.0001). Of all standard soft daily wear single vision contact lenses prescribed to males, 32.0 % were toric soft lenses, compared with 28.7 % for females (p < 0.0001). The mean age of toric soft lens wearers was 30.5 ± 12.5 years, compared to 27.9. ± 12.1 years for spherical soft lens wearers (p < 0.0001). Analysis of 13,582 recent toric soft lens fits (2019–2023, inclusive), in terms of material type and replacement frequency, revealed the following proportions: reusable silicone hydrogel – 51 %; daily disposable silicone hydrogel – 27 %; daily disposable hydrogel – 12 %; and reusable hydrogel – 10 %.

Conclusion
There has been a substantial increase in toric soft lens fitting throughout the 24 years of this survey, to a point whereby almost all clinically significant astigmatism is being corrected among those wearing standard soft daily wear single vision lenses.

Efron,N., Morgan,P., Woods,C. A., Jones,D. A., Jones,L., Nichols,J. International trends in prescribing silicone hydrogel contact lenses for daily wear (2000–2023): An update Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Purpose
Introduced around the turn of the 21st century, silicone hydrogel contact lenses alleviated hypoxic anterior eye complications due to their high oxygen transmissibility. The purpose of this work is to update earlier surveys by describing international trends in silicone hydrogel daily wear contact lens fitting between 2000 and 2023.

Method
An annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023. Data relating to 260,144 daily wear soft contact lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of silicone hydrogel daily wear contact lens fitting.

Results
There has been a dramatic increase in silicone hydrogel daily wear lens fits (p < 0.0001), increasing from 2.8 % of all daily wear soft lens fits in 2000 to 73.7 % in 2023. Of all daily wear soft contact lenses prescribed to males, 44.6 % were silicone hydrogel lenses, compared with 43.5 % for females (p = 0.0146). The mean age of those wearing silicone hydrogel daily wear lenses was 32.0 ± 14.5 years, compared to 30.4 ± 13.6 years for those wearing daily wear hydrogel lenses (p < 0.0001). Between 2019–2023, the average percentage of fits was – (a) material type: silicone hydrogel – 73 %; mid-water content hydrogels – 13 %; high water content hydrogels – 9 %; and low water content hydrogels – 5 %, and (b) lens design: spherical – 44 %, toric – 32 %, multifocal – 17 %, monovision – 4 %, and ‘other’ – 3 %.

Conclusion
The dramatic increase in silicone hydrogel contact lens prescribing for daily wear has been commensurate with the introduction of multiple lens brands and an ongoing expansion of lens designs, parameters and replacement frequency options. The balance between silicone hydrogel and hydrogel lens prescribing is perhaps starting to approach an equilibrium.

Fadel,D., Macedo-de-Araújo,R. J., Barnett,M. The Patient-Physician Relationship and Role of Empathic Communication in Contact Lens Practice Journal of Contact Lens Research and Science 2024;8(1):20-36

Ganguly,S., Wulff,D., Phan,C-M., Jones,L., Tang,X. Injectable and 3D Extrusion Printable Hydrophilic Silicone-Based Hydrogels for Controlled Ocular Delivery of Ophthalmic Drugs Applied Bio Materials 2024;Online ahead of print [ Show Abstract ]

While silicone elastomers have found widespread use in the biomedical industry, 3D printing them has proven to be difficult due to the material’s slow drying time, low viscosity, and hydrophobicity. Herein, we arrested the hydrophilic silicone (HS) macrochains into a semi-interpenetrating polymer network (semi-IPN) via an in situ photogelation-assisted 3D microextrusion printing technique. The flow behavior of the pregel solutions and the mechanical properties of the printed HS hydrogels were tested, showing a high elastic modulus (approximately 15 kPa), a low tan δ, high elasticity, and delayed network rupturing. The uniaxial compression tests
demonstrated a nearly negligible permanent deformation, suggesting that the printed hybrid hydrogel maintained its elastic properties. Drug loading and diffusion in the microporous hydrogel are shown via the non-Fickian anomalous transport mechanism, leading to highly tunable loading/releasing profiles (approximately 20% cumulative release) depending on the HS concentration. The drug encapsulation exhibits exceptional stability, remaining intact without any degradation even after a storage period of 1 month. As far as we know, this is the first soft biomaterial based on HS that functions as an exceptional controlled drug delivery device.

Guthrie,S. E., Luensmann, D., Woods,J., Vega,J., Orsborn,G. Relationships Between Success Factors in Daily Disposable Multifocal Contact Lenses Clinical Optometry 2024;16157-167 [ Show Abstract ]

Purpose: To explore links between subjective comfort and vision in habitual multifocal soft contact lens (MFCL) wearers when refit with daily disposable MFCLs, to determine which factors are relevant for success with MFCLs and evaluate consistency between MFCLs of different designs.

Patients and Methods: This work examined subjective measures in a randomised, participant masked, bilateral wear crossover study at five optometry practices. Fifty-eight habitual MFCL wearers wore stenfilcon A multifocal (stenA-MF; CooperVision Inc) and delefilcon A multifocal (delA-MF; Alcon) for two-weeks. Subjective ratings included satisfaction with comfort and vision and agreement questions.

Results: Agreement with “I would like to wear this MFCL in the future” was taken to indicate success with each MFCL; agreement was significantly higher with stenA-MF. There was strong correlation between agreement responses for “I would like to wear this MFCL in the future” and “MFCL met my needs for vision” with both lenses (p< 0.01). However, it was only with stenA-MF, which had higher agreement responses to both statements (p< 0.05), that responses to these two statements correlated with satisfaction with end-of-day (EOD) comfort (p< 0.01). These differences in correlations between the two lenses are seemingly driven by greater satisfaction with stenA-MF for near and intermediate vision (p< 0.05).

Conclusion: Subjective vision and comfort were only correlated when vision met the needs of most participants. Meeting participants’ needs for vision correlated strongly with wanting to wear a MFCL. Results indicate that meeting vision needs is more important than meeting comfort needs when influencing whether presbyopic patients continue wearing MFCLs.

Guthrie,S., Luensmann,D., Schulze,M., Woods,J., Jones,L. Investigation of Delefilcon A Contact Lenses for Symptomatic Daily Disposable Contact Lens Wearers with Dry Eye Disease: A Prospective Comparative Study Clinical Ophthalmology 2024;Online ahead of print [ Show Abstract ]

Purpose: This prospective comparative study aimed to assess the effects on contact lens comfort, dryness, and wear time when symptomatic daily disposable (DD) contact lens (CL) wearers were refit with delefilcon A (DT1) lenses.

Patients and methods: Thirty five symptomatic DD CL wearers with dry eye disease as determined according to the TFOS DEWS 2 guidelines, were enrolled and completed the study. Participants wore their habitual DD CLs during an initial assessment and were subsequently refit with DT1 for one month. Participants were masked to the study lens type. Subjective ratings of end-of-day comfort and dryness, average wear time, and comfortable wear time were evaluated as primary endpoints.

Results: Of the 35 participants, two participants were classified as aqueous deficient dry eye, while the remaining participants exhibited symptoms primarily due to evaporative causes. The median CLDEQ-8 score for dryness significantly improved from 17 (fair) with habitual lenses to 13 (good) with DT1 lenses (p<0.01). Participants reported significantly better end-of-day comfort (p=0.01) and less end of day dryness (p=0.01) with DT1 compared to their habitual DD lenses. The comfortable wear time was significantly longer with DT1 (8.5 ± 4.1 hours) compared to habitual DD lenses (6.7 ± 3.2 hours) (p=0.04). No significant differences were observed in vision ratings (p=0.07).

Conclusion: Refitting symptomatic DD CL wearers with DT1 resulted in improved end-of-day comfort, reduced end-of-day dryness, and extended comfortable wear time compared to their habitual lenses. These findings suggest that DT1 may offer benefits for symptomatic DD wearers with dry eye disease.

Jabeen,A., Luensmann,D., Woods,J., Hill,J., Jones,L. Evaluation of Lag of Accommodation with Full-Field Diffusion Optics Technology™ (DOT) Contrast Management Spectacle Lenses in Emmetropic Children Clinical Ophthalmology 2024;18(May):1181-1190 [ Show Abstract ]

Purpose: To evaluate the impact on the lag of accommodation (LOA) in emmetropic children after short-term wear of full-field Diffusion Optics TechnologyTM (DOT) spectacle lenses, designed to modulate retinal contrast to control myopia progression.

Patients and methods: This was a single-visit, prospective, randomized, subject-masked study of emmetropes (ametropes ±1.00D or less in each meridian) with no history of myopia control treatment. Unaided logMAR visual acuity was measured, and ocular dominance was determined using the sighting method. In a randomized order, participants wore plano full-field contrast management (DOT) spectacles (no clear central aperture) or control spectacles (standard single vision spectacle lenses). Each participant was given 5 minutes for adaptation to the respective lenses before open field autorefraction measurements were taken at 6 meters and 40 cm. Ten measurements were taken for each eye. Data were evaluated from the right eye and the dominant eye separately.

Results: A total of 30 participants (20 females and 10 males) with a mean age of 10.4 ± 2.8 (7 to 17) years completed the study. There was no significant difference in right eye mean LOA with contrast management spectacles 0.57 ± 0.39D versus control spectacles 0.62 ± 0.34D; Wilcoxon test, p = 0.37. For dominant eyes, LOA values were 0.60 ± 0.40D and 0.68 ± 0.33D with contrast management spectacles and control spectacles, respectively (p = 0.14). Additionally, no significant difference was observed in mean LOA between males and females or between age groups (7-11 years vs 12-17 years) for either right or dominant eyes with contrast management or control spectacles (all p > 0.05).

Conclusion: Full-field contrast management spectacle lenses had no significant effect on LOA compared to standard single vision spectacle lenses, indicating no differential impact on accommodative response over the short period of lens wear tested.

Jiang,Q., Zhang,Z., Niu,L., Wang,B., Fadel,D., Wei,R., Chen,Z. Changes in anterior segment after short-term scleral lens wear in healthy Chinese population Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Purpose
To evaluate the impact of short-term scleral lens (SL) wear on anterior chamber (AC) dimension and central corneal thickness (CCT) in healthy Chinese people.

Methods
This is a prospective, daily wear study. Eligible participants were dispensed SLs to correct refractive errors. Anterior segment (AS) parameters were measured by AS optical coherence tomography (AS-OCT) before, during, and after 2 and 4 hours of lens wear. Repeated-measures analysis of variance (ANOVA) was used to analyze the changes in AS parameters over time.

Results
Twelve subjects (10 females and 2 males) with a mean age of 25.3 ± 3.8 years (ranging from 21 to 34 years) were recruited. The AC parameters, including anterior chamber depth (ACD) from the endothelium (endo-ACD), angle opening distance at 500 μm (AOD500), and trabecular-iris space area at 500 μm (TISA500), significantly decreased after wearing SLs for 4 hours (P<0.05). CCT increased by 12 μm (2.29 %) after wearing SLs for 4 hours (P=0.013).

Conclusion
This study suggests that SL wear has a significant impact on AS dimensions in patients with healthy corneas in the short term with SL in situ, but tend to recover quickly after SL removal. Further research is needed to determine whether the change in AS dimensions during SL wear affects aqueous humor (AH) outflow and causes changes in intraocular pressure (IOP).

Jin,Y., Minten,C., Jenkins,M., Jones,L., Gorbet,M. Investigation of the rhythmic recruitment of tear neutrophils to the ocular surface and their phenotypes Scientific Reports 2024;147061 [ Show Abstract ]

Hundreds of thousands of polymorphonuclear neutrophils (PMNs) are collected from the ocular surface upon waking, while few are harvested during daytime. This study aimed to investigate potential factors contributing to the circadian infiltration of tear PMNs, including changes in IL-8 and C5a in tears, and their phenotypes across different time points in a 24-h cycle. Tear PMNs were collected using a gentle eyewash after 2-h and 7-h of sleep (eye closure, EC) at night, after 2-h EC during the day, and towards the end of the afternoon. Significantly fewer cells were collected after 2-h EC during the day compared to 2-h EC at night. A positive correlation between IL-8 and PMN numbers existed, but not with C5a. Tear PMNs collected after 2-h EC at night were less degranulated and possessed a larger activation potential compared to 7-h EC. Tear PMNs from 7-h EC at night exhibited hyper-segmented nuclei and more NETosis compared to 2 h EC night, indicating an aged and activated phenotype. The diurnal-nocturnal recruitment pattern of tear PMNs may be driven by increased IL-8 in nighttime tears. Higher degranulation and NETs point to the significant activation of tear PMNs on the ocular surface during prolonged eye closure at night.

Laughton,D., Hill,J. S., McParland,M., Tasso,V., Woods,J., Zhu,X., Young,G., Craven,R., Hunt,C., Neitz,J., Neitz,M., Chalberg,T., Jones,D., Wolffsohn,J. Control of myopia using diffusion optics spectacle lenses: 4-year results of a multicentre randomised controlled, efficacy and safety study (CYPRESS) BMJ Open Ophthalmology 2024;9.e001790 [ Show Abstract ]

Aims To evaluate the myopia control efficacy of Diffusion Optics Technology (DOT) spectacle lenses in children over a 4-year treatment period.

Methods CYPRESS Part 1 (NCT03623074) was a 3-year multicentre, randomised, controlled, double-masked trial comparing two investigational spectacle lens DOT designs (Test 1, Test 2) and standard single vision Control lenses in 256 North American children aged 6–10 years. Children completing Part 1 (n=200) were invited to enrol in CYPRESS Part 2 (NCT04947735) for an additional 1-year period. In Part 2, Test 1 (n=35) and Control groups (n=42) continued with their original lens assignment and the Test 2 group (n=21) were crossed over to Test 1 (DOT 0.2) lenses. The co-primary endpoints were change from baseline in axial length (AL) and cycloplegic spherical equivalent refraction (cSER).

Results Test 1 spectacle lenses demonstrated superiority to the Control in both co-primary endpoints: with a difference between means (Test 1−Control) of −0.13 mm for AL (p=0.018) and 0.33 D for cSER (p=0.008) in Part 1 and −0.05 mm for AL (p=0.038) and 0.13 D for cSER (p=0.043) in Part 2. Comparing treatment effects in Part 1 and 2 suggests that COVID-19 public health restrictions negatively impacted treatment efficacy in study years 2 and 3.

Conclusion DOT 0.2 spectacle lenses are safe and effective at reducing myopia progression, with additional benefit evident in year 4 of wear. These results support the hypothesis that a mild reduction in retinal contrast can slow myopia progression in young children. The unprecedented disruption in participant schooling and lifestyle during the COVID-19 pandemic may have depressed treatment efficacy in Part 1.

Mishra,S. K., Baidya,S., Bhattarai,A., Shrestha,S., Homagan,S., Rayamajhee,B., Hui,A., Willcox,M. Bacteriology of Endotracheal Tube Biofilms and Antibiotic Resistance: A Systematic Review Journal of Hospital Infection 2024;Online ahead of print [ Show Abstract ]

Background
Bacteria commonly adhere to surfaces and produce polymeric material to encase the attached cells to form communities called biofilms. Within these biofilms, bacteria can appear many times more resistant to antibiotics or disinfectants. This systematic review explores the prevalence and microbial profile associated with biofilm production of bacteria isolated from endotracheal tubes and its associations with antimicrobial resistance.

Methods
A comprehensive search was performed on databases PubMed, Embase, and Google Scholar for relevant articles published between January 1, 2000 and December 31, 2022. The relevant articles were exported to Mendeley Desktop 1.19.8 and screened by title and abstract, followed by full text screening based on the eligibility criteria of the study. Quality assessment of the studies was performed using the Newcastle-Ottawa Scale (NOS) customized for cross-sectional studies. Furthermore, the prevalence of antimicrobial resistance in biofilm-producers isolated from endotracheal tube specimens was investigated.

Results
Twenty studies encompassing 981 endotracheal tubes met the eligibility criteria. Pseudomonas spp. and Acinetobacter spp. were predominant isolates among the biofilm producers. These biofilms provided strong resistance against commonly used antibiotics. The highest resistance rate observed in Pseudomonas spp. was against fluoroquinolones whereas the least resistance was seen against piperacillin-tazobactam. A similar trend of susceptibility was observed in Acinetobacter spp. with a very high resistance rate against fluoroquinolones, third-generation cephalosporins and carbapenems.

Conclusion
Endotracheal tubes were associated with colonisation by biofilm forming bacteria with varying levels of antimicrobial resistance. Biofilms may promote the occurrence of recalcitrant infections in endotracheal tubes which need to be managed with appropriate protocols and antimicrobial stewardship. Research focus should shift towards meticulous exploration of biofilm-associated infections to improve detection and management.

Mohseni,M., Shokrollahi,P., Barzin, J. Gelatin/O-carboxymethyl chitosan injectable self-healing hydrogels for ibuprofen and naproxen dual release International Journal of Biological Macromolecules 2024;263, Part 1(April):Art No 130266

Morgan,P., Efron,N., Woods,C. A., Jones,D. A., Jones,L., Nichols,J. International trends in daily disposable contact lens prescribing (2000–2023): An update Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Purpose
Daily disposable contact lenses offer numerous benefits in terms of ocular health and wearer convenience. The purpose of this work is to update earlier surveys by describing global trends in daily disposable lens fitting between 2000 and 2023.

Method
An annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023, inclusive. Data relating to 265,106 daily wear soft lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of daily disposable lens fitting.

Results
Overall, daily disposable lens prescribing increased over time, from 17.1 % of daily wear soft lens fits in 2000 to 46.7 % in 2023 (p < 0.0001). There were significant differences between countries in daily disposable lens prescribing (p < 0.0001), and between the percentage of males fitted with daily disposable lenses, as a proportion of all daily wear soft lenses (37.2 %), compared to females (35.2 %) (p < 0.0001). Daily disposable lens wearers are slightly younger at fitting than reusable soft lens wearers (31.0 vs 31.2 years, respectively) (p < 0.0001), although this difference is not clinically meaningful. Analysis of 50,240 daily wear soft lenses fitted recently (2019–2023) were found to be prescribed for the following replacement frequencies: daily – 47 %; monthly – 42 %; 1–2 weekly – 9 %; and ≥3 monthly – 2 %.

Conclusion
There has been a substantial increase in daily disposable lens fitting throughout the first 24 years of this century. The gradual nature of this increase is commensurate with the staged introduction of daily disposable lens designs and expanded parameter ranges over the survey period.

Morgan,P., Efron,N., Woods,C. A., Jones,D. A., Jones,L., Nichols,J. International trends in prescribing extended wear soft contact lenses (2000–2023): An update Contact Lens Anterior Eye 2024;Online ahead of print [ Show Abstract ]

Purpose
Extended wear has long been considered as the ultimate contact lens modality in terms of user convenience. The purpose of this work is to update earlier surveys by describing international trends in extended wear soft lens fitting between 2000 and 2023, inclusive.

Method
An annual contact lens prescribing survey was sent to eye care practitioners in up to 71 countries between 2000 and 2023, inclusive. Data relating to 282,142 soft contact lens fits undertaken in 20 countries returning reliable longitudinal data were analysed in respect of extended wear soft lens fitting.

Results
Over the duration of the work there was a very small decrease in the prescribing of extended wear soft lenses (p < 0.0001). More detailed inspection shows that prescribing of these lenses steadily increased from 5.8 % of all soft lens fits in 2000 to 11.6 % in 2007, then steadily decreased to 5.2 % in 2023. Of all soft contact lenses prescribed to males, 9.2 % were fitted for extended wear, compared with 6.7 % for females (p < 0.0001). The mean age of extended wear soft lens wearers at fitting was 34.7 ± 14.7 years, compared to 31.1. ± 14.10 years for daily soft lens wearers (p < 0.0001). Analysis of 1,948 recent extended wear soft lens fits (2019–2023, inclusive), in terms of material type, revealed that, on average, 86 % and 14 % of extended wear soft lenses were fitted using silicone hydrogel and hydrogel materials, respectively.

Conclusion
A modest increase in extended wear soft lens prescribing from 2000 to 2007 corresponded with the introduction of high oxygen transmissibility silicone hydrogel lenses. However, prescribing of this lens type declined thereafter, probably due to ongoing concerns over their increased rate of microbial keratitis, resulting in a prescribing rate in 2023 (5.2%) that was little different to that observed in 2000 (5.8%).

Navascues-Cornago,M., Guthrie,S., Morgan,P., Woods,J. Determination of the Minimal Clinically Important Difference (MCID) for Ocular Subjective Responses Transl Vis Sci Technol 2024;13(8):28 [ Show Abstract ]

Purpose: To determine the minimal clinically important difference (MCID) for contact lens (CL)-related subjective responses and explore whether MCID values differ between subjective responses and study designs.
Methods: This was a retrospective analysis of data from seven one-week bilateral crossover studies and 14 one-day contralateral CL studies. For comfort, dryness, vision, or ease of insertion, participants rated on a 0-100 visual analogue scale (VAS) and indicated lens preference on a five-point Likert scale featuring strong, slight, and no preferences. For each criterion, four MCID estimates were calculated and averaged: mean VAS score difference for "slight preference," lower limit of 95% confidence interval VAS score difference for "slight preference," difference in mean VAS score difference between "slight" and "no preference" and 0.5 standard deviation of VAS scores.
Results: The four calculation methods generated a small range of MCID values. For bilateral studies, the averaged MCID was 7.2 (range 5.4-8.8) for comfort, 8.1 (5.2-10.6) for dryness, 7.1 (5.5-9.3) for vision and 7.6 (6.0-10.5) for ease of insertion. For contralateral studies, the averaged MCID was 6.9 (6.1-7.6) for comfort at insertion and 7.5 (6.8-8.2) for end-of-day comfort.
Conclusions: This work demonstrated very similar MCID values across subjective responses and study designs, in a population of habitual soft CL wearers. In all cases, MCID values were on average seven units on a 0 to 100 VAS.
Translational relevance: This work provides MCID values which are important for interpreting ocular subjective responses and planning clinical studies.

Phan,C. M., Chan,V. W. Y., Drolle,E., Hui,A., Ngo,W., Bose,S., Shows,A., Liang,S., Sharma,B., Subbaraman,L., Zheng,Y., Shi,X., Wu,J., Jones,L. Evaluating the in vitro wettability and coefficient of friction of a novel and contemporary reusable silicone hydrogel contact lens materials using an in vitro blink model Contact Lens Anterior Eye 2024;47(2):102129 [ Show Abstract ]

Purpose
To evaluate the in vitro wettability and coefficient of friction of a novel amphiphilic polymeric surfactant (APS), poly(oxyethylene)–co-poly(oxybutylene) (PEO-PBO) releasing silicone hydrogel (SiHy) contact lens material (serafilcon A), compared to other reusable SiHy lens materials.

Methods
The release of fluorescently-labelled nitrobenzoxadiazole (NBD)-PEO-PBO was evaluated from serafilcon A over 7 days in a vial. The wettability and coefficient of friction of serafilcon A and three contemporary SiHy contact lens materials (senofilcon A; samfilcon A; comfilcon A) were evaluated using an in vitro blink model over their recommended wearing period; t = 0, 1, 7, 14 days for all lens types and t = 30 days for samfilcon A and comfilcon A (n = 4). Sessile drop contact angles were determined and in vitro non-invasive keratographic break-up time (NIKBUT) measurements were assessed on a blink model via the OCULUS Keratograph 5 M. The coefficient of friction was measured using a nano tribometer.

Results
The relative fluorescence of NBD-PEO-PBO decreased in serafilcon A by approximately 18 % after 7 days. The amount of NBD-PEO-PBO released on day 7 was 50 % less than the amount released on day 1 (6.5±1.0 vs 3.4±0.5 µg/lens). The reduction in PEO-PBO in the lens also coincided with an increase in contact angles for serafilcon A after 7 days (p 0.05). The other contact lens materials had stable contact angles and NIKBUT over their recommended wearing period (p > 0.05), with the exception of samfilcon A, which had an increase in contact angle after 14 days as compared to t = 0 (p < 0.05). Senofilcon A and samfilcon A also showed an increase in coefficient of friction at 14 and 30 days, respectively, compared to their blister pack values (p < 0.05).

Conclusion
The results indicate that serafilcon A gradually depletes its reserve of PEO-PBO over 1 week, but this decrease did not significantly change the lens performance in vitro during this time frame.

Qiu,S. X., Fadel,D., Hui,A. Scleral Lenses for Managing Dry Eye Disease in the Absence of Corneal Irregularities: What Is the Current Evidence? Journal of Clinical Medicine 2024;13(13):3838 [ Show Abstract ]

Scleral lenses (SLs) are large-diameter rigid contact lenses that are a mainstay treatment for eyes with corneal irregularities. In recent years, there has been increased interest in the role of managing dry eye disease (DED) with SLs, as many patients with DED have reported symptomatic relief with SL wear. The role of SLs for DED management when there are associated corneal irregularities is supported by individual case reports and studies. This has prompted practitioners to begin advocating using SLs in DED cases, even in the absence of associated corneal irregularities and other ocular surface diseases (OSDs). There have also been discussions on potentially placing SLs earlier in the treatment hierarchy of DED, where it currently sits at a more advanced level of intervention (Step 3) in the TFOS DEWS II Report. This review will present the currently available, albeit sparse, evidence that supports and suggests this practice, as well as ancillary evidence supporting the purported benefits of SL wear in DED. The advantages of SL wear, such as corneal healing, absence of tear evaporation and contact lens dehydration, and improved visual acuity with associated increased wear comfort, and how this will benefit DED patients will be explored. Conversely, the challenges associated with fitting SLs in DED patients, including increased midday fogging, poor wettability, and subjective patient satisfaction, will also be presented, as well as a discussion on the key considerations for SL fitting in this population. Overall, while more research is needed to support the use of SLs in DED patients without associated corneal irregularities and other forms of OSD, the use of these lenses may prove to have a potentially wider role given their reported ancillary benefits in these populations.

Sara,M. Hui,A., Yasir,M., Hari Kumar,P., Kalaiselvan,P., Willcox,M. Intrastromal Corneal Ring Implants Associated Bacterial Infections Current Eye Research 2024;Online ahead of print [ Show Abstract ]

Purpose: This study examines the incidence of infection and resistance associated with Intracorneal Ring Segment (ICRS) implantation, a common outpatient surgical treatment for correcting refractive errors and corneal ectatic diseases. Although ICRS procedures are typically safe and reversible, there is a low but notable risk of microbial infections, which require prompt and sometimes invasive treatment.

Methods: Three electronic databases, PubMed, Web of Science (WoS), and Scopus, were utilised to search for literature according to PRISMA guidelines to identify infections related to the implantation of ICRS in the cornea between January 2000 and December 2022.

Results: Gram-positive organisms were involved in 86% of cases: 35.7% S. aureus, 25% coagulase-negative staphylococci species, 17.8% streptococci and 7.1% Nocardia species. Less commonly recorded were Gram-negative bacteria (14%), with Pseudomonas aeruginosa (circa 10%) and Klebsiella pneumonia (4%) being the most common Gram-negative bacteria. In rare cases, fungi have also been reported. ICRS-related bacterial infections can be categorised into early or late onset. Early onset infection typically manifests within the first few weeks after implantation and is often associated with contamination during surgery, unhygienic practices, or inadequate sterilisation techniques. On the other hand, late-onset infection may develop months or even years after the initial procedures and may be associated with persistent bacterial colonisation, secondary infections, or prolonged use of prophylactic antibiotics. S aureus is encountered in both early and late-onset infections, while Nocardia species and K. pneumoniae have generally been reported to occur in late-onset infections. In addition, vision recovery from S. aureus infections tends to be poor compared to other bacterial infections.

Conclusion: S. aureus is a predominant pathogen that often requires surgical intervention with poor outcomes. Early infections result from incision gaps and ring segment rubbing, while late infections are linked to prolonged antibiotic use. Further research is needed on novel antimicrobial ICRS to procure the vision.

Wolffsohn,J. S., Berkow,D., Chan,K. Y., Chaurasiya,S. K., Fadel,D., Haddad,M., Imane, T., Jones,L., Sheppard,A. L., Vianya-Estopa,M., Walsh,K., Woods,J., Zeri,F., Morgan,P. B. BCLA CLEAR Presbyopia: Evaluation and diagnosis Contact Lens Anterior Eye 2024;47(4):102156 [ Show Abstract ]

It is important to be able to measure the range of clear focus in clinical practice to advise on presbyopia correction techniques and to optimise the correction power. Both subjective and objective techniques are necessary: subjective techniques (such as patient reported outcome questionnaires and defocus curves) assess the impact of presbyopia on a patient and how the combination of residual objective accommodation and their natural DoF work for them; objective techniques (such as autorefraction, corneal topography and lens imaging) allow the clinician to understand how well a technique is working optically and whether it is the right choice or how adjustments can be made to optimise performance. Techniques to assess visual performance and adverse effects must be carefully conducted to gain a reliable end-point, considering the target size, contrast and illumination. Objective techniques are generally more reliable, can help to explain unexpected subjective results and imaging can be a powerful communication tool with patients. A clear diagnosis, excluding factors such as binocular vision issues or digital eye strain that can also cause similar symptoms, is critical for the patient to understand and adapt to presbyopia. Some corrective options are more permanent, such as implanted inlays / intraocular lenses or laser refractive surgery, so the optics can be trialled with contact lenses in advance (including differences between the eyes) to better communicate with the patient how the optics will work for them so they can make an informed choice.

Wong,K-Y., Liu,Y., Phan,C-M., Jones,L., Wong,M-S., Liu,J. Selection of DNA aptamers for sensing drugs treating eye disease: atropine and timolol maleate Sensors & Diagnostics 2024;Online ahead of print [ Show Abstract ]

Effective monitoring of ocular drugs is crucial for personalized medicine and improving drug delivery efficacy. However, traditional methods face difficulties in detecting low drug concentrations in small volumes of ocular fluid, such as that found on the ocular surface. In this study, we used capture-SELEX to select aptamers for two commonly used ocular drugs, timolol maleate and atropine. We identified TMJ-1 and AT-1 aptamers with binding affinities of 3.4 μM timolol maleate and 10 μM atropine, respectively. Our label-free TMJ-1 biosensor using thioflavin T staining achieved a limit of detection (LOD) of 0.3 μM for timolol maleate. The AT-1 biosensor showed an LOD of 1 μM for atropine, and exhibited a 10-fold higher sensitivity compared to UV-visible spectroscopy. Future research in this area holds promise in enhancing drug delivery monitoring and improving the treatment of ocular diseases.

Wu,T.-Y., Huang,C.-C., Tsai,H.C., Lon,T.-K., Chen,P.-Y., Darge,H. F., Hong,Z.-X., Ham,H.-J., Lin,S.-Z., Lai,J.-Y., Chen,Y.-S. Mucin-mediated mucosal retention via end-terminal modified Pluronic F127-based hydrogel to increase drug accumulation in the lungs Biomaterials Advances 2024;Jan(156):213722 [ Show Abstract ]

Noninvasive lung drug delivery is critical for treating respiratory diseases. Pluronic-based copolymers have been used as multifunctional materials for medical and biological applications. However, the Pluronic F127-based hydrogel is rapidly degraded, adversely affecting the mechanical stability for prolonged drug release. Therefore, this study designed two thermosensitive copolymers by modifying the Pluronic F127 terminal groups with carboxyl (ADF127) or amine groups (EDF127) to improve the viscosity and storage modulus of drug formulations. β-alanine and ethylenediamine were conjugated at the terminal of Pluronic F127 using a two-step acetylation process, and the final copolymers were characterized using 1H nuclear magnetic resonance (1H NMR) and Fourier-transform infrared spectra. According to the 1H NMR spectra, Pluronic F127 was functionalized to form ADF127 and EDF127 with 85 % and 71 % functionalization degrees, respectively. Rheological studies revealed that the ADF127 (15 wt%) and EDF127 (15 wt%) viscosities increased from 1480 Pa.s (Pluronic F127) to 1700 Pa.s and 1800 Pa.s, respectively. Furthermore, the elastic modulus of ADF127 and EDF127 increased, compared with that of native Pluronic F127 with the addition of 5 % mucin, particularly for ADF127, thereby signifying the stronger adhesive nature of ADF127 and EDF127 with mucin. Additionally, ADF127 and EDF127 exhibited a decreased gelation temperature, decreasing from 33 °C (Pluronic F127 at 15 wt%) to 24 °C. Notably, the in vitro ADF127 and EDF127 drug release was prolonged (95 %; 48 h) by the hydrogel encapsulation of the liposome-Bdph combined with mucin, and the intermolecular hydrogen bonding between the mucin and the hydrogel increased the retention time and stiffness of the hydrogels. Furthermore, ADF127 and EDF127 incubated with NIH-3T3 cells exhibited biocompatibility within 2 mg/mL, compared with Pluronic F127. The nasal administration method was used to examine the biodistribution of the modified hydrogel carrying liposomes or exosomes with fluorescence using the IVIS system. Drug accumulation in the lungs decreased in the following order: ADF127 > EDF127 > liposomes or exosomes alone. These results indicated that the carboxyl group-modified Pluronic F127 enabled well-distributed drug accumulation in the lungs, which is beneficial for intranasal administration routes in treating diseases such as lung fibrosis.

2023

Abdi,B., Mofidfar,M., Hassanpout,F., Cilingir,E. K., Kalajahi,S., Milani,P. K., Ghanbarzadeh,M., Fadel,D., Barnett,M., Ta,C. N., Leblanc,R. M., Chauhan,A., Abbasi,F. Therapeutic contact lenses for the treatment of corneal and ocular surface diseases: Advances in extended and targeted drug delivery International Journal of Pharmaceutics 2023;638(May):122740 [ Show Abstract ]

The eye is one of the most important organs in the human body providing critical information on the environment. Many corneal diseases can lead to vision loss affecting the lives of people around the world. Ophthalmic drug delivery has always been a major challenge in the medical sciences. Since traditional methods are less efficient (∼5%) at delivering drugs to ocular tissues, contact lenses have generated growing interest in ocular drug delivery due to their potential to enhance drug bioavailability in ocular tissues. The main techniques used to achieve sustained release are discussed in this review, including soaking in drug solutions, incorporating drug into multilayered contact lenses, use of vitamin E barriers, molecular imprinting, nanoparticles, micelles and liposomes. The most clinically relevant results on different eye pathologies are presented. In addition, this review summarizes the benefits of contact lenses over eye drops, strategies for incorporating drugs into lenses to achieve sustained release, results of in vitro and in vivo studies, and recent advances in the commercialization of therapeutic contact lenses for allergic conjunctivitis.

Akbari,E., Imani,R., Shokrollahi,P., Keshel,S. H. Corneal sustained delivery of hyaluronic acid from nanofiber-containing ring-implanted contact lens Journal of Biomaterials Application 2023;37(6):992-1006 [ Show Abstract ]

Dry eye syndrome, as a persist corneal epithelial defect (PED), is an inconvenient ocular disorder that is generally treated by high-dosage, conventional eye drops. Addressing low efficacy and rather restricted bioavailability of the conventional eye drops, drug-eluting contact lenses (CLs) are widely used as alternatives in ophthalmic drug delivery applications. In the present study, a nanofiber-containing ring implant poly (vinyl alcohol) (PVA) hydrogel is designed as a carrier for hyaluronic acid (HA) delivery. hyaluronic acid is physically encapsulated in a nanofiber-containing ring-shaped hydrogel with a 2 mm width that is implanted in the final CLs hydrogel. The designed CL has 59% porosity, 275% swelling ratio and undergoes no weight loss at physiological conditions in14 days. In-vitro release studies were performed on the CLs with and without nanofibers. The results showed that nanofiber incorporation in the designed CL was highly influential in decreasing burst release and supported sustained release of HA over 14 days. In addition, nanofiber incorporation in the designed system strengthened the lens, and the young modulus of the PVA hydrogel increased from 6 to 10 kPa. Cell viability study also revealed no cell cytotoxicity and cell attachment. Overall, the study demonstrated the effective role of nanofibers in the physical strengthening of the CL. Also, the designed system holds promise as a potential candidate for HA delivery over an extended period for treating dry eye syndrome.

Bitton,E., Jones,D., Wittich,W. Financial Inequities in Optometric Education in Canada: A Comparison of Two Optometry Programs Optometry and Vision Science 2023;Online ahead of print [ Show Abstract ]

Significance: The advancing age of the population will require increased access to eyecare services to manage eye diseases and vision correction. Optometric education requires a sound financial plan to manage student debt. This study evaluates the financial inequalities of optometric programs in Canada, and how this may impact the provision of eyecare professionals.

Purpose: The objective of this study was to compare the financial inequities in Optometric education in Canada from the 2020 graduating class.

Methods: A cross-sectional study assessed monetary variables related to the study of optometry in Canada, including academic and personal expenses, and overall debt and expenses related to the COVID-19 lockdown for the 2020 graduating class.

Results: 108 optometry students from the 2020 graduating classes of the University of Montreal and the University of Waterloo responded, with 68 (53 F:15 M, age 25.66, SD = 2.01) completing the study. Waterloo students spent more years in university (P < .001); had higher academic fees (P <.001); spent more on travelling to their family residence (P =.007) and received more provincial (P = .002) and federal (P <.001) loans than Montreal students. Overall debt prior to optometry was similar amongst students but differed (P <.001) at the end of their program, with Waterloo students having a higher debt burden.

Conclusions: There is a financial inequity in optometric education in Canada depending on the chosen program. Cumulative optometry student debt for the 2020 graduating class in Canada ranges from $CAN 0 to 189,000 with an average of $CAN 65,800 and a median of $CAN 50,000. The results of this study can assist financial, government agencies and future optometry students to better understand the financial burdens and establish a financial plan to study optometry in Canada, to respond to the growing eyecare needs of the public.

Caffery,B., Pucker,A., Chidi-Egboka,C., Obinwanne,C. J., Karkness,B., Carnt,N. A., Ng,A. Y. Lubricating drops for contact lens discomfort in adults Cochrane Database of Systematic Reviews 2023 (5):CD015751 [ Show Abstract ]

Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. To determine the efficacy and safety of lubricating drops for ocular discomfort associated with contact lens wear in adults.

Craig,J. P., Alves,M., Wolffsohn,J., Downie,L. E., Efron,N., Galor,A., Gomes,J. A. P., Jones,L., Markoulli,M., Stapleton,F., Starr,C. E., Gallant Sullivan,A., Willcox,M. D. P., Sullivan,D. A. TFOS lifestyle report introduction: A lifestyle epidemic – Ocular surface disease Ocular Surface 2023;28(April):304-309 [ Show Abstract ]

Lifestyle defines how a person lives. While the way we live can impact our environment, thed environment can influence the way we live, and both can affect our health. The ocular surface, and in particular the tear film, is susceptible to modifications due to its external (e.g. environmental conditions, lifestyle and societal challenges, and the digital environment), applied (e.g. contact lens wear and cosmetics) or internal (e.g. nutrition, and elective medications and procedures) environments. Consequently, it is critical for clinicians to understand the impact of lifestyle choices on the ocular surface so that they can communicate with their patients to optimise their health and, wherever possible, institute preventative steps to mitigate potential health risk factors.

To increase awareness of the potential impacts of lifestyle choices on ocular surface health, the Tear Film & Ocular Surface Society (TFOS) launched the TFOS Workshop entitled “A Lifestyle Epidemic: Ocular Surface Disease.” Consistent with prior TFOS Workshops [[1], [2], [3], [4]], the aim was to review existing literature, to identify gaps in knowledge and to propose future directions for research, with the long-term goal of improving the lives of individuals affected by ocular surface disease around the world.

Under the leadership of the Workshop Chair Jennifer Craig, Vice Chair Monica Alves, and Organizer David Sullivan, a Steering Committee was formed (Table 1) to plan and execute this TFOS Lifestyle Workshop. The Steering Committee was committed to an evidence-based approach and a process of open communication, dialogue and transparency, to achieve a consensus concerning the relationship(s) between lifestyle factors and their impact on ocular surface disease.

Craig,J., Alves,M., Wolffsohn,J., Downie,L., Efron,N., Galor,A., Gomes,J., Jones,L., Markoulli,M., Stapleton,F., Starr,C., Sullivan,A., Willcox,M., Sullivan,D TFOS Lifestyle Report Executive Summary: A Lifestyle Epidemic - Ocular Surface Disease Ocular Surface 2023;30(October):240-253 [ Show Abstract ]

The Tear Film & Ocular Surface Society (TFOS) Workshop entitled ‘A Lifestyle Epidemic: Ocular Surface Disease’ was a global initiative undertaken to establish the direct and indirect impacts of everyday lifestyle choices and challenges on ocular surface health. This article presents an executive summary of the evidence-based conclusions and recommendations of the 10-part TFOS Lifestyle Workshop report. Lifestyle factors described within the report include contact lenses, cosmetics, digital environment, elective medications and procedures, environmental conditions, lifestyle challenges, nutrition, and societal challenges. For each topic area, the current literature was summarized and appraised in a narrative-style review and the answer to a key topic-specific question was sought using systematic review methodology. The TFOS Lifestyle Workshop report was published in its entirety in the April 2023 and July 2023 issues of The Ocular Surface journal. Links to downloadable versions of the document and supplementary material, including report translations, are available on the TFOS website: http://www.TearFilm.org.

Efron,N., Morgan,P., Jones,L., Nichols,J. Who cites optometry journals? Journal of Optometry 2023;Online ahead of print [ Show Abstract ]

Purpose
This work seeks to identify the most impactful journals, papers, authors, institutions, and countries that cite optometry journal articles.

Methods
The Scopus database was searched for papers citing at least one article published in any of the 18 optometry journals included in that database (i.e. ‘optometry articles’). The 10 most highly cited papers that cite optometry journal articles were determined from 82,830 papers found. A h-index for “optometry journal citations” (the hOJC-index) was derived for each entity in the categories of journals, papers, authors, institutions and countries to serve as a measure of impact.

Results
The hOJC-index of the body of papers citing optometry journal articles is 370. Papers citing optometry journal articles have themselves been cited 2,054,816 times. Investigative Ophthalmology & Visual Science (hOJC = 154) is the most impactful journal citing optometry articles and Optometry and Vision Science the most prolific (5310 papers). The most impactful paper citing optometry journal articles (5725 citations) was published in Journal of Clinical Epidemiology. Ophthalmologist Seang Mei Saw (hOJC = 69) is the most impactful author and optometrist Nathan Efron is the most prolific (288 papers). Harvard University (hOJC = 127) is the most impactful and UNSW Sydney is the most prolific institution (1761 papers). The United States is the most impactful and prolific nation (hOJC = 313; 28,485 papers).

Conclusions
Optometry journal articles are cited extensively by optometrists, ophthalmologists, and vision scientists world-wide, as well as authors from a broad spectrum of non-ophthalmic research domains. This work confirms the utility and influence of optometry journals.

Fadel,D. Medmont Meridia™: Much More Than a Corneal Topographer Clinical Optometry 2023;15 283-301 [ Show Abstract ]

In recent years, advanced diagnostic instruments have become widely available in optometric practices, offering various functions that optimize clinical information gathering. This article focuses on the Medmont Meridia™, a state-of-the-art multipurpose diagnostic device with corneal topography and cutting-edge features. Corneal topography is pivotal in the early diagnosis of corneal disorders, determining baseline ocular surface assessment, helping in contact lens fitting, and monitoring ocular health over time. The Medmont Meridia boasts Placido-disc-based imaging with extensive corneal coverage. Furthermore, the Meridia accurately measures the horizontal visible iris diameter, pupil diameter, and palpebral fissure width, which assists in making contact lens parameter decisions. Additionally, it offers sagittal height data for scleral lens design and first lens selection, streamlining the fitting process. Beyond its topography capabilities, the Meridia excels as a comprehensive dry eye assessment tool. With features like tear meniscus height, tear film surface quality, and meibography capabilities, it aids in diagnosing dry eye and monitoring its progression. The device also provides customizable dry eye reports with integrated grading scales and questionnaires, making dry eye management, patient education, and compliance more accessible. In conclusion, the Medmont Meridia consolidates a multitude of examination tools in a single instrument, enhancing practice efficiency and elevating patient care and communication. Its versatility and accuracy make it an invaluable asset in optometric practices worldwide.

Fadel,D., Gildea,C. Case Report: Remote Scleral Lens Fitting for High Toric Scleras in a Keratoconus Patient Optometry and Vision Science 2023;100(12):876-881 [ Show Abstract ]

SIGNIFICANCE
Technology plays a crucial role in customizing scleral lenses and improving lens alignment, especially in challenging scleral shapes. In addition, remote fitting technology allows optometrists to extend their expertise globally, empowering patients to access to customized lenses without travel expenses.

PURPOSE
The objective of this study was to document the difficulties encountered in fitting a scleral lens in a patient with keratoconus and pronounced scleral toricity. In addition, the study aimed to present the successful remote fitting achieved by using advanced technology.

CASE REPORT
An Irish male patient diagnosed with keratoconus exhibited high scleral toricity. Generally, keratoconus eyes often exhibit significant scleral asymmetry associated with cone decentration and disease severity. Improperly aligned scleral lenses can lead to regional changes in scleral shape, lens decentration, discomfort, and visual disturbances. Indeed, previous scleral lens fits were unsuccessful because of these issues. Corneoscleral profilometry was acquired in Ireland and then used in Italy to design customized lenses, which were then delivered to the patient's optometrist in Ireland. The first lenses designed and delivered demonstrated excellent overall performance without requiring adjustments.

CONCLUSIONS
This report highlights the importance of corneoscleral profilometry to increase efficiency and reduce lens reorders and chair time, and the remote fitting in overcoming barriers to accessing specialized lens fitting.

Huynh,C. B., Nagaarudkumaran,N., Kalyaanamoorthy,S., Ngo,W. In Silico and In Vitro Approach for Validating the Inhibition of Matrix Metalloproteinase-9 by Quercetin Eye & Contact Lens 2023;49(5):193-198 [ Show Abstract ]

Purpose:
To validate the mechanism and inhibitory activity of quercetin against matrix metalloproteinase-9 (MMP-9) using a hybrid in silico and in vitro approach.

Methods:
The structure of MMP-9 was obtained from the Protein Data Bank, and the active site was identified using previous annotations from the Universal Protein Resource. The structure of quercetin was obtained from ZINC15. Molecular docking was performed to quantify the binding affinity of quercetin to the active site of MMP-9. The inhibitory effect of various concentrations of quercetin (0.0025, 0.025, 0.25, 1.0, and 1.5 mM) on MMP-9 was quantified using a commercially available fluorometric assay. The cytotoxicity of quercetin to immortalized human corneal epithelial cells (HCECs) was quantified by obtaining the metabolic activities of the cells exposed to various concentrations of quercetin for 24 hr.

Results:
Quercetin interacts with MMP-9 by binding within the active site pocket and interacting with residues LEU 188, ALA 189, GLU 227, and MET 247. The binding affinity predicted by molecular docking was −9.9 kcal/mol. All concentrations of quercetin demonstrated significant inhibition of MMP-9 enzyme activity (all P0.99).

Conclusions:
Quercetin inhibited MMP-9 in a dose-dependent manner and was well-tolerated by HCECs, suggesting a potential role in therapy for diseases with upregulated MMP-9 as part of its pathogenesis.

Jones,L., Efron,N., Bandamwar,K., Barnett,M., Jacobs,D. S., Jalbert,I., Pult,H., Rhee,M. K., Sheardown,H., Shovlin,J. P., Stahl,U., Sranila,A., Tan,J. Tavazzi,S., Ucakhan,O. O., Willcox,M. D. P., Downie,L. TFOS lifestyle: Impact of contact lenses on the ocular surface Ocular Surface 2023;29(July):175-219 [ Show Abstract ]

Several lifestyle choices made by contact lens wearers can have adverse consequences on ocular health. These include being non-adherent to contact lens care, sleeping in lenses, ill-advised purchasing options, not seeing an eyecare professional for regular aftercare visits, wearing lenses when feeling unwell, wearing lenses too soon after various forms of ophthalmic surgery, and wearing lenses when engaged in risky behaviours (e.g., using tobacco, alcohol or recreational drugs). Those with a pre-existing compromised ocular surface may find that contact lens wear exacerbates ocular disease morbidity. Conversely, contact lenses may have various therapeutic benefits. The coronavirus disease-2019 (COVID-19) pandemic has impinged upon the lifestyle of contact lens wearers, introducing challenges such as mask-associated dry eye, contact lens discomfort with increased use of digital devices, inadvertent exposure to hand sanitizers, and reduced use of lenses. Wearing contact lenses in challenging environments, such as in the presence of dust and noxious chemicals, or where there is the possibility of ocular trauma (e.g., sport or working with tools) can be problematic, although in some instances lenses can be protective. Contact lenses can be worn for sport, theatre, at high altitude, driving at night, in the military and in space, and special considerations are required when prescribing in such situations to ensure successful outcomes. A systematic review and meta-analysis, incorporated within the review, identified that the influence of lifestyle factors on soft contact lens dropout remains poorly understood, and is an area in need of further research. Overall, this report investigated lifestyle-related choices made by clinicians and contact lens wearers and discovered that when appropriate lifestyle choices are made, contact lens wear can enhance the quality of life of wearers.

Nichols,J. J., Morgan,P. B., Jones,L. W., Efron, N Bibliometric Analysis of Ophthalmic Journals JAMA Ophthalmology 2023;141(7):651-657 [ Show Abstract ]

KEY POINTS
Question: What articles, journals, authors, institutions, and countries in the ophthalmic literature are the most highly cited and prolific and have the highest h-index for ophthalmic journal articles?

Findings: In this qualitative study, the h-index for ophthalmic journal articles was determined to be 494, which appeared comparable with the journal literature of other medical disciplines.

Meaning: While these analyses excluded ophthalmology articles in general medical journals, they suggest a strong ophthalmic research base underpins eye care, with ophthalmology having the highest h-index across a range of ophthalmic and vision disciplines contributing to this literature.

ABSTRACT
Importance: The primary vehicle for reporting and testing advances in eye care is refereed ophthalmic journals, which can be characterized using targeted bibliometric analyses.

Objective: To identify all ophthalmic journals and evaluate citation metrics relating to articles, journals, authors, institutions, and countries published therein.

Design and Setting: A bibliometric analysis was undertaken of all ophthalmic journals included in the Scopus database (Elsevier). The search was restricted to all article types published in ophthalmic journals in English from inception through November 18, 2022. After excluding general medical journals, journals published in a language other than English, and spurious titles unrelated to the ophthalmic field, the Scopus database was found to list 335 ophthalmic journal titles that have published 471 184 articles, constituting the data set for this analysis. The 20 most highly cited articles were identified. Rank-order lists by article count were assembled for journals, authors, institutions, and countries.

Main Outcomes and Measures: An h-index for ophthalmic journal articles was derived from citations and article counts for each constituent of each category.

Results: The h-index for ophthalmic journal articles was determined to be 494. The journal with the highest h-index was Ophthalmology (h-index, 297). The journal with the greatest number of articles was American Journal of Ophthalmology (38 441 articles). The most highly cited article was by Quigley and Broman, 2006 (5147 citations), concerning the epidemiology of glaucoma. The author with the highest h-index for ophthalmic journal articles was Ronald Klein, MD (h-index, 126), and the most prolific was Carol L. Shields, MD (1400 articles). Johns Hopkins University (h-index, 215) was the institution with the highest h-index for ophthalmic journal articles, and Harvard University was the most prolific (10 071 articles). The United States was the nation with the highest h-index for ophthalmic journal articles (h-index, 444) and was the most prolific (180 017 articles).

Conclusions and Relevance: In this study, the most highly cited articles published in ophthalmic journals were revealed, as well as the leading journals, authors, institutions, and countries. While excluding ophthalmology articles in general medical journals, this investigation affords a means of identifying highly cited authors, institutions, and countries which individuals or institutions can use as a guide regarding contributions to the field.

Nichols,J. J., Morgan,P. B., Jones,L. W., Efron, N The history of optometry journals from a bibliometric perspective Hindsight 2023;54(2):36-43 [ Show Abstract ]

The rich history of optometric journal publications has been well documented, but the scientific impact of all optometry journals over all time has not been published. This work aims to determine the most impactful papers, authors, institutions and countries publishing in optometry journals. A h-index for “optometry journal publications” (the “hOJP-index”) was derived for each constituent of each category to serve as a measure of impact. The hOJP-index for the 34,565 papers published in all optometry journals is 136; these papers have been cited 294,239 times. Optometry and Vision Science is the most impactful and prolific journal (hOJP=118; n=13,095 papers). The most highly cited paper, by Richard Armstrong, is entitled “When to use the Bonferroni correction” (1,172 citations). Australian optometrist Nathan Efron is the most impactful and prolific author (hOJP=41; n=273). UNSW Sydney and the University of California, Berkeley are the most impactful institutions (both hOJP=58), and UNSW Sydney is the most prolific (n=963). The most impactful and prolific nation is the United States (hOJP=109; n=12,050). This quantitative bibliometric analysis demonstrates an impactful optometric research base enshrined in optometry journals.

Pereira-da-Mota,A. F., Vivero-Lopez, M., Garg,P., Phan,C-M., Concheiro,A., Jones,L., Alvarez-Lorenzo,C. In vitro–in vivo correlation of drug release profiles from medicated contact lenses using an in vitro eye blink model Drug Delivery and Translational Research 2023;13(4):1116-1127 [ Show Abstract ]

There is still a paucity of information on how in vitro release profiles from drug-loaded contact lenses (CLs) recorded in 3D printed eye models correlate with in vivo profiles. This work aims to evaluate the release profiles of two drug-loaded CLs in a 3D in vitro eye blink model and compare the obtained results with the release in a vial and the drug levels in tear fluid previously obtained from an animal in vivo study. In vitro release in the eye model was tested at two different flow rates (5 and 10 µL/min) and a blink speed of 1 blink/10 s. Model CLs were loaded with two different drugs, hydrophilic pravastatin and hydrophobic resveratrol. The release of both drugs was more sustained and lower in the 3D eye model compared to the in vitro release in vials. Interestingly, both drugs presented similar release patterns in the eye model and in vivo, although the total amount of drugs released in the eye model was significantly lower, especially for resveratrol. Strong correlations between percentages of pravastatin released in the eye model and in vivo were found. These findings suggest that the current 3D printed eye blink model could be a useful tool to measure the release of ophthalmic drugs from medicated CLs. Nevertheless, physiological parameters such as the composition of the tear fluid and eyeball surface, tear flow rates, and temperature should be optimized in further studies.

Phan,C. M., Ross,M., Fahmy,M., McEwen,B., Hofmann,I., Chan,V. Clark-Baba,C., Jones,L. Evaluating Viscosity and Tear Breakup Time of Contemporary Commercial Ocular Lubricants on an In Vitro Eye Model Translational Vision Science & Technology 2023;12(6):29 [ Show Abstract ]

Purpose: To evaluate the link between the viscosity of ophthalmic formulation and tear film stability using a novel in vitro eye model.

Methods: The viscosities and noninvasive tear breakup time (NIKBUT) of 13 commercial ocular lubricants were measured to evaluate the correlation between viscosity and NIKBUT. The complex viscosity of each lubricant was measured three times for each angular frequency (ranging from 0.1 to 100 rad/s) using the Discovery HR-2 hybrid rheometer. The NIKBUT measurements were performed eight times for each lubricant using an advanced eye model mounted on the OCULUS Keratograph 5M. A contact lens (CL; ACUVUE OASYS [etafilcon A]) or a collagen shield (CS) was used as the simulated corneal surface. Phosphate-buffered saline was used as a simulated fluid.

Results: The results showed a positive correlation between viscosity and NIKBUT at high shear rates (at 10 rad/s, r = 0.67) but not at low shear. This correlation was even better for viscosities between 0 and 100 mPa*s (r = 0.85). Most of the lubricants tested in this study also had shear-thinning properties. OPTASE INTENSE, I-DROP PUR GEL, I DROP MGD, OASIS TEARS PLUS, and I-DROP PUR had higher viscosity in comparison to other lubricants (P < 0.05). All of the formulations had a higher NIKBUT than the control (2.7 ± 1.2 seconds for CS and 5.4 ± 0.9 seconds for CL) without any lubricant (P < 0.05). I-DROP PUR GEL, OASIS TEARS PLUS, I-DROP MGD, REFRESH OPTIVE ADVANCED, and OPTASE INTENSE had the highest NIKBUT using this eye model.

Conclusions: The results show that the viscosity is correlated with NIKBUT, but further work is necessary to determine the underlying mechanisms.

Ramaswamy,M., Ho,B., Phan,C. M., Qin,N., Ren,C. L., Jones,L. Inexpensive and rapid fabrication of PDMS microfluidic devices for biological testing applications using low cost commercially available 3D printers Journal of Micromechanics and Microengineering 2023;Online ahead of print [ Show Abstract ]

Polydimethylsiloxane (PDMS) elastomers have been extensively used in the development of microfluidic devices, capable of miniaturizing biomolecular and cellular assays to the microliter and nanoliter range, thereby increasing the throughput of experimentation. PDMS has been widely used due to its optical clarity and biocompatibility, among other desirable physical and chemical properties. Despite the widespread use of PDMS in microfluidic devices, the fabrication process typically requires specialized facilities, instruments, and materials only available in a limited number of laboratories. To expand microfluidic research capabilities to a greater scientific population, we developed and characterized a simple and robust method of fabricating relatively inexpensive PDMS microfluidic devices using readily available reagents and commercially available 3D printers. The moulds produced from the 3D printers resolve designed microfluidic channel features accurately with high resolution ( >100 µm). The critical physical and chemical post-processing modifications we outline here are required to generate functional and optically clear microfluidic devices.

Schulze,M., Fadel,D., Luensmann,D., Ng,A. Y., Guthrie,S., Woods,J., Jones,L. Evaluating the Performance of verofilcon A Daily Disposable Contact Lenses in a Group of Heavy Digital Device Users Clinical Ophthalmology 2023;173165-3175 [ Show Abstract ]

Purpose: The purpose of this study was to evaluate the performance of verofilcon A daily disposable contact lenses (CL) in CL wearers who identified themselves as heavy digital device users.
Patients and Methods: This prospective, non-masked, open-label study enrolled CL wearers who reported ≥ 6 hours digital device use per day. Participants were dispensed with the verofilcon A study lenses for 14± 2 days, to be worn for at least 5 days a week and 10 hours per day, while continuing their normal routine of digital device use. Participants rated the lens performance at the Day 14 visit using a 0– 100 (with 100 being best) scale. Ratings were completed at lens insertion, after 6 hours of digital device use, just before CL removal and for overall experience. Participants also completed a 4-point (strongly agree/disagree, slightly agree/disagree) Likert scale-based questionnaire.
Results: Thirty-two participants were eligible and completed the study (27 females; age 25.8 ± 6.0 years, ranging from 19 to 40). Overall lens performance ratings at the Day 14 visit (mean ± standard deviation) for comfort, dryness, and clarity of vision were 91 ± 11, 88 ± 11, and 92 ± 9, respectively. Subjective ratings were stable throughout the day with no significant differences after insertion, after 6 hours of digital device use and before CL removal (all p> 0.05). The majority of participants agreed that the study lenses performed well, provided good all-day comfort (28/32; p< 0.01) and good all-day vision (29/32; p< 0.01). Participants also agreed that after ≥ 6 hours of digital device use they were satisfied with CL comfort (27/32; p< 0.01), vision (29/32; p< 0.01) and that the lenses provided good performance (26/32; p< 0.01).
Conclusion: Verofilcon A lenses were found to perform well, with high ratings for comfort, dryness and vision that remained high throughout the day, during extensive digital device use.

Spafford,M. M., Chow,A. H. Y., Labreche,T., Jones,D. A., Christian,L. W. T., Furtado,N. M., MacIver,S., Irving,E. L. Trust and Access: Eye Information-seeking Practices and Preferences among Canadians Optometry and Vision Science 2023;100(7):467-474 [ Show Abstract ]

SIGNIFICANCE
This study highlights the value that the public places on obtaining trusted and accessible health-related information and their preference for obtaining it from their health care practitioners. Previous research has not been specific to Canadians or vision. Findings can be used to increase eye health literacy and eye care utilization.

PURPOSE
Canadians underuse eye care and underestimate the occurrence of asymptomatic eye disease. This study explored eye information-seeking practices and preferences among a group of Canadians.

METHODS
Using snowball sampling, a 28-item online survey collected respondent perceptions about their eye and health information-seeking practices and preferences. Questions examined electronic device access, information source use, and demographics. Two open-ended questions examined information-seeking practices and preferences. Respondents were at least 18 years old and living in Canada. Individuals working in eye care were excluded. Response frequencies and z scores were computed. Written comments were assessed using content analysis.

RESULTS
Respondents searched for less eye than health information (z scores ≥ 2.25, P < .05). For eye and health information, primary care providers were the used and preferred source, and reliance on Internet searches was greater than desired. Trust and access drove information-seeking practices. Respondent comments suggested that a hierarchy of trust operates across My Health Team, My Network, and My External Sources, with a persistent threat posed by Discredited Sources. Access to information sources seemed mediated by enablers (Convenience and Accessible Features) and barriers (Unreachable Health Team and Absent Systems). Eye information was seen as more specialized and harder to find. There was a high regard for health care practitioners who provide their patients with curated trusted information.

CONCLUSIONS
These Canadians value trusted and accessible health-related information. They prefer eye and health information from their health care practitioners and value when their health team provides online curated information, particularly regarding eyes.

Stapleton,F., Abad,J. C., Barabino,S., Burnett,A., Iyer,G., Lekhanont,K., Li,T., Liu,Y., Navas,A., Obinwanne,C. J., Qureshi,R., Roshandel,D., Sahin,A., Shih,K., Tichenor,A., Jones,L. TFOS Lifestyle: Impact of societal challenges on the ocular surface Ocular Surface 2023;28(April):165-199 [ Show Abstract ]

Societal factors associated with ocular surface diseases were mapped using a framework to characterize the relationship between the individual, their health and environment. The impact of the COVID-19 pandemic and mitigating factors on ocular surface diseases were considered in a systematic review. Age and sex effects were generally well-characterized for inflammatory, infectious, autoimmune and trauma-related conditions. Sex and gender, through biological, socio-economic, and cultural factors impact the prevalence and severity of disease, access to, and use of, care. Genetic factors, race, smoking and co-morbidities are generally well characterized, with interdependencies with geographical, employment and socioeconomic factors. Living and working conditions include employment, education, water and sanitation, poverty and socioeconomic class. Employment type and hobbies are associated with eye trauma and burns. Regional, global socio-economic, cultural and environmental conditions, include remoteness, geography, seasonality, availability of and access to services. Violence associated with war, acid attacks and domestic violence are associated with traumatic injuries. The impacts of conflict, pandemic and climate are exacerbated by decreased food security, access to health services and workers. Digital technology can impact diseases through physical and mental health effects and access to health information and services. The COVID-19 pandemic and related mitigating strategies are mostly associated with an increased risk of developing new or worsening existing ocular surface diseases. Societal factors impact the type and severity of ocular surface diseases, although there is considerable interdependence between factors. The overlay of the digital environment, natural disasters, conflict and the pandemic have modified access to services in some regions.

Sullivan,D., da Costa,A. X., Del Duca,E., Doll,T., Grupcheva,C. N., Lazreg,S., Liu,S-H., McGee,S. R., Murthy,R., Narang,P., Ng,A. Y., Nistico,S., O'Dell,L., Roos,J., Shen,J., Markoulli,M. TFOS lifestyle: Impact of cosmetics on the ocular surface Ocular Surface 2023;29(July):77-130 [ Show Abstract ]

In this report the use of eye cosmetic products and procedures and how this represents a lifestyle challenge that may exacerbate or promote the development of ocular surface and adnexal disease is discussed. Multiple aspects of eye cosmetics are addressed, including their history and market value, psychological and social impacts, possible problems associated with cosmetic ingredients, products, and procedures, and regulations for eye cosmetic use. In addition, a systematic review that critically appraises randomized controlled trial evidence concerning the ocular effects of eyelash growth products is included. The findings of this systematic review highlight the evidence gaps and indicate future directions for research to focus on ocular surface outcomes associated with eyelash growth products.

Watson,S. L., Jones,L. W., Stapleton,F., Hinds,M., Ng,A.Y., Tan,J, Alster,Y., Bosworth,C., Rafaeli,O., DePuy,V, Efficacy and safety of AZR-MD-001 selenium sulfide ophthalmic ointment in adults with meibomian gland dysfunction: A vehicle-controlled, randomized clinical trial The Ocular Surface 2023;29(July):537-546 [ Show Abstract ]

Purpose
Meibomian gland dysfunction (MGD) is a chronic progressive disease with downstream effects on ocular signs and symptoms. AZR-MD-001 is a selenium sulfide ophthalmic ointment that was investigated as a potential treatment option for patients with MGD.

Methods
A Phase 2, multi-center, double-masked, parallel group study was conducted across 29 sites, with 245 patients randomized 1:1:1 to AZR-MD-001 0.5%, AZR-MD-001 1.0% or vehicle applied to the lower eyelid, twice weekly. Patients were eligible for the trial if they presented with signs and symptoms of MGD. Co-primary efficacy endpoints were the changes from baseline in number of open glands (Meibomian Glands Yielding Liquid Secretion [MGYLS] score) and patient-reported ocular surface symptoms (Ocular Surface Disease Index [OSDI] total score) at Month 3. Efficacy outcomes were captured at Day 14, Month 1.5 and Month 3. Safety and tolerability were assessed for treatment-emergent adverse events (TEAEs).

Results
AZR-MD-001 0.5% (n = 82 patients) treatment resulted in significant improvements in MGYLS score, with patients experiencing an average increase from baseline of 4.2 and 2.4 open glands secreting meibum for the drug and vehicle, respectively (p < 0.001) and from baseline a mean OSDI total score improvement of 7.3 and 3.8 for the drug and vehicle, respectively (p < 0.05). Most TEAEs were mild and transient, with 3 serious adverse events (SAEs) reported with AZR-MD-001 (none related to study drug).

Conclusions
Co-primary endpoints were met for AZR-MD-001 0.5% at Month 3, with a statistically significant improvement in the signs and symptoms of MGD. AZR-MD-001 was safe and well tolerated.

Wong,K. Y., Phan,C.M., Chan,Y.T., Chuy-Ying Yuen,A., Zhao,D., Chan,K. Y., Do,C. W., Chuen Lam,T., Han Qiao,J., Wulff,D., Hui,A., Jones,L., Wong,M. S. A review of using Traditional Chinese Medicine in the management of glaucoma and cataract Clinical and Experimental Optometry 2023;Online ahead of print [ Show Abstract ]

Traditional Chinese Medicine has a long history in ophthalmology in China. Over 250 kinds of Traditional Chinese Medicine have been recorded in ancient books for the management of eye diseases, which may provide an alternative or supplement to current ocular therapies. However, the core holistic philosophy of Traditional Chinese Medicine that makes it attractive can also hinder its understanding from a scientific perspective – in particular, determining true cause and effect. This review focused on how Traditional Chinese Medicine could be applied to two prevalent ocular diseases, glaucoma, and cataract. The literature on preclinical and clinical studies in both English and Chinese on the use of Traditional Chinese Medicine to treat these two diseases was reviewed. The pharmacological effects, safety profile, and drug-herb interaction of selected herbal formulas were also investigated. Finally, key considerations for conducting future Traditional Chinese Medicine studies are discussed.

Woods,C., Naroo,S., Zeri,F., Bakkar,M., Barodawala,F., Evans,V., Fadel,D., Kalikivayi,L., Lira,M., Maseedupally,V., Trave Huarte,S., Eperjesi,F. Evidence for commonly used teaching, learning and assessment methods in contact lens clinical skills education Contact Lens Anterior Eye 2023;46(2):101821 [ Show Abstract ]

Introduction
Evidence based practice is now an important part of healthcare education. The aim of this narrative literature review was to determine what evidence exists on the efficacy of commonly used teaching and learning and assessment methods in the realm of contact lens skills education (CLE) in order to provide insights into best practice. A summary of the global regulation and provision of postgraduate learning and continuing professional development in CLE is included.

Method
An expert panel of educators was recruited and completed a literature review of current evidence of teaching and learning and assessment methods in healthcare training, with an emphasis on health care, general optometry and CLE.

Results
No direct evidence of benefit of teaching and learning and assessment methods in CLE were found. There was evidence for the benefit of some teaching and learning and assessment methods in other disciplines that could be transferable to CLE and could help students meet the intended learning outcomes. There was evidence that the following teaching and learning methods helped health-care and general optometry students meet the intended learning outcomes; clinical teaching and learning, flipped classrooms, clinical skills videos and clerkships. For assessment these methods were; essays, case presentations, objective structured clinical examinations, self-assessment and formative assessment. There was no evidence that the following teaching and learning methods helped health-care and general optometry students meet the intended learning outcomes; journal clubs and case discussions. Nor was any evidence found for the following assessment methods; multiple-choice questions, oral examinations, objective structured practical examinations, holistic assessment, and summative assessment.

Conclusion
Investigation into the efficacy of common teaching and learning and assessment methods in CLE are required and would be beneficial for the entire community of contact lens educators, and other disciplines that wish to adapt this approach of evidence-based teaching.

Yamasaki,K., Dantam,J., Sasanuma,K., Hisamura,R., Mizuno,Y., Hui,A., Jones,L. Impact of in vitro lens deposition and removal on bacterial adhesion to orthokeratology contact lenses Contact Lens Anterior Eye 2023;Online ahead of print [ Show Abstract ]

Purpose
The purpose of this study was to explore the impact of several contact lens (CL) care solutions on the removal of proteins and lipids, and how deposit removal impacts bacterial adhesion and solution disinfection.

Methods
Lysozyme and lipid deposition on three ortho-k (rigid) and two soft CL materials were evaluated using an ELISA kit and gas chromatography respectively. Bacterial adhesion to a fluorosilicone acrylate material using Pseudomonas aeruginosa with various compositions of artificial tear solutions (ATS), including with denatured proteins, was also investigated. The impact of deposition of the different formulations of ATS on biofilm formation was explored using cover slips. Finally, the lysozyme and lipid cleaning efficacy and disinfection efficacy against P. aeruginosa and Staphylococcus aureus of four different contact lens care solutions were studied using qualitative analysis.

Results
While maximum lysozyme deposition was observed with the fluorosilicone acrylate material (327.25 ± 54.25 µg/lens), the highest amount of lipid deposition was recorded with a fluoro-siloxanyl styrene material (134.71 ± 19.87 µg/lens). Adhesion of P. aeruginosa to fluorosilicone acrylate lenses and biofilm formation on cover slips were significantly greater with the addition of denatured proteins and lipids. Of the four contact lens care solutions investigated, the solution based on povidone-iodine removed both denatured lysozyme and lipid deposits and could effectively disinfect against P. aeruginosa and S. aureus when contaminated with denatured proteins and lipids. In contrast, the peroxide-based solution was able to inhibit P. aeruginosa growth only, while the two multipurpose solutions were unable to disinfect lenses contaminated with denatured proteins and lipids.

Conclusion
Bacterial adhesion and biofilm formation is influenced by components within artificial tear solutions depositing on lenses, including denatured proteins and lipids, which also affects disinfection. The ability of different solutions to remove these deposits should be considered when selecting systems to clean and disinfect ortho-k lenses.

Zaidi,A., Seo,J., McCanna,D.J., Mahil,A., Jones,L. Molecular biology of two common ophthalmic viruses: Relevance to clinical practice Optometry in Practice 2023;24(1): [ Show Abstract ]

Due to the coronavirus pandemic, viruses have suddenly become a prominent topic of discussion. As such, it
is important to understand the life cycle and, ultimately, the process of inactivating viruses. To inactivate them
it is important to block the mechanisms that they use to induce infection. Due to their ability to survive on
various surfaces, appropriate cleaning practices to prevent viral spread and contamination of medical devices,
practice equipment and surfaces are paramount. Depending on the type of virus and genome configurations,
various mechanisms are used to induce a viral infection. Understanding the susceptibility of the viral outer
coating is crucial to preventing viral spread, whether through droplet transmission or while on surfaces (fomite
transmission). Knowledge of how viral receptors and proteins interact to facilitate the recognition, attachment
and entry of a virus into the host cell is vital for an understanding of how disinfectants and antivirals can be
effective. Viral replication, transcription and translation are also major targets of antivirals. This paper will
review the physiology of two major ophthalmic viruses: adenovirus and herpes simplex.

2022

Bzovey,B., Ngo,W. Eyelid Warming Devices: Safety, Efficacy, and Place in Therapy Clinical Optometry 2022;14133-147 [ Show Abstract ]

Meibomian gland dysfunction (MGD) is characterized by the obstruction and/or inflammation of the meibomian glands that result in decreased and altered meibum secretion. This results in deficiencies in the tear film lipid layer which contributes to increased evaporation and destabilization of the tear film. One of the mainstay therapies for MGD is medical devices that apply heat and/or pressure to the eyelids and promote the liquification and outflow of meibum into the tear film. Over the past two decades, there have been a surge of interest in diagnosing and managing MGD. As a result, numerous medical devices have been developed and each have their own unique approach to treating MGD. This narrative review was conducted to summarize the current state of knowledge on eyelid warming devices, specifically warm eye coverings, devices that direct heat and/or pressure to the eyelids, moisture chamber goggles, and light-based therapy. This review summarized 58 human clinical studies and found that most eyelid warming devices were efficacious in improving signs and symptoms in a wide range of MGD severities and were generally safe to use.

Chamberlain,P., Bradley,A., Arumugam,B., Hammond,D., McNally,J., Logan N., Jones,D., Ngo,C., Peixoto-de-Matos S., Hunt,C., Young G. Long-term Effect of Dual-focus Contact Lenses on Myopia Progression in Children: A 6-year Multicenter Clinical Trial Optom Vis Sci 2022;99(3):204-212 [ Show Abstract ]

Significance: Treatment of myopic children with a dual-focus soft contact lens (DFCL; MiSight 1 day) produced sustained slowing of myopia progression over a six-year period. Significant slowing was also observed in children switched from control to treatment lenses (3 years in each lens).

Purpose: Evaluate the effectiveness of DFCLs in sustaining slowed progression of juvenile-onset myopia over a 6-year treatment period. Assess myopia progression in children who were switched to DFCL at the end of year 3.

Methods: Part 1 was a 3-year clinical trial comparing DFCLs with control CLs (Proclear 1 day) at four investigational sites. In Part 2, subjects completing Part 1 were invited to continue for 3 additional years during which all children were treated with MiSight 1 day DFCLs (52 and 56 from the initially treated (T6) and control (T3) groups, respectively). 85 subjects (45 (T3) and 40 (T6)) completed Part 2. Cyclopleged spherical equivalent refractive errors (SERE) and axial lengths (AL) were monitored and linear mixed model was used to compare their adjusted change annually.

Results: Average age at Part 2 baseline was 13.2 ± 1.3 and 13.0 ± 1.5 for the T6 & T3 groups respectively. Slowed myopia progression in the T6 group observed during Part 1 was sustained throughout Part 2 (Mean ± SEM: Change from baseline SERE(D) = -0.52 ± 0.076 vs -0.51 ± 0.076; change in AL(mm) = 0.28 ± 0.033 vs 0.23 ± 0.033, both P > .05). Comparing progression rates in Part 2 for the T6 and T3 groups respectively indicate that prior treatment does not influence efficacy (SERE -0.51 ± 0.076 vs -0.34 ± 0.077; AL 0.23 ± 0.03 vs 0.18 ± 0.03, both P > .05). Within-eye comparisons of AL growth revealed a 71% slowing for the T3 group (3-years older than Part 1), and further revealed a small subset of eyes (10%) that did not respond to treatment.

Conclusions: DFCLs continue to slow the progression of myopia in children over a six-year period revealing an accumulation of treatment effect. Eye growth of the initial control cohort with DFCL was slowed by 71% over the subsequent 3-year treatment period.

Craig,J. P., Bitton,E., Dantam,J., Jones,L., Ngo,W., Wang,M. T. M Short-term tolerability of commercial eyelid cleansers: A randomised crossover study Contact Lens Anterior Eye 2022;45(6):101733 [ Show Abstract ]

Purpose
To evaluate the short-term tolerability of five commercially available anti-demodectic eyelid cleansers; OCuSOFT Oust Demodex (OD), I-MED I-Lid’n Lash Plus (ILL+), Labtician BlephaDex (BD), Chrissanthe Eye Cleanse (EC), and Théa Blephademodex (BDdx).

Methods
Thirty healthy non-contact lens wearers (18 female; mean ± SD age, 33 ± 12 years) were enrolled in a prospective randomised crossover study. On separate visits, spaced at least 48 h apart, participants were randomised to receive topical application of one of five eyelid cleansers or saline. Participants rated subjective ocular discomfort during the 10-minute post-application period. Visual acuity, non-invasive tear film stability, conjunctival hyperaemia, and ocular surface staining were assessed at baseline and 10 min.

Results
No inter-group differences in ocular parameters were noted at baseline (all p > 0.05). Ocular discomfort scores significantly exceeded baseline scores for 60 s following BD application, 120 s with OD, 135 s with BDdx, 150 s with ILL+, and 195 s with EC (all p < 0.05). Deterioration in non-invasive tear film stability, limbal conjunctival hyperaemia, as well as corneal, conjunctival, and lid margin staining was detected following EC application (all p < 0.05), and increased bulbar conjunctival hyperaemia was observed following both EC and ILL+ treatment (both p < 0.05).

Conclusions
Study outcomes highlight varying tolerability profiles with different anti-demodectic lid cleanser preparations, and the potential to induce tear film instability, conjunctival hyperaemia and ocular surface staining on application. Awareness of possible adverse effects arising from topical application of commercial anti-demodectic lid cleanser formulations may help clinicians set realistic patient expectations and encourage better compliance in their use of lid hygiene therapies.

Dare,E. V., Fung,C. K., McCanna,D. J., Subbaraman, L. V., Jones,L. W. Establishment of optimal culture media in corneal epithelial wound healing models Journal of Cellular Biotechnology 2022;8(1):1-12 [ Show Abstract ]

BACKGROUND: Wound healing needs to occur after injury to prevent vision loss. Models of wound healing need to be optimized to assure treatments for corneal wounds can be developed in vitro prior to investigating with in vivo studies.

OBJECTIVE: The purpose of this study was to establish the optimum media to use as a control solution in wound healing models.

METHODS: Immortalized human corneal epithelial cells were cultured in different growth media using a scratch and exclusion zone model. The effect of normoxic and hypoxic conditions on tight junctional integrity and metabolic activity of cells grown in different growth medium were also investigated.

RESULTS: Wound healing with DMEMF12 media was significantly faster than both Keratinocyte serum-free media (p < 0.05) and EpiLife (p < 0.05) after 10 hours recovery under normoxic or hypoxic conditions using the scratch model and 9 days after wounding using the exclusion zone technique (p < 0.05). Using the culture media DMEMF12, cells stained for abundant ZO-1, Cx43 and had a high metabolic activity indicating significant epithelial barrier formation, gap junction formation and high cell viability.

CONCLUSIONS: DMEMF12 led to superior wound healing under hypoxic and normoxic conditions and in two different wound healing models. © 2022-IOS Press. All rights reserved.

Desai,D. T., Maulvi,F. A., Desai,A. R., Shukla,M. R., Desai,B. V., Khadela,A. D., Shetty,K. H., Shah,D. O., Willcox,M. D. P. In vitro and in vivo evaluation of cyclosporine-graphene oxide laden hydrogel contact lenses International Journal of Pharmaceutics 2022;613121414 [ Show Abstract ]

Drug-eluting contact lens can substitute the multiple eye drop therapy. However, loading hydrophobic drug like cyclosporine in the contact lens is very challenging, due to low drug uptake (via soaking method); and alteration in the swelling and optical properties which restricts its clinical application. To address the above issues, graphene oxide (GO, large surface area with oxygen containing functional groups) was incorporated in the contact lenses during fabrication. These GO-laden contact lenses (SM-GO-Cys) as well as blank contact lenses (SM-Cys) were soaked in the solution of cyclosporine. Alternatively, cyclosporine-laden contact lenses (DL-Cys-20) and cyclosporine-GO-laden contact lenses (DL-Cys-20-GO) were fabricated by adding drug and drug-GO (at various level of GO) during fabrication, respectively. Contact angle and swelling data showed increase in water holding capacity of GO laden contact lenses. Optical property was significantly improved due to molecular dispersion of drug on the surface of GO sheets. The drug uptake and in vitro release profile was improved with GO-laden contact lenses by soaking method (SM-GO-Cys-400n) due to hydrophobic interactions between GO and drug. Adding cyclosporine-GO (DL-Cys-20-GO-800n) during fabrication significantly improved drug release kinetics with higher drug leaching (during extraction and sterilization) due to increased swelling, improved dissolution and molecular dispersion of drug on GO sheets. Ocular irritation and histopathological studies demonstrated the safety of GO-contact lens. The in vivo drug release studies in the rabbit eye showed significant improvement in mean residence time (MRT) and area under the curve (AUC) using DL-Cys-20-GO-800n contact lens compared to eye drop solution with reduction in protein adherence value. The study demonstrated that the incorporation of GO into the contact lens can control the release of cyclosporine as well as improved the lens swelling and transmittance properties.

Efron,N., Jones,L. W., Morgan,P. B., Nichols,J. J. Bibliometric analysis of the literature relating to silicone hydrogel and daily disposable contact lenses Journal of Optometry 2022;15(1):44-52 [ Show Abstract ]

Purpose
Publication metrics are derived for the fields of silicone hydrogel (SH) and daily disposable (DD) contact lenses.

Methods
A search of the Scopus database for papers in the fields of SH and DD contact lenses found 979 SH and 291 DD papers. Subject-specific h-indices for SH lenses (hSH-index) and DD lenses (hDD-index) were derived, in relation to five categories – authors, institutions, countries and journals – to serve as measures of impact. A short list of the most impactful entities was generated for each of the above five categories in the SH and DD fields.

Results
A paper entitled “Soft contact lens polymers: An evolution” by Nicholson and Vogt was the most highly cited article (495 citations) in both SH and DD fields. The most impactful entities for the SH and DD fields were: authors – Lyndon Jones (hSH = 33) and Philip Morgan (hDD = 15); institutions – the University of Waterloo (hSH = 37) and the University of New South Wales (hDD = 15); countries – the United States (hSH = 45) and the United Kingdom (hDD = 24); and journals – Optometry and Vision Science (hSH = 33) and Contact Lens and Anterior Eye (hDD = 17). Overall, the SH field (hSH = 64) is far more impactful than the DD field (hDD = 34).

Conclusions
Impactful papers, authors, institutions, countries and journals in the SH and DD fields are identified. Optometry is revealed as the leading profession in relation to SH and DD publications.

Efron,N., Morgan,P. B., Nichols,J. J., Walsh,K., Willcox,M. D., Wolffsohn,J. S. Jones,L. W. All soft contact lenses are not created equal Contact Lens Anterior Eye 2022;45(2):Article 101515 [ Show Abstract ]

Abstract
Soft contact lenses that have been prescribed by eye care practitioners are sometimes substituted for alternative lenses by unqualified, unregulated and sometimes even fully regulated lens suppliers, in the mistaken belief that there is essentially no difference between different soft lens types. This review considers the implications of inappropriately substituting soft contact lens types in terms of (a) lens properties: surface treatment, internal wetting agents, material, total diameter, back optic zone radius, thickness, edge profile, back surface design, optical design, power, colour (tint) and ultraviolet protection; and (b) lens usage: wearing modality (daily versus overnight wear) and replacement frequency. Potential aspects of patient dissatisfaction and adverse events when prescribed soft lenses are substituted for lenses with different properties or intended usage are considered. Substitution of 15 of the 16 lens properties considered (i.e. except for back surface design) was found to be related to at least one – and as many as six – potential sources of patient dissatisfaction and adverse ocular events. Contact lens are medical devices which are prescribed and fitted; they should never be substituted for another lens type in the absence of a new prescription further to a full finalised fitting, for the simple reason that all soft contact lenses are not created equal. A substituted lens may have properties that results in undesirable consequences in respect of vision, ocular health, comfort and cosmetic appearance, and may be incompatible with the lifestyle of the patient.

Guthrie,S., Ng,A. Y., Woods,J., Vega,J., Orsborn,G., Jones,L. Exploring the factors which impact overall satisfaction with single vision contact lenses Contact Lens Anterior Eye 2022;45(5):101579 [ Show Abstract ]

Purpose
To explore the impact of subjective factors (lens handling, comfort and vision) on overall single vision contact lens satisfaction.

Methods
Correlation analysis of a prospective, randomised, double-masked, bilateral crossover study involving 55 adapted lens wearers fitted with somofilcon A (SiHy) (clariti® 1 day, CooperVision) and etafilcon A (Hy) (1 DAY ACUVUE® MOIST, Johnson & Johnson Vision) was conducted. Subjective ratings of lens handling, comfort and vision collected after 1 week of lens wear for each lens type were correlated with overall satisfaction. Data were analysed by combining data for both lens types and also for each lens separately.

Results
For the combined analysis, significant correlations (p < 0.01) were found between subjective ratings of overall satisfaction and ratings of handing for application (r = 0.64), handling for removal (r = 0.50), comfort upon application (r = 0.59), comfort at end of day (r = 0.61), overall satisfaction with comfort (r = 0.88) and overall satisfaction with vision (r = 0.64).

Correlation analysis of the per lens data showed that lens specific correlations of overall satisfaction with handling for lens application varied greatly with lens material (SiHy: r = 0.26, p = 0.05 vs Hy: r = 0.72, p < 0.01). Correlation strength of comfort upon application/at end of day with overall satisfaction also varied with lens material (Application: SiHy: r = 0.40 vs Hy: r = 0.61; End of day: SiHy: r = 0.76 vs Hy: r = 0.58; all p ≤ 0.01).

Conclusion
Overall satisfaction was significantly correlated with the specific subjective evaluations of handling, vision and comfort. Correlations of overall satisfaction and ease of handling for each lens type suggest that, for habitual contact lens wearers, dissatisfaction with handling at the time of lens application can play a major role in overall dissatisfaction with a lens. Handling for application had a similar correlation (r) value as vision, suggesting that handling for application should not be underestimated when considering overall patient satisfaction.

Kao,E. C. Y., Seo,J., McCanna,D. J., Subbaraman,L. N., Jones,L. In vitro assessment of the biocompatibility of chemically treated silicone materials with human lens epithelial cells Nature - Scientific Reports 2022;12(1):Article 4649 [ Show Abstract ]

Cytotoxicity testing is a regulatory requirement for safety testing of new ocular implants. In vitro toxicity tests determine whether toxic chemicals are present on a material surface or leach out of the material matrix. A method of evaluating the cytotoxicity of ocular implants was developed using fluorescent viability dyes. To assess the assay’s sensitivity in detecting toxic substances on biomaterials, zinc diethydithiocarbamate (ZDEC) and benzalkonium chloride (BAK) were deposited on silicone surfaces at different concentrations. Human lens epithelial cells (HLEC) were added to the surface of these treated silicone surfaces and were assessed for viability. The viability of both the adherent and non-adherent cells was determined using confocal microscopy with, annexin V, ethidium homodimer, and calcein. Cell metabolism was also evaluated using resazurin and the release of inflammatory cytokines was quantified using a multiplex Mesoscale Discovery platform. Confocal microscopy was shown to be a sensitive assay for evaluating material toxicity, as significant toxicity (p < 0.05) from ZDEC and BAK-treated surfaces compared to the untreated silicone control was detected. Patterns of cytokine release from cells varied depending on the toxin evaluated and the toxin concentration and did not directly correlate with the reduction in cell metabolic activity measured by alamarBlue.

Kapadia,W., Qin,N., Zhao,P., Phan,C.-M., Haines,L., Jones,L. Ren,C. L. Shear-Thinning and Temperature-Dependent Viscosity Relationships of Contemporary Ocular Lubricants Translational Vision Science & Technology 2022;11(3):Article 1 [ Show Abstract ]

Purpose: To evaluate the shear viscosity of contemporary, commercially available ocular lubricants at various shear rates and temperatures and to derive relevant mathematical
viscosity models that are impactful for prescribing and developing eye drops to treat dry eye disease.

Methods: The shear viscosity of 12 ocular lubricants was measured using a rheometer and a temperature-controlled bath at clinically relevant temperatures at which users may experience exposure to the drops (out of the refrigerator [4.3°C]; room temperature [24.6°C]; ocular surface temperature [34.5°C]). Three replicates for each sample at each temperature were obtained using a standard volume (0.5 mL) of each sample. The viscosity of each ocular lubricant was measured over the full range of shear rates allowed
by the rheometer.

Results: The shear viscosity of the same ocular lubricant varied significantly among the three temperatures. In general, a higher temperature resulted in smaller viscosities than a lower temperature (an average of −48% relative change from 4.3°C to 24.6°C and −21% from 24.6°C to 34.5°C). At a constant temperature, the viscosity of an ocular lubricant over the studied shear rates can be well approximated by a power-law model.

Conclusions: Rheological analysis revealed that the ocular lubricants exhibited shear-thinning behavior at the measured temperatures. Differences in the ocular lubricants’ formulations and measured temperatures resulted in different viscosities.

Translational Relevance: When prescribing eye drops, eye care professionals can select the optimal one for their patients by considering a variety of factors, including its
rheological property at physiologically relevant shear rates and temperatures, which can improve residence time on the ocular surface, while ensuring appropriate comfort and vision. However, care must be taken when using the derived mathematical models in this study because the in vivo shear behavior of the ocular lubricants has not been examined and might show deviations from those reported when placed on the ocular surface.

Khanal,S., Bai,Y., Ngo,W., Nichols,K. K., Wilson,L., Barnes,S., Nichols,J. J. Human meibum and tear film derived cholesteryl and wax esters in meibomian gland dysfunction and tear film structure: Cholesteryl and wax esters in meibomian gland dysfunction Ocular Surface 2022;23(January):12-23 [ Show Abstract ]

Purpose
This study evaluated the presence and roles of cholesteryl esters (CEs) and wax esters (WEs) from human tear film and meibum in meibomian gland dysfunction (MGD).

Methods
Out of 195 enrolled subjects, 164 and 179 subjects provided tear and meibum samples, respectively. Subjects were classified into normal, asymptomatic MGD, MGD, and mixed (MGD & aqueous deficient). The precorneal tear film (PCTF) thinning rate (evaporation) was measured using optical coherence tomography. Lipids extracted from tear and meibum samples were infused into a SCIEX 5600 TripleTOF mass spectrometer. CE and WE intensities quantified with Analyst 1.7 TF and LipidView 1.3 were compared across disease groups in MetaboAnalyst 5.0 and correlated with PCTF thinning rates.

Results
The numbers of unique CEs and WEs identified in the samples were 125 and 86, respectively. Unsupervised Principal Component (PC) analysis and supervised Partial Least Square Discriminant analysis exhibited little separation among groups for both CEs and WEs in tears and meibum. Spearman's correlation analyses showed no association between either the first or second PC scores with PCTF thinning rates.

Conclusion
The abundances of human PCTF and meibum-derived CEs and WEs were independent of MGD disease status and PCTF thinning (evaporation). CEs and WEs alterations do not contribute to alterations in tear film dynamics in MGD, such as has been demonstrated by the (O-acyl) ω-hydroxy fatty acids (OAHFAs).

Leat,S. J., Saraf,A., Rose,K., Christian,L. W., Irving,E. L., Jones, D. A., McCulloch, D. L. Measuring recognition visual acuity in young children–testability with the Waterloo Differential Acuity Test (WatDAT) Clinical and Experimental Optometry 2022;Online ahead of print [ Show Abstract ]

Clinical relevance: Visual acuity measurement is important for the detection and monitoring of eye disorders. Developing accurate and sensitive visual acuity tests suitable for young children is therefore desirable.

Background: Recognition or form visual acuity (VA), which is measured with matching in children aged 3 years and up, is more sensitive for detecting visual deficits compared to resolution VA. The Waterloo Differential Acuity Test (WatDAT) is a proposed recognition VA test using the concept of identifying the "odd one out" among distractors. The WatDAT is expected to be cognitively easier than matching tests and therefore may be used in younger children. The purpose of this study is to investigate the testability of the WatDAT paradigm in children aged 12-36 months, and to determine the optimum format and number of distractors.

Methods: Fifty-one typically-developing children aged 12-36 months participated in the study. Data for Patti Pics (PP) and Face targets (FT) were collected for formats with 3, 4 and 5 distractors. The targets were presented binocularly on a computer touch screen at 30 cm. The task was to touch the face among identical non-faces or a house among circles. Following initial training, there were 5 presentations for each distractor format. Testability was defined as correctly identifying at least 4/5 presentations and was also determined for uncrowded PP symbols using matching.

Results: Of participants aged 18-36 months, 87% could perform the WatDAT PP targets with 3 distractors compared to 68% for the FT, while 48% could perform matching with PP. The testability for FT increased to 85% for children ≥22 months. Younger children showed lower testability. For the 3 distractor format, PP targets gave 9% testability in children 12 to <18 months, and FT gave a testability of 16% in children 12 to <22 months.

Conclusion: WatDAT testability is higher than matching VA tests. This indicates that the newly developed WatDAT has potential for measuring recognition VA in children 18 months and older.

Lourenco Nogueira,C., Boegel,S. C., Shukla,M., Ngo,W., Jones,L., Aucoin,M. G. Antiviral Activity of Contemporary Contact Lens Care Solutions against Two Human Seasonal Coronavirus Strains Pathogens 2022;11(4):472 [ Show Abstract ]

Background: Given that reports have suggested SARS-CoV-2 can be transmitted via conjunctiva, the ability of contact lens (CL) care products to reduce the infectiousness of two seasonal human coronavirus (HCoV) (HCoV-229E and HCoV-OC43) surrogates for SARS-CoV-2 was investigated.

Methods: Biotrue and Boston Simplus (Bausch&Lomb), OPTI-FREE Puremoist and Clear Care (Alcon), and cleadew and cleadew GP (Ophtecs) were tested. Their ability to inactivate HCoV was evaluated using contact times of 4 and 6 h as well as 1% and 10% of virus inoculum.

Results: Non-oxidative systems (Biotrue, Boston Simplus, and OPTI-FREE) did not exhibit a significant log10 reduction compared to controls for the two viral strains for either incubation time (all p > 0.05) when 10% tests were performed. For the 1% test, while Boston Simplus and OPTI-FREE exhibited a significant log10 reduction of both HCoV-229E (after 6 h) and HCoV-OC43 (after either 4 or 6 h incubation), those products showed less than 1 log10 reduction of the two infectious viruses. Oxidative systems based on hydrogen peroxide or povidone-iodine showed a significant log10 reduction compared with the controls for both HCoV-229E and HCoV-OC43 in all tested conditions (all p < 0.01). Clear Care led to virus inactivation to below the limit of quantification for tests performed with 1% of inoculum after 6 h incubation, while cleadew and cleadew GP led to inactivation of the two viruses to below the limit of quantification in all tested conditions.

Conclusion: Oxidative CL disinfection systems showed significant virucidal activity against HCoV-229E and HCoV-OC43, while non-oxidative systems showed minimal ability to inactivate the HCoV species examined.

Lourenco Nogueira,C., Boegel,S. C., Shukla,M., Ngo,W., Jones,L. Aucoin,M. G. The impact of a rub and rinse regimen on removal of human coronaviruses from contemporary contact lens materials Contact Lens Anterior Eye 2022;45(6):101719 [ Show Abstract ]

Purpose
To assess the influence of contemporary contact lens (CL) materials on human coronavirus attachment and the influence of a rub and rinse step to remove these viruses.

Methods
The binding rates of HCoV-229E and HCoV-OC43 to eight soft CL materials and four rigid gas permeable materials were analyzed. The impact of a rub and rinse step to remove these viruses from all materials was examined. The efficacy of Biotrue (Bausch & Lomb), OPTI-FREE Puremoist (Alcon), Clear Care (Alcon) and cleadew (Ophtecs) to remove virus contamination from two representative soft lens materials (etafilcon A and lotrafilcon B) was also determined.

Results
Approximately 102 to 103 infectious viral particles were recovered from each CL material. Although some materials were more prone to coronavirus adhesion, contamination of both viral types was reduced to below the limit of quantification (LQ) from all materials using a simple saline rinse step. Exposure to Clear Care and cleadew reduced the number of infectious viral particles from both etafilcon A and lotrafilcon B to below the LQ, while for Biotrue and OPTI-FREE Puremoist, infectious viral particles were reduced to below the LQ only when additional rub and rinse steps were included.

Conclusion
Human coronavirus contamination can be easily removed from CL surfaces. Although CL care products containing hydrogen peroxide and povidone-iodine efficiently removed virus contamination from CL surfaces without the need for a rub and rinse step, a full regimen including rub and rinse steps is crucial when using CL care products based on non-oxidative systems.

Luensmann,D., Schaeffer,J. L., Rumney,N. J., Stanberry,A., Fonn,D. Magnitude of astigmatism – A comparison between eyes Contact Lens Anterior Eye 2022;45(5):101510 [ Show Abstract ]

Purpose
Astigmatism is a highly prevalent refractive error and while studies typically focus to describe the axis symmetry between eyes, little is known about the refractive symmetry. Therefore, this study determined the astigmatic power symmetry between eyes in a large clinic population.

Methods
A clinical chart review was conducted at three optometric practices in the United States, the United Kingdom and Canada and subjective refraction data from 88,891 patients 14–70 years of age who presented with at least −0.25DC refractive astigmatism in at least one eye were included in the analysis. Data were obtained at these practices between January 2014 and March 2017. The overall distribution (%) and magnitude (DC) of astigmatism was determined and refractive differences between eyes were identified.

Results
The mean age of the patients was 42.1 ± 15.9 years and included 51,685 (58%) female and 37,206 (42%) male patients. In this data pool of 177,782 eyes, 10.9% required zero astigmatic correction, while 56.2% had astigmatism of −0.25 to −0.75DC. In total 23.9% of patients presented with astigmatism of at least −0.75DC in only one eye, while the other eye had 0 to −0.50DC. Overall, the difference in astigmatism between eyes was less than −0.75DC for 82.1% of astigmatic patients. For patients who presented with astigmatism of −1.00DC in the right eye, 80.8% of them had an astigmatic prescription of −1.00 ± 0.50DC in the left eye. For an astigmatic prescription of −4.00DC in the right eye, only 40.6% of patients exhibited astigmatism of −4.00DC ± 0.50DC in the left eye.

Conclusions
The majority of patients exhibited a difference in astigmatism between eyes of less than −0.75DC, however the refractive cylinder power symmetry was significantly lower in patients with higher refractive astigmatism.

Nagaarudkumaran,N., Mirzapur,P., McCanna,D. J., Ngo,W. Temporal Change in Pro-Inflammatory Cytokine Expression from Immortalized Human Corneal Epithelial Cells Exposed to Hyperosmotic Stress Current Eye Research 2022;47(11):1488-1495 [ Show Abstract ]

Purpose
To determine the metabolic activity, and cytokine expression over time from immortalized human corneal epithelial cells (HCECs) exposed to hyperosmotic stress.

Methods
HCECs were cultured and expanded in DMEM/F-12 with 10% FBS. The cells were exposed to either normal media (295 mmol/kg) or hyperosmolar media (500 mmol/kg) for 0.25, 3, 6, and 12 hours. After each exposure duration, metabolic activity was quantified using alamarBlue, and a panel of pro-inflammatory cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, TNF-α, IFN-γ, and IL-17A) was quantified using multiplexed electrochemiluminescence (Meso Scale Diagnostics, Rockville, MD).

Results
Metabolic activity of the HCEC exposed to hyperosmolar conditions was significantly reduced at the 3-, 6-, and 12-hour mark compared to the control (all p < 0.01). There was no significant difference in cytokine expression between the hyperosmolar media and control at the 0.25- and 3-hour mark for all cytokines (all p ≥ 0.28). The difference in cytokine expression between the hyperosmolar media and the control was significant for IL-1β, IL-4, IL-6, IL-8, IL-12p70, IL-13, and TNF-α at the 6-hour mark (all p ≤ 0.02). No significant change in cytokine expression between the hyperosmolar media and control was noted for IL-2, IL-10, IL-17A, and IFN-γ (all p ≥ 0.74) at the 6-hour mark.

Conclusion
Hyperosmolar stress reduced cell metabolic activity and increased expression of IL-1β, IL-4, IL6, IL8, IL-12p70, IL-13, and TNF-α over a 6-hour period in an immortalized HCEC line.

Ng,A. Y., Woods,J., Jahn,T., Jones,L., Ritter,J. Effect of a novel omega-3 and omega-6 fatty acid supplement on dry eye disease: a 3-month randomized controlled trial Optometry & Vision Science 2022;99(1):67-75 [ Show Abstract ]

SIGNIFICANCE
Supplementing diet with a novel combination of omega-3 and omega-6 fatty acids significantly improved symptoms in extremely symptomatic participants with dry eye disease (DED).

PURPOSE
This study aimed to determine the effect of daily intake of a novel combination of essential fatty acids on signs and symptoms of DED.

METHODS
Participants with moderate to severe DED were enrolled in a prospective, randomized, double-masked parallel group study. Participants ingested either the treatment supplement containing omega-3 and omega-6 fatty acids (1200 mg eicosapentaenoic acid, 300 mg docosahexaenoic acid, 150 mg γ-linoleic acid) or the placebo (coconut and olive oil) daily for 3 months. To determine compliance, Omega-3 Index blood tests were conducted. At baseline and at 1 and 3 months, the following assessments were conducted: Ocular Surface Disease Index (OSDI) questionnaire and Symptom Assessment Questionnaire in Dry Eye, noninvasive tear breakup time, tear meniscus height, tear osmolarity, ocular redness, surface staining, Schirmer test, and meibography.

RESULTS
Fifty participants (mean ± standard deviation baseline OSDI score, 52.2 ± 16.5) completed the study: 24 randomized to treatment and 26 randomized to placebo. Although there was an improvement in OSDI score at 3 months for both groups (treatment: −13.4 points, P = .003; placebo: −7.8 points, P = .02), participants with baseline OSDI scores >52 demonstrated an even larger significant improvement in symptoms with the treatment at 3 months compared with baseline (n = 13, −20.8 points, P = .002). There were no significant changes in any of the ocular assessments at 1 or 3 months (all P > .05). After 3 months, Omega-3 Index increased by 34% in the treatment group (baseline, 5.3 ± 0.8; 3 months, 8.0 ± 2.1; P < .001) and did not change in the placebo group (baseline, 4.8 ± 0.8; 3 months, 4.8 ± 0.6; P = .95).

CONCLUSIONS
Supplementation with eicosapentaenoic acid, docosahexaenoic acid, and γ-linoleic acid resulted in a significant and clinically meaningful improvement of dry eye symptoms in extremely symptomatic participants with DED (OSDI ≥52).

Nichols,J. J., Morgan,P. M., Efron,N, Jones,L. W. Global optometrist research ranking derived from a science-wide author database of standardised citation indicators Clinical and Experimental Optometry 2022;105(1):20-25 [ Show Abstract ]

Clinical relevance
Publications in refereed scientific journals provide a rigorous research base that underpins clinical optometric practice. Leading optometrists who generate this literature can be identified and ranked using standardised citation indicators.

Background
This work seeks to identify and rank all optometrists included in a Science-Wide author database of standardised citation indicators (S-W) and to compare this ranking with the Global Optometrist Top 200 Research Ranking (T200).

Methods
A search was conducted for the names of all optometrists in the T200 who were included in the S-W, which is a world-wide listing of the top 2% of scientists in each of 174 subfield disciplines, ranked according to a composite citation indicator (cns) that excludes self-citations and corrects for multiple authorships and author order.

Results
The names of 66 optometrists are found in the S-W. Of these, 58 are designated as working in the primary sub-field ‘Ophthalmology & Optometry’; this listing, in rank-order of cns, is referred to as the ‘S-W-derived Optometrist Research Ranking’ (S-WORR). Australian optometrist Nathan Efron is ranked #1 in the S-WORR. The number (%) of optometrists in the S-WORR from each country is: the United States – 26 (45%), Australia – 12 (21%), the United Kingdom – 11 (19%), Canada – 5 (9%), Spain – 2 (3%), Hong Kong – 1 (2%) and South Africa – 1 (2%). The universities housing the equal highest number of optometrists in the S-WORR (five each) are the University of California, Berkeley, USA; the University of New South Wales, Australia; and Queensland University of Technology, Australia. There is a moderately strong correlation between T200 and S-WORR rankings (ρ = 0.6017, N = 58, p < 0.0001).

Conclusions
The S-WORR represents an elite cohort of optometrists who ought to be celebrated for their outstanding, leading and impactful contributions to optometric research.

Osae,E. A., Jones,L., Nichols,J. J. The impact of contact lenses on meibomian gland morphology Ocular Surface 2022;24(April):148-155 [ Show Abstract ]

Despite years of experience with contact lenses, controversy remains as to whether contact lenses adversely impact the meibomian glands (MG). This review summarizes the present body of evidence, showing that contact lens wear is associated with alterations in MG morphology (up to 80% higher gland atrophy compared to non-wearers) and qualitative changes in MG secretion. Key factors such as duration of contact lens wear, contact lens type (e.g., soft vs. rigid), edge design, and material modulus of elasticity are discussed in relation to the extent of MG morphological changes, the quality of MG secretion and other ocular surface parameters. Longitudinal studies of sufficient statistical power are needed to better understand how contact lens wear affects the MG, risk factors, and the clinical sequelae of these changes.

Pereira-da-Mota,A. F., Phan,C-M., Concheiro,A., Jones,L., Alvarez-Lorenzo,C. Testing drug release from medicated contact lenses: The missing link to predict in vivo performance Journal of Controlled Release 2022;343(March):672-702 [ Show Abstract ]

Contact lenses (CLs) offer a wide variety of advantages as ocular drug-releasing platforms, but the feasibility of medicated CL development is constrained by numerous scientific, technological, and regulatory challenges. One main difficulty is the setting of release rate specifications for each drug, since at present there are no standardized in vitro release models that can appropriately predict the performance of drug-eluting CLs once placed onto the eye. CL-adapted release tests may provide knowledge on how the drug release pattern should perform in vivo to trigger and maintain the therapeutic effects for both anterior and posterior ocular tissues. Moreover, in vitro release tests are valuable tools for quality assessment during production and to investigate the effect of a change in composition or process variables. This review aims to shed light on biorelevant ways of evaluating in vitro drug release from CLs and the feasibility of establishing in vitro-in vivo correlations (IVIVC) to predict in vivo performance. First, general guidelines and Pharmacopeia release tests for topical ophthalmic formulations as well as in vitro release tests implemented for drug-CLs in the last two decades are analyzed. Then, development of an appropriate method to investigate IVIVC is attempted from the few papers simultaneously reporting in vitro release profiles and either in vivo release or therapeutic response. Finally, key points to be considered for in vitro testing drug release from a medicated CL are suggested to pave the way to the clinical arena.

Rueff,E., Tichenor,A. A., Ngo,W., Pucker,A. D. A review of meibomian gland structure, function, and contact lens wear Contact Lens Anterior Eye 2022;45(5):101560 [ Show Abstract ]

Purpose: To provide a balanced literature review of the studies that have evaluated the effect of contact lenses on meibomian gland (MG) health.

Methods: A PubMed.gov literature search was conducted on or before May 15, 2021. No other time constraints were applied. Search terms included the following: "meibomian gland(s)" plus "contact lens(es)" or "meibography" plus "contact lens(es)". Only full text articles written in English were considered. The reference lists of recovered papers were used to identify articles missed during the primary search. Included articles were required to discuss the impact of contact lenses on MG morphology or function and were graded according to the level of evidence presented.

Results: The literature indicates that contact lenses impact MG function; however, the data are equivocal regarding contact lenses inducing MG structural changes. The literature likewise indicates that the mechanism(s) by which contact lenses impact the MGs are likely multifactorial. Recent data suggests that MGs may have some plasticity. Detected differences between studies likely stem from varied populations evaluated, study designs, and the duration of the evaluation periods.

Conclusions: With this literature review finding conflicting relationships between MG health and contact lens use, future longitudinal studies with standardized clinical MG assessments are needed to determine the true impact of contact lenses on MG health. Until these data are obtained, contact lens wearers should undergo a full MG evaluation, especially because recent data suggest that MG treatments may restore MG structure and function.

Thite,N., Desiato,A., Shinde,L., Wolffsohn,J. S., Naroo,S. A., Santodomingo Rubido,J., Cho,P., Jones,D., Villa-Collar,C., Carrillo,G., Chan,O., Wang,H., Iomdina,E., Tarutta,E., Proskurina,O., Fan,C. S., Zeri,F., Bakkar,M. M., Barodawala,F., Dabral,N., Lafosse,E., Lee,C., Nichols,J. J., Chan, J., Park,K., Nair,V., Van Der Worp,E., Vankudre,G., Maseedupally,V., Bhattarai,Y., Nagzarkar,D., Brauer,P., Gil-Cazorla,R. Differences in Practitioner Experience, Practice Type, and Profession in Attitudes Toward Growing Contact Lens Practice Eye & Contact Lens 2022;48(9):369-376 [ Show Abstract ]

Objective: To investigate eye care practitioners' attitudes and perceptions toward potential interventions that can enhance contact lens (CL) practice across the world, and how this is influenced by their practice setting.

Methods: A self-administered, anonymized survey was constructed in English and then forward and backward translated into six more languages. The survey was distributed online via social media platforms and mailing lists involving reputed international professional bodies.
Results: In total, 2,222 responses from 27 countries with sufficient responses were analyzed (53% females, median age- 37 years). Most of the respondents were optometrists (81.9%) and 47.6% were from stand-alone/independent practices. Median working experience in CL prescribing was 11.0 years (IQR: 18.0, 4-22 years). Over two-third of them declared themselves to be very hopeful (22.9%) or hopeful (45.1%) about the future of their CL practice. Among the potential interventions proposed, continuous update of knowledge and skills and competently managing CL-related complications were rated the most important (median score: 9/10 for each). Practitioners working in national/regional retail chains expressed higher proactivity in recommending CLs (9/10) than those in local chains, hospitals, and universities (for all 8/10, P<0.05). National differences were also identified in eye care practitioner attitudes and perceptions (P<0.05).

Conclusions: The study provided important information to delineate a variety of elements characterizing CL practice across the world. These insights can serve as a basis to design strategies at national and international levels

von Ahrenschildt,A., Hanneberg,L., Robich,M., Jones-Jordan,L., Marx,S., Sickenberger,W., Powell,D., Kwan,J. T., Wong,S., Srinivasan,S., Jones,L., Pucker,A. D. Morphological characteristics of Meibomian Glands and their Influence on Dry Eye disease in contact lens wearers Ocular Surface 2022;24(April):93-99 [ Show Abstract ]

Purpose:
Meibomian glands (MG) are now easily imaged via clinical meibography machines. The purpose of this work was to explore the utility of the known MG morphology metrics for predicting dry eye disease (DED) in contact lens (CL) wearers.

Methods:
Successful and previous CL wearers were recruited. DED was diagnosed if the participant's worst eye had a reduced tear meniscus height (TMH) of <0.2 mm or non-invasive tear break-up time (NITBUT) of [removed]5.0. Meibography was performed and images were subjectively graded by two examiners for the following MG characteristics: distorted, tortuous, hooked, abnormal gap, overlapping, fluffy areas, tadpoling, thinned, thickened, ghost, no extension to lid margin, shortened and dropout (atrophy). DED diagnostic ability of each metric was determined with receiver operating characteristic (ROC) analysis.

Results:
A total of 112 participants were recruited, with 18.8% having DED and 60.7% being female. The only MG morphology metrics that were marginally predictive of DED were thickened upper eyelid MGs (p = 0.046), thickened mean upper plus lower eyelid MGs (p = 0.007), and atrophy of upper eyelid MGs (p = 0.043); however, none of these metrics reached a meaningful area under the curve in ROC analysis (all <0.70).

Conclusion:
While abnormal MG morphology is likely suggestive of DED in CL wearers, none of the MG morphology metrics evaluated alone in this study had clinically meaningful predictive value for detecting DED in this group of current and previous CL wearers.

Walsh,K., Jones,L., Moody,K. Addressing common myths and misconceptions in soft contact lens practice Clinical and Experimental Optometry 2022;105(5):459-473 [ Show Abstract ]

Advances in contact lens technology over the past 50 years since the commercialisation of the first soft lenses in 1971 have been incredible, with significant changes in contact lens materials, frequency of replacement, care systems and lens designs occurring. However, despite the widespread availability of contact lenses, penetration rates for those who need vision correction remain in the low single digits and many practitioners seem to hold on to concepts around the potential value of contact lenses that appear based in the dim and distant past and are certainly no longer valid today. This review addresses 10 common ‘myths and misconceptions’ around soft contact lenses using an evidence-based approach that can hopefully dispel some of these incorrect assumptions.

Wolffsohn,J. S., Dhallu,S., Aujla,M., Laughton,D., Tempany,K., Powell,D., Gifford,K., Gifford,P., Wan,K., Cho,P, Stahl,U., Woods,J. International multi-centre study of potential benefits of ultraviolet radiation protection using contact lenses Contact Lens Anterior Eye 2022;45(6):101593 [ Show Abstract ]

Purpose
To examine the effects of long-term ultraviolet radiation (UVR) blocking wearing contact lenses on ocular surface health, eye focus and macular pigment.

Method
210 pre-presbyopic patients were recruited from Birmingham UK, Brisbane Australia, Hong Kong China, Houston USA and Waterloo Canada (n = 42 at each site). All patients had worn contact lenses for ≥ 5 years, half (test group) of a material incorporating a UVR-blocking filter. Ocular health was assessed using slit-lamp biomicroscopy and UV autofluorescence. Accommodation was measured subjectively with a push-up test and overcoming lens-induced defocus. Objective stimulus response and dynamic measures of the accommodative response were quantified with an open-field aberrometer. Macular pigment optical density (MPOD) was assessed using heterochromatic flicker photometry (MPS II).

Results
The two groups of participants were matched for age, sex, race, body-mass-index, diet, lifestyle, UVR exposure, refractive error and visual acuity. Limbal (p = 0.035), but not bulbar conjunctival redness (p = 0.903) was lower in eyes that had worn UVR-blocking contact lenses compared to controls. The subjective (8.0 ± 3.7D vs 7.3 ± 3.3D; p = 0.125) and objective (F = 1.255, p = 0.285) accommodative response was higher in the test group, but the differences did not reach significance. However, the accommodative latency was shorter in eyes that had worn UVR-blocking contact lenses (p = 0.003). There was no significant different in MPOD with UVR filtration (p = 0.869).

Conclusions
Blocking the transmission of UVR is beneficial in maintaining the eye’s ability to focus, suggesting that presbyopia maybe delayed in long-term UVR-blocking contact lenses wearers. These lenses also provide protection to the critical limbal region.

Yee,A., Phan,C-M., Jones,L. Uptake and release of polyhexamethylene biguanide (PHMB) from hydrogel and silicone hydrogel contact lenses using a radiolabel methodology Contact Lens Anterior Eye 2022;45(5):101575 [ Show Abstract ]

Purpose
The purpose of this study was to evaluate the uptake and release of radiolabelled polyhexamethylene biguanide (PHMB) on reusable daily wear contact lenses (CLs) over 7 days.

Methods
Three silicone hydrogel (SH) contact lens materials (lotrafilcon B, balafilcon A, senofilcon A) and two conventional hydrogel (CH) materials (etafilcon A, omafilcon A) were examined. In experiment 1 (1-day study), CLs were soaked in 2 mL of phosphate buffered solution (PBS) containing radiolabelled 14C PHMB (1 µg/mL) for 8 h. The release kinetics of 14C PHMB from the CLs was measured at t = 0.25, 0.5, 1, 2, 4, 8, and 24 h in fresh 2 mL PBS. In experiment 2 (7-day study), the CLs were soaked in the 14C PHMB (1 µg/mL) solution for 8 h followed by a 16-hour release in 2 mL PBS. The lens cycle was repeated daily for 7 days. After both experiments, the residual amount of PHMB remaining within the lenses was extracted to determine the total uptake of PHMB.

Results
In experiment 1, the total uptake of PHMB for etafilcon A was significantly greater than senofilcon A (p = 0.01). There were no significant differences in total uptake of PHMB between other lens materials (p > 0.05). Etafilcon A released more PHMB compared to all other lens types over a 24-hr period (p < 0.001). In experiment 2, all CL materials continued to sorb more PHMB over time (p < 0.001). By day 7, the amount of PHMB sorbed by etafilcon A was significantly greater than senofilcon A (p = 0.02). After day 2, the CH materials released significantly more PHMB than the SH materials (p < 0.01).

Conclusion
The CL materials continued to sorb PHMB with no signs of saturation after 7 days. All lens materials released a consistent amount of PHMB each day. Radioactive labelling provides a sensitive method of assessing the uptake and release of PHMB from CL materials.

2021

Bai,Y., Ngo,W., Khanal,S., Nichols,K. K., Nichols,J. J. Human precorneal tear film and lipid layer dynamics in meibomian gland dysfunction Ocular Surface 2021;21(July):250-256 [ Show Abstract ]

Purpose: To evaluate the precorneal tear film (PCTF) and lipid layer (TFLL) thicknesses and thinning rates in meibomian gland dysfunction (MGD) using a combined ultra-high-resolution optical coherence tomography (OCT) and thickness dependent fringe (TDF) interferometry system.

Methods: Based on the Tear Film and Ocular Surface Society (TFOS) International Workshop on Meibomian Gland Dysfunction diagnostic algorithm, the Ocular Surface Disease Index (OSDI) and meibum grade score (MGS) were used to classify subjects into four groups: Normal (OSDI<13 and MGS<10), MGD (OSDI≥13 and MGS≥10), Asymptomatic MGD (OSDI<13 and MGS≥10), and Mixed (OSDI≥13 and MGS<10). The OCT/TDF system was used to capture PCTF and TFLL thicknesses and thinning rates. Kruskal-Wallis was used to compare median PCTF and TFLL thicknesses and thinning rates.

Results: There were 190 subjects categorized into four groups: Normal (n = 63), MGD (n = 51), Asymptomatic MGD (n = 29), and Mixed (n = 47). The PCTF was significantly thinner in the Mixed group (3.3 [1.2]) than in the Normal (p < 0.001), MGD (p < 0.001) and Asymptomatic MGD (p = 0.009) groups. Relative to the Normal (4.5 [4.5] μm/min) and Mixed (5.0 [2.0] μm/min) groups, the rate of PCTF thinning was faster in the MGD (8.1 [3.0] μm/min, both p < 0.001) and Asymptomatic MGD (6.9 [3.1] μm/min, p = 0.009 and p = 0.04, respectively) groups. The correlation between PCTF thinning rate and TFLL thickness was ρ = −0.46, p < 0.001.

Conclusions: Symptomatic and asymptomatic MGD shows rapid PCTF thinning rates (evaporation), while the PCTF thickness was reduced in mixed disease. Thicker lipid layers were associated with slower PCTF thinning.

Chan,V. W. Y., Phan,C-M., Ngo,W., Jones,L. Lysozyme Deposition on Contact Lenses in an In Vitro Blink-Simulation Eye Model Versus a Static Vial Deposition Model Eye & Contact Lens 2021;47(7):388-393 [ Show Abstract ]

Purpose:
To evaluate active lysozyme deposition on daily disposable (DD) contact lenses (CL) using a novel in vitro blink model.

Methods:
Three conventional hydrogel DD CL materials (etafilcon A, omafilcon A, nelfilcon A) and three silicone hydrogel DD CL materials (delefilcon A, senofilcon A, somofilcon A) were tested. The device blink rate was set to 6 blinks/min with a tear flow rate of 1 μL/min using an artificial tear solution (ATS) containing lysozyme and other typical tear film components. After incubation at 2, 4, or 8 hr, lenses were removed, and lysozyme activity was measured. A separate experiment was conducted with lenses incubated in a static vial containing 480 μL of ATS.

Results:
Etafilcon A deposited significantly higher amounts of active lysozyme (402±102 μg/lens) than other lens materials after 8 hr (P<0.0001). Etafilcon A had a higher amount of active lysozyme using the blink model compared with the static vial (P=0.0435), whereas somofilcon A (P=0.0076) and senofilcon A (P=0.0019) had a higher amount of lysozyme activity in the vial compared with the blink model.

Conclusion:
The blink model can be tuned to provide quantitative data that closely mimics ex vivo studies and can be used to model deposition of lysozyme on CL materials.

Chan,V. W. Y., Phan,C-M., Walther,H., Ngo,W., Jones,L. Effects of Temperature and Blinking on Contact Lens Dehydration of Contemporary Soft Lens Materials Using an In Vitro Blink Model Translational Vision Science & Technology 2021;10(8):11 [ Show Abstract ]

Purpose: The purpose of this studywas to evaluate the effects of temperature and blinking on contact lens (CL) dehydration using an in vitro blink model.

Methods: Three silicone hydrogel (delefilcon A, senofilcon A, and comfilcon A) and two conventional hydrogel (etafilcon A and omafilcon A) CL materials were evaluated at 1
and 16 hours. The water content (WC) of the CLs was measured using a gravimetric method. Lenses were incubated on a blink model, internally heated to achieve a clinically relevant surface temperature of 35°C. An artificial tear solution (ATS) was delivered to the blink model at 4.5 μL/min with a blink rate of 6 blinks/min. A comparison set of lenses were incubated in a vial containing either 2 mL of ATS or phosphate-buffered saline (PBS) at 35°C.

Results: Increasing temperature to 35°C resulted in a decrease in WC for all tested CLs over time (P ≤ 0.0052). For most CLs, there was no significant difference in WC over time between ATS or PBS in the vial (P > 0.05). With the vial system, WC decreased and plateaued over time. However, on the blink model, for most CLs, the WC significantly decreased after 1 hour but returned toward initial WC levels after 16 hours (P > 0.05).

Conclusions: The reduction in WC of CLs on the eye is likely due to both an increase in temperature and dehydration from air exposure and blinking.

Translational Relevance: This study showed that the novel, heated, in vitro blink model could be used to provide clinical insights into CL dehydration on the eye.

Chang,J. M. L., Seo,J., Kwan,M. M. Y., Oh,S., McCanna,D. J., Subbaraman,L., Jones,L. Determining the Toxicity of UV Radiation and Chemicals on Primary and Immortalized Human Corneal Epithelial Cells Journal of Visualized Experiments 2021;173(July):e62675 [ Show Abstract ]

This article describes the methods of measuring the toxicity of ultraviolet (UV) radiation and ocular toxins on primary (pHCEC) and immortalized (iHCEC) human corneal epithelial cell cultures. Cells were exposed to UV radiation and toxic doses of benzalkonium chloride (BAK), hydrogen peroxide (H2O2), and sodium dodecyl sulfate (SDS). Metabolic activity was measured using a metabolic assay. The release of inflammatory cytokines was measured using a multi-plex interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-alpha (TNF-α) assay, and cells were evaluated for viability using fluorescent dyes.

The damaging effects of UV on cell metabolic activity and cytokine release occurred at 5 min of UV exposure for iHCEC and 20 min for pHCEC. Similar percent drops in metabolic activity of the iHCEC and pHCEC occurred after exposure to BAK, H2O2, or SDS, and the most significant changes in cytokine release occurred for IL-6 and IL-8. Microscopy of fluorescently stained iHCEC and pHCEC BAK-exposed cells showed cell death at 0.005% BAK exposure, although the degree of ethidium staining was greater in the iHCECs than pHCECs. Utilizing multiple methods of assessing toxic effects using microscopy, assessments of metabolic activity, and cytokine production, the toxicity of UV radiation and chemical toxins could be determined for both primary and immortalized cell lines.

Craig,J.P., Muntz,A., Wang,M.T.M., Luensmann,D., Tan,J., Travé-Huarte,S., Xue,A.L., Jones,L.W., Willcox,M.D.P., Wolffsohn,J.S. Developing evidence-based guidance for the treatment of dry eye disease with artificial tear supplements: A six-month multicentre, double-masked randomised controlled trial Ocular Surface 2021;20(April):62-69 [ Show Abstract ]

Purpose
To assess the six-month therapeutic profiles of lipid and non-lipid-based artificial tear supplements in managing dry eye disease (DED).

Methods
Ninety-nine participants fulfilling the TFOS DEWS II diagnostic criteria for DED (64% females; mean ± SD age, 44 ± 16 years) were enrolled in a prospective, multicentre, double-masked, parallel group, randomised controlled trial. Participants instilled lipid-based nanoemulsion drops or non-lipid-based aqueous drops for six months, at least four times daily. Symptomology, tear film and ocular surface characteristics were assessed at Days 0, 30, 60, 90, 120, 150 and 180.

Results
Sustained reductions in OSDI, DEQ-5, and SANDE symptom scores from baseline were observed from Day 30 onwards in both groups (all p < 0.05) and decreased superior lid wiper epitheliopathy grades from Day 60 onwards (all p ≤ 0.01). Improvements in non-invasive tear film breakup time, and sodium fluorescein and lissamine green staining scores followed from Day 120 onwards in both groups (all p < 0.05). Tear lipid layer grades increased from Day 90 onwards only with the lipid-based drops, and with significantly greater improvement in those with suboptimal lipid layer thickness at baseline (grade ≤3; p = 0.02). By Day 180, 19% of participants no longer fulfilled the diagnostic criteria for DED.

Conclusions
Over a six-month treatment period, improvements in dry eye symptomology preceded tear film and ocular surface changes with regular use of both lipid and non-lipid-based artificial tear supplements. Both formulations addressed most mild-to-moderate forms of aqueous deficient and evaporative DED, while evaporative cases benefitted preferentially from lipid-based supplementation. This represents a first step towards mapping DED therapeutic strategies according to disease subtype and severity.

Das,N., Menon,N., DeAlmeida,L., Woods,P., Heynen,M., Jay,G., Caffery,B., Krawetz,R., Schmidt,T. Dufour,A. Proteomics analysis of tears and saliva from Sjogren’s syndrome patients Frontiers in Pharmacology 2021;12(3299):787193 [ Show Abstract ]

Sjogren's syndrome (SS) is characterized by dysfunctional mucous membranes and dysregulated moisture-secreting glands resulting in various symptoms, including dry mouth and dry eyes. Here, we wanted to profile and compare the tear and saliva proteomes of SS patients to healthy controls. Tear and saliva samples were collected and subjected to an isotopic dimethylation labeling shotgun proteomics workflow to identify alterations in protein levels. In tear samples, we identified 83 upregulated and 112 downregulated proteins. Pathway enrichment analysis of the changing proteins by Metascape identified leukocyte transendothelial migration, neutrophil degranulation, and post-translation protein phosphorylation in tears of SS patients. In healthy controls' tears, an enrichment for proteins related to glycolysis, amino acid metabolism and apoptotic signaling pathway were identified. In saliva, we identified 108 upregulated and 45 downregulated proteins. Altered pathways in SS patients' saliva included cornification, sensory perception to taste and neutrophil degranulation. In healthy controls' saliva, an enrichment for proteins related to JAK-STAT signaling after interleukin-12 stimulation, phagocytosis and glycolysis in senescence were identified. Dysregulated protease activity is implicated in the initiation of inflammation and immune cell recruitment in SS. We identified 20 proteases and protease inhibitors in tears and 18 in saliva which are differentially expressed between SS patients and healthy controls. Next, we quantified endogenous proteoglycan 4 (PRG4), a mucin-like glycoprotein, in tear wash and saliva samples via a bead-based immune assay. We identified decreased levels of PRG4 in SS patients' tear wash compared to normal samples. Conversely, in saliva, we found elevated levels of PRG4 concentration and visualized PRG4 expression in human parotid gland via immunohistological staining. These findings will improve our mechanistic understanding of the disease and changes in SS patients' protein expression will help identify new potential drug targets. PRG4 is among the promising targets, which we identified here, in saliva, for the first time.

Downie,L. E., Bandlitz,S., Bergmanson,J. P. G., Craig,J. P., Dutta,D., Maldonado-Codina,C., Ngo,W., Sowjanya Siddireddy,J., Wolffsohn,J. S. CLEAR - Anatomy and physiology of the anterior eye Contact Lens Anterior Eye 2021;44(2):132-156 [ Show Abstract ]

A key element of contact lens practice involves clinical evaluation of anterior eye health, including the cornea and limbus, conjunctiva and sclera, eyelids and eyelashes, lacrimal system and tear film. This report reviews the fundamental anatomy and physiology of these structures, including the vascular supply, venous drainage, lymphatic drainage, sensory innervation, physiology and function. This is the foundation for considering the potential interactions with, and effects of, contact lens wear on the anterior eye. This information is not consistently published as academic research and this report provides a synthesis from all available sources. With respect to terminology, the report aims to promote the consistent use of nomenclature in the field, and generally adopts anatomical terms recommended by the Federative Committee for Anatomical Terminology. Techniques for the examination of the ocular surface are also discussed.

Efron,N., Jones,L. W., Morgan,P. B., Nichols,J. J. Bibliometric analysis of the literature relating to scleral contact lenses Contact Lens Anterior Eye 2021;44(4):101447 [ Show Abstract ]

Adolf Eugene Fick, a German ophthalmologist working in Zurich, published the first journal paper on contact lenses in 1888. In this paper, he described the process of fabricating and fitting afocal scleral contact lenses first on rabbits, then on himself and finally on a small group of volunteer patients with keratoconus.

Efron,N., Jones,L. W., Morgan,P. B., Nichols,J. J. On the art and science of rigid contact lens fitting Clinical and Experimental Optometry 2021;104(6):684-690 [ Show Abstract ]

Examination of the literature can help answer the age-old question of the extent to which rigid contact lenses can be considered an art versus a science.

Efron,N., Morgan,P. B., Jones,L. W., Morgan,G. A., Nichols,J. J. Global optometrist top 200 research ranking Clinical and Experimental Optometry 2021;104(4):471-485 [ Show Abstract ]

Clinical relevance: Clinical optometric practice is underpinned by a rigorous research base, the
primary evidence for which is publications in refereed scientific journals. Leading optometrists who
publish this work should be identified and celebrated.
Background: This work aims to derive publication metrics of the leading optometric researchers
worldwide.
Methods: An extensive global search was conducted to discover leading optometric researchers; 480
names were identified. A custom-designed bibliographic search tool was developed to interrogate
the Scopus database (Elsevier) and extract publication metrics using the unique Scopus Author
Identifier number for each optometrist. On 13 January 2021, the full list was reduced to 200
optometrists (the ‘Top 200’) ranked by h-index – the ‘Global Optometrist Top 200 Research
Ranking’. The output from the custom tool automatically updates every 24 hours and is available at
www.optomrankings.com.
Results: The Top 200 have h-indices ranging from 20 to 67 and have published between 28 and 440
papers. Sixty one (30.5%) are women. Konrad Pesudovs has the highest h-index (67) and citations
(51,193). The most prolific author is Robert Hess (442 papers). David Piñero is publishing at the
fastest rate (17.6 papers per year). The Top 200 work in 13 nations, of whom 172 (86.0%) work in
four nations: USA – 76 (38.0%), Australia – 43 (21.5%), UK – 41 (20.5%) and Canada – 16 (8.0%). Of
the 72 institutions represented, the University of California, Berkeley, USA is home to the most Top
200 optometrists (17) and has the highest combined h-index of Top 200 optometrists (132).
Conclusions: The optometric profession is supported by a robust research base, prosecuted by
a large international cohort of optometric researchers who publish extensively on a broad range of
ophthalmic issues and whose work is highly cited. The 200 most impactful optometrists in the world
are identified

Efron,N., Morgan,P. B., Jones,L. W., Nichols,J. J. 21st century citation analysis of the field of contact lenses Clinical and Experimental Optometry 2021;104(5):634-638 [ Show Abstract ]

Clinical relevance: The scientific foundations for clinical contact lens practice are rooted in the ophthalmic literature. This analysis of contact lens papers celebrates contemporary research achievements in the contact lens field.

Background: This work aims to assemble contact lens-related publication metrics so as to identify the most impactful papers published so far this century, as well the top countries, authors, institutions and journals.

Methods: A search was undertaken of the titles of papers on the Scopus database to identify contact lens-related articles published this century. The ten most highly cited papers were determined from the total list of 4,164 papers found. Rank-order lists by count were assembled for the ‘top 25ʹ in each of four categories: authors, institutions, countries and journals. A 20-year subject-specific contact lens h-index (hCL-20-index) was derived for each author, institution, country and journal to serve as a measure of impact in the field. The top 10 constituents (of the top 25) of each category were ranked by hCL-20-index and tabulated for consideration.

Results: The most highly cited paper this century is entitled ‘Soft contact lens polymers: An evolution’, by Nicholson and Vogt. Lyndon Jones is the most impactful author, with a hCL-20-index of 32. The University of New South Wales (Australia) produces the most impactful contact lens-related papers, and the United States is the most highly-ranked country. Optometry and Vision Science is the most impactful journal in the contact lens field.

Conclusions: Contact lens materials and lens-associated keratitis are topics of high interest in the contemporary contact lens literature, with an emerging interest in orthokeratology for myopia control and glucose monitoring. Impactful 21st century authors, institutions, countries and journals are identified. Optometry is revealed as the leading profession in relation to the publication of impactful contact lens-related papers.

Efron,N., Morgan,P. B., Jones,L. W., Nichols,J. J. Bibliometric analysis of the refractive error field Clinical and Experimental Optometry 2021;104(5):641-643 [ Show Abstract ]

Research into the epidemiology, aetiology, and optics of ametropia is a fundamental cornerstone of the correction and management of refractive errors by eye care practitioners. At present, much of this work is driven by the clinical concern that myopia is a common cause of vision loss, with uncorrected myopia the leading cause of vision impairment globally. Holden et al. predict that by 2050, about 50% of the population of the world will be myopic.
The aetiology of myopia continues to be hotly debated, centring around the relative impact of nature (genetics) versus nurture (environment). Research aimed at optimising optical (spectacles and contact lenses) and surgical (laser refractive techniques) modes of correcting refractive error continues unabated, and novel approaches for arresting the progression of myopia, using ophthalmic lenses, contact lenses (including orthokeratology), pharmacological approaches, or lifestyle modification, are also under active investigation. As is the case in all fields of investigation, the foundation of these various lines of refractive error research is rooted in the ophthalmic literature. Modern bibliographic search tools enable targeted interrogation of this vast literature to facilitate identification of the research foundations that underpin our understanding of refractive error. This Viewpoint uses
these bibliographic search tools and employs a subjectspecific measure of impact to identify key papers, authors, institutions, countries, and journals in the field of refractive error research.

Efron,N., Morgan,P. B., Jones,L. W., Nichols,J. J. Bibliometric analysis of the keratoconus literature Clinical and Experimental Optometry 2021;21(Sep):1-6 [ Show Abstract ]

Clinical Relevance
Clinicians, researchers funding agencies and indeed the general public can benefit from knowledge of the most highly cited papers and most impactful authors, institutions, countries and journals in the field of keratoconus.

Background
Bibliometrics relating to the keratoconus literature were derived to enable identification of the most impactful papers published, as well as the leading authors, institutions, countries and journals.

Methods
A search was undertaken of the titles of papers on the Scopus database to identify keratoconus-related articles. The 20 most highly cited papers were determined from the total list of 4,419 papers found. Rank-order lists by count were assembled for the ‘top 20ʹ in each of four categories: authors, institutions, countries and journals. A subject-specific keratoconus-related h-index (hKC-index) was derived for each constituent of each category to serve as a measure of impact in the field. The top 10 constituents of each category were ranked by hKC-index and tabulated for consideration.

Results
The hKC-index of the keratoconus field is 125. The 4,419 papers have been cited a total of 98,010 times, and 18.5% of these papers have never been cited. The most highly cited paper is a general review of keratoconus by Yaron Rabinowitz, who is also the most impactful author in the field (hKC = 31). The Cedars Sinai Medical Center in the United States produces the most impactful keratoconus-related papers (hKC = 36), and the United States is the most impactful country (hKC = 91). The Journal of Cataract and Refractive Surgery is the most impactful journal (hKC = 55).

Conclusion
Keratoconus is a topic of high interest in the clinical and scientific literature. Highly cited papers and impactful authors, institutions, countries and journals are identified.

Efron,N., Morgan,P. B., Jones,L. W., Nichols,J. J. Bibliometric Analysis of the Emerging Field of Myopia Management Optometry & Vision Science 2021;98(9):1039-1044 [ Show Abstract ]

SIGNIFICANCE
Identification of the most impactful articles, authors, institutions, countries, and journals in myopia management provides a useful baseline reference for clinicians, researchers, and funding agencies in respect of this emerging field.

This work aims to assemble publication metrics for myopia management to identify the most impactful articles, authors, institutions, countries, and journals in this emerging field of research. A search of the titles of articles was undertaken on the Scopus database to identify myopia management–related articles. The 25 most highly cited articles were determined from the total list of 1064 articles found. Rank-order lists by count were assembled for the top 25 in each of four categories: authors, institutions, countries, and journals. A subject-specific myopia management–related h-index (hMM-index) was derived for the entire field, in addition to each of the four categories, to serve as measures of impact in the field. Top 15 lists were generated for each category ranked by hMM-index and tabulated for consideration. An article by Christine Wildsoet and colleagues, describing choroidal and scleral mechanisms of compensation for spectacle lenses in chicks, has generated the most citations (412); Earl Smith is the most impactful author (hMM = 19); the University of Houston produces the most impactful articles (hMM = 31); the United States is the most highly ranked country (hMM = 60); and Optometry and Vision Science is the most impactful journal. Although still in its infancy, myopia management is a topic of emerging interest in the clinical and scientific ophthalmic literature. Impactful authors, institutions, countries, and journals are identified. Optometry is revealed as the leading profession in relation to the publication of myopia management–related articles.

Heynen,M., Ng,A., Martell,E., Subbaraman,L. N., Jones,L. Activity of Deposited Lysozyme on Contemporary Soft Contact Lenses Exposed to Differing Lens Care Systems Clinical Ophthalmology 2021;15(April):1727-1733 [ Show Abstract ]

Purpose: The amount of protein deposition on soft contact lenses and to what extent the proteins are denatured may have an impact on comfortable wearing times of contact lenses. The purpose of this study was to evaluate the effects of two lens care systems on total protein and the quantity and activity of lysozyme deposited on worn senofilcon A, silicone hydrogel contact lenses.

Participants and Methods: Thirty symptomatic soft contact lens wearers were enrolled into a 4-week prospective, randomized, bilateral eye, daily-wear, crossover, double-masked study. Participants were fitted with biweekly senofilcon A lenses and were assigned either a polyquaternium-1 and myristamidopropyl dimethylamine-containing system (OPTI-FREE RepleniSH) or a peroxide-based system (CLEAR CARE). After each wear period, proteins were extracted from the lenses and analyzed for total protein, total lysozyme quantity and activity.

Results: The use of either the peroxide-based system or the polyquaternium-1 and myristamidopropyl dimethylamine-containing system resulted in no difference (P> 0.05) to the amount of total protein deposited on the lenses (6.7 ± 2.8 micrograms/lens versus 7.3 ± 2.8 micrograms/lens, respectively) or to the amount of denatured lysozyme deposits (0.8 ± 0.7 versus 0.9 ± 0.7 micrograms/lens), respectively. The total amount of lysozyme deposited on the lenses was significantly lower when using the peroxide-based system (1.3 ± 0.9 micrograms/lens) compared to the polyquaternium-1 and myristamidopropyl dimethylamine-containing system (1.7 ± 1.0 micrograms/lens) (P=0.02).

Conclusion: The inactivation of lysozyme deposited on senofilcon A lenses when disinfected with the peroxide-based or the polyquaternium-1 and myristamidopropyl dimethylamine-containing systems were neither statistically nor clinically significant and the overall amounts of denatured lysozyme recovered from the lenses were low (< 1 microgram/lens).

Huynh,C. B., Ngo,W. Quantifying the Effect of Spectacle Frame Dimensions on Wind-Induced Ocular Plane Evaporation Using an in Vitro Model Eye & Contact Lens 2021;47(347):351 [ Show Abstract ]

Purpose: To quantify the effect of spectacle frame dimensions on wind-induced ocular plane evaporation.

Methods: A drop of 0.5 μL water was pipetted onto an eye of a mannequin head. The face was fitted with a spectacle frame. A fan positioned 10 cm away directed air (185 CFM) toward the face and the time required for the drop to evaporate was recorded. This procedure was repeated with 31 different frames to obtain evaporation times for various eye sizes, vertical heights, vertex distances, temperature, and humidity. This was also repeated 30 times without spectacle wear to obtain evaporation times for various temperature and humidity conditions.

Results: Spectacle wear increased evaporation times compared with nonspectacle wear, in both high (>35%) and low humidity (<30%) conditions (both P<0.01). Humidity was correlated with evaporation time, regardless of spectacle and nonspectacle wear (both P<0.01). Evaporation time did not correlate with spectacle eye size, vertical height, or vertex distance (all P≥0.21).

Conclusion: This study showed that spectacle wear guarded against wind-induced evaporation at the ocular plane compared with nonspectacle wear. However, once spectacles were worn, eye size, vertical height, and vertex distance were not correlated with evaporation times. Humidity drove evaporation independent of spectacle wear.

Jin,Y., Dixon,B., Jones,L., Gorbet,M. The Differential Reactive Oxygen Species Production of Tear Neutrophils in Response to Various Stimuli In Vitro International Journal of Molecular Sciences 2021;22(23):12899 [ Show Abstract ]

A large number of polymorphonuclear neutrophils (PMNs) invade the ocular surface during prolonged eye closure (sleep); these leukocytes are commonly referred as tear PMNs. PMNs contribute to homeostasis and possess an arsenal of inflammatory mediators to protect against pathogens and foreign materials. This study examined the ability of tear PMNs to generate reactive oxygen species (ROS), an essential killing mechanism for PMNs which can lead to oxidative stress and imbalance. Cells were collected after sleep from healthy participants using a gentle eye wash. ROS production in stimulated (phorbol-12-myristate-13-acetate (PMA), lipopolysaccharides (LPS) or N-Formylmethionyl-leucyl-phenylalanine (fMLP)) and unstimulated tear PMNs was measured using luminol-enhanced chemiluminescence for 60 min. A high level of constitutive/spontaneous ROS production was observed in tear PMNs in the absence of any stimulus. While tear PMNs were able to produce ROS in response to PMA, they failed to appropriately respond to LPS and fMLP, although fMLP-stimulated tear PMNs generated ROS extracellularly in the first three minutes. Higher ROS generation was observed in isolated tear PMNs which may be due to priming from the magnetic bead cell separation system. The differential responses of tear PMNs in ROS generation provide further evidence of their potential inflammatory roles in ocular complications involving oxidative stress.

Jones,L., Hui,A., Phan,C-M., Read,M. L., Azar,D., Buch,J., Ciolino,J. B., Naroo,S. A., Pall,B., Romond,K., Saknaridurg,P., Schnider,C. M., Terry,L., Willcox,M. CLEAR - Contact lens technologies of the future Contact Lens Anterior Eye 2021;44(2):398-430 [ Show Abstract ]

Contact lenses in the future will likely have functions other than correction of refractive error. Lenses designed to control the development of myopia are already commercially available. Contact lenses as drug delivery devices and powered through advancements in nanotechnology will open up further opportunities for unique uses of contact lenses.

This review examines the use, or potential use, of contact lenses aside from their role to correct refractive error. Contact lenses can be used to detect systemic and ocular surface diseases, treat and manage various ocular conditions and as devices that can correct presbyopia, control the development of myopia or be used for augmented vision. There is also discussion of new developments in contact lens packaging and storage cases.

The use of contact lenses as devices to detect systemic disease has mostly focussed on detecting changes to glucose levels in tears for monitoring diabetic control. Glucose can be detected using changes in colour, fluorescence or generation of electric signals by embedded sensors such as boronic acid, concanavalin A or glucose oxidase. Contact lenses that have gained regulatory approval can measure changes in intraocular pressure to monitor glaucoma by measuring small changes in corneal shape. Challenges include integrating sensors into contact lenses and detecting the signals generated. Various techniques are used to optimise uptake and release of the drugs to the ocular surface to treat diseases such as dry eye, glaucoma, infection and allergy. Contact lenses that either mechanically or electronically change their shape are being investigated for the management of presbyopia. Contact lenses that slow the development of myopia are based upon incorporating concentric rings of plus power, peripheral optical zone(s) with add power or non-monotonic variations in power. Various forms of these lenses have shown a reduction in myopia in clinical trials and are available in various markets.

Khanal,S., Ngo,W., Nichols,K. K., Wilson,L., Barnes,S., Nichols,J. J. Human meibum and tear film derived (O-acyl)-omega-hydroxy fatty acids in meibomian gland dysfunction Ocular Surface 2021;21(July):118-128 [ Show Abstract ]

Purpose: The molecular basis of the tear film and lipid layer alterations in meibomian gland dysfunction (MGD) is unknown. This study aimed to identify and compare (O-acyl)-omega-hydroxy fatty acids (OAHFAs) derived from human meibum and tears in MGD. Methods: Of 195 eligible subjects (18–84 years, 62.6% female), 183 and 174 provided samples for tears and meibum, respectively. Subjects were classified into four groups: Normal, Asymptomatic MGD, MGD, and Mixed. Samples from the right eye of each subject were infused into the SCIEX 5600 TripleTOF mass spectrometer in negative ion mode. Lipid intensities identified with Analyst1.7 TF and SCIEX LipidView1.3 were normalized by an internal standard and total ion current, then statistically compared in MetaboAnalyst 4.0. Results: In meibum and tears, 76 and 78 unique OAHFAs were identified, respectively. The five most frequent and abundant OAHFAs were 18:2/16:2, 18:1/32:1, 18:1/30:1, 18:2/32:1, and 18:1/34:1. Two OAHFAs, 18:2/20:2 and 18:2/20:1, were identified only in tears. Initial univariate analysis revealed three differently regulated OAHFAs in meibum and eight in tears. Partial Least Square Discriminant Analysis showed 18:1/32:1, 18:2/16:2, 18:1/34:1 and 18:0/32:1 in tears, and 18:2/16:2, 18:1/32:1 and 18:2/32:2 in meibum, had variable importance in projection scores >1.5 and contributed the most to the separation of groups. In both meibum and tears, all OAHFAS except 18:2/16:2 were reduced in MGD compared to the normal group. Conclusion: MGD is accompanied by differential expression of specific OAHFAs in meibum and tears. These results suggest OAHFAs play a role in the altered biochemical profile of the tear film lipid layer in humans with MGD.

Kondela,T., Dushanov,E., Vorobyeva,M., Mamatkulov,K., Drolle,E., Soloviov,D., Hrubovcak,P., Kholmurodov,K., Arzumanyan,G., Leonenko,Z., Kucerka,N Investigating the competitive effects of cholesterol and melatonin in model lipid membranes Biochimica et Biophysica Acta - Biomembranes 2021;1863(9):183651 [ Show Abstract ]

We have studied the impact of cholesterol and/or melatonin on the static and dynamical properties of bilayers made of DPPC or DOPC utilizing neutron scattering techniques, Raman spectroscopy and molecular dynamics simulations. While differing in the amplitude of the effect due to cholesterol or melatonin when comparing their interactions with the two lipids, their addition ensued recognizable changes to both types of bilayers. As expected, based on the two-component systems of lipid/cholesterol or lipid/melatonin studied previously, we show the impact of cholesterol and melatonin being opposite and competitive in the case of three-component systems of lipid/cholesterol/melatonin. The effect of cholesterol appears to prevail over that of melatonin in the case of structural properties of DPPC-based bilayers, which can be explained by its interactions targeting primarily the saturated lipid chains. The dynamics of hydrocarbon chains represented by the ratio of trans/gauche conformers reveals the competitive effect of cholesterol and melatonin being somewhat more balanced. The additive yet opposing effects of cholesterol and melatonin have been observed also in the case of structural properties of DOPC-based bilayers. We report that cholesterol induced an increase in bilayer thickness, while melatonin induced a decrease in bilayer thickness in the three-component systems of DOPC/cholesterol/melatonin. Commensurately, by evaluating the projected area of DOPC, we demonstrate a lipid area decrease with an increasing concentration of cholesterol, and a lipid area increase with an increasing concentration of melatonin. The demonstrated condensing effect of cholesterol and the fluidizing effect of melatonin appear in an additive manner upon their mutual presence.

Mirzapour,P., McCanna,D. J., Jones,L. In vitro analysis of the interaction of tear film inflammatory markers with contemporary contact lens materials Contact Lens Anterior Eye 2021;44(5):101430 [ Show Abstract ]

Purpose
Several clinical studies have suggested that reusable silicone hydrogel contact lens materials exhibit a two-times increased rate of corneal infiltrative events compared to reusable hydrogels. One potential factor contributing to this complication relates to the differential uptake of tear film-based pro-inflammatory cytokines. The purpose of this study was to use an in vitro assay to investigate whether four pro-inflammatory cytokines differed in their uptake onto six contemporary contact lens materials.

Methods
Conventional hydrogel (etafilcon A, omafilcon A) and silicone hydrogel (balafilcon A, comfilcon A, senofilcon A, somofilcon A) contact lens materials were soaked in solutions containing pro-inflammatory cytokines IL-1β, IL-6, IL-8 and TNF-α. Samples of the soaking solutions were collected over various time points and analyzed using the Meso Scale Discovery system, which served as a measurement of cytokine uptake onto the contact lens materials.

Results
Both conventional hydrogels (etafilcon A, omafilcon A) and two of the four silicone hydrogels tested (balafilcon A, comfilcon A), exhibited some uptake of IL-1β, IL-8 or TNF-α (p 0.05). There was no uptake of IL-6 onto any of the contact lens materials investigated (p > 0.05).

Conclusion
The contact lens materials tested did not exhibit any uptake of IL-6 and furthermore, did not exhibit more than 10 ± 3 % to 25 ± 12 % uptake of IL-1β, IL-8 or TNF-α. Numerous factors could contribute to the reported increase in corneal infiltrative events with reusable silicone hydrogel materials, however, based on these results, it appears that uptake of these four cytokines are unlikely to contribute to this finding.

Morgan,P. B., Murphy,P. J., Gifford,K. L., Gifford,P., Golebiowski,B., Johnson,L., Makrynioti,D., Moezzi,A. M., Moody, K., Navascues-Cornago,M., Schweizer,H., Swiderska,K., Young,G., Willcox,M. CLEAR - Effect of contact lens materials and designs on the anatomy and physiology of the eye Contact Lens Anterior Eye 2021;44(2):192-219 [ Show Abstract ]

This paper outlines changes to the ocular surface caused by contact lenses and their degree of clinical significance. Substantial research and development to improve oxygen permeability of rigid and soft contact lenses has meant that in many countries the issues caused by hypoxia to the ocular surface have largely been negated. The ability of contact lenses to change the axial growth characteristics of the globe is being utilised to help reduce the myopia pandemic and several studies and meta-analyses have shown that wearing orthokeratology lenses or soft multifocal contact lenses can reduce axial length growth (and hence myopia).

However, effects on blinking, ptosis, the function of Meibomian glands, fluorescein and lissamine green staining of the conjunctiva and cornea, production of lid-parallel conjunctival folds and lid wiper epitheliopathy have received less research attention. Contact lens wear produces a subclinical inflammatory response manifested by increases in the number of dendritiform cells in the conjunctiva, cornea and limbus. Papillary conjunctivitis is also a complication of all types of contact lenses. Changes to wear schedule (daily disposable from overnight wear) or lens materials (hydrogel from SiHy) can reduce papillary conjunctivitis, but the effect of such changes on dendritic cell migration needs further study. These changes may be associated with decreased comfort but confirmatory studies are needed. Contact lenses can affect the sensitivity of the ocular surface to mechanical stimulation, but whether these changes affect comfort requires further investigation.

In conclusion, there have been changes to lens materials, design and wear schedules over the past 20+ years that have improved their safety and seen the development of lenses that can reduce the myopia development. However, several changes to the ocular surface still occur and warrant further research effort in order to optimise the lens wearing experience.

Nichols,J. J., Jones,L., Morgan,P. B., Efron,N. Bibliometric analysis of the meibomian gland literature Ocular Surface 2021;20(April):212-214 [ Show Abstract ]

There is a rich history of interest in the sebaceous glands located posterior to the tarsal plates in the eyelids, to which we refer today as the meibomian glands (MGs). Although there is acknowledgement of the MGs preceding the work of Johann Heinrich Meibom in the 1600's, he is credited with advancing our knowledge and study of these glands.

The MGs produce a distinct lipid secretion (‘meibum’) made up of a variety of lipid classes, mostly composed of nonpolar wax and cholesterol esters, although other nonpolar and polar lipids are certainly known to exist in the meibum. The normal function of meibum is to make its way to the tear film lipid layer, ultimately forming a resistive barrier to evaporation of the aqueous component of the tear film. In disease, the MGs lose their ability to secrete a normal meibum composition and/or are impeded due to factors such as atrophy of the MGs, keratinization of the orifice of the gland from which the meibum is secreted onto the eyelid margin, or bacterial colonization of the eyelid, altering the secretion itself once expressed. These conditions today are known as blepharitis, including anterior and posterior blepharitis (which includes meibomian gland dysfunction).

Given the extensive study of MGs, a bibliometric analysis is warranted to acknowledge and celebrate those contributing to this important part of ophthalmic research.

Nichols,J. J., Jones,L., Morgan,P. B., Efron,N. Bibliometric analysis of the orthokeratology literature Contact Lens Anterior Eye 2021;44(4):101390 [ Show Abstract ]

The wearing of rigid lenses can result in changes to corneal curvature and the planned, temporary reduction of myopia by wearing flat-fitting rigid lenses (termed orthokeratology) was first reported in the 1960’s [1]. In the late 1970’s and early 1980’s, several studies evaluated this concept and concluded that the reduction in myopia was relatively short-lived, unpredictable, inconsistent and limited to only a low degree of myopia; as such, orthokeratology was largely ignored at this time [2, 3, 4].
A renewed interest in orthokeratology occurred in the late 1990’s and early 2000’s due to the simultaneous development of corneal topographers, highly oxygen permeable rigid lens materials and the development of sophisticated reverse geometry lenses that produced more predictable reductions in myopia [5, 6, 7, 8, 9]. This permitted contact lens fitters to adopt the concept of ‘overnight orthokeratology’, where patients wore the lenses during sleep and corneal shape changes occurred that reduced the degree of myopia to the point where the patient could remove the lens on waking and spend several days with no vision correction being required [10,11].
In 2005, Cho and colleagues reported that orthokeratology lenses used in children could slow the progression of myopia and this observation resulted in a resurgence in interest in orthokeratology [12]. Numerous publications since have shown that this myopia control effect is repeatable and many practitioners now adopt this modality on a routine basis to slow the progression of myopia, particularly in Asian countries [9,13, 14, 15, 16, 17].
The purpose of this paper is to report a bibliometric analysis of the literature on orthokeratology lenses so as to determine the most widely cited papers and most prolific authors, institutions, countries and journals related to this topic, and to recognise and celebrate the key stakeholders in this area of contact lens research.

Nichols,J. J., Morgan,P. M., Jones,L. W., Efron,N 21st century bibliometric analysis of the field of dry eye disease Clinical and Experimental Optometry 2021;104(5):639-640 [ Show Abstract ]

In 2012, the lead author of this paper (JJN) conducted a citation analysis of dry eye research to identify the leading papers, authors, institutions, countries and journals in the field. That analysis was essentially an historical overview of publications on this topic extending back over the past century. Because a strong and growing foundation of scientific literature is a fundamental component of evidenced-based clinical care of patients, the current work was conducted to update the research community on trends in the 21st century dry eye literature, and to compare this new literature with the prior analysis in the context of events or trends in the dry eye field.

Omali,N. B., Subbaraman,L. N., Heynen,M., Lada,M., Canavan,K., Fadli,Z., Ngo,W., Jones,L. Lipid deposition on contact lenses in symptomatic and asymptomatic contact lens wearers Cont Lens Anterior Eye 2021;44(1):56-61 [ Show Abstract ]

Purpose
Lipid deposition on contact lenses (CL) has traditionally been believed to reduce comfort during CL wear. The purpose of this study was to quantify lipid deposition on CL in a group of symptomatic and asymptomatic adapted CL wearers.

Methods
This was a single-masked, randomized clinical trial. Only confirmed symptomatic (comfortable lens wear time (CWT) 10 h and minimal reduction in comfort over the course of the day) participants were recruited to participate in the study. Participants wore senofilcon A lenses in combination with a polyquaternium-based care solution (OPTI-FREE Replenish). Worn CL samples were collected on Day 14. Deposited lipid amounts from the lenses (including cholesteryl ester, cholesterol and triolein) were quantified using a liquid chromatography-mass spectrometry technique.

Results
Lipid deposition was significantly higher in CL extracts of asymptomatic wearers compared to the symptomatic wearers for all lipid types quantified, including cholesteryl ester (2.1 ± 0.6 vs 1.6 ± 0.5 log μg/lens), cholesterol (1.5 ± 0.3 vs 1.1 ± 0.3 log μg/lens) and triolein (0.3 ± 0.2 vs 0.1 ± 0.1 log μg/lens) (all p < 0.002). The amount of cholesteryl ester deposited was greatest (p = 0.0001), followed by cholesterol, then triolein, for both the asymptomatic and symptomatic groups (both p = 0.0001).

Conclusion
This study demonstrated that the asymptomatic group deposited a significantly greater amount of lipid on their CL. Although lipid levels measured are considered low to trigger any observable clinical deposition, they may influence other clinical outcomes, particularly comfort.

Phan,C. M., Qiao,H., Yee,A., Jones,L. Deposition of Fluorescently Tagged Lysozyme on Contact Lenses in a Physiological Blink Model Eye & Contact Lens 2021;47(2):127-133 [ Show Abstract ]

PURPOSE: To visualize the deposition of fluorescein isothiocyanate (FITC) lysozyme on daily disposable contact lenses (CLs) using a novel blink model.

METHODS: Three daily disposable conventional hydrogel CLs (etafilcon A, omafilcon A, and nelfilcon A) and three silicone hydrogel CLs (delefilcon A, senofilcon A, and somofilcon A) were evaluated in the study. The CLs were mounted onto a novel blink model and exposed to an artificial tear solution containing FITC lysozyme for 2 and 10 hr. The flow rate and blink speed were set to 1 μL/min and 6 blinks/min, respectively. After the incubation period, a 5-mm-diameter disc was punched out from the center of the lens and mounted on a microscope slide. The slides were imaged using the Zeiss 510 Meta confocal laser scanning microscope, which scanned the lens from the front to the back surface at 5-μm increments.

RESULTS: There was an increase in deposition of FITC lysozyme for all lens types with increasing incubation time (P0.05). The conventional hydrogel CLs deposited higher amounts of FITC lysozyme than the silicone hydrogel CLs (P<0.001), with etafilcon A depositing the highest at all time points (P<0.05). Interestingly, at the 2-hr incubation time, most CLs showed a higher amount of deposition at the front surface than the back surface of the lens. In particular, etafilcon A showed preferred deposition at the front surface at all time points.

CONCLUSION: The results suggest that there is differential deposition at the front surface of the CL, which is exposed to the prelens tear film, compared with the back surface of the CL, which is exposed to the postlens tear film. Therefore, it may be beneficial to design CL materials with differing surface properties for the front and back surfaces of the CL to enhance interactions with the tear film and ocular surface.

Phan,C. M., Shukla,M., Walther,H., Heynen,M., Suh,D., Jones,L. Development of an In Vitro Blink Model for Ophthalmic Drug Delivery Pharmaceutics 2021;13(Article 300):1-10 [ Show Abstract ]

Purpose: The purpose of this study was to develop an advanced in vitro blink model that
can be used to examine the release of a wide variety of components (for example, topical ophthalmic
drugs, comfort-inducing agents) from soft contact lenses. Methods: The model was designed using
computer-aided design software and printed using a stereolithography 3D printer. The eyelid and
eyeball were synthesized from polyvinyl alcohol and silicone material, respectively. Simulated
tear fluid was infused through tubing attached to the eyelid using a syringe pump. With each
blink cycle, the eyelid slides and flexes across the eyeball to create an artificial tear film layer. The
flow-through fluid was collected using a specialized trough. Two contact lenses, etafilcon A and
senofilcon A, were incubated in 2 mL of a water-soluble red dye for 24 h and then placed on the eye
model (n = 3). The release of the dye was measured over 24 h using a tear flow rate of 5 µL/min.
Results: Approximately 25% of the fluid that flowed over the eye model was lost due to evaporation,
nonspecific absorption, and residual dead volume. Senofilcon A absorbed more dye (47.6 ± 2.7 µL)
than etafilcon A (22.3 ± 2.0 µL). For etafilcon A, the release of the dye followed a burst-plateau
profile in the vial but was sustained in the eye model. For senofilcon A, the release of the dye was
sustained in both the vial and the eye model, though more dye was released in the vial (p < 0.05).
Overall, the release of the dye from the contact lenses was higher in the vial compared with the eye
model (p < 0.05). Conclusion: The blink model developed in this study could be used to measure
the release of topical ophthalmic drugs or comfort agents from contact lenses. Simulation of a blink
mechanism, an artificial tear film, and nonspecific absorption in an eye model may provide better
results than a simple, static vial incubation model.

Schulze,M., Ng,A. Y., Yang,M., Panjwani,F., Srinivasan,S., Jones,L., Senchyna,M. Bulbar redness and dry eye disease: comparison of a validated subjective grading scale and an objective automated method Optometry & Vision Science 2021;98(2):113-120 [ Show Abstract ]

SIGNIFICANCE
In this study, assessments of conjunctival redness were performed to evaluate whether patients with or without dry eye disease (DED) could be discriminated based on this measure. Our findings suggest that subjectively grading redness by quadrant, as opposed to automated en face measurements, may be more suitable for this purpose.

PURPOSE
This study aimed to quantify bulbar redness using the validated bulbar redness (VBR) grading scale and an automated objective method (Oculus Keratograph 5M; K5M) in participants with DED and non-DED controls.

METHODS
Participants with DED (Ocular Surface Disease Index score ≥20 and Oxford scale corneal staining ≥2) and controls (Ocular Surface Disease Index score ≤10 and corneal staining ≤1) attended two study visits. In part 1A of visit 1, baseline bulbar redness was graded with the VBR scale in each conjunctival quadrant of both eyes, followed by automated measurements of temporal and nasal redness with the K5M. This was immediately followed by part 1B, during which a topical vasoconstrictor was instilled into both eyes. Redness assessments were repeated 5 and 30 minutes after instillation with both instruments. Participants returned 14 days later for visit 2, where the same assessments as for visit 1A were repeated.

RESULTS
Seventy-four participants (50 DED and 24 controls) completed the study. There were statistically significant differences in redness between the DED and control groups when assessed with the VBR scale (14/16 comparisons; all, P < .05), whereas no significant differences in K5M-derived redness between the DED and non-DED groups were found at any location or time point. Both subjective and objective instruments detected statistically significant reductions in redness 5 and 30 minutes after instillation of the vasoconstrictor (all, P < .01).

CONCLUSIONS
Although both subjective and objective instruments were sensitive to detecting changes in redness induced by vasoconstriction, statistically significant differences in redness between DED and control groups were only found using the VBR scale.

Spafford,M. M., Jones,D. A., Christian,L. W., Labreche,T., Furtado,N. M., MacIver,S., Irving,E. L. What the Canadian public (mis)understands about eyes and eye care Clinical and Experimental Optometry 2021;Online ahead of print [ Show Abstract ]

Clinical relevance
Inadequate public knowledge about eyes and eye care poses avoidable risks to vision-related quality of life.

Background
This study of eye care knowledge among Canadians extends earlier findings from focus groups.

Methods
Perceptions about eyes and eye care were sought using a 21-item online survey and snowball sampling. Inclusion criteria were living in Canada and being at least 18-years old; eye care professionals and staff were excluded. Response frequencies were converted to percentages, with eye condition items analysed according to ‘expected’ or ‘unexpected’ eye impacts. Proportions selecting these impacts or ‘unsure’ were determined.

Results
There were 424 respondents: 83.0% aged 20-65 years and 69.6% female. Mismatches existed between perceived recommendations and behaviours for booking eye exams: within two years (86.7% vs. 68.4%) and symptom-driven (3.3% vs. 13.0%). First eye exams after age one year were deemed appropriate by 43.6%. Few respondents associated glaucoma with no symptoms (6.0%) or amblyopia with blurred vision (13.5%). A notable proportion incorrectly related tunnel vision with age-related macular degeneration (AMD, 36.8%) and cataract (21.9%). Identifying all ‘expected’ responses was unlikely for glaucoma (1.9%), amblyopia (6.7%), and cataract (12.0%). Most respondents identified no ‘expected’ effects for glaucoma (63.8%) and AMD (46.2%) and some ‘expected’ effects for cataract (59.5%) and amblyopia (72.6%). Selecting ‘unsure’ was 9-10 times more common among respondents choosing no ‘expected’ impacts than those choosing some. Awareness of thyroid-associated eye disease was lowest (32.4%) of seven conditions. Respondents were most likely to consult optometrists for routine eye exams, eye disease, diabetes eye checks and blurred vision but family physicians for red eyes and sore eyes. Respondents typically paid for their eye exams and eyewear but wanted government to pay.

Conclusion
Vision-threatening knowledge gaps and misinformation about eyes and eye care among Canadian respondents highlight the need for accessible, targeted public education.

Stapleton,F., Bakkar,M., Carnt,N., Chalmers,R., Kumar Vijay,A., Marasini,S., Ng,A. Y., Tan,J., Wagner,H., Woods,C., Wolffsohn,J. S. CLEAR - Contact lens complications Contact Lens Anterior Eye 2021;44(2):330-367 [ Show Abstract ]

Contact lens-related complications are common, affecting around one third of wearers, although most are mild and easily managed. Contact lenses have well-defined anatomical and physiological effects on the ocular surface and can result in other consequences due to the presence of a biologically active material. A contact lens interacts with the tear film, ocular surface, skin, endogenous and environmental microorganisms, components of care solutions and other antigens which may result in disease specific to contact lens wear, such as metabolic or hypersensitivity disorders. Contact lens wear may also modify the epidemiology or pathophysiology of recognised conditions, such as papillary conjunctivitis or microbial keratitis. Wearers may also present with intercurrent disease, meaning concomitant or pre-existing conditions unrelated to contact lens wear, such as allergic eye disease or blepharitis, which may complicate the diagnosis and management of contact lens-related disease.

Complications can be grouped into corneal infection (microbial keratitis), corneal inflammation (sterile keratitis), metabolic conditions (epithelial: microcysts, vacuoles, bullae, tight lens syndrome, epithelial oedema; stromal: superficial and deep neovascularisation, stromal oedema [striae/folds], endothelial: blebs, polymegethism/ pleomorphism), mechanical (corneal abrasion, corneal erosion, lens binding, warpage/refractive error changes; superior epithelial arcuate lesion, mucin balls, conjunctival epithelial flaps, ptosis, discomfort), toxic and allergic disorders (papillary conjunctivitis, solution-induced corneal staining, incomplete neutralisation of peroxide, Limbal Stem Cell Deficiency), tear resurfacing disorders/dry eye (contact lens-induced dry eye, Meibomian gland dysfunction, lid wiper epitheliopathy, lid parallel conjunctival folds, inferior closure stain, 3 and 9 o'clock stain, dellen, dimple veil) or contact lens discomfort. This report summarises the best available evidence for the classification, epidemiology, pathophysiology, management and prevention of contact lens-related complications in addition to presenting strategies for optimising contact lens wear.

Thite,N., Desiato,A., Shinde,L., Wolffsohn,J. S., Naroo,S. A., Santodomingo-Rubido,J., Cho,P., Jones,D., Villar-Collar,C., Carillo,G., Chan,O., Wang,H., Iomdina,E., Tattura,E., Proskurina,O., Shing Fan,C., Zeri,F., Bakkar,M. M., Barodawala,F., Dabral,N., Lafosse,E., Lee,C., Nichols,J. J., Chan,J., Park,K., Nair,V., van der Worp,E., Vankudre,G., Maseedupalli,V., Bhattarai,Y., Nagzarkar,D., Brauer,P., Gil-Cazorla,R. Opportunities and threats to contact lens practice: A global survey perspective Contact Lens Anterior Eye 2021;44(6):101496 [ Show Abstract ]

Aim
To understand the views of contact lens (CL) practitioners across the globe regarding what they perceive as opportunities and threats in CL practice.

Methods
A self-administered anonymised questionnaire, constructed in English and translated in six more languages, was distributed through reputed international professional bodies and academic institutions worldwide. The questionnaire included items on demographic characteristics, type of practice, and questions designed to explore practitioners’ perspective on the future of their CL practice over the next five years.

Results
A total of 2408 valid responses were analysed. Multifocal CLs for presbyopia, CLs for myopia control, use of daily disposable (DD) CLs for occasional wear, and biocompatible materials to improve comfort were identified as promising areas of opportunities by practitioners (all 8/10). Respondents from North America, and Europe valued DDCLs for occasional wear moderately more favourable (Median: 9/10 for all) as compared to colleagues in Asia (Median: 8/10, p < 0.001), South America (Median: 8/10, p < 0.01), and Africa (Median: 8/10p < 0.01). Multifocal CLs for presbyopia was perceived as a better opportunity by practitioners in North America and Europe (Median: 9/10 for both), as well as in Australasia (Median: 8/10), in comparison to Asia, Africa, and Middle East (for all Median: 6/10, p < 0.001). Practitioners expressed concerns about the availability of CLs and CL prescriptions online without direct professional involvement (both 9/10).

Conclusions
Overall, the most appealing opportunities for CL practice growth were identified in occasional use of DD CLs, biocompatible materials to reduce CL discomfort, multifocal CLs for presbyopia correction and management of myopia control with CLs. Lack of regulation in CL sales, especially online, seemed to be a constant threat. The insights from this study can be used to design targeted strategies to enhance CL practice across the globe and in specific geographical areas.

Tichenor,A., Cofield,S., Gann,D., Elder,M., Ng,A. Y., Walsh,K., Jones,L., Nichols,J. Frequency of Contact Lens Complications Between Contact Lens Wearers Using Multipurpose Solutions Versus Hydrogen Peroxide in the United States and Canada Eye & Contact Lens 2021;47(5):277-282 [ Show Abstract ]

Objectives: To retrospectively compare frequency of contact lens (CL) complications in soft CL users of hydrogen peroxide (H2O2) and multipurpose solutions (MPS).

Methods: This was a multicenter, retrospective chart review of CL records from each patient's three most recent eye examinations at academic and private practices. Patients must have used the same solution type for at least 3 years. Univariate analyses were conducted using t tests, and chi-square or Fisher's exact test for categorical measures.

Results: There were 1,137 patients included, with 670 (59%) using MPS and 467 (41%) H2O2. In total, 706 (62%) experienced at least one complication; 409 used MPS and 297 used H2O2. There was no difference in the proportion of patients experiencing at least one complication between MPS (61%) and H2O2 (64%) (P=0.38). Multipurpose solutions users were more likely to report discomfort compared with H2O2 users (P=0.04). Presumed microbial keratitis was experienced by 16 MPS and nine H2O2 users (P=0.60).

Conclusions: No significant differences were found in the frequency of CL complications between MPS and H2O2. H2O2 users were less likely to report discomfort and thus switching to a H2O2 system may be an alternative in CL users with discomfort.

Ulkuseven,E., McCanna,D. J., Subbaraman,L. N., Jones,L. W. The Effect of Antimicrobial Peptides on the Viability of Human Corneal Epithelial Cells Probiotics and Antimicrobial Proteins 2021;13(2):518-526 [ Show Abstract ]

Antimicrobial peptides are polypeptides composed of less than 100 amino acids and are a class of antibiotics with strong activity against some infectious bacteria. This study examined the safety of four chosen antimicrobial peptides using primary human corneal epithelial cells (HCEC) and explored their potential therapeutic use. The efficacy of the peptides was also studied by evaluating the minimum inhibitory concentrations (MIC) against Gram-negative and Gram-positive bacteria. One of the peptides (polymyxin E) was found to have antibacterial efficacy against a common Gram-negative bacterium (MIC 1.56 μg/mL for Pseudomonas aeruginosa), and another one (nisin) was found to have antibacterial efficacy against a common Gram-positive bacterium (MIC 125 μg/mL for Staphylococcus aureus). Metabolic activity and live/dead/apoptotic effects were measured with fluorescent dyes after HCEC were exposed to the peptides for 30 min. Three of the peptides exhibited lower toxicity against HCEC than a currently marketed eye drop product. Regarding both efficacy and safety, two of the peptides (polymyxin E and nisin) were found to have potential use for treating ocular infections.

Vincent,S. J., Cho,P., Yin Chan,K., Fadel,D., Ghorbani-Mojarrad,N., González-Méijome,J. M., Johnson,L., Michaud,L., Simard,P., Jones,L. CLEAR - Orthokeratology Contact Lens Anterior Eye 2021;44(2):240-269 [ Show Abstract ]

Orthokeratology (ortho-k) is the process of deliberately reshaping the anterior cornea by utilising specialty contact lenses to temporarily and reversibly reduce refractive error after lens removal. Modern ortho-k utilises reverse geometry lens designs, made with highly oxygen permeable rigid materials, worn overnight to reshape the anterior cornea and provide temporary correction of refractive error. More recently, ortho-k has been extensively used to slow the progression of myopia in children.

This report reviews the practice of ortho-k, including its history, mechanisms of refractive and ocular changes, current use in the correction of myopia, astigmatism, hyperopia, and presbyopia, and standard of care. Suitable candidates for ortho-k are described, along with the fitting process, factors impacting success, and the potential options for using newer lens designs. Ocular changes associated with ortho-k, such as alterations in corneal thickness, development of microcysts, pigmented arcs, and fibrillary lines are reviewed. The safety of ortho-k is extensively reviewed, along with an overview of non-compliant behaviours and appropriate disinfection regimens. Finally, the role of ortho-k in myopia management for children is discussed in terms of efficacy, safety, and potential mechanisms of myopia control, including the impact of factors such as initial fitting age, baseline refractive error, the role of peripheral defocus, higher order aberrations, pupil size, and treatment zone size.

Walther,H., Lorentz,H., Heynen,M., Kay,L., Jones,L. W. The Impact of Incubation Conditions on in Vitro Phosphatidylcholine Deposition on Contact Lens Materials Optometry & Vision Science 2021;98(4):341-349 [ Show Abstract ]

SIGNIFICANCE: Previous in vitro measurements of contact lenses commonly investigate the impact of nonpolar
tear film lipids (i.e., sterols). Polar lipids, however, are equally important stabilizing components of the tear film.
This research explores and presents further knowledge about various aspects of polar lipid uptake that may impact
contact lens performance.

PURPOSE: This study evaluated the impact of incubation time, lipid concentration, and replenishment of an artificial
tear solution (ATS) on the uptake of phosphatidylcholine (PC) onto conventional hydrogel (CH) and silicone
hydrogel (SH) contact lens materials.

METHODS: Four SHs and two CH lens materials (n = 4) were soaked in a complex ATS containing radioactive
14C-PC as a probe molecule. Phosphatidylcholine uptake was monitored at various incubation time points (1, 3,
7, 14, and 28 days), with different ATS lipid concentrations (0.5, 1, 2) and with and without regular replenishment
of the ATS. Phosphatidylcholine was extracted from the lenses, processed, and counted by a β counter,
and accumulated PC (μg/lens) was extrapolated from standard lipid calibration curves.

RESULTS: All materials exhibited increasing PC deposition over time. Conventional hydrogel materials showed significantly lower PC uptake rates (P < .001) than any of the SH materials. Increasing lipid concentration in the ATS
resulted in increased PC binding onto the contact lens materials (P < .001). Replenishing the ATS every other day,
however, impacted the PC deposition differently, showing increased binding (P < .001) on CHs and reduced PC
deposition for SH materials (P < .001).

CONCLUSIONS: Length of incubation, lipid concentration in the ATS, and renewal of the incubation solution all
influenced the amount of PC that sorbed onto various lens materials and therefore need to be considered when
conducting future in vitro deposition studies.

Willcox,M., Keir,N., Maseedupallu,V., Masoudi,S., McDermott,A., Mobeen,R., Purslow,C., Santodomingo-Rubio,J., Tavazzi,S., Zeri,F., Jones,L. W. CLEAR - Contact lens wettability, cleaning, disinfection and interactions with tears Contact Lens Anterior Eye 2021;44(2):157-191 [ Show Abstract ]

Contact lens materials have undergone significant changes over the past 20 years, particularly with respect to the introduction of silicone hydrogel materials. Whilst this development addressed hypoxic issues, other important areas relating to contact lens success, notably comfort, require further research.

Contact lens wettability remains a crucially important part of biocompatibility. Contact lenses can be made more wettable by incorporation of surfactants into blister packs, internal wetting agents, surface treatments or care solutions. However, there remains no clear association between contact lens wettability and comfort, making it challenging to determine the potential for these approaches to be of significant clinical benefit. Most contact lenses are used on a daily wear, reusable basis, which requires them to be disinfected when not worn. The ideal disinfecting solution would also improve comfort during wear. However, balancing these requirements with other factors, including biocompatibility, remains a challenge. Soft lens materials invariably take up and subsequently release certain components of disinfecting solutions onto the ocular surface. This may affect tear film stability and the normal ocular microbiome, and further research is needed in this area to determine whether this has any affect on comfort. Finally, contact lens materials sorb components of the tear film, and these interactions are complex and may change the biochemistry of the tear film, which in turn may affect their comfort.

In conclusion, the interaction between lens materials, tear film and disinfection solution plays an important role in the biocompatibility of lenses. However, the exact role and whether this can be altered to improve biocompatibility and comfort during wear remains debatable. This report summarises the best available evidence to examine this complex relationship and the opportunities for practitioners to enhance in-eye comfort of contemporary lenses, along with providing suggestions for areas of study that may provide further information on this topic.

Wolffsohn,J. S., Dumbleton,K., Huntjens,B., Kandel,H., Koh,S., Kunnen,C. M. E., Nagra,M., Pult,H., Sulley,A. L., Vianya-Estopa,M., Walsh,K., Wong,S., Stapleton,F. CLEAR - Evidence-based contact lens practice Contact Lens Anterior Eye 2021;44(2):368-397 [ Show Abstract ]

Evidence-based contact lens -->practice involves finding, appraising and applying research findings as the basis for patient management decisions. These decisions should be informed by the strength of the research study designs that address the question, as well as by the experience of the practitioner and the preferences and environment of the patient. This reports reviews and summarises the published research evidence that is available to inform soft and rigid contact lens history and symptoms taking, anterior eye health examination (including the optimised use of ophthalmic dyes, grading scales, imaging techniques and lid eversion), considerations for contact lens selection (including the ocular surface measurements required to select the most appropriate lens parameter, lens modality and material selection), evaluation of lens fit, prescribing (teaching self-application and removal, adaptation, care regimen and cleaning instructions, as well as -->minimising risks of lens wear through encouraging compliance) and an aftercare routine.

Wolffsohn,J. S., Morgan,P. B., Barnett,M., Downie,L. E., Jacobs,D. S. Jones,L. W., Richdale, K., Stapleton,F., Vincent,S. J., Willcox,M. Contact Lens Evidence-Based Academic Reports (CLEAR) Contact Lens Anterior Eye 2021;44(2):129-131 [ Show Abstract ]

Since contact lenses were invented in 1887, innovations have included advances in optical design, material, care systems, wear modality, lens size, lens shape and applications. Over 19,000 peer reviewed academic papers on the contact lenses have been published. The Contact Lens Evidence-based Academic Reports (CLEAR) follow the exemplary work of organisations such as the Tear Film and Ocular Surface Society dry eye, meibomian gland disease, contact lens discomfort and dry eye II workshops and the International Myopia Institute white papers on myopia control, in collating and appraising the academic literature in an ocular field of interest. CLEAR represent the work of nearly 100 multidisciplinary experts in the field, who set out to critically review, synthesise and summarise the research evidence on contact lenses to date; this serves to inform both clinical practice, manufacturing innovation and future research directions.

Wolffsohn,J. S., Travé-Huarte,S., Jones,L., Craig,J. P., Wang,M. T. M., the TFOS ambassadors. Clinical practice patterns in the management of dry eye disease: A TFOS international survey Ocular Surface 2021;21(July):78-86 [ Show Abstract ]

Purpose
To examine clinical management and prescribing patterns for dry eye disease (DED), in relation to severity and subtype, by eye care practitioners across the globe.

Methods
An online, anonymous cross-sectional survey (on Qualtrics) translated into 14 languages was distributed to eye care practitioners across the globe. The survey included six questions around the management of DED, in relation to severity and subtype.

Result
The survey was completed by 1139 eyecare professionals (37% ophthalmologists and 58% optometrists) from 51 countries. Management varied significantly by continent and country (p < 0.01). The most commonly recommended management approaches, internationally, included general advice (87%), low (85%) and high (80%) viscosity-enhancing unpreserved lubricants and lid wipes/scrubs (81%). Some treatments were prescribed largely independently of severity (e.g. artificial tears and nutritional supplements) while oral antibiotics, punctal occlusion, topical anti-inflammatory/immunosuppressants, secretagogues, biologics, therapeutic contact lenses and surgical approaches were prescribed by more practitioners as severity increased. Essential fatty acids, lipid sprays/drops, lid hygiene, warm compresses, intense pulsed light therapy and antibiotics (topical or oral) were more commonly recommended for evaporative DED, while punctal occlusion, therapeutic contact lenses, secretagogues and biologics were more commonly recommended for aqueous deficient DED.

Conclusions
DED management differs across continents and countries. A wide range of management strategies are utilised at each severity level and between subtypes. The survey results enable clinicians to benchmark their practice to that of their peers, indicate where further research is required to optimise patient management and inform industry on how best to target product development.

Woods,J., Jones,D., Jones,L., Jones,S., Hunt,C., Chamberlain,P., McNally,J Ocular health of children wearing daily disposable contact lenses over a 6-year period Contact Lens Anterior Eye 2021;44(4):101391 [ Show Abstract ]

Purpose
To report on the ocular health and safety of children fit with soft hydrogel daily-disposable contact lenses, and followed for 6-years in a double-masked clinical trial investigating the performance of a dual-focus contact lens designed to control myopia progression.

Methods
Children aged 8−12 years, naïve to contact lens wear, were enrolled across four international sites. During years 1–3, children were randomised to either MiSight® 1 day or Proclear® 1 day (both omafilcon A, CooperVision, Inc.). The lenses were identical in material and geometry except for the front optical zone design. At the end of year-3, all those wearing Proclear 1 day were switched to MiSight 1 day, therefore all wore MiSight 1 day in years 4−6. Subjects agreed to wear the lenses at least 10-hours/day, 6-days/week. After dispensing, study visits were at 1-week, 1-month, 6-months and every 6-months until 6-years. At each visit, ocular measurements and subjective responses were recorded. Biomicroscopy used 0–4 grading scales; grade 0 represented no findings.

Results
144 children were enrolled: 69F:75M; mean age 10.1 years; mean cycloplegic spherical-equivalent refraction -2.11D; ethnicities included 34 East-Asian, 12 West-Asian, and 79 Caucasian. 92 completed the 6-years. Only three subjects discontinued due to an ocular adverse event (AE). No contact lens related AEs were classified as serious. The incidence rate of infiltrative AEs was 0.61% (6.1/1000 wearing-years; 95%CI: 0.24%–1.57%). The most common biomicroscopy findings were limbal, bulbar and tarsal hyperaemia and tarsal roughness. 99% of all biomicroscopy findings were grade-1 or lower. After 6-years of lens wear, ocular health by biomicroscopy was similar to pre-lens wear.

Conclusions
Across the 6-years, there were no contact lens related serious AEs and biomicroscopy showed no significant changes. Results suggest that children this age can successfully wear daily-disposable hydrogel contact lenses with minimal impact on ocular physiology.

Xu,M., Sivak,J. G., McCanna,D. J. Neutralization of the eye and skin irritant benzalkonium chloride using UVC radiation Cutaneous and Ocular Toxicology 2021;40(2):78-84 [ Show Abstract ]

Benzalkonium chloride (BAK) is a widely used disinfectant and preservative which is effective against a wide range of viruses (e.g. SARS-CoV and SARS-CoV-2), bacteria and fungi. However, it is toxic to the eye and skin. This study investigated the neutralization of BAK using ultraviolet C (UVC) radiation as an effort to reduce BAK toxicity potential.

Methods
BAK solutions were irradiated with a germicidal UVC lamp at various doses. Human corneal epithelial cells (HCEC) were then exposed to the UVC-irradiated BAK solutions for 5 minutes. After exposure, the cultures were assessed for metabolic activity using PrestoBlue; for cell viability using confocal microscopy with viability dyes; and for tight junction proteins using immunofluorescence staining for zonula occludens (ZO)-1.

Results
UVC radiation reduced BAK toxicity on cell metabolic activity in a dose-dependent manner. When the solution depth of BAK was 1.7 mm, the UVC doses needed to completely neutralize the toxicity of BAK 0.005% and 0.01% were 2.093 J/cm2 and 8.374 J/cm2, respectively. The cultures treated with UVC-neutralized BAK showed similar cell metabolic activity and cell viability to those treated with phosphate buffered saline (PBS) (p = 0.806 ∼ 1.000). The expression of ZO-1 was greatly disturbed by untreated BAK; in contrast, ZO-1 proteins were well maintained after exposure to UVC-neutralized BAK.

Conclusions
Our study demonstrates that the cell toxicity of BAK can be neutralized by UVC radiation, which provides a unique way of detoxifying BAK residues. This finding may be of great value in utilizing the antimicrobial efficacy of BAK (e.g. fighting against SARS-CoV-2) while minimizing its potential hazards to human health and the environment.

Yamasaki,K., Drolle,E., Nakagawa,H., Hisamuare,R., Ngo,W., Jones,L. W. Impact of a low molecular weight hyaluronic acid derivative on contact lens wettability Cont Lens Anterior Eye 2021;44(3):101334 [ Show Abstract ]

Purpose
To investigate the interaction of a novel low molecular weight hyaluronic acid derivative containing hydrophobic groups with soft contact lenses and its effect on lens hydrophilicity compared with a conventional form of hyaluronic acid.

Methods
This investigation studied the uptake of fluorescently-labelled hyaluronic acid and a low molecular weight hyaluronic acid derivative to four types of contact lenses using fluorescent microscopy and confocal laser scanning microscopy. Further, the four lens types were used to compare efficacy in improving hydrophilicity, as well as maintenance of contact angle measurements, in commercially available multipurpose solutions that contained either hyaluronic acid, the low molecular weight hyaluronic acid derivative, or an alternative wetting agent.

Results
The low molecular weight hyaluronic acid derivative was found to sorb more readily to silicone hydrogel lenses and exhibit a greater accumulation over time than conventional hyaluronic acid. Multipurpose solutions containing the low molecular weight hyaluronic acid derivative showed an increase in lens hydrophilicity through decreases in contact angle measurements when compared with those obtained from lenses treated with multipurpose solutions containing conventional hyaluronic acid or alternative wetting agents. This increase in lens hydrophilicity associated with the low molecular weight hyaluronic acid derivative was also maintained over multiple cycles in phosphate buffered saline, while alternative solutions with conventional hyaluronic acid did not.

Conclusion
Overall, lens treatment using a low molecular weight hyaluronic acid derivative-based solution lead to improved in vitro lens hydrophilicity.

Yamasaki,K., Mizuno,Y., Kitamura,Y., McCanna,D. J., Ngo,W., Jones,L. W. The efficacy of povidone-iodine, hydrogen peroxide and a chemical multipurpose contact lens care system against Pseudomonas aeruginosa on various lens case surfaces Cont Lens Anterior Eye 2021;44(1):18-23 [ Show Abstract ]

Purpose
To determine the antimicrobial efficacy of a povidone-iodine system (PVP-I; cleadew, OPHTECS Corporation, Kobe, Japan), a peroxide system (AOSEPT Plus with HydraGlyde, Alcon, Fort Worth, TX), and a chemical multipurpose system (renu fresh, Bausch & Lomb, Rochester, NY) on contact lens case surfaces that are both in contact and not in contact with the solutions during lens disinfection.

Methods
The surfaces of the inner walls, underside of the lid, and lens holder (if applicable) of the cases were inoculated with P. aeruginosa ATCC 27853. The cases were disinfected with the solutions as per their manufacturer instructions. After disinfection, the inoculated surfaces were swabbed and the amount of surviving P. aeruginosa was determined. Following this experiment, separate cases were inoculated and disinfected as before. This time the cases were agitated after recommended disinfection time and the amount of P. aeruginosa in the disinfecting solution was quantified immediately, and again after resting for 7 days. Experiments were conducted in triplicate (n = 3).

Results
Units are expressed in log CFU. All three solutions significantly reduced P. aeruginosa on direct-contact surfaces (all p < 0.039). On non-contact surfaces, the reduction of P. aeruginosa in the PVP-I system (pre-disinfection: 6.8 ± 0.5, post-disinfection: 1.0 ± 0.0; p < 0.001) was significant, but not for the hydrogen peroxide system (pre-disinfection: 6.3 ± 0.6, post: 5.5 ± 0.5; p = 0.194) and the chemical multipurpose system (pre-disinfection: 6.6 ± 0.1, post-disinfection: 5.6 ± 0.8; p = 0.336). After 7 days post-disinfection, no P. aeruginosa regrowth was observed in the PVP-I system (Day 1: 1.0 ± 0.0, Day 7: 1.0 ± 0.0; p = 1) and the chemical multipurpose system (Day 1: 4.2 ± 0.2, Day 7: 1.8 ± 0.9; p = 0.012), however regrowth was observed in the hydrogen peroxide system (Day 1: 3.4 ± 0.6, Day 7: 6.1 ± 0.4; p = 0.003).

Conclusion
The PVP-I system was more effective against P. aeruginosa on non-contact surfaces than the hydrogen peroxide system or the chemical multipurpose system and is capable of inhibiting regrowth of P. aeruginosa for at least 7 days post-disinfection.

Yang,M., Ngo,W., Srinivasan,S., Heynen,M. L., Dantam,J., Subbaraman,L. N., Jones,L., Senchyna,M. Optimization of goblet cell density quantification methods Experimental Eye Research 2021;207(June):108607 [ Show Abstract ]

The purpose of this study was to develop a standardized, accurate and efficient method for estimating conjunctival goblet cell density (GCD) via optimizing sample storage conditions and quantification methods. Conjunctival impression cytology (CIC) membranes were collected from both eyes of 32 participants and were randomized to two storage durations (2-3 weeks, 6-7 weeks) and two storage container types (microcentrifuge tube, flat histology cassette). The CIC membranes were stained and subdivided into 25 areas (5 mm × 5 mm) for imaging and the GCs were counted under 200X magnification using three different methods: (1) full CIC membrane GC count of the 25 images with cell-counting software ("full"; reference method), (2) partial membrane GC count of 9 images with cell-counting software ("partial"), and (3) manual counting of the 25 images ("manual"). In all cases, GCD was determined by dividing the GC count by the counting area. The average time required for quantification was recorded to gauge efficiency. Results showed no significant difference in GC count between the two storage durations (p = 0.745) or storage container types (p = 0.552). The median (interquartile range (IQR)) time required to quantify a CIC membrane for the full, partial, and manual methods of GC counting, was 14.8(17.6), 4.6(5.2) and 5.0 (5.0) minutes, respectively. The agreement of GCD values between the full and manual methods (bias: 0.4, 95% LOA: [-4.6, 5.5]) was stronger than that comparing the full and partial methods (bias: 0.5, 95% LOA: [-18, 17]). All together, through systematic examination of key procedural variables, an optimized method for GCD quantification within 7 weeks of sample collection was outlined. Adaption of procedures described in this paper to facilitate accurate and efficient GCD quantification may serve as a valuable step in clinical trials investigating DED pathophysiology and/or novel DED treatment strategies.

Yee,A., Chan,V., Heynen,M., Phan,C. M., Jones,L. Uptake and release of a multipurpose solution biocide (MAP-D) from hydrogel and silicone hydrogel contact lenses using a radiolabel methodology Eye & Contact Lens 2021;47(5):249-255 [ Show Abstract ]

Purpose:
The purpose of this study was to evaluate the uptake and release of radiolabelled myristamidopropyl dimethylamine (MAP-D) on reusable daily wear contact lenses (CLs) over 7 days.

Methods:
Three silicone hydrogel (SH) CL materials (lotrafilcon B, balafilcon A, senofilcon A) and two conventional hydrogel (CH) materials (etafilcon A, omafilcon A) were tested. A short-term (experiment 1, N=4) and a longer-term (experiment 2, N=3) study was conducted. In experiment 1, the CLs were incubated in 2 mL of phosphate buffered solution (PBS) containing 14C MAP-D (5 μg/mL) for 8 hrs. The release of 14C MAP-D was measured at t=0.25, 0.5, 1, 2, 4, 8, and 24 hr in PBS. In experiment 2, the CLs were incubated in the 14C MAP-D solution for 8 hrs followed by a 16-hr release in PBS. This cycle was repeated daily for 7 days. At the end of both experiments, lenses were extracted to determine the total uptake of MAP-D. The radioactivity was measured using a beta scintillation counter.

Results:
In experiment 1, all three SH lenses sorbed similar amounts of MAP-D (P=0.99), all of which were higher than the two CH materials (P<0.01). However, the CH materials released a greater amount of MAP-D than the SH materials (P<0.01). In experiment 2, the uptake of MAP-D in SH materials increased over 7 days, whereas the amount of MAP-D remained constant in the CH materials (P=0.99). Similar to experiment 1, the CH lenses released more MAP-D than SH lenses after 7 days (P<0.01).

Conclusion:
The SH materials absorbed greater amounts of MAP-D compared to CH materials. However, the CH materials released the greatest amount of MAP-D. Radioactive labelling of MAP-D offers a highly sensitive method of assessing the uptake and release profiles of biocides to CL materials.

Yee,A., Walsh,K., Schulze,M., Jones,L The impact of patient behaviour and care system compliance on reusable soft contact lens complications Contact Lens Anterior Eye 2021;44(5):101432 [ Show Abstract ]

Reusable soft daily wear contact lenses (CLs) remain popular and were fit to just over half of all wearers in the most recent international CL prescribing survey. Unlike daily disposable CLs, reusables require cleaning and disinfecting after every use, along with storage in a CL case. These additional requirements add a number of steps to the daily wear and care routine, increasing the opportunities for CL wearers to exhibit non-compliant behaviour. The impact of non-compliance ranges from poor lens comfort through to potentially sight- threatening infective keratitis. The coronavirus pandemic has refocused the profession on the importance of hand hygiene in particular, and the need for promoting safe CL wear in general. This review summarises typical non-compliant behaviour related to reusable CLs, and examines strategies and opportunities to better support wearers. Patient education has a central role in encouraging compliant behaviour, although patient recall of information is low, and personal belief systems may result in continuation of non-compliant behaviour despite awareness of the risks. CL care solutions are required for the daily disinfection of lenses, however misuse of multipurpose solutions (MPS) and hydrogen peroxide (H2O2)-based care systems can challenge their ability to be fully efficacious. Standard efficacy testing is reviewed, with consideration of how well current protocols model real-world use of CL solutions. Although some recommendations are in place for the inclusion of additional variables such as lens cases, CL materials, organic soil and efficacy against Acanthamoeba, opportunity still exists to reevaluate global standards to ensure consistency of testing in all markets. Finally, potential future innovations are discussed which may further support increased safety in reusable lens wear through novel antimicrobial additions to both CL materials and cases

2020

Bitton,E., Elder,M., Srinivasan,S., Luensmann,D., Jones,L. Dry Eye Disease in University-based Clinics in Canada: A Retrospective Chart Review Optometry & Vision Science 2020;97(11):944-953 [ Show Abstract ]

SIGNIFICANCE
Dry eye disease (DED) imposes a substantial burden on patients, which can lead to significant economic consequences for society. We provide insights into the DED patient population and DED diagnostic/management practices in Canada, which to date have been inadequately addressed in the literature.

PURPOSE
The purpose of this study was to describe DED patient demographic/clinical characteristics alongside DED diagnosis/management in university-based optometry clinics in Canada.

METHODS
This was a retrospective chart review of nonconcurrent non-Sjögren patients with DED at two university-based optometry clinics in Montreal and Waterloo. Waterloo charts with a diagnosis of DED and all charts from the Montreal dry eye clinic were considered for inclusion.

RESULTS
Overall, 200 charts were reviewed. Most patients were female (Montreal, 76%; Waterloo, 72%), and the mean age was 57.2 ± 14.9 years at Montreal and 52.6 ± 20.1 years at Waterloo. Patients commonly reported multiple health conditions (e.g., allergies [Montreal, 44%; Waterloo, 36%]), and high use of systemic nonocular medications was observed (Montreal, 76%; Waterloo, 62%). Clinical signs and symptoms of DED were recorded more often in Montreal patients than in Waterloo patients (e.g., dryness symptoms, 100 vs. 72%; tear breakup time, 100 vs. 60%). Warm compresses (Montreal, 63%; Waterloo, 83%) and artificial tears (Montreal, 94%; Waterloo, 96%) were the most frequently recommended nonmedical treatment and ocular lubricant, respectively. Topical steroids were the most frequently prescribed medications (Montreal, 22%; Waterloo, 21%), with typically three to four different interventions recommended per patient at each clinic. No relationship was found between symptoms and clinical signs or recommended interventions.

CONCLUSIONS
This retrospective chart review provided the demographics, clinical characteristics, diagnosis, and management options for DED patients in Canadian university-based optometry clinics. The more comprehensive assessments conducted at Montreal may be beneficial to better monitor the progression of DED and to determine treatment effects over time.

Cheung,S., Subbaraman,L. N., Ngo,W., Jay,G. D., Schmidt,T. A., Jones,L. Localization of full-length recombinant human proteoglycan-4 in commercial contact lenses using confocal microscopy Journal of Biomaterials Science, Polymer Edition 2020;31(1):110-122 [ Show Abstract ]

The aim of this study was to determine the sorption location of full-length recombinant human proteoglycan 4 (rhPRG4) tagged with fluorescein isothiocyanate (FITC) to four silicone hydrogel contact lenses [balafilcon A (PureVision, Bausch + Lomb), senofilcon A (Acuvue Oasys, Johnson & Johnson), comfilcon A (Biofinity, CooperVision), lotrafilcon B (Air Optix, Alcon)] and one conventional hydrogel lens [etafilcon A (Acuvue 2, Johnson & Johnson)], using confocal laser scanning microscopy (CLSM). Lenses (n = 3 each) were incubated under two conditions: (1) FITC-rhPRG4 solution at 300 μg/mL and (2) phosphate-buffered saline, for 1 h at 37 °C in darkness with gentle shaking. The central 4 mm of each lens was removed and viewed with the Zeiss 510 CLSM using an argon laser at 488 nm (FITC excitation 495 nm, emission 521 nm). Depth scans were taken at 1 μm intervals to a maximum depth of 100 μm. All lens materials demonstrated sorption of rhPRG4. Both senofilcon A and balafilcon A revealed FITC-rhPRG4 penetration into the bulk of the lens, generally favoring the surface. rhPRG4 was observed exclusively on the surface of lotrafilcon B, with no presence within the bulk of the lens. rhPRG4 was evenly distributed throughout the bulk of the lens, as well as on the surface, for comfilcon A and etafilcon A. The sorption profile of FITC-rhPRG4 was successfully visualized using CLSM in various contact lens materials. The polymer composition, surface treatment and pore size of the material can influence the sorption of rhPRG4.

Dantam,J., Subbaraman,L. N., Jones,L. Adhesion of Pseudomonas aeruginosa, Achromobacter xylosoxidans, Delftia acidovorans, Stenotrophomonas maltophilia to contact lenses under the influence of an artificial tear solution Biofouling 2020;36(1):32-43 [ Show Abstract ]

Corneal infection is a devastating sight-threatening complication that is associated with contact lens (CL) wear, commonly caused by Pseudomonas aeruginosa. Lately, Achromobacter xylosoxidans, Delftia acidovorans, and Stenotrophomonas maltophilia have been associated with corneal infection. This study investigated the adhesion of these emerging pathogens to CLs, under the influence of an artificial tear solution (ATS) containing a variety of components commonly found in human tears. Two different CL materials, etafilcon A and senofilcon A, either soaked in an ATS or phosphate buffered saline, were exposed to the bacteria. Bacterial adhesion was investigated using a radio-labeling technique (total counts) and plate count method (viable counts). The findings from this study revealed that in addition to P. aeruginosa, among the emerging pathogens evaluated, A. xylosoxidans showed an increased propensity for adherence to both CL materials and S. maltophilia showed lower viability. ATS influenced the viable counts more than the total counts on CLs.

Desai,A. R., Maulvi,F. A., Desai,D. M., Shukla,M. R., Ranch,K. M., Vyas,B. A., Shah,S. A., Sandeman,S., Shah,D. O. Multiple drug delivery from the drug-implants-laden silicone contact lens: Addressing the issue of burst drug release Materials Science and Engineering: C 2020;112(July):110885 [ Show Abstract ]

A fixed combination of bimatoprost/timolol eye drop solution is used to manage the elevated intra-ocular pressure in glaucoma patients, including individuals whose condition is poorly controlled by monotherapy. Eye drop solutions are generally given in high dose, due to poor ocular bioavailability. The high ocular dose of bimatoprost and timolol lead to hyperaemia and systemic cardiac side effects respectively. Here, we introduce multiple implant-laden contact lenses (IM) to passively deliver timolol, bimatoprost and hyaluronic acid at therapeutically relevant doses without high burst release. The drug-loaded implants were individually implanted in the outer periphery of the silicone contact lenses. Atomic force microscopy showed the smooth surface of the implant contact lens, as the implants were inside the contact lens matrix. The implant lens (IM) showed major loss of drugs [timolol = 60.60%, bimatoprost = 61.75% and HA = 46.03%] during the monomer extraction and wet sterilization, while the option of dry radiation sterilization (IM-R lens) and hydration for 24 h prior to use showed relatively lower loss of drugs [timolol = 16.87%, bimatoprost = 47.95% and HA = 24.41%]. The in-vitro drugs release data of IM-R lens, showed sustained release for 72 h, with low burst release in comparison to the soaked (SM) and direct drug-laden contact lenses (DL). The in vivo drug release data in the rabbit tear fluid showed sustained release using IM-R lens in comparison to the SM lens and eye drop therapy. The burst release with the IM-R lens was many folds reduced, which could bypass the side effects associated with multiple eye drop therapy. The in vivo pharmacodynamic study in the rabbit model showed peak and valley profile with multiple eye drop therapy, while IM-R lens showed prolong reduction in intra ocular pressure (IOP) for 120 h. The study demonstrates the application of implantation technology to deliver multiple drug through contact lenses to treat glaucoma.

Drolle,E., Ngo,W., Leonenko,Z., Subbaraman,L., Jones,L. Nanoscale Characteristics of Ocular Lipid Thin Films Using Kelvin Probe Force Microscopy 2020;9(7):1-11 [ Show Abstract ]

Purpose: To describe the use of Kelvin probe force microscopy (KPFM) to investigate the electrical surface potential of human meibum and to demonstrate successful use of this instrument on both human meibum and a meibum model system (six-lipid stock [6LS]) to elucidate nanoscale surface chemistry and self-assembly characteristics.

Materials and Methods: 6LS and meibum were analyzed in this study. Mica-supported thin films were created using the Langmuir-Blodgett trough. Topography and electrical surface potential were quantified using simultaneous atomic force microscopy/KPFM imaging.

Results: Both lipid mixtures formed thin film patches on the surface of the mica substrate, with large aggregates resting atop. The 6LS had aggregate heights ranging from 41 to 153 nm. The range in surface potential was 33.0 to 125.9 mV. The meibum thin films at P = 5 mN/m had aggregates of 170 to 459 nm in height and surface poten- tial ranging from 15.9 to 76.1 mV, while thin films at P = 10 mN/m showed an aggregate size range of 147 to 407 nm and a surface potential range of 11.5 to 255.1 mV.

Conclusions: This study showed imaging of the differences in electrical surface poten- tial of meibum via KPFM and showed similarities in nanoscale topography. 6LS was also successfully analyzed, showing the capabilities of this method for use in both in vitro and ex vivo ocular research.

Translational Relevance: This study describes the use of KPFM for the study of ocular surface lipids for the first time and outlines possibilities for future studies to be carried out using this concept.

Efron,N., Brennan,N. A., Chalmers,R. L., Jones,L. W., Lau,C., Morgan,P. B., Nichols,J. J., Szczotka-Flynn,L. B., Willcox,M. D. Thirty years of ‘quiet eye’ with etafilcon A contact lenses Contact Lens Anterior Eye 2020;43(3):285-297 [ Show Abstract ]

Frequent replacement contact lenses made from the etafilcon A hydrogel lens material were introduced onto the market over 30 years ago, and etafilcon A remains the most widely used hydrogel lens material today. Although the prescribing of silicone hydrogel lenses is increasing, millions of lens wearers globally have been wearing hydrogel lenses for many years and exhibit a physiologically-stable ‘quiet eye’, with a low profile of adverse events. Hydrogel lenses are demonstrated to maintain a low inflammatory response and infection risk profile during daily wear, which in the case of etafilcon A, may be related to its low modulus, and the naturally-protective, anti-microbial, non-denatured lysozyme absorbed into the lens from the tear fluid. Although improved corneal physiology from decreased hypoxia with silicone hydrogel lenses is well accepted, equivalent levels of corneal oxygenation are maintained during daily wear of low to medium powered hydrogel lenses, which do not impede the daily corneal de-swelling process, and do not induce clinically significant changes in ocular health. Therefore, hydrogel lenses remain an important alternative for daily wear in modern contact lens practice.

Jin,Y., Jones,L., Gorbet,M. Investigation of the response of tear-film neutrophils to interleukin 8 and their sensitivity to centrifugation, fixation, and incubation Scientific report 2020;10(1):19690 [ Show Abstract ]

During eye closure, a large number of neutrophils (polymorphonuclear neutrophils, PMNs) invade the ocular surface and are often referred to as tear-film PMNs. While immunophenotyping experiments have been performed on tear-film PMNs, the impact of commonly used experimental procedures on their phenotype as well as their response to interleukin-8 (IL-8), a physiological inflammatory mediator, have not yet been investigated. A gentle eye wash method was used to collect cells at home. In the morning upon awaking, participants washed their eyes with sterile phosphate buffer saline (PBS) and collected the runoff into a sterile polypropylene tube. The cell collection was then delivered to the lab within two hours. The effects of centrifugation, incubation and fixation with paraformaldehyde (PFA) before (pre-fixed staining) or after (post-fixed staining) incubation with antibodies were characterized. Tear-film PMNs as well as blood PMNs (used for comparison) were also stimulated with IL-8. To assess the reproducibility of cell collection and variability in receptor expression over time, participants were also asked to collect cells three times over a period of a month. The change in expression of surface receptors, CD11b, CD16, CD55, CD66b, important inflammatory and activation markers, and CD45 (PAN leukocyte marker) was assessed by flow cytometry. Fixing tear-film PMNs prior to the staining with antibodies resulted in a significant (fivefold or more) reduction in the expression of CD11b, CD16 and CD45 when compared to unfixed samples, while CD16 was the only receptor to undergo significant downregulation upon post-staining fixation. Furthermore, additional centrifugation step prior to antibody incubation as well as long (4 h) incubation at 37 °C resulted in significant reductions in expression of CD11b, CD16 and CD55 when compared to control samples. As opposed to blood PMNs, stimulating tear-film PMNs with IL-8 did not induce any significant changes in expression of CD11b, CD16, CD55 and CD66b. When working with collected tear-film PMNs, our results suggest that any additional centrifugation and incubation step should be avoided, or at least limited, and post fixation staining is recommended in order to preserve cell phenotype and cell integrity of tear film PMNs. Our study also adds further information on the reproducibility of the gentle eye wash as well as the inability of tear-film PMNs to modulate their surface receptors upon stimulation with IL-8. The latter may be due to prior exposure to IL-8, activation in the closed-eye environment, or a reduced ability to respond to inflammatory stimulus. Further mechanistic studies will be needed to gain a better understanding of the tear-film neutrophil phenotype.

Jones,L., Walsh,K., Willcox,M., Morgan,P., Nichols,J. The COVID-19 pandemic: Important considerations for contact lens practitioners Cont Lens Anterior Eye 2020;43(3):196-203 [ Show Abstract ]

A novel coronavirus (CoV), the Severe Acute Respiratory Syndrome Coronavirus - 2 (SARS-CoV-2), results in the coronavirus disease 2019 (COVID-19). As information concerning the COVID-19 disease continues to evolve, patients look to their eye care practitioners for accurate eye health guidance. There is currently no evidence to suggest an increased risk of contracting COVID-19 through contact lens (CL) wear compared to spectacle lens wear and no scientific evidence that wearing standard prescription spectacles provides protection against COVID-19 or other viral transmissions.

During the pandemic there will potentially be significant changes in access to local eyecare. Thus, it is imperative CL wearers are reminded of the steps they should follow to minimise their risk of complications, to reduce their need to leave isolation and seek care. Management of adverse events should be retained within optometric systems if possible, to minimise the impact on the wider healthcare service, which will be stretched. Optimal CL care behaviours should be the same as those under normal circumstances, which include appropriate hand washing (thoroughly with soap and water) and drying (with paper towels) before both CL application and removal. Daily CL cleaning and correct case care for reusable CL should be followed according to appropriate guidelines, and CL exposure to water must be avoided. Where the availability of local clinical care is restricted, practitioners could consider advising patients to reduce or eliminate sleeping in their CL (where patients have the appropriate knowledge about correct daily care and access to suitable lens-care products) or consider the option of moving patients to daily disposable lenses (where patients have appropriate lens supplies available). Patients should also avoid touching their face, including their eyes, nose and mouth, with unwashed hands and avoid CL wear altogether if unwell (particularly with any cold or flu-like symptoms).

Luensmann,D., Omali,N. B., Suko,A., Drolle,E., Heynen,M., Subbaraman,L. S., Scales,C., Fadli,Z., Jones,L. Kinetic Deposition of Polar and Non-polar Lipids on Silicone Hydrogel Contact Lenses Current Eye Research 2020;45(12):1477-1483 [ Show Abstract ]

Purpose: This study investigated kinetic lipid uptake to four silicone hydrogel (SiHy) lenses over a period of four weeks, using an in-vitro radiolabel method.

Methods: Four contemporary monthly replacement SiHy lenses (lotrafilcon B, senofilcon C, comfilcon A, samfilcon A) were incubated in three different solutions: 1) An artificial tear solution (ATS) containing 14C-labeled phosphatidylcholine (PC), 2) an ATS containing 14C-cholesteryl oleate (CO) and 3) an ATS containing four 14C-radiolabeled lipids (PC, phosphatidylethanolamine, CO, and cholesterol (total lipid)). After 16 hours, lipids were extracted twice from the lenses with chloroform:methanol and the radioactive counts determined the lipid quantities to simulate 1 day of wear. OPTI-FREE PureMoist (Alcon) was used to clean and disinfect the remaining lenses daily and the lipid quantities were further determined after 2 weeks and 4 weeks.

Results: The amount of total lipid increased for all lenses over time (p < .01). After four weeks, total lipid accumulated was 20.26 ± 0.15 µg/lens for senofilcon C, which was significantly higher (p < .01) than all other lens materials (samfilcon A - 17.84 ± 0.21; comfilcon A - 16.65 ± 0.12; lotrafilcon B - 7.41 ± 0.56 µg/lens). CO was highest on lotrafilcon B (1.26 ± 0.13 µg/lens) and senofilcon C attracted the most PC (3.95 ± 0.12 µg/lens) compared to the other materials.

Conclusion: The amount of both polar and non-polar lipid deposition on monthly replacement SiHy lenses increased over 4 weeks, with significant differences being seen between lens materials.

Luensmann,D., van Doorn,K., May,C., Srinivasan,S., Jones,L. The Impact of Cosmetics on the Physical Dimension and Optical Performance of Contemporary Silicone Hydrogel Contact Lenses Eye & Contact Lens 2020;46(3):166-173 [ Show Abstract ]

Purpose: Contact lens wearers may inadvertently expose their lenses during the lens insertion and removal process or while wearing their lenses to cosmetic products being used. This study investigated the impact of
various cosmetics on the physical dimension and optical properties of three recently marketed monthly replacement silicone hydrogel contact lenses.

Methods: In this in vitro study, three monthly replacement silicone hydrogel lens types including senofilcon C (ACUVUE VITA, Johnson & Johnson), samfilcon A (Bausch+Lomb ULTRA, Bausch+Lomb), and lotrafilcon
B+EOBO (polyoxyethylene-polyoxybutylene) (AIR OPTIX plus HydraGlyde, ALCON), were individually coated with cosmetic products followed by a 1-hr soak in phosphate-buffered saline. Cosmetic products
included; three hand creams (HC1: Glysomed; HC2: Vaseline Healthy Hand & Nail Conditioning; and HC3: Intense Relieve), three make-up removers (MR1: Lid-Care Towelettes; MR2: Gentle waterproof eye and
Lip Makeup Remover; and MR3: Oil-Free Makeup Remover), and three mascaras (MA1: Great Lash—waterproof; MA2a: Wonder’Lash—waterproof, and MA3: Voluminous Original). The contact lens dimensions were
determined for diameter, sagittal depth, and base curve, using the Chiltern (Optimec Limited), whereas lens power and optical quality were assessed using the Contest Plus II (Rotlex). Six replicates for each lens/cosmetic combination were used. The impact of cosmetics was tested between lenses and compared with uncoated control lenses.

Results: For lens diameter, makeup removers (MR2 & MR3) demonstrated the largest impact, with an increase of up to 0.26 mm (MR2) and 0.35 mm (MR3) for senofilcon C and samfilcon A, respectively (P,0.01 compared to baseline), whereas lotrafilcon B+EOBO showed a decrease of 0.01 mm (P,0.01 between lens types). For sagittal depth, mascara MA1 demonstrated the greatest impact, followed by makeup removers MR2 & MR3. All lenses showed increases in sagittal depth after MA1 exposure (0.1660.06 mm in lotrafilcon B+EOBO, 0.2460.22, and 0.2660.09 mm in samfilcon A and senofilcon C, respectively; P,0.01 for all lenses compared with baseline). For base curve, the makeup removers (MR2 & MR3) caused increases for both senofilcon C (up to 0.36 mm) and samfilcon A (up to 0.35 mm), but lotrafilcon B+EOBO was unaffected. Lens power changes were generally minor (,0.25 D). However, senofilcon C showed a significant change of 21.1860.65 D (more minus) after MA1 exposure (P,0.001). Image quality was most affected by mascaras, although given that all lens types were adversely affected to similar degrees, none of the lenses performed better or worse after mascara application (P.0.05). The parameters of the different lens types were not significantly affected by the hand creams.

Conclusion: Makeup removers and mascaras changed the lens parameters to varying degrees, which may affect the fit and overall performance of the lens, whereas no such effect was noted with hand creams. Lotrafilcon B+EOBO was typically less affected compared with senofilcon C or samfilcon A.

Maulvi,F. A., Parmar,R. J., Desai,A. R., Desai,M. D., Shukla,M. R., Ranch,K. M., Shah,S. A., Shah,D. O. Tailored gatifloxacin Pluronic® F-68-loaded contact lens: Addressing the issue of transmittance and swelling. International journal of pharmaceutics International Journal of Pharmaceutics 2020;581(May 15):119279 [ Show Abstract ]

Loading of gatifloxacin in contact lenses affects critical lens properties (optical and swelling) owing to drug precipitation in the contact lens matrix. The presence of Pluronic® F-68 in the packaging solution creates in-situ micelles in the contact lens to dissolve gatifloxacin precipitates and provide sustained drug release. The micelles further improved the drug uptake from the drug-packaging solution to create an equilibrium of drug between the lens matrix and the packaging solution. In this study, we optimized gatifloxacin-pluronic-loaded contact lenses to achieve the desired optical transmittance, swelling, and gatifloxacin loading capacity as well as sustained drug delivery. Optimization of gatifloxacin-pluronic-loaded contact lens was carried out using a 32 factorial design by tailoring the concentration of Pluronic® F-68 in the packaging solution (X1) and the amount of gatifloxacin in the monomer solution (X2) to achieve the desired lens properties. The optimized batch (X1 = 0.3%w/v and X2 = 0.3%w/v) showed an optical transmittance of 92.84%, swelling of 92.36% and gatifloxacin loading capacity of 92.56 μg. The in vitro flux data of the optimized batch (GT-Pl-CL) showed sustained release up to 72 h, whereas soaked contact lenses (SM-CL) and direct gatifloxacin-loaded contact lenses (DL-CL) showed a sustained release up to 48 h. The in vivo gatifloxacin release data for rabbit tear fluid showed sustained release with a high gatifloxacin level for the GT-Pl-CL lens in comparison to the SM-CL and the eye drop solution. This study demonstrates the application of the 32 full factorial design to optimize gatifloxacin-pluronic-loaded contact lenses to achieve the desired optical transmittance, swelling, and drug loading capacity.

Maulvi,F. A., Patel,P. J., Soni,P. D., Desai,A. R., Desai,D. T., Shukla,M. R., Ranch,K. M., Shah,S. A., Shah,D. O. Novel Poly(vinylpyrrolidone)-Coated Silicone Contact Lenses to Improve Tear Volume During Lens Wear: In Vitro and In Vivo Studies ACS Omega 2020;5(29):18148-18154 [ Show Abstract ]

Poly(vinylpyrrolidone) (PVP-K90) is widely used to manage dry eye syndrome (DES). The marketed eye drop solutions (high dose) need frequent instillation, affecting the routine lifestyle of patients. PVP-K90-laden contact lenses can be used to overcome the limitations of eye drop solutions (low bioavailability and frequent instillation). However, the conventional methods of PVP-K90 loading show poor loading capacity and short duration of effect. In the present study, we have developed PVP-K90-coated contact lenses via a short curing approach to increase the PVP-K90 loading capacity with a sustained release profile to manage dry eye syndrome. PVP-K90 was loaded by a soaking method (SM-PVP), direct loading (during fabrication, DL-PVP), a combination of soaking and direct loading (DL-SM-PVP), and a novel coating process (SM-PVP-C and DL-SM-PVP-C). The swelling studies suggested improvement in the water uptake (hydration) property of the contact lenses due to the presence of PVP-K90. The optical transparency was within an acceptable range. The in vitro release of PVP-K90 was in the following order: PVP-coated contact lens (168 h) > DL-SM-PVP (168 h) > DL-PVP (96 h) > SM-PVP (72–96 h). PVP-coated contact lenses showed a high burst effect (lubricating effect) and sustained release (3161–448 ng/h between 24 and 168 h) due to high PVP loading/coating in comparison to the uncoated respective contact lenses (964–113 ng/h between 24 and 96 h). In animal studies, the PVP-K90-coated contact lens showed higher tear volume in comparison to the respective uncoated contact lenses and an eye drop solution. This study demonstrates a novel approach of coating a high amount of PVP-K90 on contact lenses for sustained release to manage several ocular diseases like dry eye syndrome, conjunctivitis, and other ocular injuries.

Muntz,A., Subbaraman,L.N., Craig,J. P., Jones,L. Cytomorphological assessment of the lid margin in relation to symptoms, contact lens wear and lid wiper epitheliopathy Ocular Surface 2020;18(2):214-220 [ Show Abstract ]

Purpose: Lid wiper epitheliopathy (LWE) is insufficiently understood from a cytological perspective. This study explored the relationship between lid margin cytomorphology, LWE, contact lens wear, and lens-related symptoms. Methods: Habitual, symptomatic (n = 20) and asymptomatic (n = 20) soft, rigid gas permeable (n = 18) and non-contact lens wearers (n = 19) were enrolled. LWE was graded using lissamine green and the Korb scale. Subjective symptoms were assessed using the Ocular Surface Disease Index and the Contact Lens Dryness Evaluation Questionnaire. Impression cytology samples obtained from the central upper and lower lid margins of both eyes stained histologically to highlight keratinization and imaged using high-resolution microscopy. A masked investigator digitally delimited and measured the average sagittal width of the lid wiper conjunctiva and mucocutaneous junction using ImageJ. Results: The upper lid wiper conjunctiva measured 424 ± 171 μm, 404 ± 75, 667 ± 219 and 266 ± 64 in asymptomatic soft, symptomatic soft, rigid and non-contact lens wearers, respectively. The corresponding lower lid wiper conjunctivae measured 141 ± 57 μm, 232 ± 150, 519 ± 212 and 225 ± 102, which was significantly narrower than that of the upper eyelid in most cases (p < 0.05). Symptoms were not associated with lid margin changes; however, rigid lens wear and clinical LWE were associated with histologically enlarged lid wiper conjunctival areas and increased keratinization. Conclusion: A novel, exploratory account of histological measures of LWE and cytomorphological change associated with contact lens wear suggests mechanical or frictional cellular insult is occurring at the lid wiper conjunctiva.

Qiao,H., Luensmann,D., Heynen,M., Drolle,E., Subbaraman,L. N., Scales,C., Riederer,D., Fadli,Z., Jones,L. In Vitro Evaluation of the Location of Cholesteryl Ester Deposits on Monthly Replacement Silicone Hydrogel Contact Lens Materials Clinical Ophthalmology 2020;14(September):2821-2828 [ Show Abstract ]

Purpose: The deposition profile of cholesteryl ester on the surface and throughout the matrix of silicone hydrogel contact lens (CL) materials was determined under conditions that mimic a daily wear regimen.

Methods: In this in vitro study, four SiHy CL materials (senofilcon C, lotrafilcon B, comfilcon A and samfilcon A) were incubated in an artificial tear solution (ATS) for up to 30 days. CL incubation was alternated between the ATS (16 hours) and a multipurpose care regimen (8 hours). The ATS included fluorescently tagged cholesteryl ester (5-cholesten-3ß-ol 6-[(7-nitro-2-1,3-benzoxadiazol-4-yl)amino]caproate; CE-NBD) and confocal laser scanning microscopy visualized the distribution of the lipid through the CLs.

Results: The distribution of CE-NBD was homogenous from the anterior to posterior surface in senofilcon C and comfilcon A, at all time points. For lotrafilcon B and samfilcon A, CE-NBD localization was heterogeneous, with greater amounts on the surfaces on Day 1 and Day 14 compared to the lens matrix; however, differences in concentration between the surface and bulk diminished by Day 30.

Conclusion: The distribution of the non-polar lipid CE-NBD varied with lens material chemistry. While some lens materials deposited the lipid primarily on the surface after 16 hours of exposure, all materials exhibited a homogenous distribution after one month.

Keywords: lipid distribution, silicone hydrogel contact lenses, cholesteryl ester, artificial tear solution

Rangarajan,R., Ketelson,H. A., Do,R., McCanna,D. J., Suko,A., Enstone,D., Subbaraman,L., Dantam,J., Jones,L. W. Effect of Artificial Tear Formulations on the Metabolic Activity of Human Corneal Epithelial Cells after Exposure to Desiccation Journal of Visualized Experiments 2020 (159):e60812 [ Show Abstract ]

Artificial lipid-containing tear formulations are developed to reduce tear evaporation by the restoration of a deficient tear lipid layer. Artificial tear formulations that prevent cell desiccation will result in ocular surface protection and the maintenance of cell metabolic activity. During dehydration, cells undergo the process of loss of metabolic activity and subsequently cell death. This work describes a method for assessing the efficacy of artificial tear formulations. The metabolic dye (i.e., alamarBlue) changes from a low fluorescent molecule resazurin to a fluorescent molecule resorufin in viable cells. The biological performance of an artificial tear formulation is measured as the ability of the formulation to (a) maintain cell viability and (b) provide cell protection from desiccation. Growth media and saline are used as controls for the cell viability/desiccation tests. Cells are incubated with test solutions for 30 min and then desiccated for 0 or 5 min at 37 °C and 45% relative humidity. Cell metabolic activity after initial exposure and after cell desiccation is then determined. The results show the comparative effects of eye drop formulations on cell metabolic activity and desiccation protection. This method can be used to test dry eye formulations that are designed to treat individuals with evaporative dry eye.

Shows,A., Redfern,R. L., Sickenberger,W., Fogt,J. S., Schulze,M., Lievens,C., Szcottka-Flynn,L., Schwarz,S., Tichenor,A. A., Marx,S., Lemp-Hull,J. M. Lipid Analysis on Block Copolymer–containing Packaging Solution and Lens Care Regimens: A Randomized Clinical Trial Optometry & Vision Science 2020;97(8):565-572 [ Show Abstract ]

SIGNIFICANCE: Lotrafilcon B lenses packaged in and cared for with block copolymer–containing (polyoxyethylenepolyoxybutylene; EOBO) lens care solutions resulted in lower cholesterol extraction than each of the habitual silicone hydrogel lens/multipurpose solution (MPS) regimens tested.

PURPOSE: This study aimed to compare the extracted cholesterol of lotrafilcon B lenses packaged in and cared for with EOBO-containing lens care solutions with the extracted cholesterol of habitual silicone hydrogel lenses cared for with MPS not containing EOBO.

METHODS: In this prospective, randomized, observer-masked parallel study, habitual wearers of senofilcon C, senofilcon A, comfilcon A, and samfilcon A contact lenses using a non-EOBO MPS were randomized 1:1 to lotrafilcon B lenses packaged in and cared for with EOBO-containing solutions or to their habitual lenses and MPS. Subjects randomized to lotrafilcon B were further randomized to one of two EOBO-containing lens care solutions, OPTI-FREE PUREMOIST or CLEAR CARE PLUS with HydraGlyde (Alcon Laboratories, Inc., Fort Worth, TX). A subset of right eye lenses was collected after wear, and total cholesterol was extracted and measured using a fluorometric enzymatic assay.

RESULTS: Of 143 lenses analyzed, 95 were from subjects randomized to their habitual lenses/MPS and 48 to lotrafilcon B + EOBO lenses plus CLEAR CARE PLUS with HydraGlyde or OPTI-FREE PUREMOIST. The mean amounts of cholesterol extracted from lotrafilcon B + EOBO lenses cared for with CLEAR CARE PLUS with HydraGlyde (0.28 ± 0.18 μ g/lens) and OPTI-FREE PUREMOIST (0.28 ± 0.48 μ g/lens) were significantly lower than those extracted from senofilcon C (4.18 ± 3.25 μ g/lens), senofilcon A (2.19 ± 2.69 μ g/lens), comfilcon A (2.17 ± 1.47 μ g/lens), and samfilcon A (2.07 ± 1.48 μ g/lens) lenses used with MPS (P < .0001 each).

CONCLUSIONS: Cholesterol sorption was significantly lower in wearers of lotrafilcon B lenses cared for with polyoxyethylene-polyoxybutylene–containing lens care solutions than in users of habitual silicone hydrogel lenses cared for with non–polyoxyethylene-polyoxybutylene MPS.

Silverstein,S., Yeu,E., Tauber,J., Guillon,M., Jones,L., Galarreta,D., Srinivasan,S., Manoj,V. Symptom Relief Following a Single Dose of Propylene Glycol-Hydroxypropyl Guar Nanoemulsion in Patients with Dry Eye Disease: A Phase IV, Multicenter Trial Clinical Ophthalmology 2020;14(October):3167-3177 [ Show Abstract ]

Purpose: To evaluate symptom relief in patients with dry eye disease (DED) following a single drop of propylene glycol-hydroxypropyl guar (PG-HPG) nanoemulsion (Systane® Complete) lubricant eye drops.

Methods: This was a Phase IV, multicenter, open-label, interventional study in adult patients with DED of aqueous-deficient, evaporative, and mixed subtypes. Patients instilled one drop of PG-HPG in each eye at Day 1. Endpoints included change from baseline in dry eye symptom and soothing sensation scores on Day 1 at 0, 4, and 8 hours post-dose. Symptom scores were assessed on a 0– 10 scale (0=no symptoms; 10=worst imaginable symptom). Tolerability of the drop was assessed based on assessment score on Day 1 following instillation for overall cohort and by DED subtype.

Results: A total of 134 patients received treatment (mean age: 56.6 years; female: 75.4%). Median changes from baseline at Day 1 in dry eye symptom scores were − 1.0 (95% confidence interval [CI]:-3.0,-1.0), − 2.0 (95% CI:-3.0,-2.0), and − 2.0 (95% CI:-2.0,-1.0) at 0, 4, and 8 hours respectively. Subgroup analysis showed a median change from baseline in dry eye symptom score of − 2 (95% CI:-3.0,-1.0) for aqueous-deficient and evaporative subtypes and − 1 (95% CI:-3.0,-1.0) for mixed subtype at 8 hours. Median soothing sensation scores were 3 at 0 and 4 hours and 3.5 at 8 hours, with a range of 0– 10. Median (range) tolerability assessment scores were 0 (0– 8) for burning sensation, stinging sensation, blurring, and 0 (0– 10) for foreign body sensation. Tolerability assessment scores by DED subtype confirmed that the majority of patients reported scores in the range of 0– 5 for all components and in all subgroups analyzed.

Conclusion: Our study demonstrated that PG-HPG nanoemulsion provided instant/immediate and sustained symptom relief for 8 hours post-single application and was well tolerated in patients with DED, demonstrated by their responses on each of the assessment scales.

Keywords: aqueous-deficient dry eye, dry eye disease, evaporative dry eye, propylene glycol-hydroxypropyl guar nanoemulsion ocular lubricant, mixed dry eye

Tse,J., Rizwan,M., Rasmussen,J., Jones,L., Yim,E. K. F. Gelatin Methacrylate as an Enzyme-Controlled Release Vehicle of Hyaluronic Acid for the Treatment of Recurrent Corneal Erosion Applied Bio Materials 2020;3(9):6214-6223 [ Show Abstract ]

Recurrent corneal erosion (RCE) is a condition where the superficial corneal epithelial cells sporadically shed because of poor attachment to the underlying basement membrane, resulting in pain and discomfort. RCE-afflicted corneas exhibit elevated biological factors and enzymes, such as matrix metalloproteinase (MMP)-9. Soft bandage contact lenses (BCLs) are a commonly recommended treatment as they permit continued vision during recovery. However, they do not outperform alternative treatments as they currently lack active ingredients for ocular surface repair. Development of BCLs with a sustained release of active ingredients to promote RCE wound healing over an extended period of time would be clinically valuable. We fabricated gelatin methacrylate (GelMA) hydrogels with MMP-9-triggered controlled release for further BCL development. GelMA disks were characterized to determine the optimal concentration and methacrylation degree for sustained release in the presence of MMP-9. The chosen active ingredient, 60 kDa hyaluronic acid (HA), was verified to promote wound healing in rabbit corneal epithelial cell and human corneal epithelial cell wound assays. The active ingredient was loaded into GelMA hydrogels, and the bioavailability of the vehicle was determined. The GelMA hydrogels revealed a tunable profile for diffusion and enzyme-mediated controlled release of a model molecule. The 60 kDa HA-loaded GelMA disks showed improvement in wound healing at HA loadings of 150 and 250 μg by improving the wound healing rates by 28% (68.7% wound closure) and 26% (67.9% wound closure), respectively, compared to the control (50.5% wound closure) at 24 h. The HA-loaded GelMA disks with 150 and 250 μg HA also exhibited shortened wound closure time of 75 h compared to >147 h with a bolus daily delivery of HA for wound closure. Overall, we demonstrated that the fabricated GelMA hydrogels offered an enzyme-triggered option as a sustained release material for future RCE treatments.

van der Worp,E., Wolffsohn,J., Jones,L. When was the last time you fitted a soft lens? Cont Lens Anterior Eye 2020;43(5):415-417 [ Show Abstract ]

A recent webinar “discussing the topic of soft lenses, examining dropout rates and putting forward suggestions for how eye care practitioners can ‘get control’ over their fitting” was hosted by the British Contact Lens Association (BCLA). However, the webinar and this editorial addresses much more than merely’ lens fitting’ and ‘dropouts.’ It seems that the profession is almost at a crossroads in which its future is defined by whether the profession stands as contact lens fitters and specialists or whether contact lenses are simply a commodity that can be sold over the internet.

Willcox,M. D. P., Walsh,K. Nichols,J. J., Morgan,P. B., Jones,L. W. The ocular surface, coronaviruses and COVID‐19 Clinical and Experimental Optometry 2020;103(4):418-424 [ Show Abstract ]

The ocular surface has been suggested as a site of infection with Coronavirus‐2 (SARS‐CoV‐2) responsible for the coronavirus disease‐19 (COVID‐19). This review examines the evidence for this hypothesis, and its implications for clinical practice. Severe Acute Respiratory Syndrome Coronavirus‐2 (SARS‐CoV‐2), responsible for the COVID‐19 pandemic, is transmitted by person‐to‐person contact, via airborne droplets, or through contact with contaminated surfaces. SARS‐CoV‐2 binds to angiotensin converting enzyme‐2 (ACE2) to facilitate infection in humans. This review sets out to evaluate evidence for the ocular surface as a route of infection. A literature search in this area was conducted on 15 April 2020 using the Scopus database. In total, 287 results were returned and reviewed. There is preliminary evidence for ACE2 expression on corneal and conjunctival cells, but most of the other receptors to which coronaviruses bind appear to be found under epithelia of the ocular surface. Evidence from animal studies is limited, with a single study suggesting viral particles on the eye can travel to the lung, resulting in very mild infection. Coronavirus infection is rarely associated with conjunctivitis, with occasional cases reported in patients with confirmed COVID‐19, along with isolated cases of conjunctivitis as a presenting sign. Coronaviruses have been rarely isolated from tears or conjunctival swabs. The evidence suggests coronaviruses are unlikely to bind to ocular surface cells to initiate infection. Additionally, hypotheses that the virus could travel from the nasopharynx or through the conjunctival capillaries to the ocular surface during infection are probably incorrect. Conjunctivitis and isolation of the virus from the ocular surface occur only rarely, and overwhelmingly in patients with confirmed COVID‐19. Necessary precautions to prevent person‐to‐person transmission should be employed in clinical practice throughout the pandemic, and patients should be reminded to maintain good hygiene practices.

Wolffsohn,J. S., Calossi,A., Cho,P., Gifford,K., Jones,L., Jones,D., Guthrie,S., Li,M., Lipener,C., Logan,N. S., Malet,F., Peixoto-de-Matos,S. C., González-Méijome,J. M., Nichols,J. J., Orr,J. B., Santodomingo-Rubido,J., Schaefer,T., Thite,N., van der Worp,E., Tarutta,E., Iomdina,E., Ali,B. M., Villa-Collar,C., Abesamis-Dichoso,C., Chen,C., Pult,H., Blaser,P., Parra Sandra Johanna,G., Iqbal,F., Ramos,R., Carrillo Orihuela,G., Boychev,N. Global trends in myopia management attitudes and strategies in clinical practice – 2019 Update Cont Lens Anterior Eye 2020;43(1):9-17 [ Show Abstract ]

Purpose: A survey in 2015 identified a high level of eye care practitioner concern about myopia with a reported moderately high level of activity, but the vast majority still prescribed single vision interventions to young myopes. This research aimed to update these findings 4 years later. Methods: A self-administrated, internet-based questionnaire was distributed in eight languages, through professional bodies to eye care practitioners globally. The questions examined: awareness of increasing myopia prevalence, perceived efficacy of available strategies and adoption levels of such strategies, and reasons for not adopting specific strategies. Results: Of the 1336 respondents, concern was highest (9.0 ± 1.6; p < 0.001) in Asia and lowest (7.6 ± 2.2; p < 0.001) in Australasia. Practitioners from Asia also considered their clinical practice of myopia control to be the most active (7.7 ± 2.3; p < 0.001), the North American practitioners being the least active (6.3 ± 2.9; p < 0.001). Orthokeratology was perceived to be the most effective method of myopia control, followed by pharmaceutical approaches and approved myopia control soft contact lenses (p < 0.001). Although significant intra-regional differences existed, overall, most practitioners did not consider single-vision distance under-correction to be an effective strategy for attenuating myopia progression (79.6 %), but prescribed single vision spectacles or contact lenses as the primary mode of correction for myopic patients (63.6 ± 21.8 %). The main justifications for their reluctance to prescribe alternatives to single vision refractive corrections were increased cost (20.6 %) and inadequate information (17.6 %). Conclusions: While practitioner concern about myopia and the reported level of activity have increased over the last 4 years, the vast majority of eye care clinicians still prescribe single vision interventions to young myopes. With recent global consensus evidence-based guidelines having been published, it is hoped that this will inform the practice of myopia management in future.

Xu,M., Sivak,J. G., McCanna,D. J. Ocular toxicology: synergism of UV radiation and benzalkonium chloride
Cutaneous and Ocular Toxicology 2020;39(4):370-379 [ Show Abstract ]

Purpose: To investigate the combined toxic effect of ultraviolet (UV) radiation and benzalkonium chloride (BAK), a common preservative in ophthalmic eye drops, on human corneal epithelial cells (HCEC).

Methods: Cultured HCEC were exposed to different combined and separate UV (280-400 nm) and BAK solutions at relevant human exposure levels. Human exposure to UV can occur before, during, or after eye drop installation, therefore, three different orders of ocular exposures were investigated: UV and BAK at the same time, UV first followed by BAK, and BAK first followed by UV. Control treatments included testing HCEC exposed to BAK alone and also HCEC exposed to UV alone. In addition, phosphate-buffered saline (PBS) was used as a negative control. After exposure, cell metabolic activity of the cultures was measured with PrestoBlue, and cell viability was determined using confocal microscopy with viability dyes.

Results: BAK alone reduced the metabolic activity and cell viability of HCEC in a dose- and time-dependent manner. UV alone at a low dose (0.17 J/cm2) had little toxicity on HCEC and was not significantly different from PBS control. However, UV plus BAK showed combined effects that were either greater than (synergistic) or equal to (additive) the sum of their individual effects. The synergistic effects occurred between low dose UV radiation (0.17 J/cm2) and low concentrations of BAK (0.001%, 0.002%, 0.003%, and 0.004%).

Conclusions: This investigation determined that at relevant human exposure levels, the combination of UV radiation (280-400 nm) and BAK can cause synergistic and additive toxic effects on human corneal epithelial cells. This finding highlights the importance of considering the combined ocular toxicity of BAK and solar radiation in the risk assessment of BAK-preserved ophthalmic solutions.

Yeu,E., Silverstein,S., Guillon,M., Schulze,M., Galaretta,D., Srinivasan,S., Manoj,V. Efficacy and Safety of Phospholipid Nanoemulsion-Based Ocular Lubricant for the Management of Various Subtypes of Dry Eye Disease: A Phase IV, Multicenter Trial Clinical Ophthalmology 2020;14:2561-2570 [ Show Abstract ]

Purpose: To evaluate the clinical efficacy and safety of propylene glycol/hydroxypropylguar (PG-HPG)-based nanoemulsion (Systane ® Complete) lubricant eye drops in participants with dry eye disease (DED).

Participants and Methods: In this phase IV, open-label, single-arm, interventional, multicenter study, adult participants with DED – subtyped into aqueous deficient, evaporative, and mixed dry eye – were instructed to instill one drop of PG-HPG in each eye twice a day for 28 days. Endpoints included change from baseline in tear film break-up time (TFBUT) (primary) and ocular discomfort visual analog scale (VAS) score at Day 14 and TFBUT at Day 28 (secondary). Safety was assessed throughout the study. Data were analyzed for overall patient cohort and by DED subtypes. Results: A total of 134 participants received treatment (mean age: 56.6 years; female: 75.4%). At Day 14, the mean (standard deviation [SD]) TFBUT increased from 2.6 (1.00) seconds at baseline to 4.2 (2.92) seconds (mean change: 1.5 [2.80] seconds); median change was 0.8 seconds (95% CI: 0.52, 1.19) for the overall cohort; the change was maintained at Day 28 (mean change: 1.4 (2.80) seconds, median change: 0.8 seconds (95% CI: 0.49, 1.17). Subgroup analysis showed a mean change (SD) from baseline in TFBUT of 1.1 (2.41) seconds for aqueous deficient, 2.4 (3.17) seconds for evaporative, and 1.2 (2.63) seconds for mixed dry eye at Day 14, respectively. The ocular discomfort VAS score improved (decreased) from baseline at Day 14 (mean [SD] change: −17.3 [24.80]) for the overall cohort, −22.0 [21.73] for aqueous deficient, −17.6 [24.17] for evaporative and −13.1 [27.49] for mixed dry eye subgroups). Adverse events (AEs) were reported in 9 (6.7%) participants. No serious AEs were reported during the study.

Conclusion: Our study findings demonstrated that PG-HPG-based nanoemulsion lubricant eye drops were effective and well tolerated in participants with DED and all of its subtypes. Keywords: aqueous deficient dry eye, dry eye disease, evaporative dry eye, propylene glycol/hydroxypropyl guar-nanoemulsion ocular lubricant, mixed dry eye

2019

Bitton,E., Ngo,W., Dupont,P. Eyelid hygiene products: A scoping review Cont Lens Anterior Eye 2019;42(6):591-597

Chamberlain,P., Gonzalez-Meijome,J., Ngo,C., Jones,D., Young,G. A three-year randomised clinical trial of MiSight lenses for myopia control Optometry & Vision Science 2019;96(8):556-567 [ Show Abstract ]

SIGNIFICANCE: Results of this randomized, double-masked clinical trial demonstrate the effectiveness of the MiSight soft contact lens in slowing myopia progression over multiple years.

PURPOSE: The purpose of this study was to quantify the effectiveness of MiSight daily disposable soft contact lens in slowing the progression of juvenile-onset myopia.

METHODS: Myopic children (spherical equivalent refraction, -0.75 to -4.00 D; astigmatism, <1.00 D) aged 8 to 12 years with no prior contact lens experience were enrolled in a 3-year, double-masked, randomized clinical trial at four investigational sites in four countries. Subjects in each group were matched for age, sex, and ethnicity and were randomized to either a MiSight 1-day contact lens (test) or Proclear 1-day (control; omafilcon A) and worn on a daily disposable basis. Primary outcome measures were the change in cycloplegic spherical equivalent refraction and axial length.

RESULTS: Of the subjects enrolled, 75.5% (109/144) completed the clinical trial (53 test, 56 control). Unadjusted change in spherical equivalent refraction was -0.73 D (59%) less in the test group than in the control group (-0.51 ± 0.64 vs. -1.24 ± 0.61 D, P < .001). Mean change in axial length was 0.32 mm (52%) less in the test group than in the control group (0.30 ± 0.27 vs. 0.62 ± 0.30 mm, P < .001). Changes in spherical equivalent refraction and axial length were highly correlated (r = -0.90, P < .001). Over the course of the study, there were no cases of serious ocular adverse events reported. Four asymptomatic corneal infiltrative (one test, three control) events were observed at scheduled study visits.

CONCLUSIONS: Results of this clinical trial demonstrate the effectiveness of the MiSight daily disposable soft contact lens in slowing change in spherical equivalent refraction and axial length.

TRIAL REGISTRATION: ClinicalTrials.gov NCT01729208.

Fonn,D., Jones,L. Hand hygiene is linked to microbial keratitis and corneal inflammatory events Cont Lens Anterior Eye 2019;42(2):132-135 [ Show Abstract ]

Lack of or inadequate hand washing is a risk factor in the development of contact lens related microbial keratitis and corneal inflammatory events. In the public health domain there is compelling evidence that proper hand washing with soap can save lives. The purpose of this review is to draw attention to some of the public health literature in support of hand washing and how education can influence patients’ hand hygiene behavior. Contact lens wearers are also guilty of poor hand washing behavior but there is scant evidence that education of hand washing procedures of lens wearers alters patient non-compliance. It is well known that pathogenic microbial contamination of contact lenses, lens cases, care solutions and anterior ocular components have been found with contact lens wear. However while the originating source may be hands or water, it is most likely both of these. Besides proper hand washing this paper will include mitigating strategies for avoiding microbial contamination.

Holland,E. J., Darvish,M., Nichols,K. K., Jones,L., Karpecki,P. M. Efficacy of topical ophthalmic drugs in the treatment of dry eye disease: A systematic literature review Ocul Surf 2019;17:412-423 [ Show Abstract ]

Dry eye disease (DED) is a multifactorial and complex disease of the ocular surface, with a high prevalence in adults. We systematically reviewed efficacy and safety data from published articles reporting results from prospective, controlled trials of topical ophthalmic drugs for DED. PubMed was searched from January 1997 to October 2017. Twenty-six unique trials investigating 13 ophthalmic drugs were identified, including trials of the approved drugs cyclosporine A, cyclosporine A cationic emulsion, diquafosol, rebamipide and lifitegrast. All identified studies provided level 1 evidence. None of the large (N > 100) studies demonstrated statistical significance of primary endpoints for both a sign and a symptom endpoint versus a control treatment in the same published trial. Publications on lifitegrast reported statistical superiority in a symptom or sign endpoint versus the control group in a large (N > 200), multicenter trial, with results repeated in trials of similar design. The most common adverse events associated with the approved drugs related to ocular discomfort upon instillation, especially burning/stinging and ocular irritation. The trial design and endpoints used across the studies varied considerably, highlighting the importance of standardization in clinical trials for DED. Recent advances in drug delivery and improved understanding of DED should contribute to new ophthalmic drug approvals.

Jones,L., Drobe,B., González-Méijome,J. M., Gray,L., Kratzer,T., Newman,S., Nichols,J.J., Ohlendorf,A., Ramdass,S., Santodomingo-Rubido,J., Schmid,K. L., Tan,D., Tan,K. O., Vera-Diaz,F. A., Wong,Y. L., Gifford,K. L., Resnikoff,S. IMI - Industry Guidelines and Ethical Considerations for Myopia Control Report Invest Ophthalmol Vis Sci 2019;60(3):M161-M183 [ Show Abstract ]

PURPOSE:
To discuss guidelines and ethical considerations associated with the development and prescription of treatments intended for myopia control (MC).

METHODS:
Critical review of published papers and guidance documents was undertaken, with a view to carefully considering the ethical standards associated with the investigation, development, registration, marketing, prescription, and use of MC treatments.

RESULTS:
The roles and responsibilities of regulatory bodies, manufacturers, academics, eye care practitioners, and patients in the use of MC treatments are explored. Particular attention is given to the ethical considerations for deciding whether to implement a MC strategy and how to implement this within a clinical trial or practice setting. Finally, the responsibilities in marketing, support, and education required to transfer required knowledge and skills to eye care practitioners and academics are discussed.

CONCLUSIONS:
Undertaking MC treatment in minors creates an ethical challenge for a wide variety of stakeholders. Regulatory bodies, manufacturers, academics, and clinicians all share an ethical responsibility to ensure that the products used for MC are safe and efficacious and that patients understand the benefits and potential risks of such products. This International Myopia Institute report highlights these ethical challenges and provides stakeholders with recommendations and guidelines in the development, financial support, prescribing, and advertising of such treatments.

Korogiannaki,M., Jones,L. W., Sheardown, H. The impact of a hyaluronic acid-grafted layer on the surface properties of model silicone hydrogel contact lenses Langmuir 2019;35(4):950-961 [ Show Abstract ]

The introduction of high oxygen transmissibility silicone hydrogel lenses ameliorated hypoxia-related complications, making them the most prescribed type of contact lens. Despite the progress made over the last two decades to improve their clinical performance, symptoms of ocular dryness and discomfort and a variety of adverse clinical events are still reported. Consequently, the rate of contact lens wear discontinuation has not been appreciably diminished by their introduction. Aiming to improve the interfacial interactions of silicone hydrogel contact lenses with the ocular surface, a biomimetic layer of the hydrophilic glycosaminoglycan hyaluronic acid (HA) (100 kDa), was covalently attached to the surface of model poly(2-hydroxyethyl methacrylate-co-3-methacryloxypropyl-tris-(trimethylsiloxy)silane) (pHEMA-co-TRIS) silicone hydrogel materials via UV-induced thiol-ene "click" chemistry. The surface structural changes after each modification step were studied by FTIR-ATR and XPS. Successful grafting of a homogenous HA layer to the surface of the model silicone hydrogels was confirmed by the consistent appearance of N (1s) and the significant decrease of the Si (2p) peaks, as determined by the low-resolution angle-resolved XPS. The HA-grafted surfaces demonstrated reduced contact angles, dehydration rate and nonspecific deposition of lysozyme and albumin, while maintaining their optical transparency (>90%). In vitro studies demonstrated that the HA-grafted pHEMA-co-TRIS materials did not show any toxicity to human corneal epithelial cells. These results suggest that surface immobilization of HA via thiol-ene "click" chemistry can be used as a promising surface treatment for silicone hydrogel contact lenses.

Moezzi,A. M., Varikooty,J., Luensmann,D., Schulze,M., Ng,A. Y., Karkkainen,T., Xu,J., Jones,L. The short-term physiological impact of switching reusable silicone hydrogel wearers into a hydrogel daily disposable multifocal Clinical Ophthalmology 2019;13:1193-1202 [ Show Abstract ]

Purpose: To evaluate ocular physiological responses to etafilcon A multifocal (etMF) daily disposable (DD) lenses after 4 weeks of wear, when switching from habitual silicone hydrogel (SiHy) daily wear.
Method: A single-arm, open-label, bilateral dispensing study was conducted in 39 habitual spherical SiHy wearers (14 hyperopes; 25 myopes). Clinical visits occurred with habitual SiHy (control) at baseline and after 4 weeks of etMF DD open-eye lens wear at exit. Objective limbal/bulbar hyperemia using the Oculus K5M (0–4) and subjective grading of lid wiper epitheliopathy (LWE) (0–4) were tested for non-inferiority (NI), using a margin of 1 grade. Corneal thickness along a 10 mm cord was measured using the Visante OCT and tested for NI using a 30 μm margin. Corneal staining area was graded (0–100%).
Results: The least-square mean differences (LSMD) and 95% confidence interval (95% CI) between etMF DD and habitual SiHy in central and peripheral corneal thickness (μm) were 3.64 (−2.0, 9.29) and 3.0 (−7.72, 13.72) in hyperopic, and 3.56 (−0.66, 7.78) and 6.40 (−1.62, 14.42) in myopic subjects. The LSMD (95% CI) for bulbar and limbal hyperemia were −0.08 (−0.19, 0.02) and −0.01 (−0.12, 0.09) in hyperopes, and 0.04 (−0.03, 0.12) and 0.04 (−0.04, 0.11) in myopes. The LSMD (95% CI) for LWE were 0.11 (−0.39, 0.60) and 0.30 (−0.07, 0.67) for hyperopes and myopes, respectively.
Conclusions: No clinically significant differences in a variety of physiological responses were found when habitual reusable SiHy daily wear subjects were refitted into hydrogel etMF, when the subjects were followed for 4 weeks.

Ngo,W., Srinivasan,S., Jones,L. An Eyelid Warming Device for the Management of Meibomian Gland Dysfunction J Optom 2019;12(2):120-130 [ Show Abstract ]

PURPOSE: To determine the effectiveness of the MGDRx EyeBag in managing meibomian gland dysfunction.

METHODS: This was a prospective, randomized, controlled, observer-masked, bilateral eye study that enrolled 29 participants. Participants were randomized into either the EyeBag group or the control group. The EyeBag group used the EyeBag 10minutes 2x/day, and the control group remained on their own dry eye treatment regimen (if applicable). All participants were observed at baseline, 2 weeks (2wk) and 4 weeks (4wk). At 4wk, participants in the EyeBag group were asked to stop using the EyeBag. All participants were seen again at 8 weeks (8wk). Primary outcomes were the Ocular Surface Disease Index (OSDI), Current Symptoms Questionnaire (CSQ), meibomian gland score (MG score), and non-invasive tear breakup time (NIBUT).

RESULTS: Twenty-five participants completed the study (mean age 38±15 years, 7 male). There was a significant change in OSDI over time for the EyeBag group (mean[lower 95% CI, upper 95% CI], baseline: 39.1[31.1,47.0], 2wk: 26.8[19.7,33.9], 4wk: 26.6[16.5,36.7], 8wk: 27.7[18.4,37.0]; p=0.01), but not in the control group (p=0.22), but no significant difference between groups at all time points (all p>0.27). Symptoms immediately improved after conducting the EyeBag based on at-home CSQ scores (Δ=-5.0 points, p<0.01), but not in the control group. For both groups, there was no significant change (p-value EyeBag,p-value control) in MG score (0.21,0.17) and NIBUT (0.49,0.06) over time.

CONCLUSIONS: The EyeBag may relieve symptoms of dry eye, but the effect on meibomian gland function and tear stability when used for only 4 weeks was undetectable.

Nichols,J. J., Chalmers,R. L., Dumbleton,K., Jones,L., Lievens,C. W., Merchea,M. M., Szczotka-Flynn,L. The Case for Using Hydrogen Peroxide Contact Lens Care Solutions: A Review Eye & Contact Lens 2019;45(2):69-82 [ Show Abstract ]

Despite their established disinfection and safety benefits, the use of hydrogen peroxide (H2O2) lens care systems among today's wearers of reusable contact lenses remains low in comparison with multipurpose solution (MPS) use. Multipurpose solution systems, however, present several potential drawbacks that may impact patient outcomes, including the use of chemical preservatives for disinfection, biocompatibility issues, and challenges with respect to lens care compliance. Given their unique composition and mechanism of action, one-step H2O2 systems offer the opportunity to avoid many of the challenges associated with MPS use. This article reviews the evolution of H2O2 lens care systems and examines the current scientific and clinical evidence regarding the relative ease of use, lens and tissue compatibility, disinfection efficacy, and ocular surface safety of H2O2 systems. Evaluation of the available data indicates that in comparison with MPS, one-step H2O2 systems tend to promote more favorable compliance, efficacy, comfort, and ocular surface outcomes for a wide range of contact lens–wearing patients. Based on the current published evidence, the authors recommend that eye care practitioners consider making one-step H2O2 systems their first-line contact lens care recommendation for most wearers of reusable lenses.

Phan,C. M., Subbaraman,L., Jones,L. Uptake and release of polyvinyl alcohol from hydrogel daily disposable contact lenses Optom Vis Sci 2019;96(3):180-186 [ Show Abstract ]

SIGNIFICANCE:
Polyvinyl alcohol is a wetting agent that could reduce the symptoms of dry eye and contact lens discomfort. Currently, only one lens type, nelfilcon A (DAILIES AquaComfort Plus), releases polyvinyl alcohol. The concept of releasing this agent from contact lenses could be applied to other lens materials.

PURPOSE:
The purpose of this study was to measure the release of polyvinyl alcohol from commercially available hydrogel daily disposable contact lenses using refractive index and iodine-borate methods.

METHODS:
Etafilcon A, omafilcon A, and nelfilcon A were soaked in phosphate-buffered saline and 0.2% trifluoroacetic acid/acetonitile for 24 hours to remove residual blister pack components. The lenses were then incubated in a 10-mg/mL solution of polyvinyl alcohol for 24 hours. After the incubation period, the lenses were placed in 2 mL of phosphate-buffered saline. At specified time intervals, t = 0.5, 1, 2, 4, 8, 12, and 24 hours, the samples were evaluated using refractive index and an iodine-borate assay. Polyvinyl alcohol uptake was determined by extracting the lenses with methanol for 24 hours.

RESULTS:
There were no differences in the uptake of polyvinyl alcohol between lens types (P > .05). The release of this wetting agent for all lens types followed a burst-plateau profile after the first 30 minutes (P > .05). Nelfilcon A had a slightly higher release of polyvinyl alcohol (P .05).

CONCLUSIONS:
The results suggest that the contact lenses tested in this study have similar efficiency in delivering polyvinyl alcohol.

Phan,C. M., Walther,H., Qiao,H., Shinde,R., Jones,L. Development of an eye model with a physiological blink mechanism Translational Vision Science & Technology 2019;8(5):Article 1 [ Show Abstract ]

Purpose: To develop an eye model with a physiological blink mechanism.

Methods: All parts of the eye model were designed using computer-aided design software. The eyelid consisted of a unique 3D printed structure containing teeth to physically secure a flexible membrane. Both the eyeball and eyelid membrane were synthesized using polyvinyl alcohol (PVA). Four molecular weights of PVA (89–98, 85–124, 130, and 146–186 kDa) were tested at a range of concentrations between 5% and 30% weight/volume. The wettability and water content of these materials were compared with the bovine cornea and sclera. The model was connected to a microfluidic pump, which delivers artificial tear solution (ATS) to the eyelid. A corneal topographer was used to evaluate the tear break-up and tear film regeneration.

Results: The eyelid flexes and slides across the eyeball during each blink, which ensures direct contact between the two surfaces. When loaded with an ATS, this mechanism evenly spreads the solution over the eyeball to generate an artificial tear film. The artificial tear film in this eye model had a tear break-up time (TBUT) of 5.13 ± 0.09 seconds at 1.4 μL/min flow rate, 6 blinks/min, and <25% humidity.

Conclusions: This model simulates a physiological blink actuation and an artificial tear film layer. Future studies will examine variations in flow rates and ATS composition to simulate clinical values of TBUT.

Translational Relevance: The eye model could be used to study in vitro TBUT, tear deposition, and simple drug delivery.

Phan,C. M., Walther,H., Riederer,D., Lau,C., Lorentz,H., Subbaraman,L., Jones,L. Analysis of polyvinyl alcohol release from commercially available daily disposable contact lenses using an in vitro eye model J Biomed Mater Res B Appl Biomater 2019;107(5):1662-1668 [ Show Abstract ]

The purpose of this work was to determine the release of polyvinyl alcohol (PVA) from etafilcon A, omafilcon A, and nelfilcon A daily disposable hydrogel contact lenses using a novel in vitro model. PVA is an ocular lubricant that can be found in multiple formulations of artificial tears. Nelfilcon A innately contains PVA, so only the release of PVA from this lens was evaluated. Etafilcon A and omafilcon A lenses were incubated in a PBS solution containing PVA. The release of PVA was evaluated using a novel in vitro blink platform with Milli-Q water and PBS under various blink conditions and flow rates. Nelfilcon A lenses significantly released more PVA than other lenses at 0.5 and 1.5 h in both PBS and Milli-Q water (p 0.05). All tested groups and lenses showed a burst release within the first 4.5 h and rapidly plateaued thereafter. The current study demonstrates that releasable PVA (whether through uptake or through being inherently available from the material) is loosely bound on hydrogel lenses, and the majority is released within 4.5 h.

Pucker,A. D., Jones-Jordan, L.A., Marx,S., Powell,D. R., Kwan,J. T., Srinivasan,S., Sickenberger,W., Jones,L., The role of soft contact lens wear on meibomian gland morphology and function Eye & Contact Lens 2019;45(4):276-277 [ Show Abstract ]

The impact of a contact lens on the eye has long been of interest to practitioners who prescribe contact lenses and to the patients who wear them. One particular area of concern within the past several years has been related to how a contact lens may impact the meibomian glands (MGs) because changes in MG structure and/or function have the potential to impact the overall integrity of the ocular surface and contact lens success. Ucakhan and Arslanturk-Eren's recent manuscript published in Eye & Contact Lens has attempted to expand our knowledge of this topic by studying a group of contact lens–wearing and non–contact lens–wearing subjects and seeking to understand how the use of silicone hydrogel contact lenses may impact MG health. Their study overall concluded that “soft CL wear causes significant morphological and functional changes in MG with thickening of MG presenting an early diagnostic finding of MG dysfunction on meibography.”

Pucker,A. D., Jones-Jordan, L.A., Marx,S., Powell,D. R., Kwan,J. T., Srinivasan,S., Sickenberger,W., Jones,L., Contact Lens Assessment of Symptomatic Subjects (CLASS) Study Group Clinical factors associated with contact lens dropout Cont Lens Anterior Eye 2019;42(3):318-324 [ Show Abstract ]

PURPOSE: Contact lens (CL) dropout is estimated to be approximately equal to the number of new wearers per year, resulting in virtually no growth in the global CL market. The purpose of this study was to determine ocular and CL factors associated with CL dropout.

METHODS: This five-site study recruited subjects 18-45 years of age who had ceased CL wear within the past 6-12 months due to discomfort. Dropout subjects were compared to age- and sex-matched currently successful CL wearers. Each subject was administered a symptoms survey and a study-specific survey that queried general CL history and compliance. Clinical testing included non-invasive tear break-up time, tear meniscus height, blepharitis assessment, meibum quality and expression, and meibography.

RESULTS: A total of 56 matched-pairs were recruited. Dry eye was found to significantly increase a subject's odds of dropping out of CLs. The odds of dropping out of CLs was also significantly increased with each worsening grade of upper or lower eyelid meibomian gland (MG) plugging, upper eyelid meibum quality, and upper eyelid MG tortuosity. No other factors analyzed increased a subject's odds of dropping out of CLs.

CONCLUSIONS: CL dropout may be precipitated by underlying dry eye symptoms, though most dry eye signs, with the exception of MG structure and function, had minimal predictive value for CL dropout. Nevertheless, evidence suggests that practitioners should screen for and educate CL patients about the importance of maintaining healthy MGs, which may potentially allow them to maintain comfortable CL use and increase their CL longevity.

Pucker,A. D., Jones-Jordan,L. A., Kunnen,C. M. E., Marx,S., Powell,D. R., Kwan,J. T., Srinivasan,S., Sickenberger,W., Jones,L. Impact of meibomian gland width on successful contact lens use Cont Lens Anterior Eye 2019;42(6):646-651 [ Show Abstract ]

Purpose: To evaluate meibomian gland (MG) width and determine its impact on successful contact lens (CL) use and ocular health.
Methods: A five-site study was conducted by recruiting 18- to 45-year-old subjects who had dropped out of CLs because of discomfort. CL dropouts were compared to age- and sex-matched successful CL wearers. Right eyes were evaluated for tear break-up time, tear meniscus height, MG expressibility, meibum quality, and meibography. Central MG widths were evaluated with a custom MATLAB program.
Results: CL dropouts (n = 56) and successful CL (n = 56) wearers had similar grades for upper (p = 1.0) and lower (p = 0.22) MG atrophy, upper (p = 0.07) and lower (p = 0.89) MG tortuosity, and upper (p = 0.92) and lower (p = 0.97) MG widths. Upper eyelid MG widths were narrower than lower eyelid MG widths (p = 0.03). Upper and lower MG tortuosity (p < 0.001) and widths (p = 0.03) were associated, but not atrophy (p = 0.42). Lower eyelid MG widths were associated with MG expressibility (p = 0.01), but MG widths were not with any other factors.
Conclusions: Successful CL wear does not appear to be clinically influenced by MG width or other measures of MG structural integrity. Lower eyelid MGs were wider than upper eyelid MGs and narrower lower eyelid MGs were associated with worse MG expressibility, suggesting that narrower MGs may produce abnormal meibum. Data also suggests that MG factors of both eyelids should be evaluated in practice.

Troilo,D., Smith,E. L. 3rd, Nickla,D. L., Ashby,R., Tkatchenko,A. V., Ostrin,L. A., Gawne,T. J., Pardue,M. T., Summers,J. A., Kee,C. S., Schroedl,F., Wahl,S., Jones,L. IMI - Report on Experimental Models of Emmetropization and Myopia Invest Ophthalmol Vis Sci 2019;60(3):M31-M88 [ Show Abstract ]

The results of many studies in a variety of species have significantly advanced our understanding of the role of visual experience and the mechanisms of postnatal eye growth, and the development of myopia. This paper surveys and reviews the major contributions that experimental studies using animal models have made to our thinking about emmetropization and development of myopia. These studies established important concepts informing our knowledge of the visual regulation of eye growth and refractive development and have transformed treatment strategies for myopia. Several major findings have come from studies of experimental animal models. These include the eye's ability to detect the sign of retinal defocus and undergo compensatory growth, the local retinal control of eye growth, regulatory changes in choroidal thickness, and the identification of components in the biochemistry of eye growth leading to the characterization of signal cascades regulating eye growth and refractive state. Several of these findings provided the proofs of concepts that form the scientific basis of new and effective clinical treatments for controlling myopia progression in humans. Experimental animal models continue to provide new insights into the cellular and molecular mechanisms of eye growth control, including the identification of potential new targets for drug development and future treatments needed to stem the increasing prevalence of myopia and the vision-threatening conditions associated with this disease.

Walsh,K., Jones,L. The use of preservatives in dry eye drops Clinical Ophthalmology 2019;13:1409-1425 [ Show Abstract ]

Topical ocular preparations are widely recommended by health care professionals, or chosen by patients, to help manage dry eye disease (DED). The chronic and progressive nature of DED may result in the administration of topical products several times a day, over a period of many years. Given DED is a condition that by definition affects the ocular surface, it is important to understand how the repeated use of eye drops may impact the ocular surface, influence clinical signs, affect symptoms, and impact the overall disease process of dry eye. The component in topical preparations with the greatest potential to adversely affect the ocular surface is the preservative. This paper reviews the literature in relation to the use of preservatives in formulations for dry eye. The ocular effects of benzalkonium chloride (BAK) are summarised and compared to the performance of alternative preservatives and preservative-free formulations. Use of preserved and preservative-free drops in relation to the management of varying stages of DED is discussed.

Walther,H., Subbaraman,L, N., Jones,L. Efficacy of Contact Lens Care Solutions in Removing Cholesterol Deposits From Silicone Hydrogel Contact Lenses. Eye & Contact Lens 2019;45(2):105-111 [ Show Abstract ]

PURPOSE: To determine the efficacy of multipurpose solutions (MPSs) on the removal of cholesterol deposits from silicone hydrogel (SH) contact lens materials using an in vitro model.
MATERIALS AND METHODS: Five SH lens materials: senofilcon A, comfilcon A, balafilcon A, lotrafilcon A, and lotrafilcon B were removed from the blister pack (n=4 for each lens type), incubated for 7 days at 37°C in an artificial tear solution containing C radiolabeled cholesterol. Thereafter, lenses were stored in a preserved saline solution control (Sensitive Eyes Saline Plus) or cleaned with 1 of the 5 MPSs incorporating different preservatives (POLYQUAD/ALDOX, polyquaternium-1/alexidine, polyquaternium-1/PHMB, and 2 based on PHMB alone) using a rub and rinse technique, according to the manufacturer's recommendations, and stored in the MPS for a minimum of 6 hr. Lenses were then extracted with 2:1 chloroform:methanol, analyzed in a beta counter, and μg/lens of cholesterol was determined.
RESULTS: Balafilcon A and senofilcon A lens materials showed the highest amounts of accumulated cholesterol (0.93±0.02 μg/lens; 0.95±0.01 μg/lens, respectively), whereas lotrafilcon A and lotrafilcon B deposited the lowest amounts (0.37±0.03 μg/lens; 0.47±0.12 μg/lens, respectively). For all lens materials, the MPS preserved with POLYQUAD/ALDOX removed more deposited cholesterol than any other test solution; however, the amount of removed cholesterol contamination from the individual contact lenses was only statistically significant for balafilcon A and senofilcon A (P=0.006 and P=0.042, respectively). Sensitive eyes and the other evaluated MPSs showed no significant effect on cholesterol removal (P>0.05).
CONCLUSION: Cholesterol-removal efficacy varies depending on the combination of lens material and solution. Only 1 MPS showed a statistically significant reduction of cholesterol deposit for only 2 of the 5 tested lens materials.

Walther,H., Subbaraman,L. N., Jones,L. Novel in vitro method to determine pre-lens tear break-up time of hydrogel and silicone hydrogel contact lenses Cont Lens Anterior Eye 2019;42(2):178-184 [ Show Abstract ]

PURPOSE:
To develop an in vitro model to determine pre-lens non-invasive break-up time (NIBUT) and to subsequently use this method to compare the NIBUT over contemporary daily disposable (DD) contact lenses (CL).
METHODS:
Three silicone hydrogel (SH) and two conventional hydrogel (CH) DD CLs were incubated in an artificial tear solution (ATS). A model blink cell (MBC) was utilised to mimic intermittent air exposure. CLs were repeatedly submerged for 3 seconds (s) and exposed to air for 10 s over periods of 2, 6, 12, and 16 hours (h). NIBUTs (n = 4) were determined out of the blister pack (T0) and at the end of each incubation period.
RESULTS:
Overall, nesofilcon A showed the longest NIBUTs (p < 0.001). At T0, CHs revealed significantly longer NIBUTs (p ≤ 0.001) than SHs. After 2 h, nesofilcon A showed the longest NIBUT, however, this was only statistically significant compared with delefilcon A (p ≤ 0.001). After 6 h, nesofilcon A NIBUT was significantly longer than all other CLs (p ≤ 0.001). Etafilcon A showed a significantly longer NIBUT (p ≤ 0.001) after 12 h and delefilcon A had the longest NIBUT (p ≤ 0.001) after 16 h. Statistically significant (p ≤ 0.05) changes of NIBUT within the lens materials varied between time points. After 16 h, all CLs showed significant reductions in NIBUTs (p ≤ 0.001) in comparison to T0.
CONCLUSION:
NIBUT values reduced gradually over time and varying levels of deposition impacted measured pre-lens NIBUTs. While NIBUT of CH materials are longer immediately out of the blister pack, after tear film exposure, the NIBUTs obtained using this methodology became very similar.

Wolffsohn,J. S., Flitcroft,D. I., Gifford,K. L., Jong,M., Jones,L., Klaver,C. C. W., Logan,N. S., Naidoo,K., Resnikoff,S., Sankaridurg,P., Smith,E. L. 3rd, Troilo,D., Wildsoet,C. F. IMI - Myopia Control Reports Overview and Introduction Invest Ophthalmol Vis Sci 2019;60(3):M1-M19 [ Show Abstract ]

With the growing prevalence of myopia, already at epidemic levels in some countries, there is an urgent need for new management approaches. However, with the increasing number of research publications on the topic of myopia control, there is also a clear necessity for agreement and guidance on key issues, including on how myopia should be defined and how interventions, validated by well-conducted clinical trials, should be appropriately and ethically applied. The International Myopia Institute (IMI) reports the critical review and synthesis of the research evidence to date, from animal models, genetics, clinical studies, and randomized controlled trials, by more than 85 multidisciplinary experts in the field, as the basis for the recommendations contained therein. As background to the need for myopia control, the risk factors for myopia onset and progression are reviewed. The seven generated reports are summarized: (1) Defining and Classifying Myopia, (2) Experimental Models of Emmetropization and Myopia, (3) Myopia Genetics, (4) Interventions for Myopia Onset and Progression, (5) Clinical Myopia Control Trials and Instrumentation, (6) Industry Guidelines and Ethical Considerations for Myopia Control, and (7) Clinical Myopia Management Guidelines.

Wolffsohn,J. S., Kollbaum,P. S., Berntsen,D. A., Atchison,D. A., Benavente,A., Bradley,A., Buckhurst,H., Collins,M., Fujikado,T., Hiraoka,T., Hirota,M., Jones,D., Logan,N. S., Lundström,L., Torii,H., Read,S. A., Naidoo,K. IMI - Clinical Myopia Control Trials and Instrumentation Report Invest Ophthalmol Vis Sci 2019;60(3):M132-M160 [ Show Abstract ]

The evidence-basis based on existing myopia control trials along with the supporting academic literature were reviewed; this informed recommendations on the outcomes suggested from clinical trials aimed at slowing myopia progression to show the effectiveness of treatments and the impact on patients. These outcomes were classified as primary (refractive error and/or axial length), secondary (patient reported outcomes and treatment compliance), and exploratory (peripheral refraction, accommodative changes, ocular alignment, pupil size, outdoor activity/lighting levels, anterior and posterior segment imaging, and tissue biomechanics). The currently available instrumentation, which the literature has shown to best achieve the primary and secondary outcomes, was reviewed and critiqued. Issues relating to study design and patient selection were also identified. These findings and consensus from the International Myopia Institute members led to final recommendations to inform future instrumentation development and to guide clinical trial protocols.

Wong,S., Srinivasan,S., Murphy,P. J., Jones,L. Comparison of meibomian gland dropout using two infrared imaging devices Cont Lens Anterior Eye 2019;42(3):311-317 [ Show Abstract ]

Purpose: To measure the degree of meibomian gland (MG) dropout in the lower eyelid determined by analysis of images obtained from the LipiView II (LVII) and the Keratograph 5M (K5M).

Methods: The inferior eyelid of each participant was imaged in a random order using both devices. All images were subjectively assessed by a single-masked investigator to determine the extent of MG loss using the Arita 4-point meiboscore grading scale. The images were also semi-objectively analyzed with ImageJ to calculate the percentage of MG dropout, by tracing around the non-glandular area and the total exposed area of the lower lid.

Results: Twenty participants (mean age 37 years, range 23–60, 60% female) completed the study. A significant difference in meiboscore (mean ± SD) was obtained between the LVII and the K5M (1.43 ± 0.78 vs. 1.90 ± 0.81, Z = 3.25, p = 0.001). The meiboscore 95% limit of agreement (LOA) ranged from −1.88 to +0.93. A significant difference was found with mean ImageJ percentage dropout between the LVII and the K5M (31.5% vs 43.4%, t = −4.8, p = 0.00003). The percentage dropout 95% LOA ranged from −42.79% to +19.06%.

Conclusions: LVII images had significantly lower meiboscores and less percentage MG dropout. Varying amounts of dropout were observed between the devices due the amount of eyelid that was typically everted and because of differences in image quality. These results indicate that these devices should not be used interchangeably to evaluate MG dropout.

Woods,J., Hutchings,N., Srinivasan,S., Jones,L. Geographic distribution of corneal staining in symptomatic dry eye Ocul Surf 2019;18(2):258-266 [ Show Abstract ]

Purpose
To describe the geographic distribution of corneal fluorescein staining across the five corneal zones, among non contact lens wearers who report symptoms of dry eye and determine which corneal zone most frequently exhibited the worst staining.

Methods
Prior studies conducted at the Centre for Ocular Research & Education, Canada, were reviewed for inclusion in the analysis. Each study assessed dry eye symptoms using OSDI and also assessed corneal fluorescein staining in five corneal zones. For each subject, the corneal zones were ranked 1–5 according to their relative staining grade, Rank-1 representing the highest grade.

Results
Data from 13 studies and 368 subjects were included. The total number of zones assigned Rank-1 (worst) staining was 449 (across 264 subjects). The inferior zone had the most Rank-1 counts of all zones at 193/43%, which involved 52.5% of all subjects. The nasal zone had 77/17% involving 20.9% of subjects, followed by the temporal (69/15.5%, 18.8% subjects) and superior zones (63/14%, 17.1% subjects). The central zone had the lowest count of Rank-1 designations, at only 47/10.5%, involving 12.8% of subjects. Bayesian analysis was used to generate distributions of the credible proportions of subjects likely to present with staining in a single peripheral zone, with or without central zone staining. It illustrated that staining in a peripheral zone without central staining was more credible. The worst single zone staining was most likely to present in the inferior zone (67.9%), followed by the nasal zone (11.3%), the superior zone (9.2%), and the temporal zone (5.6%).

Conclusion
In the presence of dry eye symptoms, the inferior zone typically presents the most severe grade of corneal staining, more likely without central zone staining. This knowledge is valuable when developing a strategy to treat dry eye signs, as the inferior corneal zone has the highest grade of staining thus has the potential to exhibit the greatest reduction in staining post-treatment.

2018

Blackie,C. A., Coleman,C. A., Nichols,K. K., Jones,L., Chen,P. Q., Melton,R., Kading,D. L., O’Dell,L. E., Srinivasan,S. A single vectored thermal pulsation treatment for meibomian gland dysfunction increases mean comfortable contact lens wearing time by approximately 4 hours per day Clinical Ophthalmology 2018;12:169-183 [ Show Abstract ]

Purpose: To evaluate the effect of a single vectored thermal pulsation (VTP) treatment in contact lens wearers with meibomian gland dysfunction (MGD) and dry eye symptoms. Methods: The prospective, nonsignificant risk, open-label, randomized, multi-center clinical trial included 55 soft contact lens (SCL) wearers with MGD and evaporative dry eye. Subjects were randomized to the single VTP treatment group or an untreated control. The controls received a crossover VTP treatment at 3 months (crossover treatment group). Primary effectiveness measures were meibomian gland secretion (MGS) score and Standard Patient Evaluation of Eye Dryness (SPEED) that were evaluated at baseline, at 1 and 3 months post-VTP treatment, and at 1 month post-VTP treatment in the crossover treatment group. Exploratory variables included fluorescein tear break-up time (TBUT), lid wiper epitheliopathy (LWE), lid parallel conjunctival folds (LIPCOF), ocular surface staining, frequency of over-the-counter (OTC) drop use, and hours of comfortable contact lens wear. Results: At 3 months, the treatment group showed significantly greater mean change from baseline in MGS (12.4±9.1 vs 1.4±6.4, p˂0.0001), SPEED (−8.4±4.7 vs −0.7±4.4, p˂0.0001) and significantly greater improvement in exploratory variables (TBUT, LWE, and frequency of OTC drop use) relative to the controls. Mean comfortable contact lens wearing time increased by 4.0±3.9 hours at 1 month. This was sustained for 3 months with no change in the control group. The crossover treatment group demonstrated similar results to the treatment group at 1 month post-VTP. Conclusion: In SCL wearers with MGD, a single VTP treatment significantly improved mean meibomian gland function and significantly reduced dry eye signs and symptoms compared to an untreated control. The treatment increased mean comfortable lens wearing time by 4 hours (approximately doubling the pretreatment findings). This was sustained for up to 3 months post-treatment on average.

Chen,P. Z., Pollit,L., Jones,L., Gu,F. X. Functional Two- and Three-Dimensional Architectures of Immobilized Metal Nanoparticles Chem 2018;4(10):2301-2328 [ Show Abstract ]

Recent methodological advances have led to unprecedented precision in the immobilization of metal nanoparticles. These methodologies come from a broad range of disciplines and organize nanoparticle building blocks into a diverse selection of distinct architectures—from small arrays to ordered superstructures. Because properties can be dictated by assembly, architectures can present enhanced properties of the constituent nanoparticles or generate emergent properties of the collective architecture that are unavailable to their constituent nanoparticles. Functional architectures use these properties to further tailor and optimize performance in myriad applications. This review discusses the methodological advances that enable the immobilization of metal nanoparticles in distinct two- and three-dimensional architectures. Discussion will include their distinctions, properties associated with the assemblies and their applications, and the key challenges and future directions in this growing field. The integration of nanomaterials has transformed key applications in a multitude of scientific fields, such as in energy, environmental technologies, water, medicine, and chemical processing. Metal nanoparticles, the predominant type of nanomaterial, are at the center of many of these applications. Conventionally, the physical properties of metal nanoparticles, such as size and shape, are engineered to alter properties and enhance performance. Recent work has developed a new approach: immobilizing metal nanoparticles in architectures. These structures generate enhanced or emergent properties, which can be used to further improve performance in applications, and promise the next generation of applications of metal nanoparticles in science and society. This review discusses the methods (from a wide range of disciplines) that immobilize nanoparticles in precise two- and three-dimensional architectures. Also discussed are the properties that arise from and the utility of the architectures. Metal nanoparticles present enhanced, or emergent, properties when immobilized in precisely configured two- and three-dimensional architectures. Recent methodological advances in a broad range of fields enable the construction of a diverse selection of such architectures. This review discusses these methodologies, their constructed products, and the properties exhibited by the architectures. It also discusses the distinctions, sometimes subtle, between methodologies that often dictate the types of architectures that they can construct and thus the resultant properties that can be presented.

Delaveris,A., Stahl,U., Madigan,M., Jalbert,I. Comparative performance of lissamine green stains Contact Lens and Anterior Eye 2018;41(1):23-27 [ Show Abstract ]

Purpose To investigate the performance of lissamine green strips from different manufacturers. Additionally, the repeatability, need for sequential dye instillation and impact of repeated lid evertion on lid wiper staining were assessed. Methods Study 1 was a prospective, randomised cross-over study where controlled volumes of lissamine green solution prepared from strips (Biotech, Lissaver, GreenGlo, OPGreen) were instilled (right eye: single; left eye: double instillation) on five different days, with OPGreen being tested twice. Lids were everted and digital photographs taken, which were later assessed by a masked observer. Study 2 was an investigator-masked, randomised, controlled study testing the impact of single versus repeated lid evertion. Lid wiper staining was graded (0 to 3 in 0.5 steps). Results Lid wiper staining differed significantly between lissamine green solutions, with GreenGlo showing the highest amount of staining, and Lissaver the least (all p > 0.009). There were no differences in lid wiper staining over two days, using the OPGreen solution (all p > 0.05). The number of drops instilled (single versus double) did not significantly affect lid wiper staining (all p > 0.05). Repeated lid evertion increased lid wiper staining (p = 0.007 when combined with double drop instillation). Light absorbance patterns and measured concentrations aligned with clinical findings. Conclusion There were significant differences in performance between lissamine green solutions. Lid wiper staining was impacted by repeated lid evertion but sequential instillation and use of the Korb grading scale provided little advantage over simpler methods Clinicians must consider this when investigating lid wipers, especially when interpreting a negative finding. © 2017 British Contact Lens Association

Luensmann,D., Schaeffer,J. L., Rumney,N. J., Stanberry,A., Walsh,K., Jones,L. Spectacle prescriptions review to determine prevalence of ametropia and coverage of frequent replacement soft toric contact lenses Contact Lens and Anterior Eye 2018;41(5):412-420 [ Show Abstract ]

Purpose: To determine the prevalence of ametropia and astigmatism in a clinic population and to estimate the coverage of frequent replacement soft toric lenses. Methods: A review of patient files was conducted at three clinical sites. Prescription data collected between January 2014 and March 2017 in a patient cohort 14 to 70 years of age inclusive were analyzed to determine prevalence of ametropia and astigmatism. The percent coverage of frequent replacement soft toric contact lenses has further been estimated using different ranges for sphere, cylinder and axis availability. Results: In total 101,973 patients were included in the analysis of which 69.5% were considered myopic, 26.9% hyperopic and 3.5% emmetropic as determined by the eye with the larger absolute value of the spherical equivalent refraction. Astigmatism in at least one eye was found in 87.2% of the population, with 37.0% of the patients exhibiting astigmatism of at least −1.00DC in at least one eye. With-the-rule astigmatism was most prevalent in the 14 to 20 year-olds (53.0%), while against-the-rule astigmatism was most prevalent in the 41 to 70 year-olds (50.7%). For astigmatic eyes with a cylinder of at least −0.75DC (n = 83,540; 41% of all eyes), the coverage with toric soft lenses varied greatly depending on parameter availability and ranged between 30.7% (sphere: Plano to −3.00D, cylinder: up to −1.75DC, axes: 90 ± 10° and 180 ± 10°) and 96.4% (sphere: + 6.00D to −10.00D, cylinders: up to −2.75DC, 18 axes). Conclusion: Currently available frequent replacement soft toric contact lenses provide coverage for up to 96.4% of potential patients.

McCanna,D. J., Oh,S., Seo,J., Coles-Brennan,C., Fadli,Z., Subbaraman,L. N., Jones,L. W. The effect of denatured lysozyme on human corneal epithelial cells Investigative Ophthalmology and Visual Science 2018;59(5):2006-2014 [ Show Abstract ]

PURPOSE. During contact lens wear, the amount of lysozyme deposited on contact lenses varies depending on the lens material. The binding of lysozyme to some contact lens materials may result in a conformational change that denatures the protein to an inactive form. This investigation evaluated the effect that denatured lysozyme has on human corneal epithelial cells (HCECs) by measuring cell viability and the release of inflammatory cytokines. METHODS. HCECs were exposed to lysozyme that was denatured to various activity levels. After 24-hour exposure to the lysozyme (1.9 mg/mL) in growth media, the cells were evaluated for cell viability using confocal microscopy. The metabolic activity of the cells was determined using an alamarBlue assay. Cell supernatants were analyzed for inflammatory cytokines. RESULTS. Using confocal microscopy, there was no detectable change in the viability of the HCECs after exposure to the denatured lysozyme. However, using alamarBlue, a decrease in the metabolic activity of the HCECs exposed to denatured lysozyme was detected. HCECs exposed to lysozyme that was 67%, 47%, and 22% active showed a reduction in metabolic activity when compared with native (100% active) lysozyme and the media controls (P < 0.05). Exposure to the denatured lysozyme also caused an increase in the release of inflammatory cytokines (P < 0.05) from the HCECs. CONCLUSIONS. The results of this study show that denatured lysozyme can have a detrimental effect on HCECs. Both a reduction in metabolic activity and an increase in the release of inflammatory cytokines occurred after HCEC exposure to denatured lysozyme. © 2018 The Authors.

Moezzi,A., Hutchings,N., Fonn,D., Simpson,T. L. Mixed Model Analysis of Between-Subject Variability in Overnight Corneal Swelling and Deswelling With Silicone Hydrogel Lenses Invest Ophthalmol Vis Sci 2018;59(6):2576-85 [ Show Abstract ]

PURPOSE: To model between subject variability of corneal swelling (CS) and deswelling after overnight wear of silicone hydrogel (SiHy) contact lenses.

METHODS: A total of 29 neophyte subjects wore 12 SiHy lenses with central transmissibility range of 31 to 211 Dk/t units on separate nights, in random order, and on one eye only. The contralateral eye served as the control. Central corneal thickness was measured using digital optical pachymetry before lens insertion, immediately after lens removal on waking, then 20, 40 minutes, 1, 2, and 3 hours later. Mixed modelling was conducted for simultaneous analysis of group and between-subject effects of CS and deswelling.

RESULTS: The best model for overnight CS versus Dk/t was linear with a random intercept showing constant between-subject differences in CS for different Dk/t values. The best fit for corneal deswelling versus time was a curvilinear random intercept and random slope model. About 90% of the total between-subject deswelling variance in either lens or control eyes was due to the intercept variability with much less (∼10%) being due to the variability of the individual deswelling rate (slope). Subject age, sex, and ametropia were not predictors of individual corneal swelling in the swelling versus Dk/t analysis. Age, however, was a significant (inverse) predictor of the rate of corneal deswelling, only in lens-wearing eyes.

CONCLUSIONS: A large proportion of variability in corneal swelling is because of subject-specific differences in corneal response to hypoxia. This shows that "low swellers" and "high swellers" actually do exist.

Ng,A. Y., Keech,A., Jones,L. Tear osmolarity changes after use of hydroxypropyl-guar-based lubricating eye drops Clinical Ophthalmology 2018;12:695-700 [ Show Abstract ]

Purpose: To evaluate tear osmolarity after using a hydroxypropyl-guar (HP-guar)-based lubricating eye drop four times daily (QID) for 3 weeks. Methods: Thirty-one participants with dry eye disease (Ocular Surface Disease Index [OSDI] score ≥20 and tear osmolarity ≥300 mOsm/L in at least one eye) were enrolled in this prospective, dispensing, non-randomized study involving a baseline visit and 3‑week follow-up. Tear osmolarity, non-invasive tear break up time (NITBUT), conjunctival hyperemia, corneal and conjunctival staining were determined at baseline. Participants were instructed to instill one drop of a HP-guar-based drop QID in each eye for 3 weeks. At the follow-up visit, the symptoms and ocular surface parameters were reassessed. At this visit, one HP-guar drop was instilled into each eye and osmolarity was measured after 15 minutes, to examine short-term changes in osmolarity. Results: Twenty-eight participants completed the study (5M, 23F; median age 54 yrs, range 25-83 yrs). At baseline, mean OSDI score was 44.9±15.2 and mean osmolarities were 314.63±11.9/306.6±10.1 mOsm/L (worst eye [WE]/better eye [BE]). After 3 weeks, mean osmolarity reduced to 307.7±15.7/303.9±11.3 mOsm/L (WE/BE; p<0.05 and p=0.228, respectively) and mean OSDI scores reduced to 28.3±17.0 (p<0.01). A significant reduction in osmolarity was observed 15 minutes after instilling the lubricating drop (p<0.05 WE, p=0.09 BE). Significant improvements in central corneal staining (p<0.05 OU) and NITBUT (p0.05). Conclusions: A significant reduction in tear osmolarity and improvements in dry eye symptoms, corneal staining, and NITBUT were observed after 3 weeks of QID use of a HP-guar-based lubricant drop. A decrease in osmolarity was also demonstrated 15 minutes after drop instillation.

Ngo,W., Jones, L., Bitton, E. Short-Term Comfort Responses Associated With the Use of Eyelid Cleansing Products to Manage Demodex folliculorum Eye and Contact Lens 2018;44(Suppl 2):S87-S92 [ Show Abstract ]

PURPOSE: To quantify the discomfort over time of various eyelid cleansers against Demodex.
METHODS: This was a prospective, randomized, controlled, crossover, open-label study that enrolled 26 participants. The cleansers used in this study were Biotissue Cliradex (CD), OCuSOFT Lid Scrubs Plus (OP), OCuSOFT OUST Demodex Swabstix (ODS), TheraTears Theralid (TT), NovaBay Avenova (NA). Bausch+Lomb Sensitive Eyes Plus saline was used as a control. Participants were asked to close their eyes as the product was gently rubbed (10 cycles of gentle lateral motion) into the eyelashes. Participants verbally rated their discomfort (0 = no discomfort, 10 = maximum tolerable discomfort) every 15 sec for the first 5 min, and every 30 sec for 5 min after, for a total of 10 min. The order of products used was randomized, and washout period between cleansing was 48 hr.
RESULTS: Twenty-five participants completed the study (mean age=26±6). There was no significant difference in discomfort scores at pre-application. The discomfort levels of saline, OP, and NA over the 10-min period were not significantly different than their pre-application discomfort at all time points (all P≥0.99). The discomfort of CD was significantly higher than pre-application levels between t=15 sec and t=180 sec (all P≤0.01), with maximum median (interquartile range [IQR]) discomfort of 3.0 (5.0) occurring at t=45 sec. The discomfort of TT was significantly higher than pre-application levels between t=45 and t=90 (all P<0.02), with maximum median (IQR) discomfort of 1.0 (1.5) occurring at t=75 sec. The discomfort of ODS was significantly higher than pre-application levels starting from t=60 sec and onward, with maximum median (IQR) discomfort of 6.0 (5.0) occurring at t=300 sec.
CONCLUSION: Of the cleansers used in this study, the ones that induced significant discomfort were CD, TT, and ODS. The results from this study may help clinicians educate patients about what to expect when approaching the topic of eyelid Demodex treatment.

Ngo,W., Srinivasan,S., Jones, L., A comparison of dry eye diagnostic tests between symptomatic and asymptomatic age-matched females Eye and Contact Lens 2018;44(Suppl 1):S110-S114 [ Show Abstract ]

PURPOSE: To quantify the strength of association of dry eye (DE) symptoms to DE diagnostic tests in age-matched females.
METHODS: Twenty females with DE symptoms (Ocular Surface Disease Index, OSDI, ≥13) were age-matched with 20 females without DE symptoms (OSDI<13) in this cross-sectional study. Noninvasive tear breakup time (NIBUT), ocular staining, meibum quality, number of obstructed meibomian glands (MGs), lid wiper epitheliopathy, Marx line placement, eyelid margin score, Schirmer test, meibography, and visual acuity were assessed in both groups.
RESULTS: Twenty participant pairs completed the study. The age (median/interquartile range [IQR]) of the symptomatic group was 60/15 and the asymptomatic group was 62/15. The tests (median/IQR, P value) that were significantly different between the symptomatic group and the asymptomatic group were OSDI (35.4/35.4 vs. 3.1/6.7, P<0.01), NIBUT (2.1/0.7 sec vs. 3.0/3.0 sec, P=0.01), meibum quality (3.0/0.0 grade units vs. 2.0/1.0 grade units, P<0.01), number of obstructed MGs (7.0/2.0 glands vs. 5.0/4.8 glands, P<0.01), and ocular staining (5.5/3.8 grade units vs. 0.5/1.0 grade units, P<0.01). The tests (area under curve, [AUC], odds ratio [OR]) that were most strongly associated with DE symptoms were ocular staining (0.93, 5.0), number of obstructed MGs (0.79, 2.6), meibum quality (0.76, 2.4), and NIBUT (0.74, 3.2) (all P0.05), and similarly, no significant association to DE symptoms (all P>0.05).
CONCLUSION: The diagnostic tests most strongly associated with DE symptoms in older women were ocular staining, meibum quality, number of obstructed MGs, and tear film stability.

Oh,S., McCanna,D., Subbaraman,L.N., Jones,L. Cytotoxic and inflammatory effects of contact lens solutions on human corneal epithelial cells in vitro Contact Lens and Anterior Eye 2018;41(3):282-289 [ Show Abstract ]

Purpose: To ascertain the effect that four contact lens (CL) multipurpose solutions (MPS) have on the viability and release of pro-inflammatory cytokines from human corneal epithelial cells (HCEC). Methods: HCEC were exposed to four different MPS at various concentrations for 18 hours. The cells were also exposed to phosphate buffer, borate buffer, and PHMB. The cell viability was evaluated using the alamarBlue assay. The release of pro-inflammatory cytokines was measured using a Multiplex electrochemiluminescent assay. Results: MPS-A, MPS-B and MPS-C all reduced cell metabolic activity p < 0.05 from control with MPS-A showing the greatest cytotoxic effect (maximum reduction, 90.6%). In contrast, MPS-D showed no significant reductions in cytotoxicity except at the highest concentration tested (19% reduction at 20% MPS concentration). Of the four cytokines evaluated MPS-C showed a substantial increase in the release of IL-1β, IL-6, IL-8, and TNF-α at higher concentrations when compared to control p < 0.05. At the 20% concentration of MPS-A and MPS-B the release of IL-1 β increased p 0.05. Exposing the cells to borate buffer and PHMB caused an increase in the release of TNF-α p < 0.05. Conclusions: This investigation demonstrates that at different concentration levels, several of the MPS tested showed a decrease in viability and an increase in the release of inflammatory cytokines from HCEC. The borate buffer component as well as PHMB appears to contribute to this pro-inflammatory reaction.

Omali,N.B., Subbaraman,L.N., Heynen,M., Ng,A., Coles-Brennan,C., Fadli,Z., Jones,L. Surface versus bulk activity of lysozyme deposited on hydrogel contact lens materials in vitro Contact Lens and Anterior Eye 2018;41(4):329-334 [ Show Abstract ]

Purpose: To determine and compare the levels of surface versus bulk active lysozyme deposited on several commercially available hydrogel contact lens materials. Methods: Hydrogel contact lens materials [polymacon, omafilcon A, nelfilcon A, nesofilcon A, ocufilcon and etafilcon A with polyvinylpyrrolidone (PVP)] were incubated in an artificial tear solution for 16 h. Total activity was determined using a standard turbidity assay. The surface activity of the deposited lysozyme was determined using a modified turbidity assay. The amount of active lysozyme present within the bulk of the lens material was calculated by determining the difference between the total and surface active lysozyme. Results: The etafilcon A materials showed the highest amount of total lysozyme activity (519 ± 8 μg/lens, average of Moist and Define), followed by the ocufilcon material (200 ± 5 μg/lens) and these two were significantly different from each other (p < 0.05). The amount of surface active lysozyme on etafilcon and ocufilcon lens materials was significantly higher than that found on all other lenses (p < 0.05). There was no active lysozyme quantified in the bulk of the nelfilcon material, as all of the active lysozyme was found on the surface (1.7 ± 0.3 μg/lens). In contrast, no active lysozyme was quantified on the surface of polymacon, with all of the active lysozyme found in the bulk of the lens material (0.6 ± 0.6 μg/lens). Conclusions: The surface and bulk activity of lysozyme deposited on contact lenses is material dependent. Lysozyme deposited on ionic, high water content lens materials such as etafilcon A show significantly higher surface and bulk activity than many other hydrogel lens materials.

Otchere,H., Jones,L., Sorbara,L. The Impact of Scleral Contact Lens Vault on Visual Acuity and Comfort. Eye and Contact Lens 2018;44(Suppl 2):S54-S59 [ Show Abstract ]

PURPOSE: To assess how varying degrees of corneal clearance of scleral contact lenses (ScCL) impact visual acuity (VA) and comfort in patients with corneal ectasia.
METHOD: Three ScCL were fitted to 20 subjects with previous diagnosis of either keratoconus (n=18) or pellucid marginal degeneration (n=2). Fitting of ScCL was based on corneal sagittal height (CSH) measured with Visante OCT at a 15-mm chord on the horizontal meridian. To select the ScCL from the diagnostic lens set, values of 325, 375, and 425 μm were randomly added in sequence to CSH. Subjects wore ScCL for 1 hr. Central corneal clearance (CCC) and topographic corneal clearance (TCC) along the vertical meridian were assessed using an ultralong optical coherence tomographer. High-contrast VA (HCVA) and low-contrast VA (LCVA) were measured using a logarithm of the minimum angle of resolution VA chart, and comfort ratings were obtained with a standard comfort scale (0-100).
RESULTS: Mean CSH in the horizontal meridian was 3.78±0.53 (range: 3.33-4.17) mm at a 15-mm chord. Mean CCC was 190±100 μm (TCC: 160±94 μm at +3 mm and 180±94 μm at -3 mm), 360±120 μm (TCC: 260±100 μm at +3 mm and 330±110 μm at -3 mm), and 450±170 μm (TCC: 320±120 μm at +3 mm and 400±120 μm at -3 mm) for each lens (P=0.001). Mean HCVA for lenses 1, 2, and 3 were 0.05±0.12, 0.07±0.11, and 0.11±0.08 respectively, which were significantly different (P=0.02). Tukey post hoc analysis showed that this difference was only significant between lenses 1 and 3 (P=0.01). Similar findings were found for LCVA. Comfort ratings for lenses 1, 2, and 3 were 74.9±9.2, 79.7±11.6, and 78.6±10.8, respectively (P=0.24).
CONCLUSION: The CSH is an effective method of determining the appropriate lens/cornea relationship. Lens 2 (+375 μm) gave the best combination of acuity and comfort ratings. Evaluation of the fluorescein pattern must be balanced with VA and comfort ratings for successful fitting in a clinical setting.

Phan,C. -M, Walther,H., Smith,R. W., Riederer,D., Lau,C., Lorenz,K. O., Subbaraman,L. N., Jones L. Determination of the release of PEG and HPMC from nelfilcon A daily disposable contact lenses using a novel in vitro eye model. J Biomater Sci Polym Ed 2018;29(17):2124-2136 [ Show Abstract ]

The traditional method to measure release of components from CLs is a vial containing a static volume of PBS (phosphate buffered saline). However, this model does not simulate physiologically relevant tear volume and natural tear flow, air exposure, and mechanical rubbing. These factors can significantly impact release kinetics. We have developed an in vitro eye model (OcuFlow) that simulates these parameters. The aim of the study was to measure the release of PEG (polyethylene glycol), and HPMC (hydroxypropyl methylcellulose) from a daily disposable hydrogel contact lens material (nelfilcon A; Dailies AquaComfort PLUS; DACP;) over 24 hrs using the OcuFlow platform. The elution of PEG and HPMC from DACP lenses was analyzed using LCMS (liquid chromatography mass spectrometry). The release of all wetting agents from the lenses followed a burst release pattern, which occurred within the first 1.5 hrs (P < 0.05). The release of PEG was greater than that of HPMC (P < 0.05). The amount of PEG and HPMC released at any given time was less than 1% of the amount in the blister pack solution. Our results suggest that HPMC and PEG are rapidly released from the CL.

Phan,C. -M, Weber,S., Mueller,J., Yee,A., Jones,L. A rapid extraction method to quantify drug uptake in contact lenses Translational Vision Science and Technology 2018;7(2):11 [ Show Abstract ]

Purpose: To develop a simple extraction procedure to quantify the uptake of four topical ocular pharmaceutical drugs into contact lenses (CLs). Methods: Four silicone hydrogel (SH) CLs (balafilcon A, senofilcon A, lotrafilcon B, comfilcon B) and four conventional hydrogel (CH) CLs (nesofilcon A, hilafilcon B, nelfilcon A, etafilcon A) were evaluated. The drugs studied were natamycin, moxifloxacin, timolol maleate, and ketotifen fumarate. For drug incubation, three CLs of each type were placed in 1 mL of 1 mg/mL drug-loading solution for 24 hours. The lenses were then extracted in 2 mL methanol for 2 hours. This process was repeated to obtain a total of three extraction cycles. Detection of natamycin, moxifloxacin, ketotifen fumarate, and timolol maleate were measured by absorbance at 305, 287, 297, and 295 nm, respectively. Results: The majority of the drugs were extracted after the first extraction cycle (P 0.05). Conclusions: This study provides a simple approach to determine drug uptake into CLs. This method can also be modified, such as changing the extraction time, extraction cycles, or extraction solvent to better suit other drugs and CL combinations. Translational Relevance: There is considerable interest in using CLs for ocular drug delivery. Accurately quantifying drug uptake on CLs has been a challenge. Hence, this study provides a simple method to quantify drug uptake in CLs. © 2018 The Authors.

Qiao,H., Phan,C. -M., Walther,H., Subbaraman,L. N., Jones,L. Depth Profile Assessment of the Early Phase Deposition of Lysozyme on Soft Contact Lens Materials Using a Novel In Vitro Eye Model 2018;44(Suppl 2):S11-S18 [ Show Abstract ]

OBJECTIVE: To characterize the location of fluorescently labeled lysozyme on commercial contact lenses (CLs) using an in vitro eye model that simulates tear volume, tear flow, air exposure, and mechanical wear.
METHODS: One commercially available conventional hydrogel CL material (etafilcon A) and three silicone hydrogel CL materials (balafilcon A, lotrafilcon B, and senofilcon A) were evaluated in this study. The CLs were mounted on the in vitro eye model and exposed to artificial tear fluid containing fluorescein isothiocyanate (FITC)-labeled lysozyme for 2 and 10 hrs. After these short incubation periods, circular discs were punched from the CLs at the center and periphery and were prepared for confocal laser scanning microscopy (CLSM). The CLSM captured a series of consecutive images spaced 5 μm apart, and the resulting images were rendered into two dimensional cross-sectional views of the CL. The mean fluorescence at each 5 μm slice was used to generate a histogram depicting the penetration of FITC-lysozyme into CLs.
RESULTS: For both incubation periods, the CLSM images and histogram of etafilcon A showed that FITC-lysozyme is more concentrated at the lens surface, with a moderate amount of deposition in the lens matrix. For balafilcon A, FITC-lysozyme was evenly distributed throughout the lens. For lotrafilcon B, there was a greater amount of FITC-lysozyme deposition on the surfaces of the lens versus the matrix. Senofilcon A had differential FITC-lysozyme distribution profiles depending on the location of the lens. At the lens periphery, FITC-lysozyme primarily deposited on the surface, whereas FITC-lysozyme was uniformly distributed at the center of the lens.
CONCLUSIONS: With the use of a sophisticated in vitro eye model, the study revealed a complex deposition pattern of FITC-labeled lysozyme on various CL materials after short periods of exposure. An understanding of the early deposition pattern of lysozyme on different CL material may elucidate new insights into the processes behind CL discomfort.

Stahl,U., Jalbert,I. Exploring the links between contact lens comfort, osmolarity and lid wiper staining Contact Lens and Anterior Eye 2018;41(1):110-116 [ Show Abstract ]

Purpose Contact lens discomfort remains poorly understood, not least due to lack of associations between clinical signs and symptoms. This study aimed to explore the relationships between osmolarity, comfort and lid wiper epitheliopathy in contact lens wear. Methods Twenty subjects participated in a randomized, cross-over study where comfilcon A and lotrafilcon A lenses were each worn for 10 days separated by a 7 days washout period. Tear and contact lens osmolarity, ocular symptoms including comfort, tear stability and production, and lid wiper epitheliopathy were measured. Results Comfort and tear stability decreased and upper lid wiper staining and foreign body sensation increased with lens wear. These were not affected by lens type. A reduction in tear production was seen after 10 days of comfilcon A lens wear. High proportions of lid wiper epitheliopathy were observed at the upper (range 65%–85%) and lower (range 90%–100%) lid margins. Tear and contact lens osmolarity were unaffected by lens wear or type. Contact lens osmolarity was associated with comfort (r = 0.45, p = 0.009). Tear osmolarity moderately correlated with tear stability (r = -0.53, p = 0.014) and tear production (r = -0.44, p = 0.012) but not with lid wiper staining. Conclusions A relationship between comfort and contact lens osmolarity and between tear osmolarity and tear stability and production were found, however, this study was unable to demonstrate an association between comfort and tear osmolarity or lid wiper epitheliopathy. Further studies using contact lenses with a wider range of comfort responses are warranted to investigate these associations further. © 2017 British Contact Lens Association

Wallerstein,A., Jackson,W.B., Chambers,J., Moezzi,A., Lin,H., Simmons,P.A Management of post-LASIK dry eye: a multicenter randomized comparison of a new multi-ingredient artificial tear to carboxymethylcellulose Clinical Ophthalmology 2018;12:839-848 [ Show Abstract ]

Purpose: To compare the efficacy and safety of a preservative-free, multi-ingredient formulation of carboxymethylcellulose 0.5%, hyaluronic acid 0.1%, and organic osmolytes (CMC-HA), to preservative-free carboxymethylcellulose 0.5% (CMC) in the management of postoperative signs and symptoms of dry eye following laser-assisted in situ keratomileusis (LASIK).
Methods: This was a double-masked, randomized, parallel-group study conducted in 14 clinical centers in Canada and Australia. Subjects with no more than mild dry eye instilled CMC-HA or CMC for 90 days post-LASIK. Ocular Surface Disease Index© (OSDI; primary efficacy measure), corneal staining, tear break-up time (TBUT), Schirmer’s test, acceptability/tolerability surveys, and visual acuity were assessed at screening and days 2, 10, 30, 60, and 90 post-surgery. Safety analyses included all enrolled.
Results: A total of 148 subjects (CMC-HA, n=75; CMC, n=73) were enrolled and assigned to receive treatment, and 126 subjects completed the study without any protocol violations. Post-LASIK, dry eye signs/symptoms peaked at 10 days. OSDI scores for both groups returned to normal with no differences between treatment groups at day 90 (P=0.775). Corneal staining, Schirmer’s test, TBUT, and survey results were comparable. Higher mean improvements in uncorrected visual acuity were observed in the CMC-HA group at all study visits, reaching statistical significance at day 30 (P=0.013). Both treatments were well tolerated.
Conclusion: CMC-HA-containing artificial tears relieved post-LASIK ocular dryness as well as CMC alone, and demonstrated incremental benefit in uncorrected vision, with a favorable safety profile. Results support use of CMC-HA eye drops to reduce signs and symptoms of ocular dryness post-LASIK.

Walther,H., Phan,C. -M., Subbaraman,L. N., Jones,L. Differential deposition of fluorescently tagged cholesterol on commercial contact lenses using a novel in vitro eye model Translational Vision Science and Technology 2018;7(2):18 [ Show Abstract ]

Purpose: We evaluate the differences in lipid uptake and penetration in daily disposable (DD) contact lenses (CL) using a conventional “in-vial” method compared to a novel in vitro eye model. Methods: The penetration of fluorescently labelled 22-(N-(7-Nitrobenz-2-Oxa-1,3- Diazol-4-yl)Amino)-23,24-Bisnor-5-Cholen-3beta-Ol (NBD)–cholesterol on three silicone hydrogel (SH) and four conventional hydrogel (CH) DD CLs were investigated. CLs were incubated for 4 and 12 hours in a vial, containing 3.5 mL artificial tear solution (ATS), or were mounted on an in vitro eye-blink platform designed to simulate physiologic tear flow (2 mL/24 hours), tear volume and “simulated” blinking. Subsequently, CLs were analyzed using laser scanning confocal microscopy and ImageJ. Results: Penetration depth and fluorescence intensities of NBD-cholesterol varied between the incubation methods as well as lens materials. Using the traditional vial incubation method, NBD-cholesterol uptake occurred equally on both sides of all lens materials. However, using our eye-blink model, cholesterol penetration was observed primarily on the anterior surface of the CLs. In general, SH lenses showed higher intensities of NBD-cholesterol than CH materials. Conclusions: The traditional “in-vial” incubation method exposes the CLs to an excessively high amount of ATS, which results in an overestimation for cholesterol deposition. Our model, which incorporates important ocular factors, such as intermittent air exposure, small tear volume, and physiological tear flow between blinks, provides a more natural environment for in vitro lens incubation. Translational Relevance: In vitro measurements of CLs are a common approach to predict their interactions and performance on the eye. Traditional methods, however, are rudimentary. Therefore, this study presents a novel in vitro model to evaluate CLs, which consequently will enhance elucidations of the interactions between CLs and the eye.

Wong,S., Murphy,P.J., Jones,L. Tear evaporation rates: What does the literature tell us? Contact Lens and Anterior Eye 2018;41(3):297-306 [ Show Abstract ]

Purpose: A previous literature review reported tear evaporation rates (TERs) from studies conducted on rabbits and humans between 1941 and 2003. Closer examination of the presented data revealed inaccuracies in the reporting of some values. This paper presents updated tables of TERs using values from the original papers cited in the review, in addition to incorporating new studies published between 2003 and 2016. Methods: A copy of each paper cited in the literature review was obtained and checked against the evaporation rate reported in the review. If the expected value could not be found in the cited paper, other papers by the same author were consulted to see if the value had been reported elsewhere. A PubMed and Scopus database search was conducted to find papers published on tear evaporimetry since 2003. Results: Two new tables of TERs were created, based on the values reported by the original author. To aid in interpretation, the majority of results are expressed in units of x 10−7 g/cm2/sec. Where it was not possible to convert these values, some values are expressed as x 10−7 g/sec, x 10−7 g/sec/eye or W/min. Conclusions: Two new tables of TERs have been compiled to provide an accurate representation of the values reported in the original papers. These tables can be used as a point of reference for other researchers to compare their results.

Woods,J., Varikooty,J., Fonn,D., Jones,L. A novel scale for describing corneal staining Clinical Ophthalmology 2018;12:2369-2375 [ Show Abstract ]

The assessment of corneal staining is a commonly conducted procedure in both clinical practice and as part of various research studies. Different grading scales are employed by many clinicians and researchers to undertake this procedure for corneal staining comparisons between eyes, products and over time. This paper describes the development and use of a grading scale for corneal staining undertaken at an academic research site. The scale involves assessment of three factors across five corneal zones: type, area and depth. Staining type and area are graded on a 0–100 scale, and depth is graded on a 0–4 scale. These factors can be combined to create a three- or two-factor staining grade, or the factors may be reported individually. An additional benefit of this scale is that the staining scores may be reported by zone as “zone staining scores” or the scores of zones may be combined to provide an overall corneal “global staining score”.

Yang,M., Luensmann,D., Fonn,D., Woods,J., Jones,D., Gordon,K., Jones,L. Myopia prevalence in Canadian school children: A pilot study Eye 2018;32(6):1042-1047 [ Show Abstract ]

Purpose: A pilot study to determine the prevalence of myopia, proportion of uncorrected myopia and pertinent environmental factors among children in a suburban region in Canada. Methods: Refraction with cycloplegia and ocular biometry were measured in children of two age groups. Myopia was considered at a spherical equivalent refraction (SER) ≤-0.50 D in at least one eye. Parents completed a questionnaire that captured the child's daily activities. Results: A total of 166 children completed the study (83 aged 6-8 and 83 aged 11-13). Myopia prevalence was 17.5% among the overall group, 6.0% among ages 6-8 and 28.9% among ages 11-13. Mean subjective SER in myopic children was -1.10 D (95% confidence interval (CI), -0.34 to -1.86 D) at ages 6-8 and -2.44 D (95% CI, -1.71 to -3.18 D) at ages 11-13. In this study, 34.5% of the myopic children were uncorrected, which represented 6.0% of the entire group of children. Mean axial length (AL) increased by 1.03 mm from ages 6-8 (mean 22.62 mm; 95% CI, 22.45 to 22.79 mm) to ages 11-13 (mean 23.65 mm; 95% CI, 23.45 to 23.84 mm; p < 0.01). The correlation coefficient between AL and SER was -0.618 (p < 0.01). Binary logistic regression between outdoor time and the prevalence of myopia showed that one additional hour of outdoor time per week lowered the odds of a child having myopia by 14.3% (p = 0.007). Conclusion: Myopia prevalence increased from 6% at ages 6-8 to 29% at ages 11-13. Thirty-five per cent of the myopes in this study were uncorrected. More time outdoors may be beneficial to protect against myopia onset.

2017

Craig,J. P., Nelson,J. D., Azar,D. T., Belmonte,C., Bron,A. J., Chauhan,S. K., de Paiva,C. S., Gomes,J. A. P., Hammitt,K. M., Jones,L., Nichols,J. J., Nichols,K. K., Novack,G. D., Stapleton,F. J., Willcox,M. D. P., Wolffsohn,J. S., Sullivan,D. A. TFOS DEWS II Report Executive Summary Ocular Surface 2017;15(4):802-812 [ Show Abstract ]

This article presents an Executive Summary of the conclusions and recommendations of the 10-chapter TFOS DEWS II report. The entire TFOS DEWS II report was published in the July 2017 issue of The Ocular Surface. A downloadable version of the document and additional material, including videos of diagnostic and management techniques, are available on the TFOS website: www.TearFilm.org.

Craig,J. P., Nelson,J. D., Azar,D. T., Belmonte,C., Bron,A. J., Chauhan,S. K., de Paiva,C. S., Gomes,J. A. P., Hammitt,K. M., Jones,L., Nichols,J. J., Nichols,K. K., Novack,G. D., Stapleton,F. J., Willcox,M. D. P., Wolffsohn,J. S., Sullivan,D. A. TFOS DEWS II Report Executive Summary Ocular Surface 2017;15(4):802-812 [ Show Abstract ]

This article presents an Executive Summary of the conclusions and recommendations of the 10-chapter TFOS DEWS II report. The entire TFOS DEWS II report was published in the July 2017 issue of The Ocular Surface. A downloadable version of the document and additional material, including videos of diagnostic and management techniques, are available on the TFOS website: www.TearFilm.org.

Hall,B., Forrest,J. A., Jones,L. A Review of Techniques to Measure Protein Sorption to Soft Contact Lenses Eye and Contact Lens 2017;43(5):276-286 [ Show Abstract ]

Purpose: To compare and critically evaluate a variety of techniques to measure the quantity and biological activity of protein sorption to contact lenses over short time periods. Methods: A literature review was undertaken investigating the major techniques to measure protein sorption to soft contact lens materials, with specific reference to measuring protein directly on lenses using in situ, ex situ, protein structural, and biological activity techniques. Results: The use of in situ techniques to measure protein quantity provides excellent sensitivity, but many are not directly applicable to contact lenses. Many ex situ techniques struggle to measure all sorbed proteins, and these measurements can have significant signal interference from the lens materials themselves. Techniques measuring the secondary and tertiary structures of sorbed proteins have exhibited only limited success. Conclusions: There are a wide variety of techniques to measure both the amount of protein and the biological activity of protein sorbed to soft contact lens materials. To measure the mass of protein sorbed to soft contact lenses (not just thin films) over short time periods, the method of choice should be I 125 radiolabeling. This technique is sensitive enough to measure small amounts of deposited protein, provided steps are taken to limit and measure any interaction of the iodine tracer with the materials. To measure the protein activity over short time periods, the method of choice should be to measure the biological function of sorbed proteins. This may require new methods or adaptations of existing ones. © 2017 Contact Lens Association of Ophthalmologists.

Heynen,M., Babaei Omali,N., Fadli,Z., Coles-Brennan,C., Subbaraman,L. N., Jones,L. Selectivity and localization of lysozyme uptake in contemporary hydrogel contact lens materials Journal of Biomaterials Science, Polymer Edition 2017;28(13):1351-1364 [ Show Abstract ]

The purpose of this study was to investigate the early and selective uptake of lysozyme and the location of deposited lysozyme on contemporary hydrogel contact lens (CL) materials after exposure to an artificial tear solution (ATS) for 16 h. Seven different hydrogel CL materials [polymacon, omafilcon A, nelfilcon A, nesofilcon A, ocufilcon B, etafilcon A (Acuvue Moist), and etafilcon A (Acuvue Define)] were incubated in an ATS for various times. Total protein deposition was determined using a modified Bradford technique. Lysozyme, lactoferrin, and albumin deposition on CLs were determined using 125I-radiolabeling method. A confocal laser scanning microscopy (CLSM) technique was utilized to map the location of lysozyme uptake in an asymmetric environment. All lens materials had significant amounts of lysozyme after 1 min of exposure to ATS. After 16 h of incubation, higher levels of total protein deposited on the two etafilcon A-based lenses (Moist and Define), followed by ocufilcon B and both were significantly higher than all other CLs tested (p = 0.0001). The two etafilcon A materials (Moist and Define) also deposited the highest amounts of lysozyme (514.8 ± 28.4 and 527.1 ± 14.7 µg/lens respectively) when compared to other test CLs (p = 0.0001). The CLSM technique revealed that the non-ionic CLs tended to have symmetric distribution of lysozyme throughout the lens materials, while the ionic CLs had an asymmetric distribution, with the highest concentration of lysozyme on and near the exposed surface. The quantity and nature of proteins deposited on CLs varies, depending upon the chemical composition of the material. Among the various lenses tested, etafilcon A deposited the highest amount of total protein, most of it represented by lysozyme, which was largely located near the surface of the lens. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

Hui,A., Bajgrowicz-Cieslak,M., Phan,C. -M, Jones,L. In vitro release of two anti-muscarinic drugs from soft contact lenses Clinical Ophthalmology 2017;11:1657-1665 [ Show Abstract ]

The purpose of this study was to investigate the release of the anti-myopia drugs atropine sulfate and pirenzepine dihydrochloride from commercially available soft contact lenses. Standard ultraviolet (UV) absorbance-concentration curves were generated for atropine and pirenzepine. Ten commercially available contact lenses, including four multifocal lenses, were loaded by soaking in atropine or pirenzepine solutions at two different concentrations (10 mg/mL and 1 mg/mL). The release of the drugs into phosphate-buffered saline was determined over the course of 24hours at 34°C using UV absorbance. Materials with surface charge released the greatest amount of atropine when loaded with either concentration when compared to the other lens types (p<0.05), releasing upward of 1.026±0.035mg/lens and 0.979±0.024mg/lens from etafilcon A and ocufilcon A, respectively. There were no significant differences in the amount of atropine or pirenzepine released from the multifocal and non-multifocal lenses made from the same lens materials. Narafilcon A material demonstrated prolonged release of up to 8 hours when loaded with pirenzepine, although the overall dose delivered from the lens into the solution was among the lowest of the materials investigated. The rest of the lenses reached a plateau within 2 hours of release, suggesting that they were unable to sustain drug release into the solution for long periods of time. Given that no single method of myopia control has yet shown itself to be completely effective in preventing myopia progression, a combination of optical and pharmaceutical devices comprising a drug delivering contact lens presents a novel solution that warrants further investigation. © 2017 Hui et al.

Jones,L., Downie,L. E., Korb,D., Benitez-del-Castillo,J. M., Dana,R., Deng,S. X., Dong,P. N., Geerling,G., Hida,R. Y., Liu,Y., Seo,K. Y., Tauber,J., Wakamatsu,T. H., Xu,J., Wolffsohn,J. S., Craig,J. P. TFOS DEWS II Management and Therapy Report Ocular Surface 2017;15(3):575-628 [ Show Abstract ]

The members of the Management and Therapy Subcommittee undertook an evidence-based review of current dry eye therapies and management options. Management options reviewed in detail included treatments for tear insufficiency and lid abnormalities, as well as anti-inflammatory medications, surgical approaches, dietary modifications, environmental considerations and complementary therapies. Following this extensive review it became clear that many of the treatments available for the management of dry eye disease lack the necessary Level 1 evidence to support their recommendation, often due to a lack of appropriate masking, randomization or controls and in some cases due to issues with selection bias or inadequate sample size. Reflecting on all available evidence, a staged management algorithm was derived that presents a step-wise approach to implementing the various management and therapeutic options according to disease severity. While this exercise indicated that differentiating between aqueous-deficient and evaporative dry eye disease was critical in selecting the most appropriate management strategy, it also highlighted challenges, based on the limited evidence currently available, in predicting relative benefits of specific management options, in managing the two dry eye disease subtypes. Further evidence is required to support the introduction, and continued use, of many of the treatment options currently available to manage dry eye disease, as well as to inform appropriate treatment starting points and understand treatment specificity in relation to dry eye disease subtype.

Nelson,J. D., Craig,J. P., Akpek,E. K., Azar,D. T., Belmonte,C., Bron,A. J., Clayton,J. A., Dogru,M., Dua,H. S., Foulks,G. N., Gomes,J. A. P., Hammitt,K. M., Holopainen,J., Jones,L., Joo,C. -K, Liu,Z., Nichols,J. J., Nichols,K. K., Novack,G. D., Sangwan,V., Stapleton,F., Tomlinson,A., Tsubota,K., Willcox,M. D. P., Wolffsohn,J. S., Sullivan,D. A. TFOS DEWS II Introduction Ocular Surface 2017;15(3):269-275

Ngo,W., Srinivasan,S., Houtman,D., Jones,L. The relief of dry eye signs and symptoms using a combination of lubricants, lid hygiene and ocular nutraceuticals Journal of Optometry 2017;10(1):26-33 [ Show Abstract ]

Purpose To determine the combined effect of TheraTears® Lubricant Eye Drops, TheraTears® SteriLid Eyelid Cleanser, and TheraTears® Nutrition on dry eye signs and symptoms. Methods This prospective study enrolled 28 dry eye participants. Participants were instructed to use the Lubricant Eye Drops at least 2–4× a day, SteriLid 1–2× a day, and Nutrition 3 gel caps once a day. Participants were followed up at baseline, 1 month and 3 months. Outcome variables were the Ocular Surface Disease Index (OSDI), Symptom Assessment iN Dry Eye (SANDE) questionnaire, non-invasive tear break-up time (NIBUT), osmolarity, number of meibomian glands blocked (#MG blocked), meibum quality, eyelid margin features, Schirmer's test, tear film lipid layer thickness (LLT), meniscus height, corneal and conjunctival staining. Results Twenty participants (mean age = 43, from 23 to 66, 17F, 3M) completed the study. Participants reported having used, on average, the Lubricant Eye Drop 2.4×/day, the SteriLid 1.1×/day, and the Nutrition 3 gel caps 1×/day. There was a significant change over time (p < 0.05) for OSDI (-21.2 points), SANDE (-32.4 points), NIBUT (+0.43 s), eyelid margin features (-1.1 grade), meibum quality (-1.0 grade), and #MG blocked (-4.0 glands). Conclusion By using a combination of TheraTears® Lubricant Eye Drop, SteriLid, and Nutrition, patients experience significant relief in both dry eye symptoms and signs. © 2016 Spanish General Council of Optometry

Ngo,W., Srinivasan,S., Keech,A., Keir,N., Jones,L. Self versus examiner administration of the Ocular Surface Disease Index© Journal of Optometry 2017;10(1):34-42 [ Show Abstract ]

Purpose To compare the difference in Ocular Surface Disease Index© (OSDI) scores when participants were given the OSDI to complete on their own (self-guided, SG), versus under the guidance of the examiner (examiner-guided, EG). Methods 100 participants enrolled in this prospective two-visit study (fifty under-45 years old, 38F/12M; and fifty 45 years-and-older, 42F/8M). Participants who scored =1 on the Subjective Evaluation of Symptoms of Dryness (SESoD) were included in this study. Participants completed the OSDI SG during the first visit. Participants returned the next day and repeated the OSDI, but with EG (with standardized instructions). Participants were under deception and believed that they were comparing the OSDI to the SESoD. Results The mean OSDI score of the SG and EG administration was 32.0 ± 17.3 and 33.8 ± 19.6 respectively (p > 0.05) with 95% limits of agreement between -20.6 and +24.2. The correlation between SG and EG administration was Spearman's r = 0.81, p 0.05) for both the under-45 group, and 45-and-older group. The 95% limits of agreement for the under-45 group were smaller than the 45-and-older group (under-45: [-15.5, +13.1,], 45-and-older: [-23.3, +32.2]). A significant difference was found between 8 of the 12 questions items (all p = 0.01). However, the mean difference for each was <0.6 and was not considered to be clinically significant. Conclusion There was no clinically significant difference in OSDI score between SG and EG administration, however having instructions provided with EG administration affected variability of scores in the older group more than the younger group. © 2016 Spanish General Council of Optometry

Omali,N. B., Lada,M., Lakkis,C., Morgan,P. B., Nichols,J. J., Subbaraman,L. N., Jones,L. W. Lipid Deposition on Contact Lenses when Using Contemporary Care Solutions Optometry and Vision Science 2017;94(9):919-927 [ Show Abstract ]

SIGNIFICANCE There remains only a small amount of data from human studies demonstrating the effect of contact lens/lens care solution combinations on the deposition of lipids. Therefore, information on the degree to which modern materials deposit lipids when used with contemporary care solutions would be valuable. PURPOSE The present study aims to determine the effect of lens care system combinations on levels of total lipid, cholesterol, and cholesteryl esters extracted from three different contact lenses (CLs) when used with four contemporary care systems. METHODS Experienced CL wearers were recruited to participate in this study. Combinations of three CLs (etafilcon A [ETA], galyfilcon A [GALY], and senofilcon A [SENO]) and four CL care solutions (Biotrue, ClearCare, OPTI-FREE PureMoist, and RevitaLens Ocutec) were investigated. A total of 791 CLs were analyzed. Subjects were randomized to one lens type and then used all four lens care solutions in random sequence for 10-14 days before the CLs were collected and analyzed for the amount of cholesterol, cholesteryl esters, and total lipids. RESULTS The mean range of cholesterol recovered across the different care solutions was 0.34-2.77 µg/lens, 3.48-4.29 µg/lens, and 4.75-6.20 µg/lens for ETA, SENO, and GALY lenses, respectively. Use of OPTI-FREE PureMoist with ETA lenses led to a significantly greater amount of cholesterol being recovered when compared to the use of the other solutions with ETA lenses (P .05). CONCLUSIONS This study did not demonstrate conclusively that any of the solution/CL combinations were superior to any of the other combinations when the amounts of lipid deposition were compared among the tested lenses. © Lippincott Williams & Wilkins.

Omali,N. B., Subbaraman,L. N., Heynen,M., Fadli,Z., Coles-Brennan,C., Jones,L. W. In Vitro Effect of Lysozyme on Albumin Deposition to Hydrogel Contact Lens Materials Optometry and Vision Science 2017;94(11):1047-1051 [ Show Abstract ]

SIGNIFICANCE: Albumin deposition on contact lenses could be detrimental to contact lens (CL) wear because this may increase the risk of bacterial binding and reduce comfort. Lysozyme deposition on selected lens materials would reduce albumin deposition on lenses. PURPOSE: This study aims to determine if lysozyme deposition on CLs could act as a barrier against subsequent albumin adsorption, using an in vitro model. METHODS: Six hydrogel CL materials (etafilcon A, polymacon, nelfilcon A, omafilcon A, ocufilcon B, and nesofilcon A) were evaluated. Four CLs of each type were soaked in lysozyme solution for 16 hours at 37°C. Lysozyme-coated lenses were then placed in vials with 1.5 mL of artificial tear solution containing 125I-labeled albumin for 16 hours at 37°C with shaking. Four uncoated lenses of each type were used as controls. Lenses soaked in radiolabeled albumin were rinsed in a phosphate-buffered saline solution, and radioactive counts were measured directly on lenses using a gamma counter. Albumin uptake on lenses was measured using a calibration curve by plotting radioactive counts versus protein concentration. RESULTS: Results are reported as mean ± SD. Lysozyme-coated etafilcon A lenses exhibited lower levels of deposited albumin than uncoated etafilcon A lenses (58 ± 12 vs. 84 ± 5 ng/lens; P .05). Uncoated nesofilcon A lenses deposited the highest amount of albumin when compared with other uncoated lenses (P <.05). CONCLUSIONS: This study demonstrates that lysozyme deposited onto etafilcon A resists the deposition of albumin, which may potentially be beneficial to CL wearers. Copyright © 2017 American Academy of Optometry.

Otchere,H., Jones,L. W., Sorbara,L. Effect of Time on Scleral Lens Settling and Change in Corneal Clearance Optometry and Vision Science 2017;94(9):908-913 [ Show Abstract ]

SIGNIFICANCE With the increase in the use of scleral contact lenses among practitioners, questions regarding lens settling are gradually gaining attention. This is because current studies support the notion that scleral lenses settle back over time. More research is needed to understand the exact cause and the factors that underpin such phenomenon. PURPOSE The present study aims to assess the effect of time on topographic corneal clearance of three scleral contact lenses of varying sagittal depths. METHODS Three scleral contact lenses were fitted to 20 subjects with previous diagnosis of keratoconus (n = 18) or pellucid marginal degeneration (n = 2). The fit was based on corneal sagittal height measured with the Visante optical coherence tomographer (OCT) at 15 mm along the horizontal meridian. To select an appropriate lens from the diagnostic lens set, values of 325 μm (lens 1), 375 μm (lens 2), and 425 μm (lens 3) were randomly added in sequence to the corneal sagittal height. Subjects wore each lens for 1 hour. Corneal clearance was measured at 10-minute intervals for 1 hour using a custom ultra-long OCT. To assess change in clearance, central point and two mid-peripheral points (+3 mm and -3 mm) along an 8-mm chord were measured by taking differences at each time point up to 1 hour. Measurements were repeated for the two other lenses. RESULTS Mean central corneal clearance loss for all three lenses was 33.83 ± 48.40 μm. This was 26 ± 27 μm (13 ± 14 μm, +3 mm; 34 ± 37 μm, -3 mm), lens 1; 35 ± 59 μm (38 ± 61 μm, +3 mm; 52 ± 69 μm, -3 mm), lens 2; and 41 ± 54 μm (33 ± 26 μm, +3 mm; 52 ± 48 μm, -3 mm), lens 3, respectively. There was no significant difference (P = 0.06) at central and other locations for lens 1 (location and over time). There were significant differences for both lenses 2 and 3 (P <.001, P =.01, respectively) for all three locations and over time. CONCLUSIONS There is a likelihood of clearance loss after 1 hour of lens wear. This varies between subjects, initial lens-fit relationship, and over time.

Regmi,S. C., Samsom,M. L., Heynen,M. L., Jay,G. D., Sullivan,B. D., Srinivasan,S., Caffery,B., Jones,L., Schmidt,T. A. Degradation of proteoglycan 4/lubricin by cathepsin S: Potential mechanism for diminished ocular surface lubrication in Sjögren's syndrome Experimental eye research 2017;161:1-9 [ Show Abstract ]

Sjögren's syndrome (SS) is an autoimmune disease affecting the lacrimal and salivary glands with hallmark clinical symptoms of dry eye and dry mouth. Recently, markedly increased cathepsin S (CTSS) activity has been observed in the tears of SS patients. Proteoglycan 4 (PRG4), also known as lubricin, is an effective boundary lubricant that is naturally present on the ocular surface. While PRG4 is susceptible to proteolytic digestion, the potential effect of CTSS on PRG4 remains unknown. The objective of this study was to assess the ability of CTSS to enzymatically degrade purified PRG4, and PRG4 naturally present in human tears, and alter ocular surface boundary lubricating properties. To assess the potential time course and dose-dependency of PRG4 digestion by CTSS, full-length recombinant human PRG4 (rhPRG4) was incubated at 37 °C with or without CTSS in an enzymatic digestion buffer. Digestion of PRG4 by CTSS was also examined within normal human tear samples, both with and without supplementation by rhPRG4. Finally, digestion of endogenous PRG4 by CTSS, and the effect of a CTSS inhibitor, was examined in SS tears on Schirmer strips. Digestion products were separated on 3–8% SDS-PAGE and visualized by protein staining and western blotting. The boundary lubricating ability of rhPRG4 samples was assessed using an in vitro human eyelid-cornea friction test. Finally, SDS-PAGE protein stain bands resulting from rhPRG4 digestion were submitted for tandem mass spectrometry analysis to confirm their identity as PRG4 and identify non-tryptic cleavage sites. CTSS digested rhPRG4 in a time and dose dependent manner. CTSS digestion of rhPRG4 at 1% (where % is the mass ratio of CTSS to rhPRG4) resulted in a time dependent decrease in the full-length, ~460 kDa, monomeric rhPRG4 band, and an appearance of lower MW fragments. After 20 h, no full-length rhPRG4 was observed. Furthermore, with an increased relative enzyme concentration of 3%, no protein bands were observed after 2 h, indicating complete digestion of rhPRG4. Western blotting demonstrated PRG4 is present in normal human tears, and that rhPRG4, tears, and tears supplemented with rhPRG4 incubated with 3–9% CTSS demonstrated decreased intensity of high MW PRG4 bands, indicative of partial degradation by CTSS. Similarly, western blotting of PRG4 in SS tears incubated with CTSS demonstrated decreased intensity of high MW PRG4 bands, which was reversed in the presence of the CTSS inhibitor. CTSS treatment of rhPRG4 resulted in an increased friction coefficient, compared to untreated controls. Lastly, the lower MW bands were confirmed to be PRG4 fragments by tandem mass spectrometry, and 6 non-tryptic cleavage sites were identified. rhPRG4 is susceptible to proteolytic digestion by CTSS, both alone and in human tears, which results in diminished ocular surface boundary lubricating ability. Moreover, endogenous PRG4 is susceptible to proteolytic digestion by CTSS, both in normal and SS tears. Given the elevated activity of CTSS in SS tears, and the role intact PRG4 plays in ocular surface health and lubrication, degradation of PRG4 by CTSS is a potential mechanism for diminished ocular surface lubrication in SS. Collectively these results suggest that tear supplementation of PRG4 may be beneficial for SS patients. © 2017 Elsevier Ltd

Stapleton,F., Alves,M., Bunya,V. Y., Jalbert,I., Lekhanont,K., Malet,F., Na,K. -S, Schaumberg,D., Uchino,M., Vehof,J., Viso,E., Vitale,S., Jones,L. TFOS DEWS II Epidemiology Report Ocular Surface 2017;15(3):334-365 [ Show Abstract ]

The subcommittee reviewed the prevalence, incidence, risk factors, natural history, morbidity and questionnaires reported in epidemiological studies of dry eye disease (DED). A meta-analysis of published prevalence data estimated the impact of age and sex. Global mapping of prevalence was undertaken. The prevalence of DED ranged from 5 to 50%. The prevalence of signs was higher and more variable than symptoms. There were limited prevalence studies in youth and in populations south of the equator. The meta-analysis confirmed that prevalence increases with age, however signs showed a greater increase per decade than symptoms. Women have a higher prevalence of DED than men, although differences become significant only with age. Risk factors were categorized as modifiable/non-modifiable, and as consistent, probable or inconclusive. Asian ethnicity was a mostly consistent risk factor. The economic burden and impact of DED on vision, quality of life, work productivity, psychological and physical impact of pain, are considerable, particularly costs due to reduced work productivity. Questionnaires used to evaluate DED vary in their utility. Future research should establish the prevalence of disease of varying severity, the incidence in different populations and potential risk factors such as youth and digital device usage. Geospatial mapping might elucidate the impact of climate, environment and socioeconomic factors. Given the limited study of the natural history of treated and untreated DED, this remains an important area for future research.

Sullivan,D. A., Rocha,E. M., Aragona,P., Clayton,J. A., Ding,J., Golebiowski,B., Hampel,U., McDermott,A. M., Schaumberg,D. A., Srinivasan,S., Versura,P., Willcox,M. D. P. TFOS DEWS II Sex, Gender, and Hormones Report Ocular Surface 2017;15(3):284-333 [ Show Abstract ]

One of the most compelling features of dry eye disease (DED) is that it occurs more frequently in women than men. In fact, the female sex is a significant risk factor for the development of DED. This sex-related difference in DED prevalence is attributed in large part to the effects of sex steroids (e.g. androgens, estrogens), hypothalamic-pituitary hormones, glucocorticoids, insulin, insulin-like growth factor 1 and thyroid hormones, as well as to the sex chromosome complement, sex-specific autosomal factors and epigenetics (e.g. microRNAs). In addition to sex, gender also appears to be a risk factor for DED. “Gender” and “sex” are words that are often used interchangeably, but they have distinct meanings. “Gender” refers to a person's self-representation as a man or woman, whereas “sex” distinguishes males and females based on their biological characteristics. Both gender and sex affect DED risk, presentation of the disease, immune responses, pain, care-seeking behaviors, service utilization, and myriad other facets of eye health. Overall, sex, gender and hormones play a major role in the regulation of ocular surface and adnexal tissues, and in the difference in DED prevalence between women and men. The purpose of this Subcommittee report is to review and critique the nature of this role, as well as to recommend areas for future research to advance our understanding of the interrelationships between sex, gender, hormones and DED. © 2017 Elsevier Inc.

Willcox,M. D. P., Argüeso,P., Georgiev,G. A., Holopainen,J. M., Laurie,G. W., Millar,T. J., Papas,E. B., Rolland,J. P., Schmidt,T. A., Stahl,U., Suarez,T., Subbaraman,L. N., Uçakhan,O. Ö., Jones,L. TFOS DEWS II Tear Film Report Ocular Surface 2017;15(3):366-403 [ Show Abstract ]

The members of the Tear Film Subcommittee reviewed the role of the tear film in dry eye disease (DED). The Subcommittee reviewed biophysical and biochemical aspects of tears and how these change in DED. Clinically, DED is characterized by loss of tear volume, more rapid breakup of the tear film and increased evaporation of tears from the ocular surface. The tear film is composed of many substances including lipids, proteins, mucins and electrolytes. All of these contribute to the integrity of the tear film but exactly how they interact is still an area of active research. Tear film osmolarity increases in DED. Changes to other components such as proteins and mucins can be used as biomarkers for DED. The Subcommittee recommended areas for future research to advance our understanding of the tear film and how this changes with DED. The final report was written after review by all Subcommittee members and the entire TFOS DEWS II membership.

Wolffsohn,J. S., Arita,R., Chalmers,R., Djalilian,A., Dogru,M., Dumbleton,K., Gupta,P. K., Karpecki,P., Lazreg,S., Pult,H., Sullivan,B. D., Tomlinson,A., Tong,L., Villani,E., Yoon,K. C., Jones,L., Craig,J. P. TFOS DEWS II Diagnostic Methodology report Ocular Surface 2017;15(3):539-574 [ Show Abstract ]

The role of the Tear Film and Ocular Surface Society (TFOS) Dry Eye Workshop (DEWS) II Diagnostic Methodology Subcommittee was 1) to identify tests used to diagnose and monitor dry eye disease (DED), 2) to identify those most appropriate to fulfil the definition of DED and its sub-classifications, 3) to propose the most appropriate order and technique to conduct these tests in a clinical setting, and 4) to provide a differential diagnosis for DED and distinguish conditions where DED is a comorbidity. Prior to diagnosis, it is important to exclude conditions that can mimic DED with the aid of triaging questions. Symptom screening with the DEQ-5 or OSDI confirms that a patient might have DED and triggers the conduct of diagnostic tests of (ideally non-invasive) breakup time, osmolarity and ocular surface staining with fluorescein and lissamine green (observing the cornea, conjunctiva and eyelid margin). Meibomian gland dysfunction, lipid thickness/dynamics and tear volume assessment and their severity allow sub-classification of DED (as predominantly evaporative or aqueous deficient) which informs the management of DED. Videos of these diagnostic and sub-classification techniques are available on the TFOS website. It is envisaged that the identification of the key tests to diagnose and monitor DED and its sub-classifications will inform future epidemiological studies and management clinical trials, improving comparability, and enabling identification of the sub-classification of DED in which different management strategies are most efficacious.

2016

Berntsen,D. A., Hickson-Curran,S. B., Jones,L. W., Mathew,J. H., Maldonado-Codina,C., Morgan,P. B., Schulze,M. M., Nichols,J. J. Subjective comfort and physiology with modern contact lens care products Optometry and Vision Science 2016;93(8):809-819 [ Show Abstract ]

Purpose. To compare subjective comfort and ocular physiology with three multipurpose solutions (MPSs) to that of a peroxide-based system with three different soft contact lens materials. Methods. Habitual soft contact lens wearers (n = 236) were enrolled at three sites and completed a washout period with no contact lens solution for =4 days. Subjects were randomly assigned to one of three lens types: etafilcon A, galyfilcon A, or senofilcon A. A new lens of the assigned type was worn for 10 to 14 days each while using one of four care solutions, in random order (A - polyaminopropyl biguanide + polyquaternium, B - POLYQUAD + Aldox, C - alexidine + polyquaternium-1, and D - hydrogen peroxide) with a washout period (=4 days) between each solution. After each care solution, biomicroscopy was performed and subjective comfort was assessed using the Contact Lens User Experience (CLUE) questionnaire and other instruments including comfortable wear time (CWT). Linear mixed models were used for analysis. Comfort and biomicroscopy signs with each MPS were compared to that of the peroxide solution. Results. Subjective CLUE Comfort score across all lens types with each MPS was not significantly different than with the peroxide solution (p = 0.98). There were no differences in CWT between each MPS and the peroxide solution for any lens type (range of differences: -0.8 to 0.8 h; all p = 0.13). Six MPS/material combinations had no clinically meaningful change in corneal staining versus peroxide (<0.5 units); three combinations could increase staining by up to 0.57 units. Staining was <grade 1 for all combinations. Conclusions. Comparable levels of comfort were found between the latest generation of MPSs compared to peroxide disinfection. Three MPS/material combinations tested could result in increased corneal staining of up to 0.57 units versus a peroxide solution. Overall, these data suggest the care systems investigated are generally appropriate for usewith the contact lenses tested. © Copyright 2016 American Academy of Optometry.

Caffery,B., Dogru,M., Jones,L. W., Lin,M. C., Nichols,J. J., Papas,E., Pucker,A., Pult,H., Willcox,M. D. P. Contact lens comfort Optometry and Vision Science 2016;93(8):790-792

Cox,S. M., Berntsen,D. A., Chatterjee,N., Hickson-Curran,S. B., Jones,L. W., Moezzi,A. M., Morgan,P. B., Nichols,J. J. Eyelid margin and meibomian gland characteristics and symptoms in lens wearers Optometry and Vision Science 2016;93(8):901-908 [ Show Abstract ]

Purpose. To describe the lid margin characteristics of contact lens wearers and relate them to comfort during lens wear. Methods. Three study sites enrolled habitual contact lens wearers. Subjects completed the Comfort domain of the Contact Lens User Experience (CLUE) questionnaire, and each eye was graded for the presence of mucocutaneous junction (MCJ) displacement, lid margin irregularity, and lid margin vascularity. Examiners counted the number of meibomian gland (MG) orifices in the central centimeter of the lower eyelid and the number of those that showed pouting/plugging and vascular invasion. MG expressibility was graded according to the Shimazaki schema. Subjects were grouped based on presence/ absence of each characteristic, total number of orifices (=5 vs. 0). Descriptive statistics are reported. A linear model was used to assess the fixed effect of each characteristic on combined CLUE score and each CLUE statement, if the effect on combined CLUE score showed p < 0.10. Results. The study included 203 subjects (67.5% female) with mean age (±SD) of 30.3 ± 9.6 years. The most commonly observed characteristics were orifice pouting/plugging, compromised MG expressibility, and lid margin vascularity (35.0, 30.3, and 20.4%, respectively). MCJ displacement and MG expressibility had an effect on the combined CLUE score such that individual CLUE statements were analyzed (p = 0.01 and p = 0.06, respectively). MCJ displacement had an effect on comfort upon insertion (p = 0.01), comfort after 5 minutes (p = 0.03), end-of-day comfort (p = 0.01), and ability to maintain ocular moisture (p = 0.030). MG expressibility had a significant effect on general comfort (p = 0.01), comfort throughout the day (p = 0.02), and the ability to maintain ocular moisture (p = 0.02). Conclusions. MCJ displacement and MG expressibility have an effect on contact lens comfort. © Copyright 2016 American Academy of Optometry.

Dantam,J., McCanna,D. J., Subbaraman,L. N., Papinski,D., Lakkis,C., Mirza,A., Berntsen,D. A., Morgan,P., Nichols,J. J., Jones,L. W. Microbial contamination of contact lens storage cases during daily wear use Optometry and Vision Science 2016;93(8):925-932 [ Show Abstract ]

Purpose. To evaluate contact lens (CL) storage case contamination when used with four different CL care solutions during daily wear of three different CL materials. Methods. A parallel, prospective, bilateral, randomized clinical trial (n = 38) was conducted. Subjects were randomly assigned to use one of three CL materials (etafilcon A, senofilcon A, or galyfilcon A) on a daily wear basis. Subsequently, each subject randomly used one of four different CL care solutions (Biotrue, OPTI-FREE PureMoist, RevitaLens OcuTec, and CLEAR CARE) for 2 weeks, along with their respective storage cases. After every 2-week period, their storage cases were collected and the right and left wells of each storage case were randomized for two procedures: (1) microbial enumeration by swabbing the storage case surface and (2) evaluation of biofilm formation (multipurpose solution cases only) using a crystal violet staining assay. Results. More than 80% of storage cases were contaminated when used in conjunction with the four CL care solutions, irrespective of the CL material worn. Storage cases maintained with CLEAR CARE (mean Log colony forming units (CFU)/ well ± SD, 2.0 ± 1.0) revealed significantly (p < 0.001) greater levels of contamination, compared to those maintained with Biotrue (1.3 ± 0.8) and RevitaLens OcuTec (1.2 ± 0.8). Predominantly, storage cases were contaminated with Gram-positive bacteria (= 80%). There were significant differences (p = 0.013) for the levels of Gram-negative bacteria recovered from the storage cases maintained with different CL care solutions. Storage cases maintained withOPTI-FREE PureMoist (0.526 ± 0.629) showed significantly higher biofilm formation (p = 0.028) compared to those maintained with Biotrue (0.263 ± 0.197). Conclusions. Levels of contamination ranged from 0 to 6.4 Log CFU/storage case well, which varied significantly (p < 0.001) between different CL care solutions, and storage case contamination was not modulated by CL materials. © Copyright 2016 American Academy of Optometry.

Hall,B., Heynen,M., Jones,L. W., Forrest,J. A. Analysis of Using I125 Radiolabeling for Quantifying Protein on Contact Lenses Current eye research 2016;41(4):456-465 [ Show Abstract ]

Purpose: To investigate the accuracy of I125 radiolabeling to quantitatively determine the deposition of protein onto various commercially available contact lens (CL) materials. Methods: Commercially available silicone hydrogel and conventional hydrogel CL materials were examined for times ranging from 10 s to 1 week. Adsorption of free I125 was measured directly for the CL. The use of dialyzing labeled proteins and/or using NaI to compete with free I125 uptake was investigated as ways to minimize effects due to free I125. Results: At all time points and with all lens materials, there was 0.3 µg/lens or greater of apparent mass attributable to free I125 uptake. Dialyzing labeled proteins significantly reduced free I125 uptake for all materials investigated. The benefit of using dialyzed protein was most prominent at shorter times, as free I125 is continuously generated over time. Using NaI can reduce free I125 uptake for some lens materials, but this is shown to directly affect protein deposition on some materials. Conclusions: Periodic replenishment of incubation solutions with freshly dialyzed labeled protein to limit free I125 generation is recommended, but the incorporation of NaI onto the buffer solution is not. Irrespective of the exact procedure to limit free I125 uptake, extra steps must be performed to quantify the amount of I125 adsorbed onto contact lens materials, to determine thresholds of confidence with respect to the actual protein deposition that occurs.

Jones,D., Woods,C., Jones,L., Efron,N., Morgan,P. A sixteen year survey of Canadian contact lens prescribing Contact Lens and Anterior Eye 2016;39(6):402-410 [ Show Abstract ]

Purpose To understand long-term contact lens prescribing habits of Canadian optometrists. Methods One thousand optometrists were surveyed annually from 2000 to 2015. Information was requested on the first ten patients examined after receiving the survey. Results Over the 16-year survey period, 1987 optometrists provided information on 19,143 patients. Mean age of the patients was 32.7 ± 14.4 years. Ratio of females to males was 2:1, the ratio of new fits to refits was 2:3. Soft contact lenses represented 94.5% of all fits. Rigid lenses were more often used as a refit compared to a new fit. Over the 16 years, market share for silicone hydrogel materials grew from 0% to 69.6%, mid-water content materials declined from 75.7% to 14.1%. The multifocal market share grew at the expense of spherical designs, with no change in toric lens fitting. Monthly soft lens replacement remained the preferred option at 48.2%, followed by daily disposable at 40.8%; two-weekly replacement declined to less than10% of patients by 2015. Extended wear was likely used to refit and only to a small proportion of wearers, representing 2.6% of SCL by 2015. The lens care system of choice throughout the period was multipurpose solutions, although the proportion for peroxide systems more than doubled by 2015 from 9.6%, to 21.1%. Conclusions Over the 16-year period, SCL material preference changed to silicone hydrogels with monthly replacement being preferred; daily disposables replacing 2-weekly as the alternate. Lens care preference continued to be multipurpose solutions. Rigid lenses appear to be sustained for specialist fitting. © 2016 British Contact Lens Association

Jones,L. W., Byrne,M., Ciolino,J. B., Legerton,J., Markoulli,M., Papas,E., Subbaraman,L. Revolutionary future uses of contact lenses Optometry and Vision Science 2016;93(4):325-327

Jones,L., Chauhan,A.,DiGirolamo,N., Sheedy,J., Smith III,E. Expert views on innovative future uses for contact lenses Optometry and Vision Science 2016;93(4):328-35 [ Show Abstract ]

Over the past 10 to 15 years, the availability of new materials and technologies has resulted in revolutionary concepts for contact lenses being proposed that go well beyond correcting vision. These novel uses include their prescribing to deliver topical ocular and systemic drugs, assist with ocular surface disease management, and limit the progression of myopia and novel methods to display visual information. How likely are these concepts to become commercially available, how successful will they be, and what are the potential issues to consider for them to come to market? To answer these questions, a panel of four experts were invited to discuss the benefits and pitfalls of these technologies and what challenges lay ahead of these concepts before their availability. Their responses provide a fascinating insight for the clinician into the likelihood of such revolutionary contact lenses being available in a clinical setting.

Keir,N., Luensmann,D., Woods,C.A., Bergenske,P., Fahmy,M., Fonn,D. Effect of Masking on Subjective Responses to Daily Disposable Contact Lenses Optom Vis Sci 2016;93(8):828-35 [ Show Abstract ]

PURPOSE: To explore the effect of masking on subjective responses when wearing daily disposable (DD) contact lenses.
METHODS: In an adaptation phase, habitual wearers of Manufacturer-A (MFA) (n = 43) and Manufacturer-B (MFB) (n = 53) wore MFA-brand 1 or MFB-brand 1 DDs, respectively, for 30 days, open-label. Subjects were then randomly assigned to one of two experiments. Each experiment included two, 3-day crossover phases. An enhanced version of MFA and MFB lenses (MFA-brand 2 and MFB-brand 2) were worn contralaterally to evaluate potential differences in masking result between manufacturers. Experiment 1: subjects were fully masked to lens and packaging (FM) then unmasked (UM). Experiment 2: subjects were FM then partially masked using an over-label (PM). Comfort ratings (0-100) were recorded for each lens daily and preference between lenses was recorded on day 3 for each crossover phase. The mean difference between 0-100 ratings or preference when FM or PM versus UM for the same lens was considered a measurement of the effect associated with masking. The purpose of the study was withheld from subjects to minimize bias.
RESULTS: The effect associated with masking for habitual wearers of MFA and MFB lenses was less than 1 out of 100 (0 ± 2.5) in both experiments. Fifty-eight subjects (60%) expressed no preference when FM. This decreased to 29 (30%) when UM or PM (proportion test, p < 0.001). Approximately half the subjects had a change in lens preference when they were UM or PM, primarily in favor of their habitual lens manufacturer.
CONCLUSIONS: Masking did not have a measurable impact on 0-100 ratings with the DD lenses used in this study but did have an impact on lens preference. Subjects were more likely to express a preference when they handled the lenses and were exposed to the lens packaging and, in some cases, able to read the lens brand and lens manufacturer.

Liu,L. Y., Seo,J., McCanna,D. J., Subbaraman,L. N., Jones,L. W. Assessment of biofilm formation of E. meningoseptica, D. acidovorans, and S. maltophilia in lens cases and their growth on recovery media Contact Lens and Anterior Eye 2016;39(2):117-123 [ Show Abstract ]

Purpose: Bacterial biofilm formation in contact lens cases is a risk factor in the development of both microbial and infiltrative keratitis. This investigation evaluated three emerging pathogens: Stenotrophomonas maltophilia, Elizabethkingia meningoseptica, and Delftia acidovorans for biofilm formation and metabolic activity in lens cases. Also, growth of these bacteria on different media was assessed to optimize recovery conditions. Methods: The three bacteria were incubated in lens cases with different concentrations of tryptic soy broth. Biofilm formation was evaluated by measuring metabolic activity using MTT and enumerating the number of viable bacteria. To determine the optimal recovery media, dilutions of these microorganisms were plated on six different media. The number of colony forming units (CFU) was recorded after 48, 72, and 96 h of incubation at 32 °C and 37 °C for S. maltophilia, and at 37 °C for E. meningoseptica and D. acidovorans. Results: All three microorganisms established biofilms in the lens cases, with significant numbers of CFU recovered. Biofilms of S. maltophilia and E. meningoseptica were metabolically active. Significant reduction in metabolic activity and number of viable S. maltophilia occurred when the incubation temperature was raised from 32 °C to 37 °C (p < 0.05). The metabolic activity of the biofilms increased with greater organic load present. The highest percent recovery for all three organisms was given by Columbia blood agar, followed by chocolate. Conclusion: Based on the results, the presence of the three emerging pathogens present in lens cases and from corneal isolates can be accurately determined if proper growth media and incubation temperatures are utilized.

Liu,S., Dozois,M. D., Chang,C. N., Ahmad,A., Ng,D. L. T., Hileeto,D., Liang,H., Reyad,M. -M, Boyd,S., Jones,L. W., Gu,F. X. Prolonged ocular retention of mucoadhesive nanoparticle eye drop formulation enables treatment of eye diseases using significantly reduced dosage Molecular Pharmaceutics 2016;13(9):2897-2905 [ Show Abstract ]

Eye diseases, such as dry eye syndrome, are commonly treated with eye drop formulations. However, eye drop formulations require frequent dosing with high drug concentrations due to poor ocular surface retention, which leads to poor patient compliance and high risks of side effects. We developed a mucoadhesive nanoparticle eye drop delivery platform to prolong the ocular retention of topical drugs, thus enabling treatment of eye diseases using reduced dosage. Using fluorescent imaging on rabbit eyes, we showed ocular retention of the fluorescent dye delivered through these nanoparticles beyond 24 h while free dyes were mostly cleared from the ocular surface within 3 h after administration. Utilizing the prolonged retention of the nanoparticles, we demonstrated effective treatment of experimentally induced dry eye in mice by delivering cyclosporin A (CsA) bound to this delivery system. The once a week dosing of 0.005 to 0.01% CsA in NP eye drop formulation demonstrated both the elimination of the inflammation signs and the recovery of ocular surface goblet cells after a month. Thrice daily administration of RESTASIS on mice only showed elimination without recovering the ocular surface goblet cells. The mucoadhesive nanoparticle eye drop platform demonstrated prolonged ocular surface retention and effective treatment of dry eye conditions with up to 50- to 100-fold reduction in overall dosage of CsA compared to RESTASIS, which may significantly reduce side effects and, by extending the interdosing interval, improve patient compliance. © 2016 American Chemical Society.

Moezzi,A. M., Varikooty,J., Schulze,M., Ngo,W., Lorenz,K. O., Boree,D., Jones,L. W. Corneal Swelling with Cosmetic etafilcon A Lenses versus No Lens Wear Optometry and Vision Science 2016;93(6):619-628 [ Show Abstract ]

Purpose: To determine if the use of pigments or adding polyvinyl pyrrolidone during the fabrication of 1-DAY ACUVUE DEFINE (AD) brand contact lenses impacts open-eye corneal swelling compared with no lens wear (NLW). Methods: A partial double-masked, randomized, bilateral crossover study was conducted in 24 Asian subjects using AD, 1-DAY ACUVUE DEFINE with Lacreon (ADL), NLW, and a control lens with no tint (1-DAY ACUVUE MOIST [AM]). Central corneal thickness was measured before insertion and immediately after removal after 8 ± 1 h of open-eye wear using an optical pachymeter in one eye. Corneal thickness along a 10-mm cord was measured in the contralateral eye using the Visante optical coherence tomographer (OCT). Corneal swelling was tested for noninferiority using a 5% margin. The endothelial bleb response was measured at baseline and 20 min after lens insertion using specular microscopy. Subjective grading of corneal staining and limbal/bulbar hyperemia were also monitored. Results: After 8 ± 1 h of open-eye wear, central corneal swelling across the study lenses with either optical pachymeter or OCT methods was negligible. Peripheral corneal swelling least-square mean differences with OCT were -0.03% (95% confidence interval [95% CI], -0.65 to 0.58%) and -0.26% (95% CI, -0.87 to 0.36%) between AD and ADL and the control lens (AM), respectively, and 1.67% (95% CI, 1.06 to 2.29%) and 1.45% (95% CI, 0.84 to 2.06%) between AD and ADL and NLW, respectively. No endothelial blebs were observed. No clinically significant differences were distinguished between the lenses and NLW for corneal staining and limbal/bulbar hyperemia. Conclusions: After 8 ± 1 h of open-eye wear, central and peripheral corneal swelling along the horizontal meridian with AD, ADL, AM, and NLW were equivalent. These results confirm that the addition of polyvinyl pyrrolidone or pigments to etafilcon A to obtain a limbal ring design have no impact on corneal swelling or limbal/bulbar hyperemia during normal open-eye wear.

Muntz,A., van Doorn,K., Subbaraman,L. N., Jones,L. W. Impression cytology of the lid wiper area Journal of Visualized Experiments 2016 (114): [ Show Abstract ]

Few reports on the cellular anatomy of the lid wiper (LW) area of the inner eyelid exist and only one report makes use of cytological methods. The optimization of a method of collecting, staining and imaging cells from the LW region using impression cytology (IC) is described in this study. Cells are collected from the inner surface of the upper eyelid of human subjects using hydrophilic polytetrafluoroethylene (PTFE) membranes, and stained with cytological dyes to reveal the presence of goblet cells, mucins, cell nuclei and various degrees of pre- and parakeratinization. Immunocytochemical dyes show cell esterase activity and compromised cell membranes by the use of a confocal scanning laser microscope. Up to 100 microscopic digital images are captured for each sample and stitched into a high-resolution, large scale image of the entire IC span. We demonstrate a higher sensitivity of IC than reported before, appropriate for identifying cellular morphologies and metabolic activity in the LW area. To our knowledge, this is the first time this selection of fluorescent dyes was used to image LW IC membranes. This protocol will be effective in future studies to reveal undocumented details of the LW area, such as assessing cellular particularities of contact lens wearers or patients with dry eye or lid wiper epitheliopathy. © 2016 Journal of Visualized Experiments.

Ng,A., Evans,K., North,R. V., Jones,L., Purslow,C. Impact of Eye Cosmetics on the Eye, Adnexa, and Ocular Surface Eye and Contact Lens 2016;42(4):211-220 [ Show Abstract ]

Despite the fact that cosmetic products undergo rigorous testing to ensure they are safe for human use, some users report mild discomfort following their application. The cutaneous changes, such as allergic dermatitis, are well reported, but the ocular changes associated with eye cosmetic use are less so. Some pigmented cosmetic products may accumulate within the lacrimal system and conjunctivae over many years of use, but immediate reports of eye discomfort after application are most common. Changes to the tear film and its stability may occur shortly after application, and contact lens wearers can also be affected by lens spoliation from cosmetic products. Additionally, creams used in the prevention of skin aging are often applied around the eyes, and retinoids present in these formulations can have negative effects on meibomian gland function and may be a contributing factor to dry eye disease. The aim of this review is to summarize current knowledge regarding the impact of cosmetic products on the eye, ocular surface, and tear film. © 2015 Contact Lens Association of Ophthalmologists.

Omali,N. B., Heynen,M., Subbaraman,L. N., Papinski,D., Lakkis,C., Smith,S. L., Morgan,P. B., Berntsen,D. A., Nichols,J. J., Jones,L. W. Impact of lens care solutions on protein deposition on soft contact lenses Optometry and Vision Science 2016;93(8):963-972 [ Show Abstract ]

Purpose. To evaluate the effect of four contemporary lens care solutions on total protein, total lysozyme, and active lysozyme extracted from three contact lens materials. Methods. Adapted contact lens wearers were recruited at three sites, and all subjects were randomly assigned to daily wear of either etafilcon A, galyfilcon A, or senofilcon A for 2 weeks. Four lens care solutions (Biotrue, OPTI-FREE PureMoist, RevitaLens OcuTec, and ClearCare) were used by each subject in random order with a new pair of lenses after a washout period between solutions of at least 4 days. After 2 weeks of daily wear, contact lenses were collected for analysis. Proteins were extracted from a subset of contact lenses (n = 568) and total protein, total lysozyme, and lysozyme activity were quantified using a modified Bradford assay, an enzyme-linked immunosorbent assay, and a micrococcal assay, respectively. Results. Higher levels of total protein were extracted from etafilcon A when used with Biotrue compared to other solutions (p = 0.0001). There were higher levels of total lysozyme extracted from galyfilcon A lenses when used with PureMoist than with Biotrue or Clear Care (p < 0.006). Higher total lysozyme was extracted from senofilcon A when used with RevitaLens OcuTec compared to Biotrue (p = 0.002). Lower lysozyme activity was recovered from senofilcon A lenses with RevitaLens OcuTec when compared to all other care solutions (all p < 0.004). When Biotrue, PureMoist, or RevitaLens OcuTec were used, higher total lysozyme was extracted from galyfilcon A compared to senofilcon A(p < 0.01). When RevitaLens OcuTec was used, higher levels of active lysozyme were extracted from galyfilcon A compared to senofilcon A (p = 0.02). Conclusions. The ability of lens care solutions to remove protein from lenses varies depending upon the care solution composition and also the polymeric make-up of the contact lens material. © Copyright 2016 American Academy of Optometry.

Phan,C. -M, Bajgrowicz-Cieslak,M., Subbaraman,L. N., Jones,L. Release of Moxifloxacin from Contact Lenses Using an In Vitro Eye Model: Impact of Artificial Tear Fluid Composition and Mechanical Rubbing Transl Vis Sci Technol. 2016;5(6):3 [ Show Abstract ]

PURPOSE: The aim of this study was to evaluate and compare the release of moxifloxacin from a variety of daily disposable (DD) contact lenses (CLs) under various conditions using a novel in vitro eye model.
METHODS: Four commercially available DD conventional hydrogel (CH) CLs (nelfilcon A, omafilcon A, etafilcon A, and ocufilcon B) and three silicone hydrogel (SH) CLs (somofilcon A, narafilcon A, and delefilcon A) were evaluated. These lenses were incubated in moxifloxacin for 24 hours. The release of the drug was measured using a novel in vitro model in three experimental conditions: (1) phosphate buffered saline (PBS); (2) artificial tear solution (ATS) containing a variety of proteins and lipids; and (3) ATS with mechanical rubbing produced by the device.
RESULTS: Overall, CH CLs had a higher drug release than SH CLs (P < 0.05) under all conditions. Typically, a higher drug release was observed in PBS than ATS (P < 0.05). For CH, drug release was found to be higher in ATS with rubbing than PBS or ATS (P < 0.05). For most lens types, ATS with rubbing produced higher drug release than ATS alone (P < 0.05). Generally, the release kinetics for all conditions were sustained over the 24-hour testing period, and no burst release was observed (P < 0.05).
CONCLUSIONS: Moxifloxacin release from a CL into ATS is lower when compared to release into PBS. When mechanical rubbing is introduced, the amount of drugs released is increased.
TRANSLATIONAL RELEVANCE: Results suggest that sophisticated in vitro models are necessary to adequately model on-eye drug release from CL materials.

Phan,C. -M, Bajgrowicz,M., Gao,H., Subbaraman,L. N., Jones,L. W. Release of fluconazole from contact lenses using a novel in vitro eye model Optometry and Vision Science 2016;93(4):387-394 [ Show Abstract ]

Purpose. Rapid drug release followed by a plateau phase is a common observation with drug delivery from contact lenses (CLs) when evaluated in a vial. The aim of this study was to compare the release of fluconazole from seven commercially available daily disposable CLs using a conventional vial-based method with a novel in vitro eye model. Methods. An eye model was created using two 3-dimensional printed molds, which were filled with polydimethylsiloxane to obtain an inexpensive model that would mimic the eyeball and eyelid. The model was integrated with a microfluidic syringe pump, and the flow-through was collected in a 12-well microliter plate. Four commercial daily disposable conventional hydrogels (nelfilcon A, omafilcon A, etafilcon A, ocufilcon B) and three silicone hydrogels (somofilcon A, narafilcon A, delefilcon A) were evaluated. These CLs were incubated with fluconazole for 24 h. The drug release was measured in a vial containing 4.8 mL of phosphate-buffered saline and in the polydimethylsiloxane eye model with a 4.8-mL tear flow across 24 h. Results. Overall, conventional hydrogel CLs had a higher uptake and release of fluconazole than silicone hydrogel CLs (p < 0.05). A higher drug release was observed in the vial condition compared with the eye model (p < 0.001). In the vial system, the drugs were rapidly released from the CL within the first 2 h, followed by a plateau phase. In contrast, drug release in the eye model under low tear volume was sustained and did not reach a plateau across 24 h (p < 0.05). Conclusions. Rapid drug release results from using a vial as the release system. Under low tear volume at physiological tear flow, commercial CLs can maintain a sustained drug release profile for up to 24 h. However, eyes with fungal keratitis may have increased tearing, which would significantly accelerate drug release. © 2015 American Academy of Optometry.

Phan,C. -M, Bajgrowicz,M., McCanna,D. J., Subbaraman,L. N., Jones,L. Effects of Antifungal Soaked Silicone Hydrogel Contact Lenses on Candida albicans in an Agar Eye Model Eye and Contact Lens 2016;42(5):313-317 [ Show Abstract ]

Purpose: To evaluate the effects of two commercial silicone hydrogel contact lenses (CLs) soaked with natamycin (NA) or fluconazole (FL) on the growth of Candida albicans in an in vitro eye model. Methods: Three-D printed molds were used as a cast for making eye-shaped models comprising potato dextrose agar. Senofilcon A (SA) and lotrafilcon B (LB) CLs were incubated with either 2 mL of NA or FL at a concentration of 1 mg/mL for 24 hr. To simulate a fungal infection, the eye models were coated with C. albicans. The drug-soaked lenses were placed on top of the eye models. Seven experimental conditions were examined: (1) NA-SA, (2) NA-LB, (3) FL-SA, (4) FL-LB, (5) SA, (6) LB, and (7) control - no lens. At specified time points (t1, 8, 16, 24, 48 hr), the agar eyes from each experimental condition were removed from the incubator and photographed. The yeast cells from the 24 and 48 hr time point were also analyzed using light microscopy. Results: At 24 and 48 hr, there was considerable growth observed for all conditions except for the NA-SA and NA-LB conditions. When observed under the microscope at 24 and 48 hr, the morphology of the yeast cells in the FL-SA and SA condition were similar to that of the control (oval shaped). There was limited hyphae growth observed for LB and significant visible hyphae growth for the NA-LB group. For NA-SA, NA-LB, and FL-LB groups, the cells were significantly smaller compared with the control. Conclusions: For NA-SA and NA-LB, there was limited growth of C. albicans observed on the eye models even after 48 hr. Under the microscope, the cell morphology differ noticeably between each testing condition, and is dependent on drug-lens combinations. © 2015 Contact Lens Association of Ophthalmologists.

Phan,C. -M, Subbaraman,L., Jones,L. W. The use of contact lenses as biosensors Optometry and Vision Science 2016;93(4):419-425 [ Show Abstract ]

The tear film is a complex multilayer film consisting of various proteins, enzymes, and lipids and can express a number of biomarkers in cases of disease. The development of a contact lens sensor presents a noninvasive alternative for the detection and management of various diseases. Recent work has resulted in the commercialization of a device to monitor intraocular pressure for up to 24 h, and there are extensive efforts underway to develop a contact lens sensor capable of continuous glucose tear film monitoring to manage diabetes. This clinical perspective will highlight the major developments within this field and list some of the major challenges that still need to be addressed. © 2015 American Academy of Optometry.

Phan,C. -M, Walther,H., Gao,H., Rossy,J., Subbaraman,L. N., Jones,L. Development of an in Vitro ocular platform to test contact lenses Journal of Visualized Experiments 2016;2016(110):e53907 [ Show Abstract ]

Currently, in vitro evaluations of contact lenses (CLs) for drug delivery are typically performed in large volume vials,1-6 which fail to mimic physiological tear volumes.7 The traditional model also lacks the natural tear flow component and the blinking reflex, both of which are defining factors of the ocular environment. The development of a novel model is described in this study, which consists of a unique 2-piece design, eyeball and eyelid piece, capable of mimicking physiological tear volume. The models are created from 3-D printed molds (Polytetrafluoroethylene or Teflon molds), which can be used to generate eye models from various polymers, such as polydimethylsiloxane (PDMS) and agar. Further modifications to the eye pieces, such as the integration of an explanted human or animal cornea or human corneal construct, will permit for more complex in vitro ocular studies. A commercial microfluidic syringe pump is integrated with the platform to emulate physiological tear secretion. Air exposure and mechanical wear are achieved using two mechanical actuators, of which one moves the eyelid piece laterally, and the other moves the eyeballeyepiece circularly. The model has been used to evaluate CLs for drug delivery and deposition of tear components on CLs.

Schulze,M. -M, Srinivasan,S., Hickson-Curran,S. B., Berntsen,D. A., Howarth,G. F., Toubouti,Y., Morgan,P., Nichols,J. J., Jones,L. W. Lid wiper epitheliopathy in soft contact lens wearers Optometry and Vision Science 2016;93(8):943-954 [ Show Abstract ]

Purpose. To evaluate lid wiper epitheliopathy (LWE) in soft contact lens (SCL) wearers on initial presentation and after using various SCL and solution combinations. Methods. LWE was assessed in 253 habitual SCL wearers who attended a screening visit at one of three study sites. LWE was assessed using lissamine green and sodium fluorescein dyes (Korb scale); a final LWE grade was calculated as the averaged LWE grade of the two dyes. Eligible habitual wearers continued into the four study periods, during which they wore one of three SCL types (etafilcon A, galyfilcon A, or senofilcon A) while using each of four care solutions for 10 to 14 days in randomized order. Statistical analyses were performed using linear mixed models, testing for differences in LWE for subject characteristics and between three multipurpose (MPS) test solutions (BioTrue, OPTI-FREE PureMoist, RevitaLens OcuTec) compared to a hydrogen peroxide (Clear Care) control solution. Results. LWE was present in 85% of habitual SCL wearers. LWE was not different for age (p = 0.28), sex (p = 0.99), race (p = 0.34), and comfort (p = 0.38) and not correlated with refractive error (r = 0.07). LWE was lower in habitual senofilcon A wearers (least-squares (LS) mean ± SE = 0.82 ± 0.19) compared to wearers of lotrafilcon B (1.34 ± 0.20; p < 0.02), comfilcon A (1.41 ± 0.21; p < 0.01), and other (1.18 ± 0.16; p < 0.03). Two hundred three participants completed all four study solutions with their assigned lens type; LWE was not different between the MPSs compared to the peroxide control solution across lens materials, except for less LWE for BioTrue (0.88 ± 0.17) versus Clear Care for participants wearing galyfilcon A (1.11 ± 0.18; p < 0.01). Conclusions. On initial presentation, LWE was present in 85% of habitual wearers and found to be independent of age, sex, race, comfort, and refractive error but dependent on habitual SCL type. There were no clinically meaningful differences in LWE between the MPSs and hydrogen peroxide solution for the three lens types studied. © Copyright 2016 American Academy of Optometry.

Stahl,U., Keir,N. J., Landers,A., Jones,L. W. Effect of short recovery periods on ocular comfort during daily lens wear Optometry and Vision Science 2016;93(8):861-871 [ Show Abstract ]

Purpose. To assess the impact of lens-free intervals of varying lengths on end-of-day comfort with soft contact lenses. Methods. Twenty-five symptomatic lens wearers participated in this randomized, cross-over study involving nine individual 12-hour days: one spectacle (no lens) and eight lens wear days. On each lens wear day, lenses were worn bilaterally in 2-hour intervals, separated by lens-free (recovery) periods of 0, 30, 60, or 80 minutes (repeated throughout the day). For each 2-hour lens wear interval, new lenses were worn. Ocular comfort was rated on a 0 to 100 visual analogue scale (0 = extremely uncomfortable); tear film and ocular parameters were assessed at the beginning and end of each study day. This study involved two different types of silicone hydrogel lenses, and the order of lens type and length of recovery period was randomized. Participants were unaware of the true study purpose and that a new lens pair was used for each lens wear interval. Results. End-of-day comfort on lens wear days was significantly worse than on the spectacle day (p 0.05). Although lens wear affected noninvasive tear film break-up time and conjunctival staining, there were no effects of recovery period length on noninvasive tear film break-up time (p > 0.05), tear meniscus height (p > 0.05), corneal staining (p > 0.05), conjunctival staining (p > 0.05), bulbar conjunctival redness (p > 0.05), or limbal redness (p > 0.05). There was no consistent effect of recovery period length on lid margin staining. Conclusions. Lens-free recovery periods during a 12-hour lens wear day did not positively impact end-of-day comfort in this study. Cumulative lens wear times ranged from 8 to 12 hours, and the results suggest that once the length of lens wear exceeds the usual comfortable wear time, there is no benefit of short recovery periods. © Copyright 2016 American Academy of Optometry.

Verma,M. S., Tsuji,J. M., Hall,B., Chen,P. Z., Forrest,J., Jones,L., Gu,F. X. Towards point-of-care detection of polymicrobial infections: Rapid colorimetric response using a portable spectrophotometer Sensing and Bio-Sensing Research 2016;1015-19 [ Show Abstract ]

Infectious diseases spread rapidly because current diagnostic methods are slow, expensive, and require technical expertise. Biosensors have recently been used as devices that can be deployed at the point-of-care for rapid and accurate diagnosis. Here, we show that a “chemical nose” biosensor based on gold nanoparticles can be coupled with a portable spectrophotometer to detect monomicrobial and polymicrobial solutions of pathogenic bacteria within 2 min of data collection. The design presented here exploits the rapid kinetics of gold nanoparticle aggregation around bacteria, which leads to a dramatic color change. The “chemical nose” produces unique signals based on the surface characteristics of the bacteria—such as the presence of extracellular polymeric substances, distribution of charged lipids, and localization of proteins—and hence provides a versatile platform for detection. We present a biosensor design that can easily be translated to the point-of-care because of its rapid response and simple output. © 2016 The Authors

Verma,M. S., Wei,S. -C, Rogowski,J. L., Tsuji,J. M., Chen,P. Z., Lin,C. -W, Jones,L., Gu,F. X. Interactions between bacterial surface and nanoparticles govern the performance of "chemical nose" biosensors Biosensors and Bioelectronics 2016;83:115-125 [ Show Abstract ]

Rapid and portable diagnosis of pathogenic bacteria can save lives lost from infectious diseases. Biosensors based on a "chemical nose" approach are attracting interest because they are versatile but the governing interactions between bacteria and the biosensors are poorly understood. Here, we use a "chemical nose" biosensor based on gold nanoparticles to explore the role of extracellular polymeric substances in bacteria-nanoparticle interactions. We employ simulations using Maxwell-Garnett theory to show how the type and extent of aggregation of nanoparticles influence their colorimetric response to bacteria. Using eight different species of Gram-positive and Gram-negative bacteria, we demonstrate that this "chemical nose" can detect and identify bacteria over two orders of magnitude of concentration (89% accuracy). Additionally, the "chemical nose" differentiates between binary and tertiary mixtures of the three most common hospital-isolated pathogens: Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa (100% accuracy). We demonstrate that the complex interactions between nanoparticles and bacterial surface determine the colorimetric response of gold nanoparticles and thus, govern the performance of "chemical nose" biosensors. © 2016 Elsevier B.V.

Walther,H., Subbaraman,L., Jones,L. W. In vitro cholesterol deposition on daily disposable contact lens materials Optometry and Vision Science 2016;93(1):36-41 [ Show Abstract ]

Purpose. The goal of this study was to analyze how various incubation times affect the uptake of cholesterol on silicone hydrogel (SH) and conventional hydrogel (CH) daily disposable (DD) contact lens materials using an in vitro radiochemical detectionmethod. Methods. Three SH (somofilcon A, delefilcon A, and narafilcon A) and four CH (etafilcon A, nesofilcon A, ocufilcon A, and nelfilcon A) contact lenses were incubated in an artificial tear solution that contained major tear film components and a portion of radioactive 14C-cholesterol. Lenses (N = 4) were incubated for four incubation times (2, 6, 12, or 16 h) to assess the effects on cholesterol deposition. Subsequent to the incubation, the lenses were extracted using 2:1 chloroform:methanol, and the extracts were analyzed in a beta counter and (in nanograms per lens) extrapolated from standard curves. Results. In general, cholesterol deposited statistically significantly more on SH lenses than CHs (p e 0.033), with the exception of somofilcon A and nesolfilcon A materials (p = 0.067). Within the SH materials, narafilcon A accumulated the largest quantity of cholesterol (p G 0.05) and somofilcon A the lowest (p G 0.05). The uptake of cholesterol ranged from 22.63 T 2.98 ng/lens to 97.94 T 4.18 ng/lens for all lens materials. The accumulation of cholesterol was shown to be continuous throughout the 16 h of incubation, without reaching a plateau (p G 0.001). Conclusions. For the periods thatDDlens materials are worn, cholesterol deposits significantlymore ontoSHcontact lenses than CHs. This could have implications for wearers who have higher levels of lipid in their tears that are fitted with SH DD materials. Copyright © American Academy of Optometry.

Wolffsohn,J. S., Calossi,A., Cho,P., Gifford,K., Jones,L., Li,M., Lipener,C., Logan,N. S, Malet,F., Matos,S., Meijome,J. M. G., Nichols,J .J., Orr, J.B., Santodomingo-Rubido,J., Schaefer,T., Thite,N., van der Worp,E., Zvirgzdina, M. Global trends in myopia management attitudes and strategies in clinical practice. Contact Lens and Anterior Eye 2016;39(2):106-116

Woods,J., Jones,L. W. Pilot study to determine the effect of lens and eye rinsing on Solution-Induced Corneal Staining (SICS) Optometry and Vision Science 2016;93(10):1218-1227 [ Show Abstract ]

Purpose The main purpose of this study was to determine whether two interventions (rinsing the lens before lens insertion and rinsing the ocular surface post-lens removal) had any impact on solution-induced corneal staining (SICS). In addition, the presence of hyper-reflective epithelial cells in the presence of SICS was investigated. Methods Twenty subjects wore new balafilcon A lenses, which had been soaked overnight in a multipurpose care product containing polyhexamethylene biguanide for 2 hours. The study was conducted across three phases. In phase 1 (investigator and subject masked, randomized eye), one lens was rinsed with nonpreserved saline before lens insertion. In phase 2 (investigator masked, randomized eye), one eye was rinsed with nonpreserved saline after lens removal, before staining assessment. Corneal staining was recorded as the percentage area of the cornea exhibiting superficial punctate staining. In both phases, ocular comfort and presence of specific symptoms were captured. In phase 3, there was no randomized treatment; confocal images of the epithelium were obtained after 2 hours of wear. Results In phase 1 (lens-rinse), there was no significant difference in staining between the treated and untreated eyes (84 vs. 92%, respectively; p = 0.06). In phase 2 (eye-rinse), there was also no significant difference between the treated and untreated eye (86 vs. 86%, p = 0.92). Most subjects were asymptomatic. In phase 3, images of hyper-reflective cells were captured in 97% of the eyes imaged. Conclusions The two rinsing procedures did not affect the level of the SICS response. Hyper-reflective epithelial cells were found to be present in a significant number of eyes exhibiting SICS, and their presence warrants further investigation. © 2016 American Academy of Optometry.

2015

Bajgrowicz,M., Phan,C. -M, Subbaraman,L. N., Jones,L. Release of ciprofloxacin and moxifloxacin from daily disposable contact lenses from an in vitro eye model Investigative Ophthalmology and Visual Science 2015;56(4):2234-2242 [ Show Abstract ]

Purpose. To analyze the release of two fluoroquinolones, ciprofloxacin and moxifloxacin, from conventional hydrogel (CH) and silicone hydrogel (SH) daily disposable contact lenses (CLs), comparing release from a fixed-volume vial and a novel in vitro eye model. Methods. Four CH CLs (nelfilcon A, omafilcon A, etafilcon A, ocufilcon B) and three SH CLs (somofilcon A, narafilcon A, delefilcon A) were used. The lenses were incubated in drug solutions for 24 hours. After the incubation period, the lenses were placed in two release conditions: (1) a vial containing 4.8 mL PBS for 24 hours and (2) an in vitro eye model with a flow rate at 4.8 mL over 24 hours. Results. Release in the vial for both drugs was rapid, reaching a plateau between 15 minutes and 2 hours for all lenses. In contrast, under physiological flow conditions, a constant and slow release was observed over 24 hours. The amounts of ciprofloxacin released from the lenses ranged between 49.6 ±0.7 and 62.8 ± 0.3 µg per lens in the vial, and between 35.0 ± 7.0 and 109.0 ± 5.0 µg per lens in the eye model. Moxifloxacin release ranged from 24.0 ± 4.0 to 226.0 ± 2.0 µg per lens for the vial, and between 13.0 ± 2.0 and 151.0 ± 10.0 µg per lens in the eye model. In both systems and for both drugs, HEMA-based CLs released more drugs than other materials. Conclusions. The parameters of the release system, in particular the volume and flow rate, have a significant influence on measured release profiles. Under physiological flow, release profiles are significantly slower and constant when compared with release in a vial. © 2015, The Association for Research in Vision and Ophthalmology, Inc.

Chang,J. M. L., McCanna,D. J., Subbaraman,L. N., Jones,L. W. Efficacy of antimicrobials against biofilms of achromobacter and pseudomonas Optometry and Vision Science 2015;92(4):506-513 [ Show Abstract ]

Purpose. Achromobacter xylosoxidans and Pseudomonas aeruginosa biofilms can develop in ophthalmic products and accessories such as contact lens cases, leading to the development of ocular infections. This study evaluated the efficacy of the antimicrobials polyaminopropyl biguanide (PAPB) and benzalkonium chloride (BAK) against A. xylosoxidans and P. aeruginosa biofilms. Methods. Biofilms of A. xylosoxidans and P. aeruginosa used as a comparative control were formed by incubating the bacteria on contact lens cases and on coverslips in phosphate-buffered saline. The biofilms were then exposed to PAPB and BAK for 5 minutes and 4 hours. After exposure, alginate swabs were used to remove the biofilms from the lens cases and the bacteria were plated on tryptic soy agar for determination of survivors. Also, after exposure to these disinfectants, the A. xylosoxidans and P. aeruginosa biofilms were stained with SYTO 9 and propidium iodide. Using a confocal microscope with a 488-nm laser, the number of cells with damaged cell membranes was determined. Results. After 5 minutes of exposure to BAK or PAPB, A. xylosoxidans biofilms were more resistant to the antimicrobial effects of these disinfectants than P. aeruginosa biofilms. After 4 hours, both organisms were reduced by more than 3 logs after exposure to either BAK or PAPB. Confocal microscopy studies revealed that BAK was more effective at damaging A. xylosoxidans and P. aeruginosa cell membranes than PAPB at the concentrations used in ophthalmic products. Conclusions. Biofilms of the emerging pathogen A. xylosoxidans were more resistant to the disinfectants PAPB and BAK than biofilms of P. aeruginosa. Because of the emergence of A. xylosoxidans and the demonstrated greater resistance to the common ophthalmic preservatives BAK and PAPB than the standard Gram-negative organism P. aeruginosa, A. xylosoxidans biofilms should be assessed in antimicrobial challenge tests to assure the safety of multiuse ophthalmic products. Copyright © 2015 American Academy of Optometry.

Guthrie,S. E., Jones,L., Blackie,C. A., Korb,D. R. A Comparative Study Between an Oil-in-Water Emulsion and Nonlipid Eye Drops Used for Rewetting Contact Lenses Eye and Contact Lens 2015;41(6):373-377 [ Show Abstract ]

OBJECTIVES: The purpose of this study was to determine the clinical impact of using SYSTANE BALANCE Lubricant Eye Drops (Alcon, Fort Worth, TX), an oil-in-water emulsion, as a rewetting eye drop in symptomatic contact lens wearers.
METHODS: Subjects who had previously experienced contact lens discomfort (CLD), with a mean lens wearing history of 18.6±12.8 years, were randomly assigned to use a Test (SYSTANE BALANCE Lubricant Eye Drops; n=76) or control (habitual nonlipid contact lens rewetting eye drop; n=30) drop over their contact lenses within 5 min of lens insertion and then subsequently at 2 hr intervals up to a maximum of 4 drops per eye daily for a 1-month period. Assessments of subjective comfort, comfortable wearing time, lid wiper epitheliopathy (LWE), and corneal staining were conducted at baseline and after 1 month, after 6 hr of lens wear.
RESULTS: Comfort, wearing time, LWE, and corneal staining all showed statistically significant improvements in the test group using SYSTANE BALANCE Lubricant Eye Drops at the 1-month visit compared with baseline data (all P<0.01) and compared with the control group at the 1-month visit (P<0.01, P=0.01, P<0.01, and P=0.03, respectively).
CONCLUSIONS: The use of SYSTANE BALANCE Lubricant Eye Drops as a rewetting drop in a group of wearers who experienced symptoms of CLD improved subjective comfort scores, increased comfortable wearing time, and reduced signs of LWE and corneal staining, when compared with the use of non–lipid-containing contact lens rewetting eye drops.

Hagedorn,S., Drolle,E., Lorentz,H., Srinivasan,S., Leonenko,Z., Jones,L. Atomic force microscopy and Langmuir-Blodgett monolayer technique to assess contact lens deposits and human meibum extracts Journal of Optometry 2015;8(3):187-199 [ Show Abstract ]

Purpose The purpose of this exploratory study was to investigate the differences in meibomian gland secretions, contact lens (CL) lipid extracts, and CL surface topography between participants with and without meibomian gland dysfunction (MGD). Methods Meibum study: Meibum was collected from all participants and studied via Langmuir-Blodgett (LB) deposition with subsequent Atomic Force Microscopy (AFM) visualization and surface roughness analysis. CL Study: Participants with and without MGD wore both etafilcon A and balafilcon A CLs in two different phases. CL lipid deposits were extracted and analyzed using pressure-area isotherms with the LB trough and CL surface topographies and roughness values were visualized using AFM. Results Meibum study: Non-MGD participant meibum samples showed larger, circular aggregates with lower surface roughness, whereas meibum samples from participants with MGD showed more lipid aggregates, greater size variability and higher surface roughness. CL Study: Worn CLs from participants with MGD had a few large tear film deposits with lower surface roughness, whereas non-MGD participant-worn lenses had many small lens deposits with higher surface roughness. Balafilcon A pore depths were shallower in MGD participant worn lenses when compared to non-MGD participant lenses. Isotherms of CL lipid extracts from MGD and non-MGD participants showed a seamless rise in surface pressure as area decreased; however, extracts from the two different lens materials produced different isotherms. Conclusions MGD and non-MGD participant-worn CL deposition were found to differ in type, amount, and pattern of lens deposits. Lipids from MGD participants deposited irregularly whereas lipids from non-MGD participants showed more uniformity. © 2014 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

Hall,B., Jones,L. W., Forrest,J. A. Competitive effects from an artificial tear solution to protein adsorption Optometry and Vision Science 2015;92(7):781-789 [ Show Abstract ]

Purpose To compare the adsorption of lysozyme, lactoferrin, and albumin to various contact lens materials, between single-protein solutions and a multicomponent artificial tear solution (ATS). Additionally, extra steps were taken to distinguish loosely and tightly bound protein, the latter of which may be fully or partially denatured. Methods Using a previously described ATS, we measured the time-dependent adsorption of lys, lac, and alb onto one conventional hydrogel and four silicone hydrogel contact lens materials between the first minute and up to 1 week of protein interaction with the material surface. Proteins were quantified using I125 radiolabeling of each protein individually in ATS and buffered saline. Extra steps were taken to limit the amount of unbound I125 and to quantify the amount of reversibly bound protein. Results Comfilcon A, balafilcon A, and etafilcon A did not show any relevant competitive adsorption between the ATS components and lys, lac, or alb until after 1 week. Competitive adsorption effects for lys, lac, and alb were observed in as little as 1 minute on lotrafilcon B. Lotrafilcon B had no reversibly bound protein at any time points. The ionic materials balafilcon A and etafilcon A deposited significant amounts of reversibly bound lysozyme and lactoferrin in just 10 minutes. Senofilcon A apparent deposition was below our thresholds of confidence for this protein quantification method. Conclusions Both the competition between lys, lac, and alb and ATS components and the reversibility of these bound proteins is material specific. Coadsorption of lys, lac, and alb with ATS components can increase the reversibility of their adsorption. © 2015 American Academy of Optometry.

Hall,B., Jones,L., Forrest,J. A. Kinetics of competitive adsorption between lysozyme and lactoferrin on silicone hydrogel contact lenses and the effect on lysozyme activity Current eye research 2015;40(6):622-631 [ Show Abstract ]

To determine the effect of competitive adsorption between lysozyme and lactoferrin on silicone hydrogel contact lenses and the effect on lysozyme activity. Methods: Three commercially available silicone hydrogel contact lens materials (senofilcon A, lotrafilcon B and balafilcon A) were examined, for time points ranging from 10s to 2h. Total protein deposition was determined by I125 radiolabeling of lysozyme and lactoferrin, while the activity of lysozyme was determined by a micrococcal activity assay. Results: Senofilcon A and balafilcon A did not show any relevant competitive adsorption between lysozyme and lactoferrin. Lotrafilcon B showed reduced protein deposition due to competitive adsorption for lactoferrin at all time points and lysozyme after 7.5min. Co-adsorption of lactoferrin and lysozyme decreased the activity of lysozyme in solution for senofilcon A and lotrafilcon B, but co-adsorption had no effect on the surface activity of lysozyme for all lens types investigated. Conclusions: Competition between lysozyme and lactoferrin is material specific. Co-adsorption of lysozyme and lactoferrin does not affect the activity of surface-bound lysozyme but can reduce the activity of subsequently desorbed lysozyme. © 2015 Informa Healthcare USA, Inc.

Korogiannaki,M., Guidi,G., Jones,L., Sheardown,H. Timolol maleate release from hyaluronic acid-containing model silicone hydrogel contact lens materials. J Biomat Appl 2015;30(3):361-376

Liu,S., Chang,C. N., Verma,M. S., Hileeto,D., Muntz,A., Stahl,U., Woods,J., Jones,L. W., Gu,F. X. Phenylboronic acid modified mucoadhesive nanoparticle drug carriers facilitate weekly treatment of experimentallyinduced dry eye syndrome Nano Research 2015;8(2):621-635

Luensmann,D., Yu,M., Yang,J., Srinivasan,S., Jones,L. Impact of cosmetics on the physical dimension and optical performance of silicone hydrogel contact lenses Eye and Contact Lens 2015;41(4):218-227 [ Show Abstract ]

Objectives: To evaluate the impact of cosmetics on silicone hydrogel (SiHy) contact lens shape, lens power, and optical performance. Methods: In this in vitro experiment, 7 SiHy materials were coated with 9 marketed brands of cosmetics, including hand creams (HCs) (3), eye makeup removers (MRs) (3), and mascaras (3). Diameter, sagittal depth, and base curve were determined using the Chiltern (Optimec Limited), whereas lens power and optical performance were assessed using the Contest Plus (Rotlex). Six replicates were used for each lens and cosmetic combination.Measurements were repeated after a cleaning cycle using a one-step hydrogen peroxide solution. Results: Makeup removers had the greatest impact on diameter, sagittal depth, and base curve, resulting in changes of up to 0.5, 0.15, and 0.77 mm, respectively. The HCs and mascaras had little impact on these parameters; however, differences were observed between lens types. Optical performance was reduced with all mascaras, and a decrease of greater than 2 units on a 0 to 10 scale (10=uniform power distribution) was seen for 5 lens types exposed to waterproof mascara (P0.05). Lens cleaning resulted in some recovery of the lens parameters, and efficiency varied between cosmetics. Conclusion: Some eye MRs and waterproof mascaras changed the shape and optical performance of some SiHy lenses. Further research is needed to understand the clinical implications for SiHy lens wearers using cosmetics. © 2015 Contact Lens Association of Opthalmologists, Inc.

Menzies,Kara L., Srinivasan,Sruthi, Prokopich,C. Lisa, Jones,Lyndon Infrared Imaging of Meibomian Glands and Evaluation of the Lipid Layer in Sjögren's Syndrome Patients and Nondry Eye Controls Investigative ophthalmology & visual science 2015;56(2):836-841 [ Show Abstract ]

Purpose. The purpose of this study was to evaluate meibomian gland dropout and lipid layer thickness (LLT) in patients with and without Sjögren's syndrome dry eye (SS).Methods. We recruited 11 participants with SS (males/females [M/F], 1:10; mean age = 56.0 ± 9.1 years) and 10 control subjects without dry eye (M/F, 3:7; mean age = 58.5 ± 4.7 years). All participants completed the Ocular Surface Disease Index (OSDI) questionnaire. The LLT was assessed using the Tearscope Plus based on the appearance of the lipid layer. Noninvasive tear break-up time (NITBUT) also was measured. The lower and upper lids were everted, and the meibomian glands were imaged using the infrared camera of the Keratograph 4. A meibomian gland dropout score due to gland loss was obtained. Statistical analysis was conducted using the Mann-Whitney U test and correlations were determined using Spearman rank correlations.Results. Of the SS participants, 100% reported ocular and oral dryness symptoms in the AECC questionnaire. The SS group recorded a higher OSDI score (median = 48.00, interquartile range [IQR] 23.0–56.2 vs. 2.1, IQR 0.0–2.6; P < 0.001), reduced LLT (median [IQR] = 15.0 [15.0–15.0] vs. 60.0 [45.0–100.0] nm; P = 0.001), and lower NITBUT (median [IQR] = 3.7 [2.5–4.2] vs. 9.5 [6.4–17.6] sec; P < 0.001) compared to the controls. Digital meibomian gland dropout score (% dropout) was significantly higher for the SS group (16.0% [IQR 12.1–40.0%] vs. 6.7% [IQR 1.5–12.7%]; P = 0.01). Subjective meibomian gland dropout score (0–6 score) was significantly higher for the SS group (median [IQR] = 1.5 [1.0–4.0] vs. 1.0 [0.0–1.25]; P = 0.03).Conclusions. Patients with SS showed higher meibomian gland dropout scores and reduced LLT and NITBUT, which likely contribute to the severe dry eye symptoms reported by SS subjects.

Moezzi,A. M., Fonn,D., Varikooty,J., Simpson,T. L. Overnight corneal swelling with high and low powered silicone hydrogel lenses Journal of Optometry 2015;8(1):19-26 [ Show Abstract ]

Purpose To compare central corneal swelling after eight hours of sleep in eyes wearing four different silicone hydrogel lenses with three different powers. Methods Twenty-nine neophyte subjects wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60) and senofilcon A (Dk, 103) lenses in powers -3.00, -10.00 and +6.00 D on separate nights, in random order, and on one eye only. The contra-lateral eye (no lens) served as the control. Central corneal thickness was measured using a digital optical pachometer before lens insertion and immediately after lens removal on waking. Results For the +6.00 D and -10.00 D, lotrafilcon A induced the least swelling and galyfilcon A the most. The +6.00 D power, averaged across lens materials, induced significantly greater central swelling than the -10.00 and -3.00 D (Re-ANOVA, p < 0.001), (7.7 ± 2.9% vs. 6.8 ± 2.8% and 6.5 ± 2.5% respectively) but there was no difference between -10.00 and -3.00 D. Averaged for power, lotrafilcon A induced the least (6.2 ± 2.8%) and galyfilcon A the most (7.6 ± 3.0%) swelling at the center (Re-ANOVA, p < 0.001). Central corneal swelling with +6.00 D was significantly greater than -10.00 D lens power despite similar levels of average lens transmissibility of these two lens powers. Conclusions The differences in corneal swelling of the lens wearing eyes are consistent with the differences in oxygen transmission of the silicone hydrogel lenses. In silicone hydrogel lenses central corneal swelling is mainly driven by central lens oxygen transmissibility.

Muntz,A., Subbaraman,L. N., Sorbara,L., Jones,L. Tear exchange and contact lenses: A review Journal of Optometry 2015;8(1):2-11 [ Show Abstract ]

Tear exchange beneath a contact lens facilitates ongoing fluid replenishment between the ocular surface and the lens. This exchange is considerably lower during the wear of soft lenses compared with rigid lenses. As a result, the accumulation of tear film debris and metabolic by-products between the cornea and a soft contact lens increases, potentially leading to complications. Lens design innovations have been proposed, but no substantial improvement in soft lens tear exchange has been reported. Researchers have determined post-lens tear exchange using several methods, notably fluorophotometry. However, due to technological limitations, little remains known about tear hydrodynamics around the lens and, to-date, true tear exchange with contact lenses has not been shown. Further knowledge regarding tear exchange could be vital in aiding better contact lens design, with the prospect of alleviating certain adverse ocular responses. This article reviews the literature to-date on the significance, implications and measurement of tear exchange with contact lenses.

Ngo,W., Caffery,B., Srinivasan,S., Jones,L. W. Effect of lid debridement-scaling in sjögren syndrome dry eye Optometry and Vision Science 2015;92(9):e316-e320 [ Show Abstract ]

Purpose To evaluate the effect of lid debridement-scaling (LDS) on dry eye signs and symptoms in subjects with Sjögren syndrome (SS). Methods This prospective randomized controlled study enrolled 14 female subjects with SS. Seven subjects were randomized into the treatment group where they were selected to receive LDS; the remainder did not receive LDS and served as control subjects. Lid debridement-scaling was conducted using a stainless steel golf club spud (Hilco Wilson Ophthalmics, Plainville, MA) on both the upper and lower eyelids of both eyes. Outcome variables were assessed before LDS and again 1 month later. The outcome variables were the Ocular Surface Disease Index (OSDI), Symptom Assessment iN Dry Eye (SANDE) visual analog scores, ocular staining (SICCA OSS [Sjögren's International Collaborative Clinical Alliance Ocular Staining Score]), fluorescein tear breakup time (FLBUT), meibomian gland score (MGS), meibomian gland yielding liquid secretions (MGYLS) score, and line of Marx's (LOM) position. Results Thirteen subjects completed the study. Data from only the right eye were analyzed. For the control group (n = 6; mean [±SD] age, 62.3 [±11.6] years), the pre-LDS, post-LDS, and significance level (pre-LDS mean [±SD] vs. post-LDS mean [±SD]; p value) were as follows: OSDI (58.3 [±22.1] vs. 48.3 [±29.0]; p = 0.051), SANDE (77.4 [±22.1] vs. 89.6 [±32.6]; p = 0.20), SICCA OSS (7.0 [±4.5] vs. 8.2 [±3.5]; p = 0.25), MGS (1.3 [±1.5] vs. 1.0 [±0.9]; p = 0.75), MGYLS (0.3 [±0.5] vs. 0.0 [±0.0]; p = 0.50), FLBUT (2.99 [±1.54] vs. 2.85 [±1.79]; p = 0.63), and LOM (2.0 [±0.0] vs. 2.0 [±0.0]; p = n/a). For the treatment group (n = 7; mean [±SD] age, 58.0 [±8.1] years), the pre-LDS, post-LDS, and significance level were as follows: OSDI (63.2 [±13.3] vs. 46.9 [±19.4]; p = 0.04), SANDE (72.6 [±17.1] vs. 77.0 [±28.0]; p = 0.54), SICCA OSS (6.6 [±2.9] vs. 5.0 [±3.9]; p = 0.02), MGS (1.0 [±1.2] vs. 3.1 [±1.7]; p = 0.01), MGYLS (0.0 [±0.0] vs. 0.6 [±1.0]; p = 0.50), FLBUT (3.13 [±0.81] vs. 3.45 [±1.03]; p = 0.53), and LOM (0.9 [±0.9] vs. 1.0 [±1.0]; p = 1.00). Conclusions This pilot study showed that LDS improved symptoms, ocular staining, and meibomian gland function for the group that received LDS. This indicates that LDS can aid in the management of SS dry eye. © 2015 American Academy of Optometry.

Omali,N. B., Subbaraman,L. N., Coles-Brennan,C., Fadli,Z., Jones,L. W. Biological and clinical implications of lysozyme deposition on soft contact lenses Optometry and Vision Science 2015;92(7):750-757 [ Show Abstract ]

Within a few minutes of wear, contact lenses become rapidly coated with a variety of tear film components, including proteins, lipids, and mucins. Tears have a rich and complex composition, allowing a wide range of interactions and competitive processes, with the first event observed at the interface between a contact lens and tear fluid being protein adsorption. Protein adsorption on hydrogel contact lenses is a complex process involving a variety of factors relating to both the protein in question and the lens material. Among tear proteins, lysozyme is a major protein that has both antibacterial and anti-inflammatory functions. Contact lens materials that have high ionicity and high water content have an increased affinity to accumulate lysozyme during wear, when compared with other soft lens materials, notably silicone hydrogel lenses. This review provides an overview of tear film proteins, with a specific focus on lysozyme, and examines various factors that influence protein deposition on contact lenses. In addition, the impact of lysozyme deposition on various ocular physiological responses and bacterial adhesion to lenses and the interaction of lysozyme with other tear proteins are reviewed. This comprehensive review suggests that deposition of lysozyme on contact lens materials may provide a number of beneficial effects during contact lens wear. © 2015 American Academy of Optometry.

Pucker,A. D., Jones-Jordan,L. A., Li,W., Kwan,J. T., Lin,M. C., Sickenberger,W., Marx,S., Srinivasan,S., Jones,L. W. Associations with meibomian gland atrophy in daily contact lens wearers Optometry and Vision Science 2015;92(9):e206-e213 [ Show Abstract ]

Purpose To determine associations for contact lenses (CLs) and meibomian gland atrophy in a matched-pair study. Methods Contact lens wearers (case) and age- and sex-matched non-contact lens (NCL) wearers with no history of CL use (control) were recruited for a multicenter study. All subjects were administered the Ocular Surface Disease Index questionnaire and a comprehensive battery of clinical tests (e.g., tear breakup time, bulbar and limbal redness, meibography, etc.) were performed. Upper and lower eyelid meibomian gland atrophy were graded with both digital meibography (percent gland atrophy) and visual meiboscore methods. Conditional logistic regression analyses were then used to determine relationships among CL use, meibomian gland atrophy, and ocular surface signs and symptoms. Results A total of 70 matched pairs were analyzed. The mean (±SD) age of the CL group was 30.6 (±12.4) years, and that of the NCL group was 30.1 (±12.2) years. The subjects were 63% female. The association between CL wear and meiboscore was not significant univariately, but the best-fitting multivariate regression model showed that higher meiboscores were associated with being a CL wearer (odds ratio [OR], 2.45) in a model that included eyelid margin erythema (OR, 0.25) and lissamine green staining (OR, 1.25). Percent gland atrophy was not associated with CL wear in regression analysis (p = 0.31). Conclusions This study determined inconclusive associations with CLs and meibomian gland atrophy. This study also provided a comprehensive assessment of differences between CL and NCL wearers. © 2015 American Academy of Optometry.

Samsom,M., Chan,A., Iwabuchi,Y., Subbaraman,L., Jones,L., Schmidt,TA In vitro friction testing of contact lenses and human ocular tissues: Effect of proteoglycan 4 (PRG4) Tribology International 2015;89:27-33 [ Show Abstract ]

Contact lens friction was recently shown to correlate with in vivo comfort, with lower friction lenses providing improved comfort. Proteoglycan 4 (PRG4) is a recently discovered ocular surface boundary lubricant. The objectives of this study were to measure the friction of commercially available silicone hydrogel (SiHy) contact lenses against human cornea and eyelid tissues, and evaluate the ability of PRG4 to lubricate, and adhere to, SiHy contact lenses. The in vitro friction test employed here effectively measured and distinguished the SiHy contact lens friction coefficients against human eyelid and cornea tissues, and PRG4 functioned as an effective boundary lubricant.

Srinivasan,S., Otchere,H., Yu,M., Yang,J., Luensmann,D., Jones,L. Impact of cosmetics on the surface properties of silicone hydrogel contact lenses Eye and Contact Lens 2015;41(4):228-235 [ Show Abstract ]

Purpose: This study evaluated the impact of various cosmetics on the surface properties of silicone hydrogel (SiHy) contact lens materials. Methods: In this in vitro experiment, 7 SiHy contact lens materials were coated with 1 of 9 cosmetics, including common hand creams (3), eye makeup removers (3), and mascaras (3). Dark-field microscopy images were taken to determine pixel brightness (PB) after cosmetic exposure, which describes the visible surface deposition (n=6 for each lens type), with a higher PB indicating increased deposition. The sessile drop technique was used to determine the advancing contact angle (CA). Measurements were repeated for both methods after a single peroxide-based cleaning cycle. Results: Pixel brightness was significantly higher for mascara-coated lenses compared with the other cosmetic products (P,0.01). The peroxide-based lens care solution removed most deposits from the nonwaterproof mascara for 4 lens types, whereas deposits remained relatively unchanged for 1 waterproof mascara (P.0.05). Hand creams and makeup remover had minimal impact on PB. Changes in CA measurements after cosmetic application were highly lens dependent. Hand creams caused primarily a decrease in CA for 5 of the 7 lens types, whereas 1 of the waterproof mascaras caused a significant increase of 30 to 50° for 3 lens types. Conclusion: Some mascara-lens combinations resulted in increased CA and PB, which could have an impact on in vivo lens performance. Nonwaterproof mascara was mostly removed after a cleaning cycle. Further research is needed to understand the clinical implications for SiHy lens wearers using cosmetics. © 2015 Contact Lens Association of Opthalmologists, Inc.

Varikooty J., Srinivasan S., Subbaraman L., Woods C.A., Fonn D., Simpson T.L., Jones L.W. Variations in observable lid wiper epitheliopathy (LWE) staining patterns in wearers of silicone hydrogel lenses Contact Lens and Anterior Eye 2015;38(6):471-476

Varikooty,J., Schulze,M. M., Dumbleton,K., Keir,N., Woods,C. A., Fonn,D., Jones,L. W. Clinical performance of three silicone hydrogel daily disposable lenses Optometry and Vision Science 2015;92(3):301-311 [ Show Abstract ]

Purpose. To determine the clinical performance of DAILIES TOTAL1 (DT1), Clariti 1Day (C1D), and 1-DAY ACUVUE TruEye (AVTE) silicone hydrogel daily disposable contact lenses (SiHy DDCLs). Methods. Eligible participants, subdivided into asymptomatic and symptomatic groups, wore each SiHy DDCLs for three consecutive days. Each participant attended three visits (on day 1 at 0 hours; on days 1 and 3 after 8 hours ofwear) per lens type. The order of lens wear was randomized, with at least 1 day washout between lenses. Lens-related performance was evaluated by assessing lens surface deposits, wettability, pre-lens noninvasive tear breakup time, lens movement, and centration; ocular response assessments included conjunctival redness, corneal staining, and conjunctival staining and indentation. Results. Fifty-one asymptomatic and 53 symptomatic participantscompleted the study. For all visits, themeannoninvasive tear breakup timewas about 1 second longer withDT1 than withC1DandAVTE (p < 0.01).Overall, thewettability of all three lenses was good; however, DT1 was graded marginally better than the other lenses (both p < 0.01). On day 3, eyes wearing AVTE had significantly more dehydration-induced corneal staining compared with DT1 (AVTE, 24%; DT1, 11%; p < 0.01). After 8 hours, conjunctival staining was different between lenses (greatest with C1D and least with DT1; all p < 0.01). Conjunctival indentation was more prevalent with the C1D lenses (n = 70) compared with DT1 (n = 1; p < 0.01) and AVTE (n = 11; p < 0.01). Therewere no differences between asymptomatic and symptomatic lenswearers for any of the clinical parameters (all p 9 0.05). Conclusions. Each of the three SiHy DDCLs performed well. Noninvasive tear breakup time was longest and wettability was greater with DT1. C1D had the most conjunctival staining conjunctival indentation. There was no difference between asymptomatic and symptomatic wearers with regard to ocular response and contact lensYrelated parameters. These results suggest that SiHy DDCLs may be an excellent contact lens modality for the symptomatic patient.

Verma,M. S., Chen,P. Z., Jones,L., Gu,F. X. Controlling "chemical nose" biosensor characteristics by modulating gold nanoparticle shape and concentration Sensing and Bio-Sensing Research 2015;513-18 [ Show Abstract ]

Conventional lock-and-key biosensors often only detect a single pathogen because they incorporate biomolecules with high specificity. "Chemical nose" biosensors are overcoming this limitation and identifying multiple pathogens simultaneously by obtaining a unique set of responses for each pathogen of interest, but the number of pathogens that can be distinguished is limited by the number of responses obtained. Herein, we use a gold nanoparticle-based "chemical nose" to show that changing the shapes of nanoparticles can increase the number of responses available for analysis and expand the types of bacteria that can be identified. Using four shapes of nanoparticles (nanospheres, nanostars, nanocubes, and nanorods), we demonstrate that each shape provides a unique set of responses in the presence of different bacteria, which can be exploited for enhanced specificity of the biosensor. Additionally, the concentration of nanoparticles controls the detection limit of the biosensor, where a lower concentration provides better detection limit. Thus, here we lay a foundation for designing "chemical nose" biosensors and controlling their characteristics using gold nanoparticle morphology and concentration. © 2015 The Authors.

Verma,M. S., Rogowski,J. L., Jones,L., Gu,F. X. Colorimetric biosensing of pathogens using gold nanoparticles Biotechnology Advances 2015;33(6):666-680 [ Show Abstract ]

Rapid detection of pathogens is crucial to minimize adverse health impacts of nosocomial, foodborne, and waterborne diseases. Gold nanoparticles are extremely successful at detecting pathogens due to their ability to provide a simple and rapid color change when their environment is altered. Here, we review general strategies of implementing gold nanoparticles in colorimetric biosensors. First, we highlight how gold nanoparticles have improved conventional genomic analysis methods by lowering detection limits while reducing assay times. Then, we focus on emerging point-of-care technologies that aim at pathogen detection using simpler assays. These advances will facilitate the implementation of gold nanoparticle-based biosensors in diverse environments throughout the world and help prevent the spread of infectious diseases. © 2015 Elsevier Inc.

Woods,J., Woods,C., Fonn,D. Visual performance of a multifocal contact lens versus monovision in established presbyopes Optometry and Vision Science 2015;92(2):175-82 [ Show Abstract ]

PURPOSE: To compare subjective and objective visual performance of the Air Optix Aqua Multifocal lens to monovision in a group of subjects requiring a medium level of reading-addition power.

METHODS: Fifty participants with reading additions between 1.25 and 2.00 diopters (inclusive) were randomized into a prospective, crossover clinical trial. They wore monovision and multifocals for 2 weeks in a randomized order. High- and low-contrast logMAR (logarithm of the minimum angle of resolution) acuity and stereopsis were measured at the beginning and end of each period. During each phase, participants performed specific tasks followed by subjective rating surveys and also completed satisfaction rating surveys on days 3, 7, and 12; all were transferred in real time using BlackBerry smartphones. A general rating survey was completed at the dispensing and 2-week visits.

RESULTS: Forty-nine participants completed the study (mean age, 52 years). Distance and near high- and low-contrast acuities were significantly better (p < 0.05) with monovision at all visits. High-contrast intermediate acuity was only better (p < 0.05) with multifocals after 2 weeks. Stereopsis was equivalent after 2 weeks, but better (p < 0.05) with multifocals at dispensing. Subjective ratings were generally equivalent between modalities although there was a trend for multifocals to be rated higher for focus changing and driving, whereas monovision tended to be rated higher for near tasks. For both corrections, the satisfaction survey showed no significant change between days 3, 7, and 12, and the general survey showed that comfort was maintained but subjective vision ratings decreased significantly over the 2 weeks. Twenty-five participants (51%) preferred multifocals, 18 (37%) preferred monovision, and the remaining 6 (12%) declared both unacceptable.

CONCLUSIONS: In this cohort, distance and near acuities were better with monovision, whereas the subjective ratings tended to favor the Air Optix Aqua Multifocal, with the exception of near performance. Preference was statistically similar between both corrections, with a trend toward preferring the multifocal.

2014

Caffery,B. E., Joyce,E., Heynen,M. L., Ritter,R., Jones,L. A., Senchyna,M. Quantification of conjunctival TNF-a in aqueous-deficient dry eye Optometry and Vision Science 2014;91(2):156-162 [ Show Abstract ]

PURPOSE: This study aimed to quantify and compare conjunctival epithelial tumor necrosis factor (NF) a mRNA expression in Sjögren syndrome (SS), non-Sjögren syndrome aqueous-deficient dry eye (non-SS DE), and non-dry eye (NDE) control subjects. METHODS: A total of 76 subjects were recruited for this study: 25 SS (confirmed via American-European Consensus Criteria 2002), 25 non-SS DE (confirmed by symptoms and Schirmer scores = 10 mm), and 26 NDE. Superior and temporal bulbar conjunctival epithelial cells were collected via impression cytology. Epithelial RNA was extracted, and TNF-a mRNA expression was quantified by real-time quantitative polymerase chain reaction. RESULTS: The expression of TNF-a mRNA was found to be significantly higher in the SS group (2.48 ± 1.79) compared to both non-SS DE (0.95 ± 1.18; p < 0.05) and NDE (0.84 ± 0.51; p < 0.05) groups. No difference in TNF-a mRNA expression was found between the non-SS DE and NDE groups (p = 0.67). CONCLUSIONS: These results demonstrate that SS-associated aqueous-deficient dry eye is associated with a significant upregulation of conjunctival epithelial TNF-a mRNA relative to both non-SS DE and control groups. The degree to which TNF-a mRNA is upregulated in SS may contribute to the severe ocular surface damage observed in these patients. Copyright © 2014 American Academy of Optometry.

Cheung,S., Lorentz,H., Drolle,E., Leonenko,Z., Jones,L. W. Comparative study of lens solutions' ability to remove tear constituents Optometry and Vision Science 2014;91(9):1045-1061 [ Show Abstract ]

PURPOSE: The purpose of this study was to use atomic force microscopy to compare and characterize the cleaning abilities of a hydrogen peroxide-based system (HPS) and a polyhexamethylene biguanide-containing multipurpose solution (MPS) at removing in vitro deposited tear film constituents, as well as to determine deposition patterns on various silicone hydrogel contact lenses. METHODS: Silicone hydrogel materials - balafilcon A (BA), lotrafilcon B (LB), and senofilcon A (SA) - were incubated for 1 week in an artificial tear solution (ATS) containing representative lipids, proteins, and salts from the tear film. Atomic force microscopy was used to resolve each lens before and after being cleaned overnight in HPS or MPS. Atomic force microscopy was used again to resolve HPS/MPS-cleaned lenses, which were reincubated in fresh ATS for 1 week, before and after an overnight clean in their respective cleaning solution. RESULTS: Atomic force microscopy imaging was able to characterize lens deposits with high resolution. Lenses incubated in ATS revealed distinct differences in their deposition pattern across lens materials. The surface of BA contained about 20-nm-high deposits, whereas deposit heights up to 150 nm completely occluded the surface of SA. Lotrafilcon B lenses revealed clusters of deposits up to 90 nm. The use of either lens solution left trace amounts of tear film constituents, although components from the MPS were seen adsorbed onto the surface after cleaning. Surface roughness (Ra) measurements revealed a significant difference between ATS-incubated and HPS/MPS-cleaned SA and LB lenses (p < 0.05). Ra between first incubated and HPS/MPS-cleaned reincubated SA and LB was also significant (p < 0.05). CONCLUSIONS: Unique variations in ATS deposition patterns were seen between lenses with atomic force microscopy. The application of both HPS and MPS removed most visible surface deposits. © American Academy of Optometry.

Gorbet,M., Peterson,R., McCanna,D., Woods,C., Jones,L., Fonn,D. Human corneal epithelial cell shedding and fluorescein staining in response to silicone hydrogel lenses and contact lens disinfecting solutions Current eye research 2014;39(3):245-256 [ Show Abstract ]

Purpose: A pilot study was conducted to evaluate human corneal epithelial cell shedding in response to wearing a silicone hydrogel contact lens/solution combination inducing corneal staining. The nature of ex vivo collected cells staining with fluorescein was also examined. Methods: A contralateral eye study was conducted in which up to eight participants were unilaterally exposed to a multipurpose contact lens solution/silicone hydrogel lens combination previously shown to induce corneal staining (renu® fresh™ and balafilcon A; test eye), with the other eye using a combination of balafilcon A soaked in a hydrogen peroxide care system (Clear Care®; control eye). Lenses were worn for 2, 4 or 6 hours. Corneal staining was graded after lens removal. The Ocular Surface Cell Collection Apparatus was used to collect cells from the cornea and the contact lens. Results: In the test eye, maximum solution-induced corneal staining (SICS) was observed after 2 hours of lens wear (reducing significantly by 4 hours; p < 0.001). There were significantly more cells collected from the test eye after 4 hours of lens wear when compared to the control eye and the collection from the test eye after 2 hours (for both; n = 5; p < 0.001). The total cell yield at 4 hours was 813 ± 333 and 455 ± 218 for the test and control eyes, respectively (N = 5, triplicate, p = 0.003). A number of cells were observed to have taken up the fluorescein dye from the initial fluorescein instillation. Confocal microscopy of fluorescein-stained cells revealed that fluorescein was present throughout the cell cytoplasm and was retained in the cells for many hours after recovery from the corneal surface. Conclusion: This pilot study indicates that increased epithelial cell shedding was associated with a lens-solution combination which induces SICS. Our data provides insight into the transient nature of the SICS reaction and the nature of fluorescein staining observed in SICS. © 2014 Informa Healthcare USA, Inc.

Hall,B. J., Jones,L. W., Dixon,B. Silicone allergies and the eye: Fact or fiction? Eye and Contact Lens 2014;40(1):51-57 [ Show Abstract ]

OBJECTIVE: The purpose of this manuscript was to review the evidence concerning the role of an allergic reaction to silicone as the basis for the reported increase in contact lens-associated infiltrates in wearers of silicone hydrogel contact lenses. METHODS: A literature review was undertaken to investigate the antigenic properties of silicone and the causes of contact lens-associated inflammatory reactions. RESULTS: Immune cells cannot interact with silicone directly but can interact with antigens on these lenses. These antigens could be due to tear film deposits, microbial contamination, or components of care systems used with these lenses. CONCLUSIONS: Inflammatory reactions associated with silicone hydrogel contact lens wear are not caused by an allergic reaction to silicone alone. © 2013 Contact Lens Association of Ophthalmologists.

Hall,B., McCanna,D., Jones,L. Identification of coagulase-negative staphylococci in daily disposable contact lens wearers Letters in applied microbiology 2014;59(3):313-319 [ Show Abstract ]

This study aimed to identify and quantify the number of contaminating organisms on daily disposable (DD) soft contact lenses, which may be responsible for mild cases of keratitis that occur with this lens wear modality. Ten participants wore DD lenses, and 10 participants wore planned replacement (PR) lenses. Lenses were collected aseptically and analysed for microbial contamination. Colony-forming units (CFU) were recorded, and representative colonies were used for identification using the API identification system. The DD lenses evaluated in this study were contaminated with coagulase-negative staphylococcus (CNS), ranging from 1 to 653 CFU. PR lenses showed more diversity in the types of contaminating micro-organisms and consisted of CNS, Gram-negative bacteria (Pseudomonas), a yeast (Candida) and a mould (Aspergillus), ranging from 1 to 230 CFU. CNS was the only type of micro-organism found on DD contact lenses and therefore may be the cause of any form of keratitis observed in DD lens wearers. © 2014 The Society for Applied Microbiology.

Hall,B., Phan,C. -M, Subbaraman,L., Jones,L. W., Forrest,J. Extraction versus in Situ techniques for measuring surface-adsorbed lysozyme Optometry and Vision Science 2014;91(9):1062-1070 [ Show Abstract ]

PURPOSE: To compare two techniques for measuring the activity of lysozyme deposited onto hydrogel contact lens and to image the binding of Micrococcus lysodeikticus to contact lenses. METHODS: Using a previously described protein extraction technique and a recently developed in situ technique, we measured the time-dependent activity of adsorbed lysozyme on six different contact lens materials during the first minute and up to 1 week of interaction with the material surface. Total activity of extracted lysozyme, total in situ activity, and the activity of the outer surface layer of sorbed lysozyme were determined using the two different techniques. Micrococcal cellular interaction with surface-adsorbed lysozyme was imaged using confocal microscopy. RESULTS: The differences between total extracted activities, total in situ activities, and surface activities were both measurable and material specific. In most cases, total extracted activity is greater than total in situ activity, which, in turn, is greater than surface activity. After 1 week, etafilcon A had the highest extracted activity at 137 µg/lens, followed by omafilcon A, balafilcon A, comfilcon A, senofilcon A, and lotrafilcon B at 27.4, 2.85, 2.02, 0.46, and 0.27 µg/lens, respectively. Micrococcal cell adhesion was greatest on contact lenses with high contact angles, such as balafilcon A, omafilcon A, and senofilcon A and lowest on contact lenses with low contact angles, such as etafilcon A, comfilcon A, and lotrafilcon B. Subsequent removal/prevention of adhered micrococcal cells was greatest on balafilcon A, which had the highest surface activity, and lowest on lotrafilcon B, which had the lowest surface activity. CONCLUSIONS: This study has measured and made direct comparisons between two established techniques for measuring the activity of adsorbed lysozyme. The extraction technique determines the activity of underlying layers of lysozyme or lysozyme within the matrix of the material. Conversely, the in situ technique allows conclusions to be drawn about only the biologically relevant lysozyme including the activity of just the outer surface of adsorbed lysozyme. © American Academy of Optometry.

Hui,A., Willcox,M., Jones,L. In vitro and in vivo evaluation of novel ciprofloxacin-releasing silicone hydrogel contact lenses Investigative Ophthalmology and Visual Science 2014;55(8):4896-4904 [ Show Abstract ]

PURPOSE. The purpose of this study was to evaluate ciprofloxacin-releasing silicone hydrogel contact lens materials in vitro and in vivo for the treatment of microbial keratitis. METHODS. Model silicone hydrogel contact lens materials were manufactured using a molecular imprinting technique to modify ciprofloxacin release kinetics. Various contact lens properties, including light transmission and surface wettability, were determined, and the in vitro ciprofloxacin release kinetics elucidated using fluorescence spectrophotometry. The materials then were evaluated for their ability to inhibit Pseudomonas aeruginosa growth in vitro and in an in vivo rabbit model of microbial keratitis. RESULTS. Synthesized lenses had similar material properties to commercial contact lens materials. There was a decrease in light transmission in the shorter wavelengths due to incorporation of the antibiotic, but over 80% light transmission between 400 and 700 nm. Modified materials released for more than 8 hours, significantly longer than unmodified controls (P 0.05), which is significantly less than corneas treated with unmodified control lenses or those that received no treatment at all (P < 0.05). CONCLUSIONS. These novel contact lenses designed for the extended release of ciprofloxacin may be beneficial to supplement or augment future treatments of sight-threatening microbial keratitis. © 2014 The Association for Research in Vision and Ophthalmology, Inc.

Moezzi,A. M., Fonn,D., Varikooty,J., Simpson,T. L. Overnight corneal swelling with high and low powered silicone hydrogel lenses Journal of Optometry 2014;8(1):19-26 [ Show Abstract ]

Purpose: To compare central corneal swelling after eight hours of sleep in eyes wearing four different silicone hydrogel lenses with three different powers. Methods: Twenty-nine neophyte subjects wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60) and senofilcon A (Dk, 103) lenses in powers -3.00, -10.00 and +6.00 D on separate nights, in random order, and on one eye only. The contra-lateral eye (no lens) served as the control. Central corneal thickness was measured using a digital optical pachometer before lens insertion and immediately after lens removal on waking. Results: For the +6.00 D and -10.00 D, lotrafilcon A induced the least swelling and galyfilcon A the most. The +6.00 D power, averaged across lens materials, induced significantly greater central swelling than the -10.00 and -3.00 D (Re-ANOVA, p < 0.001), (7.7 ± 2.9% vs. 6.8 ± 2.8% and 6.5 ± 2.5% respectively) but there was no difference between -10.00 and -3.00 D. Averaged for power, lotrafilcon A induced the least (6.2 ± 2.8%) and galyfilcon A the most (7.6 ± 3.0%) swelling at the center (Re-ANOVA, p < 0.001). Central corneal swelling with +6.00 D was significantly greater than -10.00 D lens power despite similar levels of average lens transmissibility of these two lens powers. Conclusions: The differences in corneal swelling of the lens wearing eyes are consistent with the differences in oxygen transmission of the silicone hydrogel lenses. In silicone hydrogel lenses central corneal swelling is mainly driven by central lens oxygen transmissibility. © 2013 Spanish General Council of Optometry.

Mohammadi,S., Jones,L., Gorbet,M. Extended latanoprost release from commercial contact lenses: In vitro studies using corneal models PLOS ONE 2014;9(9):e106653 [ Show Abstract ]

In this study, we compared, for the first time, the release of a 432 kDa prostaglandin analogue drug, Latanoprost, from commercially available contact lenses using in vitro models with corneal epithelial cells. Conventional polyHEMA-based and silicone hydrogel soft contact lenses were soaked in drug solution ( solution in phosphate buffered saline). The drug release from the contact lens material and its diffusion through three in vitro models was studied. The three in vitro models consisted of a polyethylene terephthalate (PET) membrane without corneal epithelial cells, a PET membrane with a monolayer of human corneal epithelial cells (HCEC), and a PET membrane with stratified HCEC. In the cell-based in vitro corneal epithelium models, a zero order release was obtained with the silicone hydrogel materials (linear for the duration of the experiment) whereby, after 48 hours, between 4 to 6  of latanoprost (an amount well within the range of the prescribed daily dose for glaucoma patients) was released. In the absence of cells, a significantly lower amount of drug, between 0.3 to 0.5 , was released, (). The difference observed in release from the hydrogel lens materials in the presence and absence of cells emphasizes the importance of using an in vitrocorneal model that is more representative of the physiological conditions in the eye to more adequately characterize ophthalmic drug delivery materials. Our results demonstrate how in vitro models with corneal epithelial cells may allow better prediction of in vivo release. It also highlights the potential of drug-soaked silicone hydrogel contact lens materials for drug delivery purposes.

Ngo,W., Srinivasan,S., Schulze,M., Jones,L. Repeatability of grading meibomian gland dropout using two infrared systems Optometry and Vision Science 2014;91(6):658-667 [ Show Abstract ]

PURPOSE: To determine the interobserver and intraobserver repeatability in using the OCULUS Keratograph 4 (K4) and 5M (K5M) to grade meibomian gland (MG) dropout using meibography grading scales. METHODS: The inferior and superior eyelids of 40 participants (35 women, 5 men; mean age = 32 years) were imaged three times each on both instruments. The images were split into one training and two study sets; the latter were graded (four-point meibography scale) by two observers on two separate occasions (24 hours apart) to determine repeatability. Semiobjective quantification of percentage MG dropout was conducted using ImageJ on K4 and K5M images. A finer seven-point meibography scale was used to grade a separate set of K5M images. RESULTS: For the four-point scale, interobserver mean difference (MD) (±SD) was 0.08 (±0.55) on day 1 and 0.13 (±0.50) on day 2, and the concordance correlation coefficient (CCC) was 0.79 and 0.81 on days 1 and 2, respectively. Intraobserver MD (±SD) was 0.04 (±0.54), CCC = 0.79 for observer 1; intraobserver MD (±SD) was -0.09 (±0.60), CCC = 0.74 for observer 2. For the seven-point scale, interobserver MD (±SD) was 0.05 (±0.45), CCC = 0.89 on day 1, and interobserver MD (±SD) was 0.01 (±0.41), CCC = 0.91 on day 2. Intraobserver MD (±SD) was -0.10 (±0.35), CCC = 0.93 for observer 1, and intraobserver MD (±SD) was -0.06 (±0.30), CCC = 0.95 for observer 2. Percentage dropout measured between the K4 and K5M images showed lack of agreement, with 21.8% coefficient of repeatability. There was no significant correlation (r 0.05) between meibography score and clinical signs (corneal staining, gland expressibility, telangiectasia, vascularity, lash loss); however, there was a high correlation (r = 0.77; p < 0.05) between meibography score with percentage dropout. CONCLUSIONS: Observers graded from -1 to +1 grade units between and within themselves for a four-point scale, 95% of the time. Although the interobserver and intraobserver repeatability of the K4 and K5M were very similar, a high rate of disagreement in percentage dropout between K4 and K5M images suggests that the two instruments cannot be interchanged. Meibomian gland dropout scores did not correlate significantly with clinical signs. Using a finer scale may be beneficial for detecting change.

Phan,C. -M, Subbaraman,L. N., Jones,L. In vitro drug release of natamycin from ß-cyclodextrin and 2-hydroxypropyl-ß-cyclodextrin-functionalized contact lens materials Journal of Biomaterials Science, Polymer Edition 2014;25(17):1907-1919 [ Show Abstract ]

Purpose: The antifungal agent natamycin can effectively form inclusion complexes with beta-cyclodextrin (ß-CD) and 2-hydroxypropyl-ß-cyclodextrin (HP-ßCD) to improve the water solubility of natamycin by 16-fold and 152-fold, respectively (Koontz, J. Agric. Food. Chem. 2003). The purpose of this study was to develop contact lens materials functionalized with methacrylated ß-CD (MßCD) and methacrylated HP-ßCD (MHP-ßCD), and to evaluate their ability to deliver natamycin in vitro. Methods: Model conventional hydrogel (CH) materials were synthesized by adding varying amounts of MßCD and MHP-ßCD (0, 0.22, 0.44, 0.65, 0.87, 1.08% of total monomer weight) to a monomer solution containing 2-hydroxyethyl methacrylate (HEMA). Model silicone hydrogel (SH) materials were synthesized by adding similar concentrations of MßCD and MHP-ßCD to N,N-dimethylacrylamide (DMAA)/10% 3-methacryloxypropyltris(trimethylsiloxy)silane (TRIS). The gels were cured with UV light, washed with ethanol and then, hydrated for 24 h (h). The model materials were then incubated with 2 mL of 100 g/mL of natamycin in phosphate buffered saline (PBS) pH 7.4 for 48 h at room temperature. The release of natamycin from these materials in 2 mL of PBS, pH 7.4 at 32 ± 2 °C was monitored using UV-vis spectrophotometry at 304 nm over 24 h. Results: For both CH and SH materials, functionalization with MßCD and MHP-ßCD improved the total amount of drugs released up to a threshold loading concentration, after which further addition of methacrylated CDs decreased the amount of drugs released (p < 0.05). The addition of CDs did not extend the drug release duration; the release of natamycin by all model materials reached a plateau after 12 h (p < 0.05). Overall, DMAA/10% TRIS materials released significantly more drug than HEMA materials (p < 0.05). The addition of MHP-ßCD had a higher improvement in drug release than MßCD for both HEMA and DMAA/10% TRIS gels (p < 0.05). Conclusions: A high loading concentration of methacrylated CDs decreases overall drug delivery efficiency, which likely results from an unfavorable arrangement of the CDs within the polymer network leading to reduced binding of natamycin to the CDs. HEMA and DMAA/10% TRIS materials functionalized with MHP-ßCD are more effective than those functionalized with MßCD to deliver natamycin.

Phan,C. -M, Subbaraman,L., Jones,L. Contact lenses for antifungal ocular drug delivery: A review Expert Opinion on Drug Delivery 2014;11(4):537-546 [ Show Abstract ]

Introduction: Fungal keratitis, a potentially blinding disease, has been difficult to treat due to the limited number of approved antifungal drugs and the taxing dosing regimen. Thus, the development of a contact lens (CL) as an antifungal drug delivery platform has the potential to improve the treatment of fungal keratitis. A CL can serve as a drug reservoir to continuously release drugs to the cornea, while limiting drug loss through tears, blinking, drainage and non-specific absorption. Areas covered: This review will provide a summary of currently available methods for delivering antifungal drugs from commercial and model CLs, including vitamin E coating, impregnated drug films, cyclodextrin-functionalized hydrogels, polyelectrolyte hydrogels and molecular imprinting. This review will also highlight some of the main factors that influence antifungal drug delivery with CLs. Expert opinion: Several novel CL materials have been developed, capable of extended drug release profiles with a wide range of antifungal drugs lasting from 8 h to as long as 21 days. However, there are factors, such as first-order release kinetics, effectiveness of continuous drug release, microbial resistance, ocular toxicity and potential complications from inserting a CL in an infected eye, that still need to be addressed before commercial applications can be realized. © Informa UK, Ltd.

Phan,C. -M, Subbaraman,L., Liu,S., Gu,F., Jones,L. In vitro uptake and release of natamycin Dex -b- PLA nanoparticles from model contact lens materials Journal of Biomaterials Science, Polymer Edition 2014;25(1):18-31 [ Show Abstract ]

Purpose: To evaluate the uptake and release of the antifungal agent natamycin encapsulated within poly(D,L-lactide)-dextran nanoparticles (Dex-b-PLA NPs) from model contact lens (CL) materials. Methods: Six model CL materials (gel 1:poly(hydroxyethyl methacrylate, pHEMA); gel 2:85% pHEMA: 15% [Tris(trimethylsiloxy)silyl]-propyl methacrylate (TRIS); gel 3: 75% pHEMA: 25% TRIS; gel 4: 85% N,N dimethylacrylamide (DMAA): 15% TRIS; gel 5:75% DMAA: 25% TRIS; and gel 6: DMAA) were prepared using a photoinitiation procedure. The gels were incubated in: (1) natamycin dissolved in deionized (DI) water and (2) natamycin encapsulated within Dex-b-PLA NPs in dimethylsulfoxide/DI water. Natamycin release from these materials was monitored using UV-visible spectrophotometry at 304 nm over 7 d. Results: Natamycin uptake by all model CL materials increased between 1 and 7 d (p < 0.001). The uptake of natamycin-NPs was higher than the uptake of the drug alone in DI water (p < 0.05). Drug release was higher in materials containing DMAA than pHEMA (p < 0.05). All gels loaded with natamycin-NPs also released more drug compared to gels soaked with natamycin in DI water (p < 0.001). After 1 h, CL materials loaded with natamycin alone released 28-82% of the total drug release. With the exception of gel 6, this burst released was reduced to 21-54% for CL materials loaded with natamycin-NPs. Conclusions: Model CL materials loaded with natamycin-Dex-b-PLA NPs were able to release natamycin for up to 12 h under infinite sink conditions. DMAA-TRIS materials may be more suitable for drug delivery of natamycin due to the higher drug release observed with these materials. © 2013 Taylor & Francis.

Phan,CM, Hui,A., Subbaraman,L., Jones,L. Insights to Using Contact Lenses for Drug Delivery Clin Exp Pharmacol 2014;3(145):2161-1459 [ Show Abstract ]

There has been considerable interest in the potential application of contact lenses for ocular drug delivery. This short communication provides an overview of the challenges faced by delivering drugs using contact lenses, highlights the solutions to limitations that have already been achieved, and describes the barriers that remain before commercial application can be realized.

Samsom,M., Chan,A., Iwabuchi,Y., Subbaraman,L., Jones,L., Schmidt,TA In vitro friction testing of contact lenses and human ocular tissues: Effect of proteoglycan 4 (PRG4) Tribology International 2014;89:27-33

Verma,M. S., Chen,P. Z., Jones,L., Gu,F. X. Branching and size of CTAB-coated gold nanostars control the colorimetric detection of bacteria RSC Advances 2014;4(21):10660-10668 [ Show Abstract ]

Rapid detection of pathogenic bacteria is challenging because conventional methods require long incubation times. Nanoparticles have the potential to detect pathogens before they can cause an infection. Gold nanostars have recently been used for colorimetric biosensors but they typically require surface modification with antibodies or aptamers for cellular detection. Here, CTAB-coated gold nanostars have been used to rapidly (<5 min) detect infective doses of a model Gram-positive pathogen Staphylococcus aureus by an instrument-free colorimetric method. Varying the amounts of gold nanoseed precursor and surfactant can tune the size and degree of branching of gold nanostars as studied here by transmission electron microscopy. The size and morphology of gold nanostars determine the degree and rate of color change in the presence of S. aureus. The optimal formulation achieved maximum color contrast in the presence of S. aureus and produced a selective response in comparison to polystyrene microparticles and liposomes. These gold nanostars were characterized using UV-Visible spectroscopy to monitor changes in their surface plasmon resonance peaks. The visual color change was also quantified over time by measuring the RGB components of the pixels in the digital images of gold nanostar solutions. CTAB-coated gold nanostars serve as a promising material for simple and rapid detection of pathogens. © 2014 The Royal Society of Chemistry.

Verma,M. S., Chen,P. Z., Jones,L., Gu,F. X. "Chemical nose" for the visual identification of emerging ocular pathogens using gold nanostars Biosensors and Bioelectronics 2014;61:386-390 [ Show Abstract ]

Ocular pathogens can cause serious damages in the eye leading to severe vision loss and even blindness if left untreated. Identification of pathogens is crucial for administering the appropriate antibiotics in order to gain effective control over ocular infection. Herein, we report a gold nanostar based "chemical nose" for visually identifying ocular pathogens. Using a spectrophotometer and nanostars of different sizes and degrees of branching, we show that the "chemical nose" is capable of identifying the following clinically relevant ocular pathogens with an accuracy of 99%: S. aureus, A. xylosoxidans, D. acidovorans and S. maltophilia. The differential colorimetric response is due to electrostatic aggregation of cationic gold nanostars around bacteria without the use of biomolecule ligands such as aptamers or antibodies. Transmission electron microscopy confirms that the number of gold nanostars aggregated around each bacterium correlates closely with the colorimetric response. Thus, gold nanostars serve as a promising platform for rapid visual identification of ocular pathogens with application in point-of-care diagnostics. © 2014 Elsevier B.V.

2013

Craig,J. P., Willcox,M. D. P., Argüeso,P., Maissa,C., Stahl,U., Tomlinson,A., Wang,J., Yokoi,N., Stapleton,F. The TFOS International Workshop on Contact Lens Discomfort: Report of the contact lens interactions with the tear film subcommittee Investigative Ophthalmology and Visual Science 2013;54(11):TFOS123-TFOS156

Duench,S., Sorbara,L., Keir,N., Simpson,T., Jones,L. Impact of silicone hydrogel lenses and solutions on corneal epithelial permeability Optometry and Vision Science 2013;90(6):546-556 [ Show Abstract ]

PURPOSE: The primary purpose of this pilot study was to compare epithelial barrier function (EBF) and staining in a small group of participants using a silicone hydrogel (SH) lens worn on a daily basis with two different care regimens. Secondarily, the aim was to see if there was any correlation between corneal staining and EBF. METHODS: The corneal EBF of 10 non-lens wearers (control) and 15 age-matched asymptomatic SH contact lens wearers (test) were assessed using fluorophotometry. Biomicroscopy was performed to assess corneal staining after the EBF was measured. The lens wearers wore PureVision (FDA group V) SH lenses for two consecutive 1-month periods while using either Alcon Opti-Free Express or Renu Fresh using a randomized, investigator-masked, crossover design. Control subjects were assessed on one occasion, and lens wearers were examined before fitting with lenses and after 7, 14, and 28 days of lens wear, with each combination. RESULTS: Compared with the control group, both study groups had an increase in epithelial permeability at baseline (p = 0.04). There were no changes in EBF during the treatment period for either solution (p = 0.87). A significant difference in EBF was found between the test groups during the treatment period (p = 0.02), with greater permeability in the Renu Fresh-disinfected lenses. There was poor correlation between corneal staining and EBF (r = 0.35, p > 0.05) because of large individual variations. CONCLUSIONS: Daily wear of highly oxygen-permeable SH lenses increases corneal epithelial permeability to fluorescein probably because of increased mechanical effects. In addition, certain lens-solution interactions can add to this effect, as seen in this study. Despite having a low amount of central corneal staining in the Renu Fresh group, staining and EBF did not prove to be well correlated. The presence of central corneal staining is a confounding factor when measuring EBF. Copyright © 2013 American Academy of Optometry.

Dumbleton,K. A., Richter,D., Woods,C. A., Aakre,B. M., Plowright,A., Morgan,P. B., Jones,L. W. A multi-country assessment of compliance with daily disposable contact lens wear Contact Lens and Anterior Eye 2013;36(6):304-312 [ Show Abstract ]

Purpose: To investigate compliance with daily disposable contact lens (DDCL) wear and investigate re-use of lenses according to country and DDCL material worn. Methods: Optometrists invited eligible DDCL patients from their practices to participate in a survey on DDCL wear in Australia, Norway, the United Kingdom (UK) and the United States (US). Eligible participants completed an online or paper version of the survey. Results: 805 participants completed the survey (96% online): Australia 13%, Norway 32%, UK 17%, US 38%. The median age was 38 years; 66% were female. Silicone hydrogel (SiHy) DDCLs were worn by 14%. Overall, 9% were non-compliant with DDCL replacement; Australia 18%, US 12%, UK 7% and Norway 4%. There were no differences with respect to sex, years of contact lens wear experience or DDCL material (SiHy versus hydrogels). The primary reason for re-use was "to save money" (60%). Re-use of DDCLs resulted in inferior comfort at insertion and prior to lens removal (p= 0.001). 75% reported occasional napping and 28% reported sleeping overnight for at least one night in the preceding month, while wearing their DDCLs. Conclusion: Non-compliance with replacement of DDCLs occurred in all countries investigated; the rate was highest in Australia and lowest in Norway. Re-use of DDCLs was associated with reduced comfort. DDCL wearers often reported wearing lenses overnight. It is important for optometrists to counsel their patients on the importance of appropriate lens wear and replacement for DDCLs. © 2013 British Contact Lens Association.

Dumbleton,K. A., Spafford,M. M., Sivak,A., Jones,L. W. Exploring compliance: A mixed-methods study of contact lens wearer perspectives Optometry and Vision Science 2013;90(8):898-908 [ Show Abstract ]

PURPOSE: Using both quantitative and qualitative research methods, this article explores in detail the lens wear and care habits of adapted contact lens wearers and seeks a better understanding of what enables and constrains patient compliance with appropriate lens wear and lens care. METHODS: The study was conducted in two phases: a preliminary online questionnaire (quantitative phase), identifying types of noncompliance, and a series of sequentially conducted focus groups (qualitative phase), exploring constraints to, and enablers of, compliance. RESULTS: One hundred participants completed the online questionnaire; 12 of them also participated in one of four focus groups. The most frequently reported aspects of noncompliance revealed were failure to replace lenses when scheduled, inappropriate lens purchase and supply, sleeping while wearing lenses, use of tap water with lenses and failure to wash hands, failure to clean and replace cases regularly, and inappropriate use of care systems. Using an iterative process, a number of "themes" associated with noncompliance were identified in the focus group discussions. The most frequently occurring themes related to the consequences that may occur if patients were noncompliant with one or more aspects of their contact lens wear and the importance of receiving instructions regarding the most appropriate way to wear and care for their lenses. Most of the themes that emerged during the analysis were both constraints to, and enablers of, compliance. CONCLUSIONS: This study confirms the frequent types of noncompliance with contact lens wear and care while offering a greater understanding of what may constrain and enables contact lens wear and care compliance. Future qualitative studies may help eye care practitioners and the contact lens industry to develop strategies and tools to aid compliance and success in contact lens wear. © 2013 American Academy of Optometry.

Dumbleton,K., Caffery,B., Dogru,M., Hickson-Curran,S., Kern,J., Kojima,T., Morgan,P. B., Purslow,C., Robertson,D. M., Nelson,J. D. The TFOS International Workshop on Contact Lens Discomfort: Report of the subcommittee on epidemiology Investigative Ophthalmology and Visual Science 2013;54(11):TFOS20-TFOS36

Dumbleton,K., Richter,D., Bergenske,P., Jones,L. W. Compliance with lens replacement and the interval between eye examinations Optometry and Vision Science 2013;90(4):351-358 [ Show Abstract ]

PURPOSE: Eye care practitioners (ECPs) acknowledge that their patients do not always follow recommendations for lens replacement, but many may not realize the possible implications for their offices. The study was conducted to investigate whether there is a relationship between contact lens compliance and the interval between full eye examinations (IEE). METHODS: The study was conducted in ECP offices in the United States. Eye care practitioners and patients independently completed linked questionnaires, evaluating their contact lens wear and care. Patients were required to be current wearers of daily disposable (DD) lenses or reusable silicone hydrogel lenses with a manufacturer-recommended replacement frequency (MRRF) of 2 weeks (2WR) or 1 month (1MR). RESULTS: A total of 2147 questionnaires from 141 offices were eligible. Fifty-four percent of patients were wearing 2WR, 37% 1MR, and 9% DD lenses. Wearers of 2WR lenses were significantly less compliant with replacement than wearers of both DD and 1MR lenses (34% vs. 74% and 67%, both p < 0.001); patients purchasing an annual supply were more compliant (55% vs. 45%, p < 0.001). The mean IEE was 16 months and was longer for wearers who were noncompliant with the MRRF (17.4 months vs. 14.5 months, p < 0.001). Other factors affecting IEE were household income (p = 0.030), insurance (p < 0.001), purchase source (p < 0.001), and sex (p = 0.007). CONCLUSIONS: Patients who were not compliant with the MRRF had longer IEEs and were less likely to purchase an annual supply of lenses. Patients who purchased lenses from their ECP, had a higher household income, had eye examination insurance, and were female had shorter IEEs. Patients failing to replace their lenses when scheduled were also found to be less compliant with lens care procedures. Eye care practitioners should reinforce the importance of all aspects of lens wear and care with their patients, with the overall aim of reducing possible complications and retaining successful contact lens wearers in their offices. Copyright © 2013 American Academy of Optometry.

Dumbleton,K., Woods,C. A., Jones,L. W., Fonn,D. The impact of contemporary contact lenses on contact lens discontinuation Eye and Contact Lens 2013;39(1):93-99 [ Show Abstract ]

OBJECTIVES: Discontinuation or "dropout" from contact lens (CL) wear continues to afflict the CL industry. This study was conducted to determine whether the advent of new CL materials and designs has impacted the dropout rate and the reasons for discontinuation. METHODS: Current and lapsed CL wearers residing in Canada were recruited using Facebook to take part in an on line survey investigating CL wearing experiences during 2008 to 2010 and to establish the percentage of participants who temporarily and permanently discontinued CL wear during the period surveyed. RESULTS: Four thousand two hundred seven eligible surveys were received (64% female; median age 27 years). Forty percent had lapsed from lens wear for at least 4 months; however, 62% of the lapsed wearers (LWs) resumed wear. There were no differences between LWs and nonlapsed wearers (NLWs) with respect to gender; however, LWs were older, started lens wear when older, and had not worn lenses for as long as NLWs (all P<0.001). More NLWs than LWs wore silicone hydrogel CLs (49% vs. 38%, P<0.001) and more LWs than NLWs wore daily disposable lenses and hydrogel CLs (24% vs. 19% and 22% vs. 18%, respectively, P=0.001). Primary reasons for discontinuation were discomfort (24%), dryness (20%), red eyes (7%), and expense (7%). Compliance with lens replacement was no different between LWs and NLWs (48% vs. 45%). CONCLUSIONS: About 23% of those surveyed had discontinued CL wear permanently. The primary reasons for dropping out continue to be discomfort and dryness. Dropout rates were lower in silicone hydrogel wearers. © 2013 Lippincott Williams & Wilkins.

Efron,N., Brennan,N. A., Bright,F. V., Glasgow,B. J., Jones,L. W., Sullivan,D. A., Tomlinson,A., Zhang,J. Contact lens care and ocular surface homeostasis Contact Lens and Anterior Eye 2013;36(SUPPL.):S9-S13 [ Show Abstract ]

The early focus of contact lens wear and ocular health was on oxygen delivery. However, as we learn more about how the eye works, and investigate how the contact lens interacts with the cornea, the role of the tear film has risen in prominence. A healthy tear film is critical for normal ocular homeostasis, and abnormalities of the tear film are the primary cause of dry eye. In order to improve patient eye health and comfort during lens wear, we need to further elucidate the relationship among contact lenses, contact lens solutions, the tear film, and the corneal epithelium, and find ways to maintain homeostasis of the ocular surface. In this section, we review the latest data and opinions on this complex relationship between contact lenses and lens care solutions. © 2013 British Contact Lens Association.

Efron,N., Jones,L., Bron,A. J., Knop,E., Arita,R., Barabino,S., McDermott,A. M., Villani,E., Willcox,M. D. P., Markoulli,M. The TFOS International Workshop on Contact Lens Discomfort: Report of the contact lens interactions with the ocular surface and adnexa subcommittee Investigative Ophthalmology and Visual Science 2013;54(11):TFOS98-TFOS122

Hall,B., Jones,L., Forrest,J. A. Measuring the kinetics and activity of adsorbed proteins: In vitro lysozyme deposited onto hydrogel contact lenses over short time periods Journal of Biomedical Materials Research - Part A 2013;101 A(3):755-764 [ Show Abstract ]

A new process has been developed to determine the biological activity of an intact layer of lysozyme deposited onto a biomaterial surface. This process is applied to a number of common hydrogel contact lenses. The activity of the surface-adsorbed protein is measured using a standard micrococcal activity assay, with extra steps to distinguish between protein on the surface and protein in solution. This is in contrast to protein extraction work in which the activity of all adsorbed protein is measured. For ionic materials, which are known to deposit large amounts of protein, particularly positively charged proteins such as lysozyme, there is evidence for loosely bound protein re-entering the solution, thus making it impossible to truly separate out the surface-adsorbed protein. This optimized process provides the first quantification of the biological activity of an intact layer of surface-adsorbed protein at a hydrogel interface. © 2012 Wiley Periodicals, Inc.

Jones,L., Brennan,N. A., González-Méijome,J., Lally,J., Maldonado-Codina,C., Schmidt,T. A., Subbaraman,L., Young,G., Nichols,J. J. The TFOS International Workshop on Contact Lens Discomfort: Report of the contact lens materials, design, and care subcommittee Investigative Ophthalmology and Visual Science 2013;54(11):TFOS37-TFOS70

Jones,L., Powell,C. H. Uptake and release phenomena in contact lens care by silicone hydrogel lenses Eye and Contact Lens 2013;39(1):29-36 [ Show Abstract ]

Contact lens solutions are highly complex mixtures of biocides (preservatives), surfactants, and other agents designed to disinfect, clean, and wet contact lenses. The commercialization of silicone hydrogel (SiHy) lenses has resulted in unique challenges to the manufacturers of contact lens solutions, because the properties of these materials differ markedly from those seen previously with poly-hydroxyethyl methacrylate-based hydrogels. Historically, hydrogel lens uptake and release of low-molecular weight preservatives such as chlorhexidine and thimerosal were known to result in allergic reactions, resulting in corneal irritation, stinging, conjunctival hyperemia, development of corneal infiltrates, palpebral lid changes, and corneal staining. However, little is known about the interaction of modern care systems with modern soft lens materials. Factors to be considered when evaluating the uptake and release of care components include the water content, charge, relative hydrophobicity, surface treatment, and porosity of the lens material, in conjunction with the concentration, charge/molecule, ionicity in the product matrix, molecular weight, and hydrophobicity of the care component in question. These factors control the sorption of the solution components by lenses, resulting in a variety of differences in the amount of the component taken up into the lens material and the amount and rate of subsequent release onto the ocular surface. Because both natural (ocular) and environmental biota become part of the solution-lens system during regimen use of any lens care product, these extraneously introduced substances should also be considered regarding their potential for uptake and either subsequent release onto the ocular surface or functioning as a scaffold for the adhesion of microbes. This article will review current knowledge concerning these interactions and investigate what clinically observable complications may arise from these interactions. It also reviews whether current methods to determine these interactions could be improved on. © 2013 Lippincott Williams & Wilkins.

Keech,A., Senchyna,M., Jones,L. Impact of time between collection and collection method on human tear fluid osmolarity Current eye research 2013;38(4):428-436 [ Show Abstract ]

Aim: To generate data on the variability of tear osmolarity in a control (normal, non-dry eye) and symptomatic dry eye population (Ocular Surface Disease Index: OSDI ≥20). A secondary outcome is the determination of the effect that tear collection technique has on the osmolarity of the sample. Materials and methods: This was a two-phase study that recruited 20 subjects (n = 10 normal, n = 10 dry eye) to evaluate the influence of time between measurements (Phase I) and 30 subjects (n = 15 normal, n = 15 dry eye) to evaluate the influence of collection technique (Phase II). As part of Phase I, serial tear osmolarity measurements were performed on each eye; four separated by 15min followed by four separated by lmin, at each of three visits. Phase II compared the consecutive measurement of four in vivo tear samples to four in vitro measurements on tears collected and dispensed from a glass capillary tube. Results: During Phase I, the dry eye group had a significantly higher maximum osmolarity (334.2 ± 25.6 mOsm/L) compared to the normal group (304.0 ± 8.4mOsm/L, p = 0.002). No significant differences were observed whether collections were performed at 15 or 1 min intervals. During Phase II, the in vivo osmolarity was equivalent to in vitro measurements from glass capillary tube samples for both the dry eye group (323.0± 16.7mOsm/L versus 317.7±24.8, p = 0.496), and for the normal subjects (301.2±7. 2mOsm/L versus 301.9 ± 16.0 mOsm/L, p = 0.884). Conclusion: Symptomatic dry eye subjects exhibited a significantly higher tear osmolarity and variation over time than observed in normal subjects, reflecting the inherent tear film instability of dry eye disease. There was no change in the distribution of tear osmolarity measurements whether tears were collected in rapid succession or given time to equilibrate, and collection method had no impact on tear osmolarity. © Informa Healthcare USA Inc.

Keir,N., Jones,L. Wettability and silicone hydrogel lenses: A review Eye and Contact Lens 2013;39(1):100-108 [ Show Abstract ]

One of the major breakthroughs in the development of silicone hydrogel contact lenses has related to the ability of manufacturers to overcome the surface hydrophobicity that occurred with silicone elastomer lenses. However, the wettability of silicone hydrogel lenses continues to be of interest as a potential link between in vivo lens performance and contact lens-related comfort. This article will review some of the knowledge we have gained in the area of contact lens wettability over the past decade and will discuss some of the challenges related to its measurement. © 2013 Lippincott Williams & Wilkins.

Ng,A., Heynen,M., Luensmann,D., Subbaraman,L. N., Jones,L. Impact of tear film components on the conformational state of lysozyme deposited on contact lenses Journal of Biomedical Materials Research - Part B Applied Biomaterials 2013;101(7):1172-1181 [ Show Abstract ]

Purpose To investigate the impact of lactoferrin and lipids on the kinetic denaturation of lysozyme deposited on silicone and conventional hydrogel lenses, using a complex artificial tear solution (ATS). Methods Two silicone hydrogel lenses (AIR OPTIX AQUA; lotrafilcon B and ACUVUE OASYS; senofilcon A) and two conventional hydrogel lenses (ACUVUE 2; etafilcon A and PROCLEAR; omafilcon A) were incubated in four solutions: an ATS, ATS without lactoferrin, ATS without lipids, and ATS without lactoferrin and lipids. At various time points over a 28-day period, the percentage of active lysozyme per lens was determined using a fluorescence activity assay and an ELISA. Results After 28 days, the percentage of active lysozyme extracted from etafilcon A lenses in all solutions was significantly higher than all other lens materials (p 0.05). The inclusion of lipids in the ATS significantly increased the lysozyme denaturation on both silicone hydrogel materials (p 0.05). The inclusion of lipids in the ATS significantly increased the lysozyme denaturation on both silicone hydrogel materials (p 0.05). Conclusions Lactoferrin and lipids have an impact on the denaturation of lysozyme deposited onto silicone hydrogel contact lenses, while conventional hydrogel lenses were unaffected. Future in vitro studies should consider the impact of tear film components when investigating protein deposition and denaturation on contact lenses. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 1172-1181, 2013. Copyright © 2013 Wiley Periodicals, Inc., a Wiley Company.

Ng,A., Heynen,M., Luensmann,D., Subbaraman,L. N., Jones,L. Optimization of a fluorescence-based lysozyme activity assay for contact lens studies Current eye research 2013;38(2):252-259 [ Show Abstract ]

Purpose: To optimize a fluorescence-based lysozyme activity assay to investigate the conformational state of lysozyme in solution and to determine the impact of extraction and evaporation procedures and the possible interference of contact lens materials on lysozyme activity. Methods: The fluorescence-based lysozyme activity assay, Enzchek (Molecular Probes Inc, Eugene, OR) which utilizes fluorescently quenched Micrococcus lysodeikticus, was compared to the gold standard, classical lysozyme turbidity assay, using four differently concentrated lysozyme samples (20, 10, 5.0 and 2.0 ng/µL). Furthermore, six differently concentrated lysozyme samples (2.0, 1.0, 0.5, 0.25, 0.125 and 0.01 µg/µL) were quantified using the fluorescence-based assay in the presence of extraction solvents consisting of 0.2% and 0.02% trifluroacetic acid/acetonitrile and following evaporation procedures. Results: A standard curve was generated by the fluorescence-based assay ranging from 2 to 150 ng. The total active lysozyme quantified in the four lysozyme samples was not significantly different between the two assays (p > 0.05) and the concordance correlation coefficient was determined to be 0.995. However an average discrepancy between the two assays was found to be 0.474 ng, with the turbidity assay typically reporting higher active lysozyme measurements. The sensitivity of the fluorescence-based assay was higher than the classical turbidity assay when quantifying 20 ng or less active lysozyme. Following the extraction and evaporation procedures and the addition of lens extracts, the total active lysozyme recovered was 95% or greater. Conclusions: In comparison to the classical turbidity assay, the fluorescence-based assay is a very sensitive method, making it a favorable technique, particularly when studying contact lens materials that deposit relatively low levels of lysozyme. © Informa Healthcare USA, Inc.

Ngo,W., Srinivasan,S., Jones,L. Historical overview of imaging the meibomian glands Journal of Optometry 2013;6(1):1-8 [ Show Abstract ]

Growing knowledge of the role of the meibomian glands in dry eye disease and contact lens discomfort has resulted in a surge of interest in visualizing these glands within the eyelids. This manuscript provides an overview of the many different visualization methods that have evolved over the past 30-40 years. Some of the visualization methods covered in this review include lid transillumination, video and non-contact meibography, and imaging methods employing confocal microscopy, optical coherence tomography and ultrasound. This review has also highlighted all the studies to date that have employed meibography as part of their methods. An overview of the available meibography dropout grading systems will also be provided. © 2012 Spanish General Council of Optometry.

Nichols,J. J., Jones,L., Daniel Nelson,J., Stapleton,F., Sullivan,D. A., Willcox,M. D. P. The TFOS International Workshop on Contact Lens Discomfort: Introduction Investigative Ophthalmology and Visual Science 2013;54(11):TFOS1-TFOS6

Nichols,J. J., Willcox,M. D. P., Bron,A. J., Belmonte,C., Ciolino,J. B., Craig,J. P., Dogru,M., Foulks,G. N., Jones,L., Nelson,J. D., Nichols,K. K., Purslow,C., Schaumberg,D. A., Stapleton,F., Sullivan,D. A. The TFOS International Workshop on Contact Lens Discomfort: Executive summary Investigative Ophthalmology and Visual Science 2013;54(11):TFOS7-TFOS13

Nichols,K. K., Redfern,R. L., Jacob,J. T., Nelson,J. D., Fonn,D., Forstot,S. L., Huang,J. -F, Holden,B. A., Nichols,J. J. The TFOS International Workshop on Contact Lens Discomfort: Report of the definition and classification subcommittee Investigative Ophthalmology and Visual Science 2013;54(11):TFOS14-TFOS19

Papas,E. B., Ciolino,J. B., Jacobs,D., Miller,W. S., Pult,H., Sahin,A., Srinivasan,S., Tauber,J., Wolffsohn,J. S., Nelson,J. D. The TFOS International Workshop on Contact Lens Discomfort: Report of the management and therapy subcommittee Investigative Ophthalmology and Visual Science 2013;54(11):TFOS183-TFOS203

Phan,C. -M, Subbaraman,L. N., Jones,L. In vitro uptake and release of natamycin from conventional and silicone hydrogel contact lens materials Eye and Contact Lens 2013;39(2):162-168 [ Show Abstract ]

OBJECTIVES:: To investigate the uptake and release of the antifungal ocular drug, natamycin from commercially available conventional hydrogel (CH) and silicone hydrogel (SH) contact lens (CL) materials and to evaluate the effectiveness of this delivery method. METHODS:: Five commercial SH CLs (balafilcon A, comfilcon A, galyfilcon A, senofilcon A, and lotrafilcon B) and four CH CLs (etafilcon A, omafilcon A, polymacon, vifilcon A) were examined in this study. These lenses were incubated with natamycin solubilized in dimethyl sulfoxide, and the release of the drug from these lenses, in Unisol 4 pH 7.4 at 32±1 C, was determined using UV-visible spectrophotometry at 305 nm over 24 hours. RESULTS:: There was a significant uptake of natamycin between 0 hour and 24 hours (P0.05). There was a significant difference in release between all the SH materials (P0.05). There was a significant difference in release between all the SH materials (P0.05). There was a significant difference in release between all the SH materials (P0.05). Overall, the release of natamycin was higher in CH than SH lenses (P<0.001). CONCLUSIONS:: All CLs released clinically relevant concentrations of natamycin within 30 minutes, but this release reached a plateau after approximately 1 hour. Further CL material development will be necessary to produce a slow and sustained drug releasing device for the delivery of natamycin. © 2013 Lippincott Williams & Wilkins.

Robinson,B., Feng,Y., Woods,C. A., Fonn,D., Gold,D., Gordon,K. Prevalence of visual impairment and uncorrected refractive error-report from a canadian urban population-based study Ophthalmic epidemiology 2013;20(3):123-130 [ Show Abstract ]

Purpose: The prevalence of visual impairment due to uncorrected refractive error has not been previously studied in Canada. A population-based study was conducted in Brantford, Ontario. Methods: The target population included all people 40 years of age and older. Study participants were selected using a randomized sampling strategy based on postal codes. Presenting distance and near visual acuities were measured with habitual spectacle correction, if any, in place. Best corrected visual acuities were determined for all participants who had a presenting distance visual acuity of less than 20/25. Results: Population weighted prevalence of distance visual impairment (visual acuity <20/40 in the better eye) was 2.7% (n=768, 95% confidence interval (CI) 1.8-4.0%) with 71.8% correctable by refraction. Population weighted prevalence of near visual impairment (visual acuity <20/40 with both eyes) was 2.2% (95% CI 1.4-3.6) with 69.1% correctable by refraction. Multivariable adjusted analysis showed that the odds of having distance visual impairment was independently associated with increased age (odds ratio, OR, 3.56, 95% CI 1.22-10.35; 65 years compared to those 39-64 years), and time since last eye examination (OR 4.93, 95% CI 1.19-20.32; 5 years compared to 2 years). The same factors appear to be associated with increased prevalence of near visual impairment but were not statistically significant. Conclusions: The majority of visual impairment found in Brantford was due to uncorrected refractive error. Factors that increased the prevalence of visual impairment were the same for distance and near visual acuity measurements. © 2013 Informa Healthcare USA, Inc. All rights reserved: reproduction in whole or part not permitted.

Srinivasan,S., Heynen,M. L., Martell,E., Ritter III,R., Jones,L., Senchyna,M. Quantification of MUCIN 1, cell surface associated and MUCIN16, cell surface associated proteins in tears and conjunctival epithelial cells collected from postmenopausal women Molecular Vision 2013;19970-979 [ Show Abstract ]

Purpose: To quantify the expression of mucin 1, cell surface associated (MUC1) and mucin 16, cell surface associated (MUC16) proteins and messenger ribonucleic acid (mRNA) in a cohort of postmenopausal women (PMW), to explore the relationship between mucin expression, dry eye symptomology, and tear stability. Methods: Thirty-nine healthy PMW (>50 years of age) were enrolled in this study. No specific inclusion criteria were used to define dry eye; instead, a range of subjects were recruited based on responses to the Allergan Ocular Surface Disease Index (OSDI) questionnaire and tear stability measurements as assessed by non-invasive tear breakup time (NITBUT). Tears were collected from the inferior tear meniscus using a disposable glass capillary tube, and total RNA and total protein were isolated from conjunctival epithelial cells collected via impression cytology. Expression of membrane-bound and soluble MUC1 and MUC16 were quantified with western blotting, and expression of MUC1 and MUC16 mRNA was assessed with real-time PCR. Results: OSDI responses ranged from 0 to 60, and NITBUT ranged from 18.5 to 2.9 s. Only two statistically significant correlations were found: soluble MUC16 protein concentration and MUC16 mRNA expression with OSDI vision related (-0.47; p=0.01) and ocular symptom (0.39; p=0.02) subscores, respectively. Post hoc exploratory analysis on absolute expression values was performed on two subsets of subjects defined as asymptomatic (OSDI =6, n=12) and moderate to severe symptomatic (OSDI =20, n=12). The only significant difference between the two subgroups was a significant reduction in MUC16 mRNA expression found in the symptomatic dry eye group (1.52±1.19 versus 0.57±0.44; p=0.03). Conclusions: A broad exploration of mucin expression compared to either a sign (NITBUT) or symptoms of dry eye failed to reveal compelling evidence supporting a significant relationship, other than a potential association between MUC16 with specific symptoms. Furthermore, comparison of mucin protein and expression levels between the asymptomatic and moderate to severe symptomatic subgroups revealed only one significant difference, a reduction in MUC16 mRNA expression in the symptomatic subgroup. © 2013 Molecular Vision.

Srinivasan,S., Menzies,K. L., Sorbara,L., Jones,L. W. Imaging meibomian glands on a patient with chalazia in the upper and lower lids: A case report Contact Lens and Anterior Eye 2013;36(4):199-203 [ Show Abstract ]

Aim: To describe the meibomian gland (MG) appearance in a case of eyelid chalazia, using a novel meibography method. Methods: A 29-year-old female of South Asian origin presented with mild swelling in the lower lid of the left eye. The patient also presented with a history of a recurrent chalazion in the upper lid of the same eye, which later progressed to an active chalazion. A chalazion also developed in the upper lid of the right eye. Meibography was performed using a novel Keratograph (Keratograph 4, OCULUS, Wetzlar, Germany) to evaluate the structure of the MG in the area affected by the chalazia. Results: The area of the recurrent chalazion in the upper left lid showed partial and/or complete MG loss. The active chalazia in the lower left lid and the upper right lid showed inflammation and MG drop out at the affected site. The inflammation was found to be reduced during the follow-up visits, however disappearance of MG very specific to the region of the chalazion was observed. Conclusion: The Keratograph 4 was able to image the MG structures clearly, allowing the clinician to monitor the progression of chalazia and the MG loss in the affected areas. © 2013 British Contact Lens Association.

Varikooty,J., Keir,N., Richter,D., Jones,L. W., Woods,C., Fonn,D. Comfort response of three silicone hydrogel daily disposable contact lenses Optometry and Vision Science 2013;90(9):945-953 [ Show Abstract ]

PURPOSE: To evaluate subjective ocular comfort across the day with three silicone hydrogel daily disposables (SHDDs) in a group of adapted lens wearers. METHODS: Masked subjects (asymptomatic or symptomatic of end-of-day (EOD) dryness with habitual lenses) wore three SHDDs: DAILIES TOTAL1 (DT1), Clariti 1day (C1D), or 1-DAY ACUVUE TRUEYE (AVTE), each for 3 days. On day 2, wearing time (WT) and comfort ratings after insertion, at 4, 8, and 12 hours, and at EOD were recorded. Because not all subjects wore lenses for 12 hours, comfort was analyzed across the day (up to 8 hours, 8 to 12 hours), and a new variable ("cumulative comfort" [CC]) was calculated for EOD. RESULTS: One hundred four subjects completed the study (51 asymptomatic, 53 symptomatic). The two groups had different WTs (mean WT, 14.0 and 12.7 hours, respectively; p < 0.001). Ocular comfort was rated higher in the asymptomatic group throughout the day (p < 0.001). One hundred four subjects wore all three SHDDs for at least 8 hours, whereas 74 (45 asymptomatic, 29 symptomatic) subjects wore them for 12 hours or longer. Comfort ratings were higher with DT1 (least square means [LSM] = 91.0) than with C1D (LSM = 86.5; p < 0.001) and AVTE (LSM = 87.7; p = 0.011) for the first 8 hours and lower with C1D compared with DT1 (p = 0.012) from 8 to 12 hours. Mean EOD (± SD) comfort with the C1D lens was 72 ± 21, lower than both DT1 (mean, 79 ± 17; p = 0.001) and AVTE (mean, 78 ± 21; p = 0.010). Mean CC was higher in the asymptomatic group (mean, 1261 ± 59) compared with that in the symptomatic group (mean, 1009 ± 58; p < 0.001) and higher for DT1 (mean, 1184 ± 258) than C1D (mean, 1094 ± 318; p = 0.002) and AVTE (mean, 1122 ± 297; p = 0.046). CONCLUSIONS: All three SHDDs had average WTs of 12 hours or longer for 1 day. Comfort during the first 12 hours was highest with DT1 (similar to AVTE between 8 and 12 hours) and lowest with C1D. End-of-day comfort was lowest with C1D, and CC was highest for DT1. Cumulative comfort may be a valuable new metric to assess ocular comfort during the day. © 2013 American Academy of Optometry.

Walther,H., Lorentz,H., Heynen,M., Kay,L., Jones,L. W. Factors that influence in vitro cholesterol deposition on contact lenses Optometry and Vision Science 2013;90(10):1057-1065 [ Show Abstract ]

PURPOSE: The purpose of this study was to analyze the impact that incubation time, lipid concentration, and solution replenishment have on silicone hydrogel (SiHy) and conventional hydrogel (CH) contact lens cholesterol deposition via in vitro radiochemical experiments. METHODS: Four SiHy (senofilcon A, lotrafilcon B, comfilcon A, balafilcon A) and two CH (etafilcon A and omafilcon A) contact lenses were incubated in an artificial tear solution (ATS) that contained major tear film proteins, lipids, salts, salts, and a trace amount of radioactive C-cholesterol. Lenses were incubated for various incubation times (1, 3, 7, 14, or 28 days), with three concentrations of lipid (0.5×, 1×, 2× tear film concentration) and with or without solution replenishment to assess each variable's impact on cholesterol deposition. After incubation, the lenses were extracted using 2:1 chloroform:methanol, extracts were analyzed in a beta counter and masses (micrograms per lens) were extrapolated from standard curves. RESULTS: Within the SiHy materials, balafilcon A deposited the greatest amount of cholesterol (p replenishing > 1× > 0.5×. CONCLUSIONS: Overall, SiHy lenses deposit significantly more cholesterol than CH lens materials, and the mass of lipid deposited is dependent on the contact lens material, length of incubation, concentration of lipids in the ATS, and the replenishment of ATS. Copyright © 2013 American Academy of Optometry.

Weeks,A., Boone,A., Luensmann,D., Jones,L., Sheardown,H. The effects of hyaluronic acid incorporated as a wetting agent on lysozyme denaturation in model contact lens materials Journal of Biomaterials Applications 2013;28(3):323-333 [ Show Abstract ]

Conventional and silicone hydrogels as models for contact lenses were prepared to determine the effect of the presence of hyaluronic acid on lysozyme sorption and denaturation. Hyaluronic acid was loaded into poly(2-hydroxyethyl methacrylate) and poly(2-hydroxyethyl methacrylate)/TRIS - methacryloxypropyltris (trimethylsiloxy silane) hydrogels, which served as models for conventional and silicone hydrogel contact lens materials. The hyaluronic acid was cross-linked using 1-ethyl-3-(3-dimethylaminopropyl)- carbodiimide in the presence of dendrimers. Active lysozyme was quantified using a Micrococcus lysodeikticus assay while total lysozyme was determined using 125-I radiolabeled protein. To examine the location of hyaluronic acid in the gels, 6-aminofluorescein labeled hyaluronic acid was incorporated into the gels using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry and the gels were examined using confocal laser scanning microscopy. Hyaluronic acid incorporation significantly reduced lysozyme sorption in poly(2-hydroxyethyl methacrylate) (p < 0.00001) and poly(2-hydroxyethyl methacrylate)/TRIS - methacryloxypropyltris (trimethylsiloxy silane) (p < 0.001) hydrogels, with the modified materials sorbing only 20% and 16% that of the control, respectively. More importantly, hyaluronic acid also decreased lysozyme denaturation in poly(2-hydroxyethyl methacrylate) (p < 0.005) and poly(2-hydroxyethyl methacrylate)/TRIS - methacryloxypropyltris (trimethylsiloxy silane) (p < 0.02) hydrogels. The confocal laser scanning microscopy results showed that the hyaluronic acid distribution was dependent on both the material type and the molecular weight of hyaluronic acid. This study demonstrates that hyaluronic acid incorporated as a wetting agent has the potential to reduce lysozyme sorption and denaturation in contact lens applications. The distribution of hyaluronic acid within hydrogels appears to affect denaturation, with more surface mobile, lower molecular weight hyaluronic acid being more effective in preventing denaturation. © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Weeks,A., Subbaraman,L. N., Jones,L., Sheardown,H. Physical entrapment of hyaluronic acid during synthesis results in extended release from model hydrogel and silicone hydrogel contact lens materials Eye and Contact Lens 2013;39(2):179-185 [ Show Abstract ]

OBJECTIVES:: This study was designed to assess the duration of hyaluronic acid (HA) release from model contact lens materials when HA was physically incorporated into the hydrogel during synthesis and to assess the effects of the HA release on lysozyme sorption. METHODS:: Model conventional and silicone hydrogel contact lens materials containing HA of various molecular weights as a releasable wetting agent were prepared. The HA was released into phosphate-buffered saline and MilliQ water, and the release was monitored using ultraviolet spectroscopy. Hyaluronic acid release was quantified by enzyme-linked immunosorbent assay. The effect of the releasable HA on lysozyme sorption to the materials was also analyzed using 125-I-labeled protein. RESULTS:: Hyaluronic acid loaded into the materials using this method could be released from conventional hydrogel materials for 21 days; the model silicone hydrogels showed release of more than 7 weeks. With one exception, the releasable HA decreased lysozyme sorption. CONCLUSIONS:: Hyaluronic acid physically incorporated into contact lens materials during synthesis may therefore be released for extended periods of time of up to 7 weeks. Hyaluronic acid release leads to decreased protein adsorption in general. This method has potential for modification of conventional and silicone hydrogel lenses with releasable HA as a wetting agent. © 2013 Lippincott Williams & Wilkins.

Woods,J., Guthrie,S. E., Keir,N., Dillehay,S., Tyson,M., Griffin,R., Choh,V., Fonn,D., Jones,L., Irving,E. Inhibition of defocus-induced myopia in chickens Investigative Ophthalmology and Visual Science 2013;54(4):2662-2668 [ Show Abstract ]

PURPOSE. To determine the effect of wearing a lens with a unique peripheral optical design on the development and progression of defocus-induced myopia in newly hatched chickens.METHODS. Eighty-five newly hatched chickens underwent bilateral retinoscopy and A-scan ultrasound to determine their refractive error and axial length. They were randomly divided into Control and two Test groups, in which each chicken was fitted with a goggle-lens over the right eye, with the left eye remaining untreated. The Control group wore a lens of power - 10.00 diopters (D) of standard spherical optical design. The two Test lenses both had a central optical power -10.00 D, but used different peripheral myopia progression control (MPC) designs. For all groups, retinoscopy was repeated on days 3, 7, 10, and 14; ultrasound was repeated on day 14.RESULTS. On day 0 there was no statistical difference in refractive error (mean +6.92 D) or axial length (mean 8.06 mm) between Test and Control groups or treated and untreated eyes (all P > 0.05). At day 14, 37 (43.5%) of 85 chickens had not experienced goggle detachment and were included in the final analyses. In this cohort there was a significant refractive difference between the treated eyes of the Control group (n = 17) and those of Test 1 (n = 14) and Test 2 (n = 6) groups (both P < 0.01): Control -4.65 ± 2.11 D, Test 1 +4.57 ± 3.11 D, Test 2 +1.08 ± 1.24 D (mean ± SEM). There was also a significant axial length difference (both P < 0.01): Control 10.55 ± 0.36 mm, Test 1 9.99 ± 0.14 mm, Test 2 10.17 ± 0.18 mm.CONCLUSIONS. Use of these unique MPC lens designs over 14 days caused a significant reduction in the development of defocus-induced myopia in chickens; the degree of reduction appeared to be design specific. © 2013 The Association for Research in Vision and Ophthalmology, Inc.

2012

Dumbleton,K., Woods,C. A., Jones,L. W., Fonn,D. The impact of contemporary contact lenses on contact lens discontinuation Eye and Contact Lens 2012 [ Show Abstract ]

OBJECTIVES: Discontinuation or "dropout" from contact lens (CL) wear continues to afflict the CL industry. This study was conducted to determine whether the advent of new CL materials and designs has impacted the dropout rate and the reasons for discontinuation. METHODS: Current and lapsed CL wearers residing in Canada were recruited using Facebook to take part in an on line survey investigating CL wearing experiences during 2008 to 2010 and to establish the percentage of participants who temporarily and permanently discontinued CL wear during the period surveyed. RESULTS: Four thousand two hundred seven eligible surveys were received (64% female; median age 27 years). Forty percent had lapsed from lens wear for at least 4 months; however, 62% of the lapsed wearers (LWs) resumed wear. There were no differences between LWs and nonlapsed wearers (NLWs) with respect to gender; however, LWs were older, started lens wear when older, and had not worn lenses for as long as NLWs (all P<0.001). More NLWs than LWs wore silicone hydrogel CLs (49% vs. 38%, P<0.001) and more LWs than NLWs wore daily disposable lenses and hydrogel CLs (24% vs. 19% and 22% vs. 18%, respectively, P≤0.001). Primary reasons for discontinuation were discomfort (24%), dryness (20%), red eyes (7%), and expense (7%). Compliance with lens replacement was no different between LWs and NLWs (48% vs. 45%). CONCLUSIONS: About 23% of those surveyed had discontinued CL wear permanently. The primary reasons for dropping out continue to be discomfort and dryness. Dropout rates were lower in silicone hydrogel wearers.

Hui,A., Sheardown,H., Jones,L. Acetic and acrylic acid molecular imprinted model silicone hydrogel materials for ciprofloxacin-HCL delivery 2012;5(1):85-107 [ Show Abstract ]

Contact lenses, as an alternative drug delivery vehicle for the eye compared to eye drops, are desirable due to potential advantages in dosing regimen, bioavailability and patient tolerance/compliance. The challenge has been to engineer and develop these materials to sustain drug delivery to the eye for a long period of time. In this study, model silicone hydrogel materials were created using a molecular imprinting strategy to deliver the antibiotic ciprofloxacin. Acetic and acrylic acid were used as the functional monomers, to interact with the ciprofloxacin template to efficiently create recognition cavities within the final polymerized material. Synthesized materials were loaded with 9.06 mM, 0.10 mM and 0.025 mM solutions of ciprofloxacin, and the release of ciprofloxacin into an artificial tear solution was monitored over time. The materials were shown to release for periods varying from 3 to 14 days, dependent on the loading solution, functional monomer concentration and functional monomer:template ratio, with materials with greater monomer:template ratio (8:1 and 16:1 imprinted) tending to release for longer periods of time. Materials with a lower monomer:template ratio (4:1 imprinted) tended to release comparatively greater amounts of ciprofloxacin into solution, but the release was somewhat shorter. The total amount of drug released from the imprinted materials was sufficient to reach levels relevant to inhibit the growth of common ocular isolates of bacteria. This work is one of the first to demonstrate the feasibility of molecular imprinting in model silicone hydrogel-type materials.

Jadi,S., Heynen,M., Luensmann,D., Jones,L. Composition of incubation solution impacts in vitro protein uptake to silicone hydrogel contact lenses Molecular Vision 2012;18337-347 [ Show Abstract ]

Purpose: To determine the impact of incubation solution composition on protein deposition to silicone hydrogel (SH) contact lenses using a simplistic and a complex model of the tear film. Methods: Three SH materials - senofilcon A (SA), lotrafilcon B (LB), and balafilcon A (BA) - were incubated in two different solutions; Solution A was a simplistic augmented buffered saline solution containing a single protein, whereas Solution B was a complex artificial tear solution (ATS), containing the augmented buffered saline solution in addition to proteins, lipids, and mucins (pH=7.4). The proteins of interest (lysozyme, lactoferrin, albumin) were radiolabeled with Iodine-125 (2% protein of interest) and the accumulation of the conjugated protein to the lens materials was determined after 1, 7, 14, and 28 days of incubation. Protein deposition was measured using a gamma counter and the raw data were translated into absolute amounts (μg/lens) via extrapolation from standards. Results: After 28 days, lysozyme uptake was significantly lower on BA lenses when incubated in Solution A (33.7 μg) compared to Solution B (56.2 μg), p0.05. LB lenses also deposited similar amounts of lysozyme for both solutions (Solution A: 5.0 μg, Solution B: 4.7 μg, p>0.05). After 28 days, BA lenses accumulated approximately twice the amount of lactoferrin than the other lens materials, with 30.3 μg depositing when exposed to Solution A and 22.0 μg with Solution B. The difference between the two solutions was statistically significant (p0.05. LB lenses also deposited similar amounts of lysozyme for both solutions (Solution A: 5.0 μg, Solution B: 4.7 μg, p>0.05). After 28 days, BA lenses accumulated approximately twice the amount of lactoferrin than the other lens materials, with 30.3 μg depositing when exposed to Solution A and 22.0 μg with Solution B. The difference between the two solutions was statistically significant (p0.05). After 28 days, albumin deposition onto BA lenses was significantly greater when lenses were incubated in Solution B (1.7 μg) compared to Solution A (0.9 μg), p0.05). LB lenses incubated in Solution A deposited more albumin compared to Solution B (0.9 μg versus 0.6 μg), p=0.003. Discussion: Protein deposition onto SH materials varied when contact lenses were incubated in either a complex ATS compared to a single protein solution. More lysozyme accumulated onto BA lenses incubated in a complex analog of the human tear film, whereas lactoferrin deposited onto SA lenses independent of incubation solution composition. To better mimic the ex vivo environment, future studies should use more appropriate analogs of the tear film. © 2012 Molecular Vision.

Leiske,D. L., Leiske,C. I., Leiske,D. R., Toney,M. F., Senchyna,M., Ketelson,H. A., Meadows,D. L., Srinivasan,S., Jones,L., Fuller,G. G. Temperature-induced transitions in the structure and interfacial rheology of human meibum Biophysical journal 2012;102(2):369-376 [ Show Abstract ]

Meibomian lipids are the primary component of the lipid layer of the tear film. Composed primarily of a mixture of lipids, meibum exhibits a range of melt temperatures. Compositional changes that occur with disease may alter the temperature at which meibum melts. Here we explore how the mechanical properties and structure of meibum from healthy subjects depend on temperature. Interfacial films of meibum were highly viscoelastic at 17°C, but as the films were heated to 30°C the surface moduli decreased by more than two orders of magnitude. Brewster angle microscopy revealed the presence of micron-scale inhomogeneities in meibum films at higher temperatures. Crystalline structure was probed by small angle x-ray scattering of bulk meibum, which showed evidence of a majority crystalline structure in all samples with lamellar spacing of 49 that melted at 34°C. A minority structure was observed in some samples with d-spacing at 110 that persisted up to 40°C. The melting of crystalline phases accompanied by a reduction in interfacial viscosity and elasticity has implications in meibum behavior in the tear film. If the melt temperature of meibum was altered significantly from disease-induced compositional changes, the resultant change in viscosity could alter secretion of lipids from meibomian glands, or tear-film stabilization properties of the lipid layer. © 2012 Biophysical Society.

Leiske,D. L., Miller,C. E., Rosenfeld,L., Cerretani,C., Ayzner,A., Lin,B., Meron,M., Senchyna,M., Ketelson,H. A., Meadows,D., Srinivasan,S., Jones,L., Radke,C. J., Toney,M. F., Fuller,G. G. Molecular structure of interfacial human meibum films Langmuir 2012;28(32):11858-11865

Liu,S., Jones,L., Gu,F. X. Development of Mucoadhesive Drug Delivery System Using Phenylboronic Acid Functionalized Poly(D,L-lactide)-b-Dextran Nanoparticles Macromolecular Bioscience 2012;12(12):1622-1626 [ Show Abstract ]

Mucoadhesive NP drug carriers have attracted substantial interest as a potential treatment for anterior eye diseases. NPs composed of PLA-Dex surface functionalized with a mucoadhesive ligand, PBA, were developed as drug carriers with particle sizes ranging from 25 to 28nm. Using CycA as a model drug, we showed that NPs encapsulated up to 13.7wt% CycA and exhibited sustained release for up to 5 d in vitro at a clinically relevant dose. We fine-tuned the PBA density on the NP surface to maximize the mucin-NP interaction without compromising the particle stability in vitro. This block copolymer conjugate may be useful to improve the bioavailability of topical formulations. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lorentz,H., Heynen,M., Khan,W., Trieu,D., Jones,L. The impact of intermittent air exposure on lipid deposition Optometry and Vision Science 2012;89(11):1574-1581 [ Show Abstract ]

PURPOSE: To analyze the impact of intermittent air exposure on the in vitro deposition of two radioactive lipids on various contact lens (CL) materials, using a custom-designed model blink cell. METHODS: Six different CL materials (balafilcon A, lotrafilcon B, comfilcon A, senofilcon A, etafilcon A, and omafilcon A) were mounted on the model blink cell pistons, which cycled the lenses in and out of a complex artificial tear solution (ATS) that contained a trace amount of C-cholesterol or C-phosphatidylcholine. For the short-term experiment, air-exposed lenses were continuously cycled in and out of the ATS for 10 h. Longer term incubations for 6 days were tested with lotrafilcon B and balafilcon A materials incubated in C-cholesterol ATS. The air-exposed CLs were cycled for 14 h then submerged for 10 h each day. For both experiments, the control lenses were submerged for the entire test period. After incubation, lenses were processed, and deposited masses were quantified. RESULTS: Exposure to air resulted in increased amounts of cholesterol deposited by 1.6 to 4.3 fold on omafilcon A, balafilcon A, comfilcon A, and senofilcon A (p ≤ 0.03) compared with submerged lenses. No differences in deposition were observed for etafilcon A and lotrafilcon B (p > 0.05). The longer term incubation of lotrafilcon B and balafilcon A showed statistically significant increases in cholesterol deposition for both air-exposed lens materials (p 0.05). CONCLUSIONS: This study found that lipid deposition profiles are CL material dependent and that intermittent air exposure can influence the mass of lipid deposited. Copyright © 2012 American Academy of Optometry.

Lorentz,H., Heynen,M., Tran,H., Jones,L. Using an in vitro model of lipid deposition to assess the efficiency of hydrogen peroxide solutions to remove lipid from various contact lens materials Current eye research 2012;37(9):777-786 [ Show Abstract ]

Purpose: To test the ability of two commercially available hydrogen peroxide disinfection solutions, one containing a surfactant and one without, to remove lipid from various contact lens materials using in vitro radiochemical experiments. Methods: Etafilcon A, senofilcon A and balafilcon A contact lens materials were incubated in an artificial tear solution (ATS) containing a mixture of lipids, proteins, mucin and either 14C-cholesterol or 14C-phosphatidylcholine for 8 h. Following incubation, the lenses were removed, rinsed, and placed for 16 h in either a surfactant-containing peroxide solution (ClearCare ®), a peroxide solution devoid of a surfactant (AOSept ®) or stored without solution (control). This process was repeated every day for 1 week. The lenses were extracted with a previously optimized extraction protocol, evaporated, re-suspended, fluor added and counted for their radioactive signals. Masses of lipids deposited were calculated based on standard calibration curves, the disinfection solutions were compared and repeated measures ANOVA and post hoc statistical analysis was completed using Statistica 9. Results: The results of this experiment found that daily disinfection with hydrogen peroxide solutions reduced the amount of cholesterol and phosphatidylcholine deposited on the three contact lens materials examined, however in many cases the reduction in deposition was less than 15% when compared to the control. Disinfection with the solution containing the surfactant (ClearCare), resulted in the least deposited cholesterol and phosphatidylcholine for all materials, however not all of the comparisons were statistically significant. Conclusions: Overall, ClearCare hydrogen peroxide disinfection solution containing Pluronic 17R4 removed the most lipid from lenses when compared to the non-surfactant containing AOSept or the control, for both lipids and all lens materials. However, the differences found were quite small at times and whether these differences are clinically significant are yet to be determined. © 2012 Informa Healthcare USA, Inc.

Lorentz,H., Heynen,M., Trieu,D., Hagedorn,S. J., Jones,L. The impact of tear film components on in vitro lipid uptake Optometry and Vision Science 2012;89(6):856-867 [ Show Abstract ]

Purpose. To analyze the influence of various tear film components on in vitro deposition of two lipids (cholesterol and phosphatidylcholine) on three contact lens materials. Methods. Etafilcon A, balafilcon A, and senofilcon A were incubated in four different incubation solutions for 3 or 14 days: an artificial tear solution containing lipids and proteins, a protein tear solution containing proteins and the lipid of interest, a lipid tear solution containing lipids and no proteins, and a single lipid tear solution containing the lipid of interest only. Each incubation solution contained one of the two radiolabeled lipids: C-cholesterol (C) or C-phosphatidylcholine (PC). After soaking, lenses were removed from the incubation solution, the lipids were extracted and quantified using a beta counter, and masses of lipid were calculated using standard calibration curves. Results. This experiment examined several different parameters influencing lipid deposition on contact lenses, including lens material, length of incubation, and the composition of the incubation solution. Overall, lipid deposited differently on different lens materials (p senofilcon > etafilcon. Incubation solution had a large impact on how much lipid was deposited (p < 0.00001), although cholesterol and phosphatidylcholine demonstrated different deposition patterns. Lipid deposition after 14 days of incubation was consistently greater than after 3 days (p < 0.02). Conclusions. This in vitro study demonstrates that C and PC deposition are cumulative over time and that silicone hydrogel materials deposit more lipid than group IV conventional hydrogel materials. It also clearly demonstrates that deposition of C and PC is influenced by the composition of the incubation solution and that in vitro models must use more physiologically relevant incubation solutions that mimic the natural tear film if in vitro data is to be extrapolated to the in vivo situation. © 2012 American Academy of Optometry.

Luensmann,D., Jones,L. Protein deposition on contact lenses: The past, the present, and the future Contact Lens and Anterior Eye 2012;35(2):53-64 [ Show Abstract ]

Proteins are a key component in body fluids and adhere to most biomaterials within seconds of their exposure. The tear film consists of more than >400 different proteins, ranging in size from 10 to 2360 kDa, with a net charge of pH 1-11. Protein deposition rates on poly-2-hydroxyethyl methacrylate (pHEMA) and silicone hydrogel soft contact lenses have been determined using a number of ex vivo and in vitro experiments. Ionic, high water pHEMA-based lenses attract the highest amount of tear film protein (1300 μg/lens), due to an electrostatic attraction between the material and positively charged lysozyme. All other types of pHEMA-based lenses deposit typically less than 100 μg/lens. Silicone hydrogel lenses attract less protein than pHEMA-based materials, with <10 μg/lens for non-ionic and up to 34 μg/lens for ionic materials. Despite the low protein rates on silicone hydrogel lenses, the percentage of denatured protein is typically higher than that seen on pHEMA-based lenses. Newer approaches incorporating phosphorylcholine, polyethers or hyaluronic acid into potential contact lens materials result in reduced protein deposition rates compared to current lens materials. © 2012 British Contact Lens Association.

Luensmann,D., Moezzi,A., Peterson,R. C., Woods,C., Fonn,D. Corneal staining and cell shedding during the development of solution-induced corneal staining Optometry and Vision Science 2012;89(6):868-874 [ Show Abstract ]

Purpose. This non-dispensing cross-over study was conducted to determine if lenses presoaked in Opti-Free RepleniSH (OFR) or ReNu MultiPlus (RMP) cause solution-induced corneal staining (SICS) and subsequent cell sloughing before the typical 2 h in vivo examination point. Methods. Study lenses (PureVision) were worn bilaterally by 13 participants for periods of 15, 30, 60, and 120 min using two different contralateral care regimen pairings. The lens worn on the test eye was soaked overnight in either OFR or RMP and the control eye in Clear Care (CC). After lens removal, corneal staining was rated on a scale of 0 (negligible) to 100 (severe) for four peripheral quadrants and the central region, and the differential global staining score was calculated by subtracting baseline staining scores. Following the staining assessment, corneal cells were collected from the ocular surface using a non-contact irrigation system to determine ocular cell shedding rates. Results. Differential global staining score with OFR was greater than CC with the differences being statistically significant at 30 and 60 min (p 0.05). Conclusions. SICS occurred earlier but to a significantly lower degree when PureVision lenses were presoaked in OFR compared with RMP, while lenses presoaked in CC did not cause SICS. Ocular surface cell shedding after lens removal was not impacted by lens wear durations of ≤2 h. © 2012 American Academy of Optometry.

Ng,A., Heynen,M., Luensmann,D., Jones,L. Impact of tear film components on lysozyme deposition to contact lenses Optometry and Vision Science 2012 [ Show Abstract ]

PURPOSE: To investigate the impact of lactoferrin and lipids on the kinetic deposition of lysozyme on silicone and conventional hydrogel lenses, using a complex artificial tear solution (ATS). METHODS: Two silicone hydrogel lenses (AIR OPTIX AQUA; lotrafilcon B and ACUVUE OASYS; senofilcon A) and two conventional hydrogel lenses (ACUVUE 2; etafilcon A and PROCLEAR; omafilcon A) were investigated. Lenses were incubated in four different solutions: a complex ATS consisting of various salts, lipids, proteins, and mucins, an ATS without lactoferrin (ATS w/o Lac), an ATS without lipids (ATS w/o Lip), and an ATS without lactoferrin and lipids (ATS w/o Lac & Lip), each containing 2% radiolabeled (125I) lysozyme (1.9 mg/ml). After each time point (4, 12 h and 1, 2, 3, 5, 7, 14, 21, 28 days), the amount of lysozyme per lens was quantified. RESULTS: After 28 days, lotrafilcon B lenses incubated in ATS deposited significantly less lysozyme (9.7 ± 1.4 μg) than when incubated in solutions not containing lactoferrin and lipids (more than 11.8 μg) (p < 0.001). Lysozyme uptake to senofilcon A lenses was higher in ATS w/o Lip (5.3 ± 0.1 μg) compared with other solutions (less than 3.9 μg) (p < 0.001). Etafilcon A lenses deposited the most lysozyme in all four solutions compared with the rest of the lens types (p < 0.001). For etafilcon A lenses, less lysozyme was deposited when incubated in ATS w/o Lip (588.6 ± 0.4 μg) compared with the other solutions (more than 642.6 μg) (p < 0.001). Omafilcon A lenses in ATS w/o Lac accumulated significantly less lysozyme (12.8 ± 1.0 μg) compared with the other solutions (more than 14.2 μg) (p < 0.001). CONCLUSIONS: An ATS containing lactoferrin and lipids impacts lysozyme deposition on both silicone and conventional hydrogel contact lenses. When performing in vitro experiments to study protein deposition on contact lenses, more complex models should be used to better mimic the human tear film.

Srinivasan,S., Menzies,K., Sorbara,L., Jones,L. Infrared imaging of meibomian gland structure using a novel keratograph Optometry and Vision Science 2012;89(5):788-794 [ Show Abstract ]

PURPOSE.: To examine the ability of a novel non-contact device (Keratograph 4) to image the meibomian gland (MG) structures and their morphological changes in the upper and lower eyelids. METHODS.: Thirty-seven participants (mean age 57.8 ± 8.5 years; 3 males and 34 females) completed the Ocular Surface Disease Index questionnaire to assess dryness symptoms. Meibum secretion quality score, number of blocked gland orifices, and meibum expressibility scores were assessed. The lower lid (LL) and upper lid (UL) of all subjects were everted and images of the MGs were taken using the Keratograph 4 (OCULUS). A MG dropout score (MGDS) due to complete or partial gland loss of both lids was obtained using a subjective 4-grade scoring system, and digital analysis of the images using ImageJ was performed. Presence of tortuosity and visible acinar changes of the MGs were also noted. RESULTS.: MGDS for both lids was significantly positively correlated with the Ocular Surface Disease Index score (r = 0.51; p < 0.05). The MGDS determined using the digital grading was also significantly positively correlated (UL: r = 0.68, p < 0.05; LL: r = 0.42, p < 0.05). The sum of the MGDS for both lids using the subjective grading scale was significantly different between the non-MGD and MGD group (1.3 ± 1.0 vs. 3.1 ± 1.1; p = 0.0004). MGDS assessment using the digital grading was significantly different between non-MGD (UL = 6%, LL = 8%) and MGD group (UL = 32%, LL = 42%; p = 0.001). Tortuous MG was observed only on the UL in 6% of the participants. Visible acinar changes were noted in 40% of the study participants. CONCLUSIONS.: Infrared meibography is now possible in a clinical setting using commercially available devices, and meibography can help determine differences in MG structure in subjects symptomatic of dry eye. Copyright © 2012 American Academy of Optometry.

Subbaraman,L. N., Glasier,M. -A, Varikooty,J., Srinivasan,S., Jones,L. Protein deposition and clinical symptoms in daily wear of etafilcon lenses Optometry and Vision Science 2012;89(10):1450-1459 [ Show Abstract ]

Purpose.: To determine the relationship between clinical signs and symptoms and protein deposition over 8 h of wear of etafilcon A lenses in symptomatic and asymptomatic contact lens wearers. Methods.: Thirty adapted soft contact lens wearers (16 symptomatic and 14 asymptomatic) were fitted with etafilcon A lenses. In vivo wettability, non-invasive tear break-up time, and subjective symptoms (vision, comfort, and dryness) were assessed at baseline and after 2, 4, 6, and 8 h. After 2, 4, 6, and 8 h time points, lenses were collected, and total protein, total lysozyme, and active lysozyme deposition were assessed. Results.: There was a significant reduction (p = 0.032) in the non-invasive tear break-up time at 8 h in both groups. In the symptomatic group, there was a significant reduction in subjective comfort and dryness ratings at 6 and 8 h measurement with respect to baseline (p 94% at 8 h). Pearson's correlations between subjective symptoms and protein deposition showed poor correlations for total protein/lysozyme and any subjective factor (r 0.05), and only weak correlations between dryness and % active lysozyme (r = 0.3 to 0.5 for all time points). However, stronger correlations were found between active lysozyme and subjective comfort (r = 0.6 to 0.7; p < 0.001). Conclusions.: In addition to investigating total protein deposited on contact lenses, it is of significant clinical relevance to determine the conformational state of the deposited protein. Copyright © 2012 American Academy of Optometry.

Varikooty,J., Keir,N., Simpson,T. Estimating tear film spread and stability through tear hydrodynamics Optometry and Vision Science 2012;89(8):e1119-e1124 [ Show Abstract ]

PURPOSE.: The stability and ease of spread of the tear-film over the contact lens surface may be an indicator of contact lens surface dewetting. The present in vivo methods of determining lens dewetting are complex. This study introduces a novel and objective way of determining the upward spread and stability of the tear-film through measurement of tear-film particle dynamics. METHODS.: Ten adapted contact lens wearers wore the same type of contact lens. Using a video camera mounted to a slit-lamp, the tear-film spread over the lens surface was recorded after a blink, at 8× magnification and capture rate of 30 frames per second, at morning after lens insertion, and after 8 h of lens wear. Images from 20 videos, without blinks and without an observable change in fixation were analyzed without any further postprocessing of the images. Using a customized calibrated ImageJ macro for particle tracking, the velocity of naturally occurring reflective particles was determined. The results were analyzed using the R program and ProFit. RESULTS.: The results established that the upward particle velocity was highest immediately after a blink and declined with time. The spread of the tear film measured through upward particle velocity was different on lens insertion than after 8 h of lens wear (p ≤ 0.001). The exponential time constants ± SE were 346.02 ± 29.0 for lens insertion at morning and 1413.13 ± 419.6 after 8 h of lens wear. CONCLUSIONS.: A novel and non-invasive way to measure in vivo spread and stability of the prelens tear-film has been developed. Additional studies are needed to understand whether this simple measure is able to differentiate the performance of different soft contact lenses and how this method may help in the understanding other aspects of lens performance such as non-invasive tear breakup time, surface deposition, and lens comfort. Copyright © 2012 American Academy of Optometry.

Weeks,A., Morrison,D., Alauzun,J. G., Brook,M. A., Jones,L., Sheardown,H. Photocrosslinkable hyaluronic acid as an internal wetting agent in model conventional and silicone hydrogel contact lenses Journal of Biomedical Materials Research - Part A 2012;100 A(8):1972-1982 [ Show Abstract ]

Photocrosslinkable methacrylated hyaluronic acid (HA) was prepared and incorporated into model conventional and silicone hydrogel contact lenses as an internal wetting agent. The molecular weight of the HA, the degree of methacrylation as well as the amount (0.25 to 1.0 wt %) incorporated were varied. The HA-containing hydrogels were analyzed using a variety of techniques including water contact angles, equilibrium water content (EWC), and lysozyme sorption. The presence of HA could be detected in the materials using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopya - attenuated total reflectance. The materials containing methacrylated HA had improved hydrophilicity and reduced lysozyme sorption. Effects of modified HA on EWC were dependent upon the materials but generally increased water uptake. Increased mobility of the HA associated with a lower molecular weight and lower degree of methacrylation was found to be more effective in improving hydrophilicity and decreasing lysozyme sorption than the less mobile HA. All results found suggest that photocrosslinkable HA has significant potential in contact lens applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012. Copyright © 2011 Wiley Periodicals, Inc.

Weeks,A., Subbaraman,L. N., Jones,L., Sheardown,H. The competing effects of hyaluronic and methacrylic acid in model contact lenses Journal of Biomaterials Science, Polymer Edition 2012;23(8):1021-1038 [ Show Abstract ]

The aim of this study was to determine the influence of hyaluronic acid (HA) on lysozyme sorption in model contact lenses containing varying amounts of methacrylic acid (MAA). One model conventional hydrogel (poly(2-hydroxyethyl methacrylate) (pHEMA)) and two model silicone hydrogels (pHEMA, methacryloxypropyltris(trimethylsiloxy)silane (pHEMA TRIS) and N,N-dimethylacrylamide, TRIS (DMAA TRIS)) lens materials were prepared with and without MAA at two different concentrations (1.7 and 5%). HA, along with dendrimers, was loaded into these model contact lens materials and then cross-linked with 1-ethyl-3-(3-dimethylamino propyl)-carbodiimide (EDC). Equilibrium water content (EWC), advancing water contact angle and lysozyme sorption on these lens materials were investigated. In the HA-containing materials, the presence (P < 0.05) and amount (P < 0.05) of MAA increased the EWC of the materials. For most materials, addition of MAA reduced the advancing contact angles (P < 0.05) and for all the materials, the addition of HA further improved hydrophilicity (P < 0.05). For the non-HA containing hydrogels, the presence (P < 0.05) and amount (P < 0.05) of MAA increased lysozyme sorption. The presence of HA decreased lysozyme sorption for all materials (P < 0.05). MAA appears to work synergistically with HA to increase the EWC in addition to improving the hydrophilicity of model pHEMA-based and silicone hydrogel contact lens materials. Hydrogel materials that contain HA have tremendous potential as hydrophilic, protein-resistant contact lens materials. © Koninklijke Brill NV, Leiden, 2012.

Woods,J., Jones,L., Woods,C., Schneider,S., Fonn,D. Use of a photographic manipulation tool to assess corneal vascular response Optometry and Vision Science 2012;89(2):215-220 [ Show Abstract ]

Purpose. Corneal vasculature change in contact lens wearers has been linked to the level of hypoxia within the cornea. To assess the impact a treatment has on limbal vessels, a sensitive method of measurement and quantification is required. Methods. A group of 21 highly myopic, hydrogel wearers, with preexisting signs of corneal hypoxia, were enrolled into a study where they wore sifilcon A silicone hydrogel lenses (Dk/t = 117), on a daily wear basis for 9 months. At all scheduled visits, photographs were taken of the superior, inferior, temporal, and nasal limbal regions which were then imported into Adobe Photoshop. A red-free filter was applied to enhance the contrast of the blood columns. In each quadrant, the length of the longest visible blood column was measured and the blood columns that penetrated -0.5 mm into the cornea were counted. A control group of 11 non-lens wearers was recruited. Their photographs were taken at the beginning of the study and 9 months later. An independent, masked observer assessed the photographs. Results. There was a significant decrease in the maximum penetration of the blood column in all quadrants (p + 0.001) from baseline to the 9-month visit (e.g., superior: baseline 0.84 ± 0.39 mm; 9 months 0.63 ± 0.20 mm). There was also significant reduction in the number of visible blood columns longer than 0.5 mm in each quadrant (p + 0.001) from baseline to 9 months in all quadrants (e.g., superior: baseline 14.0 ± 8.2; 9 months 6.5 ± 6.0). The control group showed no change over time for the maximum blood column length (p = 0.638) or the number of columns >0.5 mm (p = 0.341). Conclusions. A group of highly myopic subjects exhibited reduction in the maximum length and number of blood columns in the cornea when refit with a highly permeable silicone hydrogel material. The use of photography, along with Adobe Photoshop software, provides a reliable way of measuring corneal vascular responses over time. (Optom Vis Sci 2012;89:215-220). © 2012 American Academy of Optometry.

Young,G., Chalmers,R., Napier,L., Kern,J., Hunt,C., Dumbleton,K. Soft contact lens-related dryness with and without clinical signs Optometry and Vision Science 2012;89(8):1125-1132 [ Show Abstract ]

PURPOSE.: To report demographics, wearing patterns, and symptoms from soft contact lens (SCL) wearers with significant SCL-related dryness symptoms with and without significant ocular signs of dryness. METHODS.: In a multicenter, prospective observational clinical trial, symptomatic SCL wearers reported significant SCL-related dryness via self-administered questionnaire of frequency and intensity of dryness after a dry eye (DE) examination. DE etiology was assigned post hoc by an expert panel, and those with and without significant DE-related signs were analyzed by univariate logistic regression. Possible DE etiologies were aqueous tear deficiency, SCL-induced tear instability, meibomian gland dysfunction, or "other." Wearers without signs that qualified for any DE etiology were designated as No DE Signs (NDES). RESULTS.: Of the 226 SCL symptomatic wearers examined, 23% were without signs, 30% had aqueous tear deficiency, 25% had SCL-induced tear instability, 14% had meibomian gland dysfunction, and 8% had "other" diagnoses. The NDES wearers had significantly longer pre-lens break-up time (9.8 vs. 6.6 s, p < 0.0001), better lens wetting (3.4 vs. 2.4 0 to 4 scale, p < 0.0001), lower levels of film deposits on lenses (0.45 vs. 0.92, 0 to 4 scale, p < 0.0001), and of most slit lamp signs. The NDES wearers were significantly more likely to be male (36% vs.19%, p ≤ 0.013), were less likely to have deteriorating comfort during the day (81% vs. 97%, p ≤ 0.001), reported longer average hours of comfortable wear (11 ± 3 vs. 9 ± 4 h, p ≤ 0.014), had older contact lenses (18 ± 14 vs. 13 ± 12 days, p ≤ 0.029), and greater intensity of photophobia early and late in the day (p ≤ 0.043 and 0.021). CONCLUSIONS.: Symptoms of dryness in SCL wearers stem from a variety of underlying causes. However, nearly one-quarter of these symptomatic SCL wearers appear to be free of signs of dryness. The effective management of CL-related dryness requires a comprehensive range of clinical assessments and the use of a diverse range of management strategies. Copyright © 2012 American Academy of Optometry.

2011

Dalton,K., Sorbara,L. Fitting an MSD (Mini Scleral Design) rigid contact lens in advanced keratoconus with INTACS Contact Lens and Anterior Eye 2011;34(6):274-281

Dumbleton,K. A., Woods,C. A., Jones,L. W., Fonn,D. The relationship between compliance with lens replacement and contact lens-related problems in silicone hydrogel wearers Contact Lens and Anterior Eye 2011;34(5):216-222 [ Show Abstract ]

To evaluate the relationship between compliance with replacement frequency (RF) and contact lens (CL)-related problems in silicone hydrogel (SiHy) wearers. Methods: 501 SiHy wearers from seven optometry offices completed surveys regarding their lens wear and any CL related problems which they may have experienced in the preceding 12 months. File review was subsequently conducted at their optometry offices to confirm the information provided. Results: 49% of respondents were wearing 2-week replacement (2WR) and 51% 1-month replacement (1MR) SiHy lenses. 67% wore their lenses for longer than the manufacturers' recommended RF (MRRF) and 60% for longer than their optometrist's recommended RF (ORRF). The mean RF was 2.6× the MRRF for 2WR and 1.5× for 1MR wearers (p< 0.001) with median values of 31 and 37 days, respectively. Twenty-three percent reported signs or symptoms consistent with potential complications relating to CL wear. This rate was significantly higher for wearers who were non-compliant with the ORRF than compliant wearers (26% versus 18%, p= 0.028). It was also higher for those multipurpose solution users who reported never/almost never rubbing and rinsing their lenses when compared with those who did this every night (29% versus 17%, p= 0.007). Conclusions: Two thirds of the SiHy wearers did not comply with the MRRF and 2WR wearers stretched the replacement interval of their lenses to a greater degree than 1MR wearers. Failing to replace lenses when recommended and failing to rub and rinse lenses were associated with a higher rate of patient-reported CL problems. © 2011 British Contact Lens Association.

Dumbleton,K. A., Woods,M., Woods,C. A., Jones,L. W., Fonn,D. Ability of patients to recall habitual contact lens products and enhancement of recall using photographic aids Contact Lens and Anterior Eye 2011;34(5):236-240 [ Show Abstract ]

To determine the proportion of soft contact lens (CL) wearers who are able to recall their habitual products (lenses and care system) correctly from memory, and to evaluate the value of using photographic aids (PAs) to improve recall. Methods: 103 soft lens wearers attended 2 visits to investigate their habitual CL product use. At the first visit they were asked to recall which products they were using and then to identify their products from PAs. They returned for a second visit with their products for confirmation. Results: 51% correctly reported their lens brands from memory alone, which improved to 87% with the use of the PAs (p< 0.001). 41% correctly reported their habitual care system from memory alone, which improved to 80% with the use of PAs (p< 0.001). Females were better at recalling care system brand names than males (49% versus 27% correct, p= 0.040) and wearers with more than 1 year experience with their habitual CLs had better recall than those with up to 1 year experience (63% versus 27%, p= 0.014). Conclusion: Less than 50% of contact lens wearers were able to recall the names of their habitual lens and lens care products correctly from memory. PAs improved this recall significantly for both contact lenses and contact lens care systems. © 2011 British Contact Lens Association.

Efron,N., Morgan,P. B., Helland,M., Itoi,M., Jones,D., Nichols,J. J., van der Worp,E., Woods,C. A. Soft toric contact lens prescribing in different countries Contact Lens and Anterior Eye 2011;34(1):36-38

Gorbet,M. B., Tanti,N. C., Crockett,B., Mansour,L., Jones,L. Effect of contact lens material on cytotoxicity potential of multipurpose solutions using human corneal epithelial cells Molecular Vision 2011;173458-3467 [ Show Abstract ]

Purpose: Multipurpose solutions (MPS) are used daily to clean and disinfect silicone hydrogel (SiHy) contact lenses. This in vitro study was undertaken to identify the potential for interaction between MPS, SiHy surface treatments, and lens materials, which may lead to changes in the response of human corneal epithelial cells (HCEC) to MPS-soaked lenses. Methods: The MPS tested were renu fresh (formerly known as ReNu MultiPlus; ReNu), OptiFree Express (OFX), OptiFree RepleniSH, SoloCare Aqua, and Complete Moisture Plus. The SiHy materials evaluated were lotrafilcon A, lotrafilcon B, comfilcon A, galyfilcon A, and balafilcon A (BA). MPS-soaked lenses were placed on top of adherent HCEC. The effect of MPS dilutions (0.1 to 10% final concentration in medium) was also characterized. Cell viability, adhesion phenotype and caspase activation were studied after 24-h cell exposure. OFX released from lenses was determined using UV absorbance. Results: A significant reduction in viability (between 30 to 50%) was observed with cells exposed to lenses soaked in ReNu and OFX. A significant downregulation of α3 and β1 integrins, with integrin expression ranging from 60% to 75% of control (cells with no lens), was also observed with OFX and ReNu-soaked lenses. With the exception of BA, all other lenses soaked in OFX resulted in significant caspase activation, whereby over 18% of cells stained positive for caspases. Minimal caspase activation was observed in cells exposed to ReNu and Solo soaked lenses. For both OFX and ReNu, exposing cells to at least a 5% dilution had a significant effect on viability and integrin expression. While Complete and Solo did not lead to reduction in viability, cells exposed to a 10% dilution showed reduced integrin expression down to less than 70% of control value. Comparing cell response to diluted MPS solutions and various MPS-soaked lenses showed that it is not possible to reliably use cell response to MPS dilution alone to assess MPS biocompatibility. Conclusions: Our results demonstrate that the reaction of HCEC to MPS are affected by the type of lenses the MPS is released from and may potentially be influenced by the surface treatment (or lack of it) of SiHy materials. © 2011 Molecular Vision.

Heynen,M., Lorentz,H., Srinivasan,S., Jones,L. Quantification of non-polar lipid deposits on senofilcon A contact lenses Optometry and Vision Science 2011;88(10):1172-1179

Kao,E. C. Y., McCanna,D. J., Jones,L. W. Utilization of in vitro methods to determine the biocompatibility of intraocular lens materials Toxicology in Vitro 2011;25(8):1906-1911

Keir,N. J., Simpson,T., Hutchings,N., Jones,L., Fonn,D. Outcomes of wavefront-guided laser in situ keratomileusis for hyperopia Journal of cataract and refractive surgery 2011;37(5):886-893 [ Show Abstract ]

Purpose: To determine the impact of wavefront-guided laser in situ keratomileusis (LASIK) for hyperopia on corrected distance visual acuity (CDVA), contrast sensitivity, and higher-order aberrations (HOAs). Setting: Centre for Contact Lens Research, University of Waterloo, Waterloo, Ontario, Canada. Design: Case series. Methods: This study comprised patients who had LASIK for hyperopia. The HOAs up to the 4th order (5.0 mm pupil) in right eyes were analyzed. Results: The study enrolled 31 patients. The preoperative mean values were sphere, +2.60 diopters (D) ± 1.15 (SD) (range +1.00 to +5.00 D); astigmatism, -0.87 ± 0.74 D (range 0.00 to -3.75 D); and spherical equivalent (SE), +2.16 ± 1.00 D (range +0.63 to +4.50 D). The postoperative refractive SE was within ±0.50 D in 71.0% of eyes. The uncorrected distance visual acuity was 20/20 or better in 87.2% of eyes. There was no significant change in CDVA or contrast sensitivity (all P>.05). There was a significant change in Zernike coefficients Z(0,4), Z(-1,3), Z(-3,3), and Z(3,3) (range of mean absolute change ± SEM: 0.092 ± 0.013 μm to 0.208 ± 0.018 μm; all P<.001). Coefficients Z(-1,3) and Z(3,3) increased and Z(0,4) and Z(-3,3) decreased in magnitude; each had a reversal of sign. The only significant postoperative association was between low-contrast CDVA and Z(0,4) (r = 0.617, P<.001). Conclusions: Low-contrast CDVA after LASIK surgery for hyperopia was correlated with Z(0,4). There were no significant changes in CDVA or contrast sensitivity. The relative risk for losing low-contrast CDVA increased if more than 1 Zernike term had a sign change. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. © 2011 ASCRS and ESCRS.

Lorentz,H., Heynen,M., Kay,L. M. M., Dominici,C. Y., Khan,W., Ng,W. W. S., Jones,L. Contact lens physical properties and lipid deposition in a novel characterized artificial tear solution Molecular Vision 2011;173392-3405 [ Show Abstract ]

Purpose: To characterize various properties of a physiologically-relevant artificial tear solution (ATS) containing a range of tear film components within a complex salt solution, and to measure contact lens parameters and lipid deposition of a variety of contact lens materials after incubation in this ATS. Methods: A complex ATS was developed that contains a range of salts, proteins, lipids, mucin, and other tear film constituents in tear-film relevant concentrations. This ATS was tested to confirm that its pH, osmolality, surface tension, and homogeneity are similar to human tears and remain so throughout the material incubation process, for up to 4 weeks. To confirm that silicone hydrogel and conventional hydrogel contact lens materials do not alter in physical characteristics beyond what is allowed by the International Organization for Standardization (ISO) 18369-2. The diameter, center thickness, and calculated base curve were measured for five different lens materials directly out of the blister pack, after a rinse in saline and then following a two week incubation in the modified ATS. To test the ATS and the effect of its composition on lipid deposition, two lens materials were incubated in the ATS and a modified version for several time points. Both ATS solutions contained trace amounts of carbon-14 cholesterol and phosphatidylcholine, such that deposition of these specific lipids could be quantified using standard methods. Results: This ATS is a complex mixture that remains stable at physiologically relevant pH (7.3-7.6), osmolality (304- 306 mmol/kg), surface tension (40-46 dynes/cm) and homogeneity over an incubation period of three weeks or more. The physical parameters of the lenses tested showed no changes beyond that allowed by the ISO guidelines. Incubations with the ATS found that balafilcon A lenses deposit significantly more cholesterol and phosphatidylcholine than omafilcon A lenses (p<0.05) and that removing lactoferrin and immunoglobulin G from the ATS can significantly decrease the mass of lipid deposited. Conclusions: This paper describes a novel complex artificial tear solution specially designed for in-vial incubation of contact lens materials. This solution was stable and did not adversely affect the physical parameters of the soft contact lenses incubated within it and showed that lipid deposition was responsive to changes in ATS composition. © 2011 Molecular Vision.

Maram,J., Sorbara,L., Simpson,T. Accuracy of Visante and Zeiss-Humphrey Optical Coherence Tomographers and their cross calibration with optical pachymetry and physical references Journal of Optometry 2011;4(4):147-155

Menzies,K. L., Jones,L. In vitro analysis of the physical properties of contact lens blister pack solutions Optometry and Vision Science 2011;88(4):493-501 [ Show Abstract ]

Purpose. Since the initial development of silicone hydrogels, many modifications to the bulk and surface properties of the lenses have been undertaken to improve the wettability and comfort of the lenses. Recently, manufacturers have incorporated various "wetting agents" or surface-active agents into the blister packaging solutions (BPSs) of the lenses to improve initial comfort of the lens on eye. The purpose of this study was to measure and compare the pH, surface tension (ST), viscosity, and osmolality of BPSs for a variety of silicone hydrogel and polyHEMA-based hydrogel lenses. In addition, two saline solutions were tested for comparison purposes. Methods. The pH, osmolality, ST, and viscosity were measured for the BPSs for lotrafilcon B and lotrafilcon A and lotrafilcon B with a "modified BPS" (m-lotrafilcon A, m-lotrafilcon B) (CIBA Vision, Duluth, GA); balafilcon A (Bausch & Lomb, Rochester, NY); galyfilcon A, senofilcon A, and narafilcon A (Johnson & Johnson, Jacksonville, FL); and comfilcon A and enfilcon A (CooperVision, Pleasanton, CA) and BPSs from two conventional polyHEMA-based materials-etafilcon A (Johnson & Johnson) and omafilcon A (CooperVision). The two saline solutions tested were Unisol (Alcon, Fort Worth, TX) and Softwear Saline (CIBA Vision). Results. The pH results for the two saline solutions and all BPSs remained in the pH range of tears (6.6-7.8). The ST of the modified BPS was significantly lower (p 0.05) between BPSs made by the same manufacturer but were significantly different compared with BPSs made by different manufacturers (p < 0.05). Conclusions. The incorporation of wetting agents and surfactants into BPSs does alter the physical properties of the BPSs, which may have clinical implications regarding initial in-eye comfort. Copyright © 2011 American Academy of Optometry.

Moezzi,A. M., Fonn,D., Varikooty,J., Richter,D. Distribution of overnight corneal swelling across subjects with 4 different silicone hydrogel lenses Eye and Contact Lens 2011;37(2):61-65 [ Show Abstract ]

Purpose: To determine distribution of central corneal swelling (CCS) across subjects after 8 hr of sleep in eyes wearing silicone hydrogel lenses with various oxygen transmissibility (Dk/t) values and in eyes without lenses. Methods: Twenty-nine neophytes wore lotrafilcon A (Dk, 140), balafilcon A (Dk, 91), galyfilcon A (Dk, 60), and senofilcon A (Dk, 103) lenses in powers -3.00, -10.00, and +6.00 diopters on separate nights, in random order, and on 1 eye only. The contralateral eye (no lens) served as the control. Central corneal thickness was measured using a digital optical pachometer before lens insertion and immediately after lens removal on waking. Results: The average difference between the mean (7%) and the median (6.8%) CCS of all lenses was only 0.2%, suggesting a normal distribution. There was no correlation between the mean and the range of the CCS (r=0.058, P=0.766). Normal CCS distributions were also found with each lens-wearing eye and the control eye (P>0.20 for all). There was a significant correlation between lens-wearing eye and control eye (r=0.895, P<0.001) and between lotrafilcon A and each of the other 3 lenses for mean CCS across the study participants (P<0.001 for all). Conclusions: Distribution of corneal swelling in both lens-wearing eye and control eye followed a normal curve. An individual's corneal swelling response seems to be independent of lens type. © 2011 Lippincott Williams & Wilkins.

Morgan,P. B., Efron,N., Helland,M., Itoi,M., Jones,D., Nichols,J. J., van der Worp,E., Woods,C. A. Global trends in prescribing contact lenses for extended wear Contact Lens and Anterior Eye 2011;34(1):32-35

Schulze,M. M., Hutchings,N., Simpson,T. L. Grading bulbar redness using cross-calibrated clinical grading scales Investigative Ophthalmology and Visual Science 2011;52(8):5812-5817 [ Show Abstract ]

Purpose. To determine the between-scale agreement of grading estimates obtained with cross-calibrated McMonnies/Chapman- Davies (MC-D), Institute for Eye Research (IER), Efron, and Validated Bulbar Redness (VBR) grading scales. Methods. Modified reference images of each grading scale were positioned on a desk according to their perceived redness (within a 0 to 100 range) as determined in a previous psychophysical scaling experiment. Ten observers were asked to represent perceived bulbar redness of 16 sample images by placing them, one at a time, relative to the reference images of each scale. Only 0 and 100 were marked on the scale, but not the numerical position of the reference images. Perceived redness was taken as the measured position of the placed image from 0 and was averaged across observers. Results. Overall, perceived redness depended on the sample image and the reference scale used (repeated measures ANOVA; P = 0.0008); six sample images had a perceived redness that was significantly different between at least two of the scales. Between-scale correlation coefficients of concordance ranged from 0.93 (IER vs. Efron) to 0.98 (VBR vs. Efron). Between-scale coefficients of repeatability ranged from five units (IER vs. VBR) to eight units (IER vs. Efron) of the 0 to 100 range. Conclusions. The use of cross-calibrated reference grades for bulbar redness grading scales allows comparison of grading estimates obtained with different scales. Perceived redness is dependent on the dynamic range of the reference images of the scale, with redness estimates generally being found to be higher for scales with a shorter dynamic range. © 2011 The Association for Research in Vision and Ophthalmology, Inc.

Sorbara,L., Maram,J., Bizheva,K., Hutchings,N., Simpson,T. L. Case report: Chalazion and its features visualized by ultrahigh resolution optical coherence tomography Contact Lens and Anterior Eye 2011;34(2):87-91

Subbaraman,L. N., Borazjani,R., Zhu,H., Zhao,Z., Jones,L., Willcox,M. D. P. Influence of protein deposition on bacterial adhesion to contact lenses Optometry and Vision Science 2011;88(8):959-966 [ Show Abstract ]

Purpose. The aim of the study is to determine the adhesion of Gram positive and Gram negative bacteria onto conventional hydrogel (CH) and silicone hydrogel (SH) contact lens materials with and without lysozyme, lactoferrin, and albumin coating. Methods. Four lens types (three SH-balafilcon A, lotrafilcon B, and senofilcon A; one CH-etafilcon A) were coated with lysozyme, lactoferrin, or albumin (uncoated lenses acted as controls) and then incubated in Staphylococcus aureus (Saur 31) or either of two strains of Pseudomonas aeruginosa (Paer 6294 and 6206) for 24 h at 37°C. The total counts of the adhered bacteria were determined using the H-thymidine method and viable counts by counting the number of colony-forming units on agar media. Results. All three strains adhered significantly lower to uncoated etafilcon A lenses compared with uncoated SH lenses (p 0.05). Lactoferrin coating on lenses increased binding (total and viable counts) of Saur 31 (p < 0.05). Lactoferrin-coated lenses showed significantly higher total counts (p < 0.05) but significantly lower viable counts (p < 0.05) of adhered P. aeruginosa strains. There was a significant difference between the total and viable counts (p < 0.05) that were bound to lactoferrin-coated lenses. Albumin coating of lenses increased binding (total and viable counts) of all three strains (p < 0.05). Conclusions. Lysozyme deposited on contact lenses does not possess antibacterial activity against certain bacterial strains, whereas lactoferrin possess an antibacterial effect against strains of P. aeruginosa. © 2011 American Academy of Optometry.

Szczotka-Flynn,L., Benetz,B. A., Lass,J., Albright,M., Gillespie,B., Kuo,J., Fonn,D., Sethi,A., Rimm,A. The association between mucin balls and corneal infiltrative events during extended contact lens wear Cornea 2011;30(5):535-542 [ Show Abstract ]

PURPOSE:: To determine the association between mucin ball formation and corneal infiltrative events (CIEs) during continuous wear with lotrafilcon A silicone hydrogel contact lenses. METHODS:: Subjects (n = 205) in the Longitudinal Analysis of Silicone Hydrogel Contact Lens Study wore lotrafilcon A contact lenses for 12 months of continuous wear. The primary outcome was a CIE. Kaplan-Meier methods were used to estimate the unadjusted cumulative incidence of remaining CIE free stratified by mucin ball presence. Cox proportional hazards regression was used to model the hazard of developing a CIE as a function of mucin ball formation and other covariates. RESULTS:: Over half (54.2%) of the subjects displayed some presence of mucin balls during at least 1 visit and about one third (32.8%) displayed repeated episodes. Mucin ball scores were correlated between the 2 eyes and weakly correlated with corneal curvature (P ≤ 0.005). Univariate analyses revealed that the relative hazard for a CIE was 0.35 [95% confidence interval (CI), 0.19-0.68] if a single episode of mucin balls was detected and 0.17 (95% CI, 0.06-0.43) if repeated episodes were detected. Upon multivariate analysis, repeated presence of mucin balls was associated with an 84% decreased hazard of experiencing a CIE (hazard ratio: 0.16; 95% CI, 0.06-0.44). CONCLUSIONS:: The presence of mucin balls is significantly associated with a decreased incidence of CIEs, and the effect is greatest when they are repeatedly present over time. We hypothesize that the mucin ball presence represents a more concentrated or viscous mucus layer, which prevents upregulation of the immune response against bacterial ligands. Copyright © 2011 by Lippincott Williams & Wilkins.

Tanti,N. C., Jones,L., Gorbet,M. B. Impact of multipurpose solutions released from contact lenses on corneal cells Optometry and Vision Science 2011;88(4):483-492 [ Show Abstract ]

Purpose. To assess, in vitro, the effect of the release of contact lens multipurpose solutions (MPS) from two silicone hydrogel lenses on human corneal epithelial cells. Methods. A monolayer of immortalized human corneal epithelial cells was seeded in a 24-well plate in keratinocyte serum-free medium. Lotrafilcon A (LA) and balafilcon A (BA) lenses were placed on top of the adherent cells for 8 and 24 h, after being soaked in MPS, borate-buffered (Unisol) or phosphate-buffered saline overnight. Cells were assayed for viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay or for α3, β1, and β4 integrin expression and caspase activation by flow cytometry. Results. After 8 h, LA lenses soaked in Unisol, Opti-Free Express (OFX), and ReNu MultiPlus (ReNu) showed decrease in cell viability. LA and BA soaked in Complete Moisture Plus (Complete) had similar viability at around 85% of control. After 24 h, a further decrease in viability was observed with all MPS-soaked lenses; LA soaked in OFX significantly reduced viability compared with Unisol-soaked lenses. In addition, reduced levels of integrin expression for lenses soaked in OFX and ReNu, and for BA soaked in Complete were observed. At 24 h, only LA soaked in OFX led to an increase in caspase activation. Conclusions. Our results indicate an increase in cytotoxicity with borate-based MPS solutions in vitro when compared with both phosphate-buffered saline and borate-exposed lenses, suggesting that biocides and/or additives play a role in the observed cell reaction. Moreover, the mechanism of in vitro solution-induced toxicity appeared to be mediated by lens type, suggesting differences in the preferential adsorption/release profile of certain compounds. Copyright © 2011 American Academy of Optometry.

Weeks,A., Luensmann,D.,Boone,A, Jones,L., Sheardown,H. Hyaluronic acid as an internal wetting agent in model DMAA/TRIS contact lenses 2011 1-10 [ Show Abstract ]

Model silicone hydrogel contact lenses, comprised of N,N-dimethylacrylamide and methacryloxypropyltris (trimethylsiloxy) silane, were fabricated and hyaluronic acid (HA) was incorporated as an internal wetting agent using a dendrimer-based method. HA and dendrimers were loaded into the silicone hydrogels and cross-linked using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry. The presence and location of HA in the hydrogels was confirmed using X-ray photoelectron spectroscopy and confocal laser scanning microscopy, respectively. The effects of the presence of HA on the silicone hydrogels on hydrophilicity, swelling behavior, transparency, and lysozyme sorption and denaturation were evaluated. The results showed that HA increased the hydrophilicity and the equilibrium water content of the hydrogels without affecting transparency. HA also significantly decreased the amount of lysozyme sorption (p < 0.002). HA had no effect on lysozyme denaturation in hydrogels containing 0% and 1.7% methacrylic acid (MAA) (by weight) but when the amount of MAA was increased to 5%, the level of lysozyme denaturation was significantly lower compared to control materials. These results suggest that HA has great potential to be used as a wetting agent in silicone hydrogel contact lenses to improve wettability and to decrease lysozyme sorption and denaturation.

Woods,C. A., Dumbleton,K., Jones,L., Fonn,D. Patient use of smartphones to communicate subjective data in clinical trials Optometry and Vision Science 2011;88(2):290-294 [ Show Abstract ]

Purpose. Various methods have been used in clinical trials to collect time-sensitive subjective responses, including study diaries, telephone interviews, and use of text messaging. However, all of these methods are limited by the uncertainty of when the participants enrolled in the study actually record their responses. This technical note reports on the utility of the BlackBerry smartphone to collect such data and why such a system provides advantages over other methods to report subjective ratings in clinical studies. Methods. The Centre for Contact Lens Research developed an on-line web-enabled system that permits participants to record and immediately transmit subjective rating scores in numerical form directly into a web-enabled database. This, combined with the utility of BlackBerrys, enabled time-specific e-mail requests to be sent to the study participants and then for that data to be simultaneously transmitted to the web-enabled database. This system has been used in several clinical trials conducted at the Centre for Contact Lens Research, in which data were collected at various times and in several specific locations or environments. Results. In the clinical trials conducted using this system, participants provided responses on 97.5% of occasions to the requests for data generated by the automated system. When the request was for data on a set date, this method resulted in responses of 84.1% of the time. Conclusions.The series of clinical trials reported here show the benefits of the utilization of the BlackBerry to collect time- or environment-sensitive data via a web-enabled system. Copyright © 2011 American Academy of Optometry.

Youn,H. -Y, McCanna,D. J., Sivak,J. G., Jones,L. W. In vitro ultraviolet-induced damage in human corneal, lens, and retinal pigment epithelial cells Molecular Vision 2011;17237-246

2010

Bitton,E., Jones,L., Simpson,T., Woods,C. Influence of the blink interval on tear meniscus height in soft contact lens and nonlens wearers Eye and Contact Lens 2010;36(3):156-163 [ Show Abstract ]

Purpose: Tear meniscus height (TMH) is an indirect measurement of tear film volume. This study investigated the temporal changes in the TMH during the blink interval in the morning (8-9 am) and at the end of the day (5-6 pm) in both soft contact lens (CL) and nonlens wearers (NLW). Methods: Fifty participants (25 CL; 25 NLW) were evaluated for their subjective symptoms, TMH, noninvasive break up time, and bulbar hyperemia at the am and pm visits on the same day. The TMH was measured at set intervals between 2 and 15 sec during the blink interval, using an optical coherence tomographer. Results: The NLW group revealed no changes in a variety of symptoms during the day, whereas the CL group reported an increase in dryness (P=0.03) and grittiness (P=0.02) over the day. For both groups, the TMH and calculated tear meniscus volume revealed lower values immediately after the blink and increased progressively afterwards, mainly due to reflex tearing. The am tear meniscus volume values tended to be higher than the pm values for both groups, but this was not significant (NLW P=0.13; CL P=0.82). Noninvasive break up time deteriorated during the day for both groups but was only significant for the CL group (P=0.002), whereas bulbar hyperemia revealed no statistically significant change for either group. Conclusions: Reflex tearing may play a substantial role in the TMH differences observed over the blink interval. Standardization of the time when a TMH measurement is performed will be valuable in comparing tear film clinical studies. Copyright © Contact Lens Association of Ophthalmologists, Inc.

Boone,A., Heynen,M., Joyce,E., Jones,L. Ex vivo protein deposition on bi-weekly silicone hydrogel contact lenses Optometry and Vision Science 2010;87(2):146

Caffery,B., Heynen,M. L., Joyce,E., Jones,L., Robert III,R., Senchyna,M. MUC1 expression in Sjogren's syndrome, KCS, and control subjects Molecular Vision 2010;161720-1727 [ Show Abstract ]

Purpose: To quantify and compare human mucin 1 (MUC1) protein and mRNA expression in tears and conjunctival epithelial cells collected from Sjogren's syndrome (SS), non-Sjogren's keratoconjunctivitus sicca (KCS) and non-dry eyed (NDE) control subjects. Methods: Seventy-six subjects were recruited for this study: 25 SS (confirmed via American-European Consensus Criteria 2002), 25 KCS (confirmed by symptoms and Schirmer scores ≤10 mm) and 26 NDE. Tears were collected using an eyewash technique. Impression cytology was used to gather protein and mRNA from conjunctival epithelial cells. Soluble and membrane bound MUC1 were quantified via western blotting and MUC1 mRNA was quantified by real time qPCR. Results: The SS group demonstrated significantly higher concentrations of soluble MUC1 (0.12±0.11 [SS]; 0.013±0.02 [KCS; p=0.001]; 0.0023±0.0024 [NDE; p<0.001]) and MUC1 mRNA (3.18±1.44 [SS]; 1.79±1.18 [KCS; p<0.05]; 1.60±0.74 [NDE; p<0.05]) compared to both KCS and NDE groups. Soluble MUC1 expression was also higher in the KCS group compared to the NDE group (p=0.02), where as MUC1 mRNA expression was similar in both KCS and NDE groups. Membrane bound MUC1 expression differed only between the SS and NDE groups (0.005±-0.003 [SS]; 0.003±0.002 [NDE; p=0.002]). Conclusions: These results demonstrate that SS subjects express greater quantities of MUC1 protein and mRNA compared to both KCS and control subjects. Increased soluble MUC1 expression was also found in KCS subjects compared to controls. Membrane bound MUC1 was present in higher concentration in SS versus NDE only. These significant changes in MUC1 expression may represent compensatory or protective responses to chronic insult to the ocular surface. © 2010 Molecular Vision.

Dalton,K., Schneider,S., Sorbara,L., Jones,L. Confocal microscopy and optical coherence tomography imaging of hereditary granular dystrophy Contact Lens and Anterior Eye 2010;33(1):33-40

Dumbleton,K., Richter,D., Woods,C., Jones,L., Fonn,D. Compliance with contact lens replacement in Canada and the United States Optometry and Vision Science 2010;87(2):131-139 [ Show Abstract ]

PURPOSE.: To assess eye care practitioners (ECPs) recommendations for replacement frequency (RF) of silicone hydrogel (SH) and daily disposable (DD) lenses in Canada and the U.S. and to compare noncompliance (NC) with manufacturer recommended RF by the ECP and patient, and the reasons given for NC. METHODS.: Invitations to participate were sent by e-mail to ECPs in Canada and the U.S. Twenty patient surveys were sent to 420 ECPs, and 2232 eligible surveys were received from 216 ECPs (26% Canada, 74% U.S.). Questions related to patient demographics, lens type, wearing patterns, ECP instructions for RF, and actual patient RF. ECPs provided lens information and their recommendation for RF after the surveys were completed and sealed in envelopes. Responses were anonymous. RESULTS.: DD accounted for 18% (Canada) vs. 16% (U.S.) of wearers (p > 0.05); 35% (Canada) vs. 45% (U.S.) wore 2-week replacement SH (2WR; p = 0.011); and 47% (Canada) vs. 39% (U.S.) wore 1-month replacement SH (1MR) lenses (p = 0.025). Thirty-four percent (Canada) vs. 18% (U.S.) of ECPs recommended longer RFs than the manufacturer recommended RF for 2WR lens wearers (p 0.05) and were lowest for DD (13% Canada, 12% U.S.), followed by 1MR (33% Canada, 28% U.S.). The highest NC rates were with 2WR (50% Canada, 52% U.S.). The most frequent reason for NC with 2WR and 1MR was 'forgetting which day to replace lenses' (54% Canada, 53% U.S.) and in DD wearers 'to save money' (56% Canada, 29% U.S., p < 0.001). CONCLUSIONS.: 1MR lenses are more frequently prescribed in Canada. ECPs in Canada were NC with 2WR lenses more frequently than U.S. ECPs, but patient NC rates were the same in both countries for all lens types. ECP and patient NC rates were highest for 2WR lens wearers. Copyright © 2010 American Academy of Optometry.

Dumbleton,K., Woods,C., Jones,L., Richter,D., Fonn,D. Comfort and vision with silicone hydrogel lenses: Effect of compliance Optometry and Vision Science 2010;87(6):421-425 [ Show Abstract ]

PURPOSE. Silicone hydrogel (SH) lenses are usually replaced after 2 weeks (2W) or 1 month (1M); however, many patients do not comply with the manufacturers' recommended replacement frequency (MRRF). The purpose of this analysis was to investigate the effect of compliance with MRRF on comfort and vision in SH wearers. METHODS. As a part of a larger study investigating compliance with MRRF, patients were asked to rate their subjective comfort and vision from 0 (very poor) to 10 (excellent) in the morning, at the end of the day (EVE), when lenses were new, and needed replacing (NR). RESULTS. One thousand three hundred forty-four patients wore 2W replacement modality (2WR) (n = 717) or 1M replacement modality (1MR) (n = 617) SH lenses. Comfort and vision in the morning and when lenses are new were significantly higher than for EVE and NR (p < 0.001). Twenty-nine percent (95% confidence interval 25.3-32.4) of 1MR and 59% (95% confidence interval 55.5-62.7) of 2WR wearers were non-compliant with the MRRF. Compliance had a significant effect on EVE (p = 0.002, p = 0.008) and NR (p < 0.001, p < 0.001) comfort and vision. After accounting for compliance, EVE and NR comfort and EVE vision were higher for 1MR than 2WR (p = 0.015, p = 0.044, p = 0.019). CONCLUSIONS. Compliant patients had better EVE and NR comfort and vision than non-compliant patients, regardless of replacement modality. Optimal subjective performance with SH lenses seems to be facilitated by replacing lenses as recommended. Copyright © 2010 American Academy of Optometry.

Efron,N., Morgan,P. B., Helland,M., Itoi,M., Jones,D., Nichols,J. J., van der Worp,E., Woods,C. A. Daily disposable contact lens prescribing around the world Contact Lens and Anterior Eye 2010;33(5):225-227

Efron,N., Morgan,P. B., Helland,M., Itoi,M., Jones,D., Nichols,J. J., van der Worp,E., Woods,C. A. International rigid contact lens prescribing Contact Lens and Anterior Eye 2010;33(3):141-143

Fonn,D. Editorial: Myopia control and new editorial board members Eye and Contact Lens 2010;36(4):189

Fonn,D. It's a new day Eye and Contact Lens 2010;36(3):139

Fonn,D. Just what do we mean by clinical significance Eye and Contact Lens 2010;36(1):1

Fonn,D. Editorial: Concerned parents and patients Eye and Contact Lens 2010;36(2):67

Fonn,D. What goes around comes around Eye and Contact Lens 2010;36(6):323

Fonn,D., Peterson,R., Woods,C. Corneal staining as a response to contact lens wear Eye and Contact Lens 2010;36(5):318-321 [ Show Abstract ]

Objective: To review the effects of contact lenses on the corneal surface. Methods: A review of the literature and in-house research of corneal staining and its various forms of presentation. Results: Corneal staining manifests in many different forms. The severity of staining or insult of the cornea is usually determined by the extent (area of coverage), density, and depth. The cause of staining is multifactorial, and its location is often linked to the type of lens that is being worn, the solution used to clean/disinfect the lens, the state of hydration of the soft lens, and the state of the cornea that has been affected by the lens. Conclusions: Sodium fluorescein dye effectively highlights corneal integrity changes referred to as corneal staining. This review describes the manifestations, the cause, the mechanisms, and the methods of remediation of corneal staining. © 2010 Lippincott Williams & Wilkins.

Gorbet,M. B., Tanti,N. C., Jones,L., Sheardown,H. Corneal epithelial cell biocompatibility to silicone hydrogel and conventional hydrogel contact lens packaging solutions Molecular Vision 2010;16272-282 [ Show Abstract ]

Purpose: Although all contact lenses (CLs) are applied initially to the eye directly from a packaging solution, little is known about the effects of these solutions on human corneal epithelial cells (HCECs). Due to the porous nature of CL materials, they have the potential to sorb components of the packaging solution during storage, which could then be subsequently released upon insertion of the CL on the eye. The purpose of this study was to investigate the effect of various packaging solutions on HCECs, using an in vitro model. Methods: An in vitro assay was developed whereby various silicone hydrogels and conventional, poly-2-hydroxyethylmethacrylate (polyHEMA)-based lens materials were removed directly from their packaging and then incubated for up to 24 h with HCECs. The effect of the retained and released packaging solution components on HCECs was assessed by measuring cell viability, adhesion phenotype, and apoptosis. Results: Incubation of HCECs with CLs stored in borate-buffered packaging solutions resulted in a significant reduction in cell viability. Adherent cells incubated with these CLs also exhibited reduced levels of β1 and α3 integrin. Soaking borate-buffered packaged CLs in PBS before cell incubation resolved viability and integrin expression in all cases, with the exception of galyfilcon A and balafilcon A, from which a 20% reduction in cell viability was still observed. In comparison, CLs stored in phosphate-buffered packaging solutions had cellular viability and expression of integrins similar to control cells (cells incubated in the absence of a lens). When incubated with cells at a 10% concentration in serum-free medium, borate-buffered packaging solutions and borate-containing saline (Unisol 4) significantly reduced cell viability and integrin expression. Neither caspase activation nor annexin V binding was observed on cells following exposure to borate buffer solution. However, a significant decrease in reactive oxygen species was observed at 24 h. These latter results suggest that in vitro exposure to low concentration of borate/boric acid results in cell dysfunction, leading to necrosis rather than apoptosis. Conclusions: Borate-buffered packaging solutions were shown to adversely affect the viability and integrin expression of HCECs in vitro. When used in ophthalmic packaging solutions, the antimicrobial properties of borate buffer may be outweighed by its relatively cytotoxic effects on cells. © 2010 Molecular Vision.

Hall,B. J., Jones,L. Contact lens cases: The missing link in contact lens safety? Eye and Contact Lens 2010;36(2):101-105 [ Show Abstract ]

Purpose: To summarize a variety of issues associated with contact lens case contamination and discuss appropriate methods that can limit this. Methods: A literature review was undertaken investigating the major factors associated with case contamination, with specific reference to the major pathogens associated with contamination, the role of bacterial biofilms, and methods that can limit contamination. Results: The use of antimicrobial cases, regular case cleaning and case replacement, avoidance of topping up solutions, and not using tap water to rinse cases all appear to be important in avoidance of significant case contamination. Conclusions: Contact lens case contamination is a significant public health concern and may contribute significantly to the development of microbial keratitis in contact lens wearers. Patients should be reminded that they must clean and disinfect their lens cases daily, should avoid the use of tap water for rinsing them, must not top up their solutions, must take into careful consideration where and how the cases are stored during the time that lenses are being worn and that they must be replaced regularly. The adoption of these methods will substantially reduce the levels of contamination of cases with pathogenic microbes. © 2010 Lippincott Williams & Wilkins.

Keech,A., Simpson,T., Jones,L. Repeatability of pachymetry and thinnest point localization using a Fourier-domain optical coherence tomographer Optometry and Vision Science 2010;87(10):736-741

Keir,N., Simpson,T., Fonn,D. Visual and optical performance of silicone hydrogel contact lenses for moderate myopia Journal of Optometry 2010;3(3):149-157 [ Show Abstract ]

Purpose: To compare the short-term visual and optical performance of silicone hydrogel contact lenses for myopia = -3.00D. Methods: This was a short-term, non-dispense, double-masked, randomized study investigating Night&Day (ND), PureVision (PV), O2 Optix (O2), Biofinity (BF), Acuvue Advance (AA) and Acuvue OASYS for myopia = -3.00D. Testing was conducted under scotopic conditions. Measures (one eye only) included: high- and low-contrast visual acuity (HCVA/LCVA), contrast sensitivity, subjective clarity of vision ratings (0-100 scale using reference images, with test image representing grade 50) and ocular aberrations (up to the 4th order, analyzed across individual scotopic pupil sizes). Results: Three males and 27 females participated, with a mean (± SD) age of 24.9 ± 7.7 yrs (range 19 to 53 yrs), sphere of -5.30 ± 1.73D (range -3.00 to -10.75D) and cylinder -0.36 ± 0.23D (range 0 to -0.75D). Mean (± SEM) logMAR HCVA ranged from 0.06 (PV) to 0.10 (AA) (± 0.02), LCVA from 0.33 (BF) to 0.40 (AA) (± 0.02) and contrast sensitivity from 2.33 (BF) to 2.53 (ND) (± 0.15) (differences not statistically significant; all p > 0.05). Subjective ratings for the test image ranged from 59 (PV) to 64 (ND) (± 4) and 56 (AA) to 65 (ND) (± 4), for monochromatic and polychromatic reference images, respectively (all p > 0.05). There was a statistically significant impact on ocular aberrations with all study lenses compared to no lens. Between-lens differences were statistically significant for defocus (Z 0 2), horizontal coma (Z 1 3) and spherical aberration (Z 0 4). Conclusions: Despite some differences in ocular aberrations, there were no significant differences in HCVA, LCVA, contrast sensitivity or subjective ratings across lenses. © 2010 Spanish General Council of Optometry. Published by Elsevier España, S.L. All rights reserved.

Keir,N., Woods,C. A., Dumbleton,K., Jones,L. Clinical performance of different care systems with silicone hydrogel contact lenses Contact Lens and Anterior Eye 2010;33(4):189-195

Luensmann,D., Heynen,M., Liu,L., Sheardown,H., Jones,L. The efficiency of contact lens care regimens on protein removal from hydrogel and silicone hydrogel lenses Molecular Vision 2010;16(10-11):79-92 [ Show Abstract ]

Purpose: To investigate the efficiency of lysozyme and albumin removal from silicone hydrogel and conventional contact lenses, using a polyhexamethylene biguanide multipurpose solution (MPS) in a soaking or rubbing/soaking application and a hydrogen peroxide system (H2O2). Methods: Etafilcon A, lotrafilcon B and balafilcon A materials were incubated in protein solutions for up to 14 days. Lenses were either placed in radiolabeled protein to quantify the amount deposited or in fluorescent-conjugated protein to identify its location, using confocal laser scanning microscopy (CLSM). Lenses were either rinsed with PBS or soaked overnight in H2O2 or MPS with and without lens rubbing. Results: After 14 days lysozyme was highest on etafilcon A (2,200 μg) >balafilcon A (50 μg) >lotrafilcon B (9.7 μg) and albumin was highest on balafilcon A (1.9 μg) =lotrafilcon B (1.8 μg) >etafilcon A (0.2 μg). Lysozyme removal was greatest for balafilcon A >etafilcon A >lotrafilcon B, with etafilcon A showing the most change in protein distribution. Albumin removal was highest from etafilcon A >balafilcon A >lotrafilcon B. H2O2 exhibited greater lysozyme removal from etafilcon A compared to both MPS procedures (p0.62). Albumin removal was solely material specific, while all care regimens performed to a similar degree (p>0.69). Conclusions: Protein removal efficiency for the regimens evaluated depended on the lens material and protein type. Overall, lens rubbing with MPS before soaking did not reduce the protein content on the lenses compared to nonrubbed lenses (p=0.89). © 2010 Molecular Vision.

Luensmann,D., Jones,L. Impact of fluorescent probes on albumin sorption profiles to ophthalmic biomaterials Journal of Biomedical Materials Research - Part B Applied Biomaterials 2010;94(2):327-336

Menzies,K. L., Jones,L. The impact of contact angle on the biocompatibility of biomaterials Optometry and Vision Science 2010;87(6):387-399 [ Show Abstract ]

Biomaterials may be defined as artificial materials that can mimic, store, or come into close contact with living biological cells or fluids and are becoming increasingly popular in the medical, biomedical, optometric, dental, and pharmaceutical industries. Within the ophthalmic industry, the best example of a biomaterial is a contact lens, which is worn by ∼125 million people worldwide. For biomaterials to be biocompatible, they cannot illicit any type of unfavorable response when exposed to the tissue they contact. A characteristic that significantly influences this response is that related to surface wettability, which is often determined by measuring the contact angle of the material. This article reviews the impact of contact angle on the biocompatibility of tissue engineering substrates, blood-contacting devices, dental implants, intraocular lenses, and contact lens materials. Copyright © 2010 American Academy of Optometry.

Menzies,K. L., Rogers,R., Jones,L. In vitro contact angle analysis and physical properties of blister pack solutions of daily disposable contact lenses Eye and Contact Lens 2010;36(1):10-18 [ Show Abstract ]

Objective: The purpose of this study was to measure the advancing and receding contact angles (CAs) of five daily disposable (DD) lenses and the osmolality, surface tension (ST), and pH of each blister pack solution. Methods: The advancing and receding CAs were measured directly out of the blister pack for five DD lenses: omafilcon A (CooperVision), nelfilcon A (CIBA Vision), modified nelfilcon A (CIBA Vision), etafilcon A (Johnson & Johnson), and narafilcon A (Johnson & Johnson). Advancing CAs were measured using sessile drop and Wilhelmy balance methods. Receding CAs were measured using the Wilhelmy balance method. ST, pH, and osmolality were measured for each blister pack solution from all the DD lenses. Results: The advancing CAs for the nelfilcon A lenses were statistically lower (P<0.05) than the advancing CAs of the other three lenses. The receding CAs for etafilcon A were statistically lower (P<0.05) than the receding CAs for the other four lenses. The pH of all the blister pack solutions was relatively neutral (7.01-7.43). The ST of the blister pack solution for the modified nelfilcon A was significantly lower (P<0.05) than the ST of all other blister pack solutions. The osmolality of the blister pack solutions for the etafilcon A and narafilcon A lenses were significantly higher (P<0.05) than the other blister pack solutions. Conclusions: The modified nelfilcon A lens had low advancing CAs and low receding CAs showing minimal hysteresis. The blister pack solution for the modified nelfilcon A lens had the lowest ST, a low osmolality, and a neutral pH. Copyright © Contact Lens Association of Ophthalmologists, Inc.

Morgan,P. B., Efron,N., Helland,M., Itoi,M., Jones,D., Nichols,J. J., van der Worp,E., Woods,C. A. Twenty first century trends in silicone hydrogel contact lens fitting: An international perspective Contact Lens and Anterior Eye 2010;33(4):196-198

Morgan,P. B., Efron,N., Helland,M., Itoi,M., Jones,D., Nichols,J. J., van der Worp,E., Woods,C. A. Demographics of international contact lens prescribing Contact Lens and Anterior Eye 2010;33(1):27-29

Papas,E., Wolffsohn,J. S., Jones,L. Innovation in contact lenses: Basic research and clinical science Journal of Optometry 2010;3(3):123-124

Peterson,R. C., Fonn,D., Woods,C. A., Jones,L. Impact of a rub and rinse on solution-induced corneal staining Optometry and Vision Science 2010;87(12):1030-1036 [ Show Abstract ]

Purpose.: To investigate whether the inclusion of a rub and rinse step before contact lens disinfection has an impact on solution-induced corneal staining. Methods.: This was a prospective, double-masked, single investigator study. Twenty participants were recruited for two visits, where balafilcon-A lenses were worn bilaterally for 2 h. Each pair of lenses was prepared using two different methodologies. The "control" lens was transferred from the blister pack directly into a storage case containing polyhexamethylene biguanide-based lens care solution. The contralateral "test" lens was rubbed and simultaneously rinsed using the same polyhexamethylene biguanide-based care solution, for either 60 s (visit 1) or 20 s (visit 2). Both lenses were then soaked in the solution overnight. After baseline corneal staining assessments, the lenses were inserted following a randomized contralateral model. After 2 h, lenses were removed, corneal staining was regraded, and comfort scores were obtained. Results.: Rubbed and rinsed test lenses induced significantly less corneal staining than control lenses for all participants during visit 1 (mean ± SD: 516 ± 843 vs. 2170 ± 902; p 0.05). Conclusions.: Corneal staining induced after 2 h of lens wear with the combination of balafilcon-A and polyhexamethylene biguanide-based lens care solution can be significantly reduced by including a rub and rinse step before overnight soaking. Further work is required to establish the longevity of this effect during the monthly wearing cycle. Copyright © 2010 American Academy of Optometry.

Schulze,M. M., Hutchings,N., Simpson,T. L. The conversion of bulbar redness grades using psychophysical scaling Optometry and Vision Science 2010;87(3):159-167

Situ,P., Simpson,T. L. Interaction of corneal nociceptive stimulation and lacrimal secretion Investigative Ophthalmology and Visual Science 2010;51(11):5640-5645

Situ,P., Simpson,T. L., Jones,L. W., Fonn,D. Effects of silicone hydrogel contact lens wear on ocular surface sensitivity to tactile, pneumatic mechanical, and chemical stimulation Investigative Ophthalmology and Visual Science 2010;51(12):6111-6117 [ Show Abstract ]

PURPOSE. To determine the effects of silicone hydrogel lens wear and lens-solution interactions on ocular surface sensitivity. METHODS. Forty-eight adapted lens wearers completed the study, which comprised two phases. Phase 1 included habitual lens wear, no lens wear (7 ± 3 days), and balafilcon A lenses (PV; PureVision; Bausch & Lomb, Rochester, NY) with a hydrogen peroxide-based regimen for 2 weeks; phase 2 included wear of PV with the use of a multipurpose solution containing either polyhexamethylene-biguanide (PHMB) or Polyquad/Aldox (Alcon Laboratories, Fort Worth, TX) preservative, each for 1 week, with a 2-week washout period between solutions. Tactile and pneumatic (mechanical and chemical) stimuli were delivered, and thresholds were determined by Cochet-Bonnet (Luneau Ophthalmologie, Chartres, France) and Belmonte (Cooperative Research Centre for Eye Research and Technology, Sydney, NSW, Australia) pneumatic esthesiometers, respectively. Corneal and conjunctival thresholds and staining scores were assessed at baseline, after 2 and 8 hours of lens wear on day 1 and at the end of each wearing cycle (2 hours). RESULTS. In phase 1, compared to the no-lens baseline, corneal tactile thresholds increased at the 1-day, 8-hour and the 2-week visits (P < 0.05), whereas conjunctival mechanical thresholds decreased at the 1-day, 2-hour and the 2-week visits (P < 0.05). In phase 2, the chemical thresholds were lower with PHMBpreserved solution compared with the Polyquad/Aldox system at the 1-day, 2-hour and the 1-week visits (P < 0.05). Staining scores correlated inversely with conjunctival chemical thresholds (all P < 0.05). CONCLUSIONS. Ocular surface sensitivity changed in adapted lens wearers, when lenses were refit after a no-lens interval and during lens wear with different care regimens. The corneal staining that was observed with certain lens-solution combinations was accompanied by sensory alteration of the ocular surface-that is, higher levels of staining correlated with increased conjunctival chemical sensitivity. © Association for Research in Vision and Ophthalmology.

Sorbara,L., Dalton,K. The use of video-keratoscopy in predicting contact lens parameters for keratoconic fitting Contact Lens and Anterior Eye 2010;33(3):112-118

Sorbara,L., Maram,J., Fonn,D., Woods,C., Simpson,T. Metrics of the normal cornea: Anterior segment imaging with the Visante OCT Clinical and Experimental Optometry 2010;93(3):150-156 [ Show Abstract ]

Purpose: The purpose of the study was to obtain anterior segment biometry for 40 normal eyes and to measure variables that may be useful to design large diameter gas permeable contact lenses that sit outside the region normally viewed by corneal topographers. Also, the distribution of these variables in the normal eye and how well they correlated to each other were determined. Methods: This is a cross-sectional study, in which data were collected at a single study visit. Corneal topography and imaging of the anterior segment of the eye were performed using the Orbscan II and Visante OCT. The variables that were collected were horizontal K reading, central corneal/scleral sagittal depth at 15 mm chord, and nasal and temporal angles at the 15 mm chord using the built-in software measurement tools. Results: The central horizontal K readings for the 40 eyes were 43 ± 1.73 D (7.85 ± 0.31 mm), with ± 95% confidence interval (CI) of 38.7 (8.7 mm) and 46.6 D (7.24 mm). The mean corneal/scleral sagittal depth at the 15 mm chord was 3.74 ± 0.19 mm and the range was 3.14 to 4.04 mm. The average nasal angle (which was not different from the temporal angle) at the 15 mm chord was 39.32 ± 3.07 degrees and the ± 95%CI was 33.7 and 45.5 degrees. The correlation coefficient comparing the K reading and the corneal/scleral sagittal depth showed the best correlation (0.58, p < 0.001). The corneal/scleral sagittal depth at 15 mm correlated less with the nasal angle (0.44, p = 0.004) and the weakest correlation was for the nasal angle at 15 mm with the horizontal readings (0.32, p = 0.046). Conclusion: The Visante OCT is a valuable tool for imaging the anterior segment of the eye. The Visante OCT is especially effective in providing the biometry of the peripheral cornea and sclera and may help in fitting GP lenses with a higher percentage of initial lens success, when the corneal sag and lens sag are better matched. © 2010 The Authors. Journal compilation © 2010 Optometrists Association Australia.

Srinivasan,S., Joyce,E., Boone,A., Simpson,T., Jones,L., Senchyna,M. Tear lipocalin and lysozyme concentrations in postmenopausal women Ophthalmic and Physiological Optics 2010;30(3):257-266

Subbaraman,L. N., Jones,L. Kinetics of lysozyme activity recovered from conventional and silicone hydrogel contact lens materials Journal of Biomaterials Science, Polymer Edition 2010;21(3):343-358

Varikooty,J., Keir,N., Woods,C. A., Fonn,D. Measurement of the refractive index of soft contact lenses during wear Eye and Contact Lens 2010;36(1):2-5 [ Show Abstract ]

Purpose: To determine whether the refractive index (RI) of a soft contact lens can be evaluated using refractometry while the lens remains on the eye and to compare this with more traditional ex vivo RI measurements. Methods: A slitlamp apparatus was modified to incorporate a customized Atago hand refractometer. With a double-masked study design, nine adapted symptomatic soft contact lens wearers wore a contact lens in each eye (lotrafilcon B and etafilcon A) in a randomized order. In vivo RI was determined from the relative Brix scale measurements immediately after lens insertion and after 1 and 10 hr of lens wear. Ex vivo refractometry was performed after 10 hr of lens wear for comparison. Means ± standard errors of the means are reported. Results: In vivo RI values at baseline were 1.422 ± 0.0004 (lotrafilcon B) and 1.405 ± 0.0021 (etafilcon A); after 1 hr of lens wear, values were 1.423 ± 0.0006 and 1.408 ± 0.0007, respectively; and after 10 hr of lens wear, values were 1.424 ± 0.0004 and 1.411 ± 0.0010, respectively. Ex vivo RI values at the end of the 10 hr wearing period were 1.424 ± 0.0003 (lotrafilcon B) and 1.412 ± 0.0017 (etafilcon A). The change in in vivo RI across the day was statistically significant for the etafilcon A lens (repeated-measures analysis of variance, P0.05). Conclusions: This novel adaptation of refractometry was able to measure the RI of soft contact lenses during wear (without lens removal). End of day RI measurements using in vivo and ex vivo refractometry were comparable with each other. Future work is required to determine whether this in vivo method can improve our understanding of the relationships between soft contact lens RI, hydration, on-eye lens performance, and symptomology. Copyright © Contact Lens Association of Ophthalmologists, Inc.

2009

Boone,A., Heynen,M., Joyce,E., Varikooty,J., Jones,L. Ex vivo protein deposition on bi-weekly silicone hydrogel contact lenses Optometry and Vision Science 2009;86(11):1241-1249 [ Show Abstract ]

Purpose. This study investigated the protein deposition that occurs on daily wear silicone hydrogel (SH) lenses, after 2 weeks of wear. Methods. A total of 40 subjects were divided into equal groups, based on their habitual SH contact lens [CIBA Vision O2OPTIX (O2); Johnson & Johnson ACUVUE ADVANCE with HYDRACLEAR (ADV); Bausch & Lomb PureVision (PV); CIBA Vision Night & Day (ND)]. A randomized, double-masked, cross-over study was conducted in which subjects wore either their habitual SH material or Johnson & Johnson ACUVUE OASYS with HYDRACLEAR PLUS (OAS) for 2 weeks. At the end of the 2-week period, lenses were collected for analysis of total protein, total lysozyme, and percent denatured lysozyme. Results. Total protein was greatest for PV (33 ± 6 μg/lens), with other lenses depositing 0.05). Total lysozyme was also greatest for the PV lens (11 ± 3 μg/lens), with other lenses depositing 0.05). Total lysozyme was also greatest for the PV lens (11 ± 3 μg/lens), with other lenses depositing 0.05). Total lysozyme was also greatest for the PV lens (11 ± 3 μg/lens), with other lenses depositing 0.05). The percentage of lysozyme that was denatured was greatest for ND (90 ± 8%) and lowest for PV (23 ± 10%). The lysozyme extracted from ND and O2 lenses was significantly more denatured than that extracted from the other lens materials (p 0.05) or between ADV, OAS, and PV (p > 0.05). The amount of denatured lysozyme/lens was <3 μg/lens for all materials. Lysozyme as a percentage of the total protein deposited ranged from 32 (PV) to 6% (O2). Conclusions. This study confirms that all SH lenses deposit low levels of protein, and that the amount and percentage of denatured lysozyme can vary, depending on the overall surface charge of the material and absence or type of surface treatment. © 2009 American Academy of Optometry.

Boone,A., Hui,A., Jones,L. Uptake and release of dexamethasone phosphate from silicone hydrogel and FDA group I, II, and IV hydrogel contact lenses Eye and Contact Lens 2009;35(5):260-267 [ Show Abstract ]

OBJECTIVES: To investigate the uptake and release kinetics of the synthetic glucocorticoid anti-inflammatory drug dexamethasone into various conventional and silicone hydrogel contact lens materials. METHODS: Three conventional and six silicone hydrogel lenses were used in this study. A 0.1% dexamethasone solution was formulated and used to dope the various contact lens materials. The uptake and release of the drug was measured using a UV-visible light spectrophotometer at various time points during a period of 24 hr for each phase. RESULTS: Statistical analysis showed that all lenses took up a significant amount of dexamethasone. Alphafilcon A and lotrafilcon A showed the greatest uptake of dexamethasone, at 118 +/- 10 microg/lens and 102 +/- 11 microg/lens, respectively, and galyfilcon took up the least amount of drug at 34 +/- 6 microg/lens. The release of the drug from the lens materials was also statistically significant. The majority of the lenses released between 20 and 30 microg/lens, except for alphafilcon A and lotrafilcon A, which released a statistically different amount of drug when compared with the other lens materials. Alphafilcon A released 65 +/- 1.3 microg/lens, whereas lotrafilcon A slowly released only 11 +/- 0.2 microg/lens. CONCLUSIONS: Although most of the lenses released enough drug to have anti-inflammatory action, none of the materials released drug for a long enough period of time to be clinically useful as a drug delivery device.

Chow,L. M., Subbaraman,L. N., Sheardown,H., Jones,L. Kinetics of in vitro lactoferrin deposition on silicone hydrogel and FDA group II and group IV hydrogel contact lens materials Journal of Biomaterials Science, Polymer Edition 2009;20(1):71-82 [ Show Abstract ]

The aim of this study was to compare the kinetics of lactoferrin deposition on silicone hydrogel (SH) and conventional FDA group II and group IV hydrogel contact lens materials. Seven lens materials, two conventional (etafilcon A, FDA group IV; omafilcon A, FDA group II) and five SH (lotrafilcon A, lotrafilcon B, balafilcon A, galyfilcon A and senofilcon A), were incubated in 1 ml (125)I-labeled lactoferrin solution for time periods ranging from 1 h to 28 days. At the end of specified incubation periods radioactive counts were determined on the lenses using an Automatic Gamma Counter. There was a gradual increase in lactoferrin deposition on all the lenses across all time points. At the end of 28 days the amount of lactoferrin/lens in microg was 11.3 +/- 1.9 for etafilcon A, 6.8 +/- 2.0 for omafilcon A, 2.1 +/- 0.9 for lotrafilcon A, 3.1 +/- 1.0 for lotrafilcon B, 11.8 +/- 2.9 for balafilcon A, 5.4 +/- 1.1 for galyfilcon A and 5.6 +/- 0.6 for senofilcon A. After 28 days, etafilcon A and balafilcon A deposited lactoferrin to the greatest degree (P < 0.05), but these were not different from each other (P = 0.48), while lotrafilcon A and B deposited the least (P < 0.05 vs. other lenses; P = 0.57 with each other). Galyfilcon A, senofilcon A and omafilcon A (P < 0.05 compared with other lenses; P > 0.05 with each other) deposited intermediate levels of lactoferrin. We concluded that radiochemical analysis is a sensitive and effective technique to determine the small quantities of lactoferrin deposited on SH lenses. The kinetics of lactoferrin deposition on contact lens materials depend on the chemical structure of the lens material.

Dumbleton,K., Woods,C., Fonn,D. An investigation of the efficacy of a novel ocular lubricant Eye and Contact Lens 2009;35(3):149-155 [ Show Abstract ]

OBJECTIVE: To investigate the efficacy of a novel ocular lubricant compared with a commercially marketed ocular lubricant in a group of noncontact lens wearers currently using over-the-counter products for the management of symptoms of moderate to severe dry eye. METHODS: This was a prospective, double-masked study that randomized 110 subjects in a ratio of 1:1 to receive a novel ocular lubricant (test group) or a marketed ocular lubricant (control group). Subjects were instructed to instill the lubricant eye drops at least three times daily. After enrollment, subjects were evaluated at baseline and at 7 and 30 days. They were also required to complete a series of home-based subjective questionnaires after 15 days. Main outcomes were subjective symptoms and objective clinical assessment at 7 and 30 days. RESULTS: The test group had higher overall comfort ratings than the control group (P = 0.012). Seventy-one percent of the test group and 57% of the control group said the drops used "somewhat" or "definitely" improved ocular comfort; 62% of the test group had greater end-of-day comfort compared with 45% of the control group (P = 0.015). There were no between-group differences in visual acuity, tear quality or quantity, corneal staining, conjunctival staining, or bulbar and limbal conjunctival hyperemia. CONCLUSIONS: The novel ocular lubricant offers equivalent or superior comfort compared with a marketed lubricant eye drop. Objective clinical outcomes were not statistically significantly different between the two groups. © 2009 Lippincott Williams & Wilkins.

Dumbleton,K., Woods,C., Jones,L., Fonn,D., Sarwer,D. B. Patient and practitioner compliance with silicone hydrogel and daily disposable lens replacement in the United States Eye and Contact Lens 2009;35(4):164-171 [ Show Abstract ]

OBJECTIVE: The objectives of this study were to assess current recommendations for replacement frequency (RF) of silicone hydrogel (SH) and daily disposable (DD) lenses, to determine compliance with these recommendations, and to investigate the reasons given for noncompliance. METHODS: A package containing 20 patient surveys was sent to 309 eye care practitioners (ECPs) in the United States who had agreed to participate in the study. One thousand eight hundred fifty-nine completed surveys were received from 158 ECPs and 1,654 surveys were eligible for analysis. Questions related to patient demographics, lens type, lens wearing patterns, the ECP instructions for RF, and the actual patient reported RF. ECPs were asked to provide lens information and their recommendation for RF after the surveys had been completed and sealed in envelopes. All responses were anonymous. RESULTS: Sixty-six percent of patients were women and their mean age was 34 ± 12 years. Eighty-eight percent of lenses were worn for daily wear, 12.8 ± 3.2 hours a day, 6.2 ± 1.5 days a week. Lens type distribution was 16% DD, 45% 2 week (2W) SH, and 39% 1 month (1M) SH. ECP recommendations for RF varied according to the lens type; 1% of 1M (95% CI 0.2-1.7), 4% of DD (95% CI 2.1-7.2), and 18% of 2W (95% CI 15.1-20.7) patients were given instructions that did not conform to the manufacturers' recommended RF (MRRF). When considering only those patients who were given the correct instructions for RF, 38% were not compliant with the MRRF; noncompliance rates varied according to the lens type and were 12% for DD (95% CI 8.6-17.2), 28% for 1M (95% CI 24.9-32.1), and 52% for 2W (95% CI 47.8-55.8). The most frequent reasons for over wearing lenses were "forgetting which day to replace lenses" (51%) and "to save money" (26%). Fifty-three percent believed that a reminder system would aid compliance; the most popular methods being a cell phone reminder or text message (29%) and a nominated day each week or month (26%). Discussions between the ECPs and the patients were more extensive for patients who were compliant with the MRRF. CONCLUSIONS: ECPs recommended RFs more frequently with DD and 1M SH lenses than with 2W SH lenses, consistent with manufacturers' recommendations. Patients were less compliant with RF than ECPs for all lens types investigated. Patients were most compliant with RF when wearing DD lenses and least compliant when wearing 2W SH lenses. Better communication facilitated greater compliance with RF. More than half of those not replacing lenses, when recommended, reported that this was because they forgot which day to replace their lenses. © 2009 Lippincott Williams & Wilkins, Inc.

Keech,A., Flanagan,J., Simpson,T., Jones,L. Tear meniscus height determination using the OCT2 and the RTVue-100 Optometry and Vision Science 2009;86(10):1154-1159 [ Show Abstract ]

PURPOSE: To compare anterior segment spectral-domain optical coherence tomography (SOCT) tear meniscus height (TMH) measures with those from the more commonly used time-domain OCT (TOCT). METHODS: The right eye of 50 healthy subjects had images of their TMH captured with TOCT (OCT2) and SOCT (RTVue-100). Data were acquired using two different anterior segment lenses, the cornea/anterior module-short (CAM-S) and long (CAM-L), on the SOCT. Images were then analyzed for differences in their derived TMH. RESULTS: The average TMH for TOCT was 0.280 ± 0.139 mm, whereas the mean TMH measured using the SOCT was 0.354 ± 0.163 mm and 0.345 ± 0.167 mm for the CAM-S and CAM-L, respectively. There was a significant difference (p < 0.001) when comparing TOCT with either of the SOCT lenses. There was no statistically significant difference between the CAM-L and CAM-S (p = 1.0). Bland-Altman analysis showed poor agreement between TOCT and SOCT (95% limits of agreement -0.138 to + 0.285 mm for the CAM-S and -0.185 to +0.315 mm for the CAM-L). CONCLUSIONS: The RTVue-100 produces TMH measurements that are significantly higher than OCT2 in a normal patient population. However, the RTVue-100 showed a number of other advantages over the OCT2 in the measurement and analysis of images. Future work needs to determine the causative factors behind the observed differences.

Keir,N. J., Simpson,T., Jones,L. W., Fonn,D. Wavefront-guided LASIK for myopia: Effect on visual acuity, contrast sensitivity, and higher order aberrations Journal of Refractive Surgery 2009;25(6):524-533 [ Show Abstract ]

PURPOSE: To determine the impact of wavefrontguided LASIK for myopia with or without astigmatism on high and low contrast best spectacle-corrected visual acuity (BSCVA), photopic and mesopic contrast sensitivity, and higher order aberrations. METHODS: Bilateral wavefront-guided LASIK (LADARVision4000; Hansatome microkeratome) was performed on 324 eyes (162 patients) with a mean spherical manifest refraction of -2.84±1.35 diopters (D) (range: -0.25 to -6.50 D) and astigmatism of -0.81±0.74 D (range: 0 to -4.00 D). Mean age was 37.7±9.3 years (range: 20 to 60 years). Best spectacle-corrected visual acuity and contrast sensitivity were assessed using ETDRS charts and vertical sinusoidal gratings, respectively. Higher order aberrations were measured using a Shack-Hartmann wavefront sensor, analyzed across a 5-mm pupil. Repeated measures and post hoc analyses determined statistical significance (P<.0025). Only right eyes were analyzed. RESULTS: One hundred thirty-six eyes (84%) had uncorrected visual acuity of 20/20 or better 6 months postoperative; 80.9% (131 eyes) were within ±0.50 D of attempted correction. Statistically significant postoperative improvements were noted in high and low contrast BSCVA (both P≤.001); in photopic contrast sensitivity at 3, 6, and 12 cycles per degree (cpd); and in mesopic contrast sensitivity at 12 and 18 cpd (all P<.001). With respect to higher order aberrations, a statistically significant change was seen in Zernike coefficients Z 3 -1, Z 3 1, Z 3 -3, Z 3 3, and Z 3 4 following surgery (range of mean absolute change: 0.042 to 0.142 μm; all P<.001). All increased in magnitude except for Z 3 -3, which decreased. CONCLUSIONS: Despite an increase in higher order aberrations, wavefront-guided LASIK yields excellent visual acuity and contrast sensitivity. Spherical aberration, which increases the most following non-wavefront-guided LASIK, showed no significant change.

Luensmann,D., Heynen,M., Liu,L., Sheardown,H., Jones,L. Determination of albumin sorption to intraocular lenses by radiolabeling and confocal laser scanning microscopy Journal of cataract and refractive surgery 2009;35(11):2000-2007 [ Show Abstract ]

Purpose: To determine albumin adsorption profiles and penetration depth of 3 intraocular lens (IOL) materials over time using confocal laser scanning microscopy (CLSM) and radiolabeling. Setting: Centre for Contact Lens Research, School of Optometry, and Department of Biology, University of Waterloo, Waterloo, Ontario, Canada. Methods: Poly(methyl methacrylate) (PMMA), silicone, and foldable hydrophilic acrylic IOLs were incubated in 0.5 mg/mL bovine serum albumin (BSA) for 1, 7, and 14 days. The BSA was conjugated with lucifer yellow VS to allow identification of the protein location by fluorescent imaging with CLSM. Next, the protein uptake was quantified using 2% 125I-labeled BSA. Results: Confocal laser scanning microscopy showed increasing BSA uptake for silicone and PMMA IOLs after 14 days of incubation (P<.05), with an apparent penetration depth of 8.7 μm ± 1.9 (SD) and 9.2 ± 1.4 μm, respectively. For hydrophilic acrylic IOLs, BSA was detected at a depth of 38 ± 7.4 μm after 1 day, followed by an increase to 192.7 ± 16.2 μm after 14 days. Despite the penetration depth into the hydrophilic acrylic IOLs, quantitative results confirmed that PMMA and hydrophilic acrylic deposited significantly less BSA (mean 278.3 ± 41.7 ng and 296.5 ± 33.1 ng, respectively) than silicone IOLs (mean 392.6 ± 37.6 ng) (P<.05). Conclusions: Silicone and PMMA IOL materials showed BSA sorption near the lens surface only, while BSA penetrated deep into the hydrophilic acrylic IOL matrix. Combining the qualitative CLSM method and quantitative radiolabeling technique provided detailed information on protein interactions with implantable biomaterials. © 2009 ASCRS and ESCRS.

Luensmann,D., Zhang,F., Subbaraman,L., Sheardown,H., Jones,L. Localization of lysozyme sorption to conventional and silicone hydrogel contact lenses using confocal microscopy Current eye research 2009;34(8):683-697 [ Show Abstract ]

PURPOSE: To investigate the distribution profile of hen egg lysozyme (HEL) through poly-2-hydroxyethyl methacrylate (pHEMA)-based lens materials and silicone hydrogel (SH) lens materials using confocal laser scanning microscopy (CLSM). METHODS: Five silicone SH materials (balafilcon A, lotrafilcon A, lotrafilcon B, galyfilcon A, senofilcon A) and four pHEMA-based materials (alphafilcon A, etafilcon A, omafilcon A, vifilcon A) were incubated in 1.9 mg/ml protein solution for 24 hours. The protein solution consisted of HEL, which was conjugated with either fluorescein isothiocyanate (FITC) or lucifer yellow VS dilithium salt (LY). CLSM (Zeiss LSM 510 META) identified the location of the fluorescently labeled protein by using 1 micro m depth scans through the lens. In a second experiment, lenses were incubated with 2% (125) I labeled HEL to determine the amount of deposited protein on each lens. Both techniques were combined to describe the individual HEL profiles. RESULTS: After the incubation in fluorescently labeled HEL, all pHEMA-based materials and the SH material balafilcon A accumulated protein throughout the entire lens material, while, for the SH lenses lotrafilcon A and lotrafilcon B, HEL was primarily detected on the lens surface alone. Differences in protein uptake pattern due solely to the two conjugated dyes were most apparent for the SH materials galyfilcon A and senofilcon A; HEL was detected throughout these lenses when conjugated with LY but accumulated primarily on the surface when conjugated with FITC. CONCLUSION: CLSM in combination with a radiolabel technique can describe both the location and degree of protein deposition on different contact lens materials.

Ngo,W., Heynen,M., Joyce,E., Jones,L. Impact of protein and lipid on neutralization times of hydrogen peroxide care regimens Eye and Contact Lens 2009;35(6):282-286 [ Show Abstract ]

Purpose: To investigate the effect of protein, lipid, and lens material on the neutralization kinetics of one-step hydrogen peroxide disinfection systems. Methods: A UV-based assay was used to determine the rate of neutralization of three one-step hydrogen peroxide systems (CIBA Vision Clear Care; CIBA Vision AOSEPT; Abbott Medical Optics UltraCare). Protein (bovine serum albumin and lysozyme) and various lipids were added to the lens cases during the neutralization phase to determine whether they influenced the rate of neutralization. Finally, rates were determined when the cases contained a silicone hydrogel lens material (lotrafilcon A) or Food and Drug Administration group IV (etafilcon A) lenses. Results: Neutralization for all three systems was complete within 90 minutes. The rate of neutralization for Clear Care and AOSEPT were not significantly different from each other (P=NS). UltraCare exhibited statistically higher levels of peroxide up to the 20-minute time point (P<0.001) Protein, lipid, or lens material did not significantly affect the rate of neutralization for any regimen (P=NS). Conclusions: Tablet-based one-step disinfection systems neutralize at a slower rate than disc-based peroxide systems, but this difference is only significant during the first 20 minutes after the onset of neutralization. Neither lens deposition nor lens material plays a role in the speed of neutralization of peroxide-based systems. © 2009 Lippincott Williams & Wilkins.

Papas,E. B., Decenzo-Verbeten,T., Fonn,D., Holden,B. A., Kollbaum,P. S., Situ,P., Tan,J., Woods,C. Utility of short-term evaluation of presbyopic contact lens performance Eye and Contact Lens 2009;35(3):144-148 [ Show Abstract ]

OBJECTIVES: To establish if evaluations of multifocal contact lens performance conducted at dispensing are representative of behavior after a moderate adaptation period. METHODS: Eighty-eight presbyopic subjects, across four clinical sites, wore each of four multifocal soft contact lenses (ACUVUE BIFOCAL, Focus Progressives, Proclear Multifocal, and SofLens Multifocal) for 4 days of daily wear. Comprehensive performance assessments were conducted at dispensing and after 4 days wear and included the following objective metrics: LogMAR acuity (contrast, 90% and 10%; illumination, 250 and 10 cd/m; distance, 6 m, 100 cm, and 40 cm), stereopsis (RANDOT), reading critical print size and maximum speed and range of clear vision at near. Subjective assessments were made, with 100-point numerical rating scales, of comfort, ghosting (distance, near), visual quality (distance, intermediate, and near), and the appearance of haloes. At two sites, subjects (n = 39) also rated visual fluctuation (distance, intermediate, and near), facial recognition, and overall satisfaction. RESULTS: Among the objective variables, significant differences (paired t test, P<0.05) between dispensing and 4 days were found only for range of clear vision at near (2.9 ± 2.0 cm; mean difference ± standard deviation) and high contrast near acuity in low illumination (-0.013 ± 0.011 LogMAR). With the exception of insertion comfort, all subjective variables showed significant decrements over the same period. Overall satisfaction declined by an average of 10.9 ± 5.1 points. CONCLUSIONS: Early assessment is relatively unrepresentative of performance later on during multifocal contact lens wear. Acuity based measures of vision remain substantially unchanged over the medium term, apparently because these metrics are insensitive indicators of performance compared with subjective alternatives. © 2009 Lippincott Williams & Wilkins.

Schulze,M. M., Hutchings,N., Simpson,T. L. The perceived bulbar redness of clinical grading scales Optometry and Vision Science 2009;86(11):E1250-E1258 [ Show Abstract ]

Purpose. To use a psychophysical scaling method to estimate the perceived redness of reference images of the McMonnies and Chapman-Davies (six reference levels), Institute for Eye Research (four), Efron (five), and Validated Bulbar Redness (five) bulbar redness grading scales. Methods. Regions of interest were cropped out of the grading scale reference images; three separate image sets (color, grayscale, and binarized) were created for each scale, combining to a total of 20 images per image set. Ten naïve observers were asked to arrange printed copies of the 20 images per image set across a distance of 1.5 m on a flat surface, so that separation reflected their perception of bulbar redness; only start and end point of this range were indicated. The position of each image was averaged across observers to represent the perceived redness for this image, within the 0 to 100 range. Subjective data were compared with physical attributes (chromaticity and spatial metrics) of redness. Results. For each image set, perceived redness of the reference images within each scale was ordered as expected, but not all consecutive within-scale levels were rated as having different redness. Perceived redness of the reference images varied between scales, with different ranges of severity being covered by the images. Perception of redness severity depended on the image set (repeated-measures analysis of variance; all p ≤ 0.0002). The perceived redness was strongly associated with the physical attributes of the reference images. Conclusions. Subjective estimates of redness are based on a combination of chromaticity and vessel-based components. Psychophysical scaling of perceived redness lends itself to being used to cross-calibrate these four clinical scales. © 2009 American Academy of Optometry.

Sorbara,L., Jones,L., Williams-Lyn,D. Contact lens induced papillary conjunctivitis with silicone hydrogel lenses Contact Lens and Anterior Eye 2009;32(2):93-96 [ Show Abstract ]

PURPOSE: To describe the refitting of a soft lens wearer into a silicone hydrogel lens due to neovascularization. This change, in turn, caused contact lens induced papillary conjunctivitis (CLPC) and a further refitting was necessary. METHODS: The patient was refit into a high Dk surface treated silicone hydrogel with a high modulus value. A second refitting was undertaken into a lower Dk silicone hydrogel contact lens with a lower modulus value which had no surface treatment but incorporated an internal wetting agent. RESULTS: A high Dk/t lens was used to resolve existing neovascularization and chronic hyperaemia. Subsequently, CLPC response occurred, possibly due to a combination of factors, resulting in irritation of the palpebral conjunctiva. This resulted in temporary lens discontinuation. A second silicone hydrogel lens was fit, along with the use of a non-preserved care system, which led to improvement and eventual resolution of the condition. CONCLUSION: High Dk silicone hydrogel lenses have shown excellent efficacy in resolving hypoxic complications such as neovascularization and hyperaemia. However, attention needs to be paid to their potential effect on the upper tarsal plate. More than one silicone hydrogel lens may be needed to help resolve these issues.

Sorbara,L., Peterson,R., Woods,C., Fonn,D. Multipurpose disinfecting solutions and their interactions with a silicone hydrogel lens Eye and Contact Lens 2009;35(2):92-97 [ Show Abstract ]

PURPOSE:: To assess the compatibility of a new silicone hydrogel lens, asmofilcon A (with four multipurpose disinfecting solutions: OPTIFREE RepleniSH, ReNu MultiPlus, Solo-Care Aqua and MeniCare Soft). Ocular responses and subjective responses were monitored with each lens-care system combination. METHODS:: The study was conducted as a prospective, bilateral, clinical trial with a single-masked investigator, and randomized cross-over design with four phases, (one for each care system). Each study phase comprised of two consecutive days of lens wear where the lenses were inserted on day 1 directly from the blister-packs and worn for over 8 hr, then inserted on day 2 after overnight disinfection with one of the study lens care systems. Twenty-five adapted soft contact lens wearers who were able to wear their habitual lenses comfortably for more than 12 hr were recruited. RESULTS:: There were statistically significant differences in corneal staining found for all the lens-care systems when comparing the results of day 1 (from the blister pack) with day 2 (following care system use) (P < 0.05). ReNu MultiPlus solution had the highest grade for corneal staining at the 2-hr time point on day 2 which then decreased by 6 hr (P < 0.05). There was no difference between the lens care systems and the rating of subjective comfort over either of the two days. The rating of dryness and burning sensations were only slightly increased at 6 hr for all lens care systems except ReNu MultiPlus where burning was highest on insertion (P < 0.05). CONCLUSION:: Corneal staining observed in this study does not seem to have been related to the presence of polyhexamethylene biguanide (0.0001% wv) that was present in three of the four care systems. Only one care system (ReNu MultiPlus) demonstrated an associated level of corneal staining that was statistically significant; however, this was not considered to be of clinical relevance. These results suggest that using this novel surface-treated silicone hydrogel lens may result in less lens and lens care-related interactions. © 2009 Lippincott Williams & Wilkins.

Subbaraman,L. N., Glasier,M. A., Sheardown,H., Jones,L. Efficacy of an extraction solvent used to quantify albumin deposition on hydrogel contact lens materials Eye and Contact Lens 2009;35(2):76-80 [ Show Abstract ]

OBJECTIVES: Extracting proteins from conventional hydrogel (CH) and silicone hydrogel (SH) contact lens materials using a mixture of trifluoroacetic acid/acetonitrile (TFA/ACN) is a well-established procedure for quantifying individual and total protein deposited on contact lenses. The purpose of this study was to determine the efficacy of TFA/ACN in extracting albumin from SH and a CH group IV lens material using an in vitro model. METHODS: One CH group IV lens material (etafilcon A) and five different SH lens materials (lotrafilcon A, lotrafilcon B, balafilcon A, galyfilcon A, and senofilcon A) were incubated in both simple albumin solution and a complex artificial tear protein solution containing 125I-labeled albumin. All the lens materials were incubated for 14 days at 37 degrees C with constant rotations. Following the incubation period, radioactive counts were determined and the lenses were placed in an appropriate volume of the extraction solvent. After the specified time, the lenses were removed and radioactive counts were determined again to calculate the amount of albumin remaining on the lenses post-extraction. RESULTS: Extraction efficiencies for albumin from the artificial tear protein solution were 97.2% +/- 2 for etafilcon A, 77.3% +/- 6.2 for lotrafilcon A, 73.5% +/- 5.6 for lotrafilcon B, 81.5% +/- 5.8 for balafilcon, 91.2% +/- 3.4 for galyfilcon A, and 89.2% +/- 3.4 for senofilcon A. Results were similar for the albumin extracted after incubating in the simple albumin solution. CONCLUSIONS: Although TFA/ACN is efficient at extracting albumin deposited on etafilcon lenses, it does not extract all the albumin that is deposited on SH lenses and alternative extraction procedures should be sought.

Subbaraman,L. N., Woods,J., Teichroeb,J. H., Jones,L. Protein deposition on a lathe-cut silicone hydrogel contact lens material Optometry and Vision Science 2009;86(3):244-250 [ Show Abstract ]

PURPOSE: To determine the quantity of total protein, total lysozyme, and the conformational state of lysozyme deposited on a novel, lathe-cut silicone hydrogel (SiHy) contact lens material (sifilcon A) after 3 months of wear. METHODS: Twenty-four subjects completed a prospective, bilateral, daily-wear, 9-month clinical evaluation in which the subjects were fitted with a novel, custom-made, lathe-cut SiHy lens material. The lenses were worn for three consecutive 3-month periods, with lenses being replaced after each period of wear. After 3 months of wear, the lenses from the left eye were collected and assessed for protein analysis. The total protein deposited on the lenses was determined by a modified Bradford assay, total lysozyme using Western blotting and the lysozyme activity was determined using a modified micrococcal assay. RESULTS: The total protein recovered from the custom-made lenses was 5.3 +/- 2.3 microg/lens and the total lysozyme was 2.4 +/- 1.2 microg/lens. The denatured lysozyme found on the lenses was 1.9 +/- 1.0 microg/lens and the percentage of lysozyme denatured was 80 +/- 10%. CONCLUSIONS: Even after 3 months of wear, the quantity of protein and the conformational state of lysozyme deposited on these novel lens materials was very similar to that found on similar surface-coated SiHy lenses after 2 to 4 weeks of wear. These results indicate that extended use of the sifilcon A material is not deleterious in terms of the quantity and quality of protein deposited on the lens.

Varikooty,J., Simpson,T. L. The interblink interval I: The relationship between sensation intensity and tear film disruption Investigative Ophthalmology and Visual Science 2009;50(3):1087-1092 [ Show Abstract ]

PURPOSE. To find the relationship between tear film drying and sensation during the interblink period. METHODS. One eye was taped shut, and after a blink the subjects were required to keep the other eye open. Digital video images of the ocular surface (with fluorescein) were obtained using a slit lamp biomicroscope while 23 subjects rated the intensity of the ocular surface sensation by adjusting a one-turn potentiometer to represent the strength of the sensation. They were trained to use the potentiometer before the data were collected. In addition, the characteristics of the sensation as spoken by the subject were recorded. RESULTS. The sensation was generally triphasic, with initial constant sensation and a subsequent biphasic period, with intensity increasing slowly followed by a rapid increase before the subjects blinked (correlations were all r > 0.95). Tear film drying dynamics were also biphasic, and drying and sensation were strongly associated, with a correlation of 0.94 between the break in the bilinear functions of sensation and drying. CONCLUSIONS. The method provides novel information about the development of ocular sensation during ocular surface drying. As evidenced by the complex functions required to adequately describe the relationships, tear film drying and ocular surface sensations are associated in complex ways. © Association for Research in Vision and Ophthalmology.

Woods,C. A., Cumming,B. The impact of test medium on use of visual analogue scales Eye and Contact Lens 2009;35(1):6-10 [ Show Abstract ]

OBJECTIVES: Visual analog scales are frequently used as a means of allowing participants to rate symptoms during clinical trials. The accuracy and reproducibility of these scales play an important role in determining the experimental value of the data they provide. This study was initiated to compare the data collected using paper- and computer-based (Tablet PC) analog scales to better understand the variability in data provided by a visual analog scale. METHODS: Thirty participants rated ocular comfort, redness, and clarity of vision (right and left eyes) on a nondemarcated horizontal line on both paper and a Tablet PC. Measurements were taken in the morning between the hours of 8:30 and 10:30 am and again the same day between 2:30 and 4:30 pm. RESULTS: The mean difference between the measures recorded in the morning for the 2 media was 2.6 ± 0.9 (confidence intervals, 2 standard errors of the differences) units on a 100 unit scale, with the Tablet PC having the higher mean measure. The limits of agreement (2 standard deviations of the differences) was 9.4 units. Comparing the difference of the differences (1.0 ± 1.3) between the 2 methods of measure (morning vs. afternoon) the visual analog scales on the Tablet PC seemed to have good reproducibility of agreement in comparison with the paper version. CONCLUSIONS: Discrepancy analysis yielded no significant difference and slight bias between paper- and computer-based analog scales. Repeatability of measures using the Tablet PC was also demonstrated. These results suggest that the choice of medium does not significantly influence the outcome for subjective analog scales. © 2009 Lippincott Williams & Wilkins, Inc.

Woods,J., Woods,C. A., Fonn,D. Early symptomatic presbyopes-What correction modality works best? Eye and Contact Lens 2009;35(5):221-226 [ Show Abstract ]

Purpose: To compare the performance of a low-addition silicone hydrogel multifocal soft lens with other soft lens correction options in a group of habitual soft lens wearers of distance correction who are symptomatic of early presbyopia. METHOD: This clinical study was designed as a prospective, double-masked, randomized, crossover, dispensing trial consisting of four 1-week phases, one for each of the correction modalities: a low-addition silicone hydrogel multifocal soft lens, monovision, habitual correction, and optimized distance visual correction. The prescriptions of all modalities were finalized at a single fitting visit, and the lenses were worn according to a randomized schedule. All lenses were made from lotrafilcon B material. A series of objective vision tests were conducted: high- and low-contrast LogMAR under high- and low-room lighting conditions, stereopsis, and critical print size. A number of other data collection methods used were novel: some data were collected under controlled laboratory-based conditions and others under "real-world" conditions, some of which were completed on a BlackBerry hand-held communication device. RESULTS: All participants were able to be fit with all four correction modalities. Objective vision tests showed no statistical difference between the lens modalities except in the case of low-contrast near LogMAR acuity under low-lighting levels where monovision (+0.29 ± 0.10) performed better than the multifocal (+0.33 ± 0.11, P=0.027) and the habitual (+0.37 ± 0.12, P<0.001) modalities. Subjective ratings indicated a statistically better performance provided by the multifocal correction compared with monovision, particularly for the vision associated with driving tasks such as driving during the daytime (93.3 ± 8.8 vs. 84.2 ± 23.7, P=0.05), at nighttime (88.8 ± 11.7 vs. 74.9 ± 23.6, P=0.001), any associated haloes or glare (92.0 ± 10.6 vs. 78.0 ± 22.8, P=0.003), and observing road signs (90.1 ± 11.8 vs. 79.4 ± 20.2, P=0.027). Preference for the multifocal compared with monovision was also reported when watching television (95.0 ± 6.4 vs. 82.6 ± 20.1, P=0.001) and when changing focus from distance to near (87.0 ± 13.4 vs. 66.1 ± 32.2, P<0.001). CONCLUSIONS: For this group of early presbyopes, the AIR OPTIX AQUA MULTIFOCAL-Low Add provided a successful option for visual correction, which was supported by the results of subjective ratings, many of which were made during or immediately after performing such activities as reading, using a computer, watching television, and driving. These results suggest that making a prediction of "success or not" based on consulting room acuity tests alone is probably unwise. Copyright © Contact Lens Association of Ophthalmologists, Inc.

Young,G., Keir,N., Hunt,C., Woods,C. A. Clinical evaluation of long-term users of two contact lens care preservative systems Eye and Contact Lens 2009;35(2):50-58 [ Show Abstract ]

PURPOSE: To clinically evaluate long-term users of two different contact lens care preservative systems and to investigate whether prolonged use is associated with an increase in the prevalence of dry eye. METHODS: Eighty-nine wearers of group IV hydrogel or silicone hydrogel lenses participated in this one-visit, investigator-masked study. Subjects were required to have consistently used a polyhexamethylene biguanide (PHMB) or polyquaternium-1 (PQT) based solution for 2 years. Consistent use was defined as 80% for the past 2 years and 100% for the past year. Clinical assessments included: average and comfortable wear time; overall and end-of-day comfort; signs of dryness, discomfort, burning or stinging, grittiness or scratchiness and visual changes; non-invasive and fluorescein break-up-time; pre-ocular tear film lipids, tear meniscus height, Schirmer and fluorescein clearance tests; limbal and bulbar hyperemia; palpebral roughness; corneal and conjunctival staining; lens front surface wetting; and lens film deposits. RESULTS: Significantly more grittiness or scratchiness was reported by subjects using a PHMB-containing system (67% vs. 44%; P = 0.02). Palpebral roughness and hyperemia were significantly greater in the PHMB group wearing group IV lenses (P = 0.01 and P = 0.05, respectively). Corneal staining was significantly higher in the PHMB users in all four peripheral sectors (P < 0.01). Nasal and temporal conjunctival staining was also significantly higher for users of PHMB-containing systems (P < 0.05). Front surface lens wettability was significantly better for group IV PQT users compared to PHMB users (P = 0.008), with 84% vs. 72%, respectively, with lenses graded by the investigator as having "good" or "excellent" wettability. Significantly higher levels of lens front surface film deposits were noted with PHMB users (P = 0.007), with 58% of group IV lenses treated with PHMB compared with 38% of group IV lenses treated with PQT showing some lens front surface film deposition. No significant differences between the two preservative system groups were noted for the range of dry eye evaluations nor the remaining clinical assessments. CONCLUSIONS: Differences in both ocular and lens characteristic were observed between long-term users of two preservative systems used in many contact lens multi-purpose solutions. The findings from this study did not support the hypothesis that prolonged use of PHMB-containing solutions leads to dry eye. Additional studies including a larger sample size and perhaps longer use of the systems could help to further elucidate differences in clinical performance between systems.

2008

Bitton,E., Keech,A., Jones,L., Simpson,T. Subjective and objective variation of the tear film pre- and post-sleep Optometry and Vision Science 2008;85(8):740-749 [ Show Abstract ]

PURPOSE: To date, few studies have correlated the overnight effects of the preocular tear film (POTF) with subjective symptoms. This study investigates the POTF volume and stability, bulbar hyperemia (BH), tear ferning (TF) and the participant's subjective symptoms, pre- and post-sleep. METHODS: Thirty subjects were recruited, consisting of two evenly distributed groups who were symptomatic of dry eye (DE) and those that were asymptomatic dry eye, determined using the McMonnies questionnaire. Subjects were evaluated at 10 p.m. (baseline), on waking at 7 a.m., and then hourly until 10 a.m. At each visit, tear meniscus height (TMH), various subjective factors, BH and POTF stability by non-invasive break-up time (NIBUT) were assessed. Tear collection was performed at 10 p.m, 7 and 10 a.m. for TF analysis. RESULTS: With the exception of burning, all other symptoms (comfort, dryness, clarity of vision, and grittiness) revealed an overnight change (p < 0.05) within each group, but not between the two groups (p > 0.05). Both the tear meniscus height and BH were elevated upon waking and differed significantly between test times for each group (p < 0.05), but not between groups (p > 0.05). NIBUT was lower for the DE group (p < 0.001). The non-dry eye (NDE) group did not significantly alter over time (p > 0.05), but the DE group did (p = 0.004), with a longer NIBUT in the morning. TF demonstrated a degraded pattern upon waking for both groups (p < 0.05). Most of the changes returned to baseline within an hour after waking. CONCLUSIONS: The properties of the POTF undergo a change during extended periods of eye closure and the human POTF is different upon waking to that present immediately before sleep. Most of the parameters determined rapidly revert to baseline levels once the POTF is allowed to refresh.

Caffery,B., Joyce,E., Boone,A., Slomovic,A., Simpson,T., Jones,L., Senchyna,M. Tear lipocalin and lysozyme in sjögren and non-sjogren dry eye Optometry and Vision Science 2008;85(8):661-667 [ Show Abstract ]

PURPOSE.: To evaluate the concentration of tear lipocalin, lysozyme, and total protein in Sjogrens Syndrome (SS), non-Sjogrens keratoconjunctivitis sicca (KCS), and non-dry-eyed (NDE) individuals. METHODS.: Seventy-six subjects were recruited for this study: 25 SS subjects; 25 KCS subjects, and 26 NDE individuals. Symptoms were measured with a visual analogue scale. Tear flow was measured by the Schirmer I test without anesthesia. Tears were collected using an eye wash technique. Total tear protein was quantified using the DC Protein Assay Kit. Tear lipocalin and lysozyme were quantified via Western blotting performed on a Phast System. RESULTS.: By definition, the SS and KCS groups both had significantly lower mean Schirmer scores (5.12 ± 5.96 mm and 7.84 ± 7.35 mm) compared with the NDE group (23.83 ± 7.85 mm; p < 0.0001). There was no difference in mean Schirmer scores between SS and KCS groups (p = 0.19). The tear film of the SS group was characterized by significantly reduced (p < 0.0001) total protein and lipocalin concentrations compared with both KCS and NDE groups. No difference between the KCS and NDE groups was found in total protein (p = 0.92) or lipocalin (p = 0.19) concentration. In contrast, the concentration of tear film lysozyme was found to be statistically similar in all three groups examined. No statistically significant correlation was found in any group between mean Schirmer values compared with total protein, lipocalin or lysozyme concentration. CONCLUSION.: Our data demonstrate a biochemical distinction between the Sjogrens group compared with both KCS and control groups, in that both tear lipocalin and total tear protein were significantly reduced. Although correlations were not found between protein measurements and tear flow, a combination of tests including Schirmer I and quantitation of tear film biomarkers may allow for the identification of SS patients without the need for invasive testing. © 2008 American Academy of Optometry.

Dalton,K., Subbaraman,L. N., Rogers,R., Jones,L. Physical properties of soft contact lens solutions Optometry and Vision Science 2008;85(2):122-128 [ Show Abstract ]

Purpose. To investigate the physical properties of commercially available soft contact lens solutions.
Methods. The pH, osmolality, surface tension (ST), and viscosity of various soft contact lens solutions were measured at room temperature. Viscosity measurements were also taken at 34°C. The solutions examined were Opti-Free Express (OFX), Opti-Free RepleniSH (OFR), Complete Moisture Plus (COM), UltraCare (UC), ReNu MultiPlus, Sensitive Eyes, AOSept (AO), Clear Care, SoloCare Aqua, and SoftWear saline. The peroxide solutions were measured before and after neutralization.
Results. The pH of most solutions was close to neutral (range 7.00-7.36), except for OFX and neutralized AO and Clear Care. The osmolality values of most solutions were in the 275 to 310 mOsm/kg range. OFX exhibited a significantly lower osmolality (225 mOsm/kg; p < 0.001), whereas UC was significantly higher (329 mOsm/kg; p < 0.001). Neutralized AO and SoftWear saline had ST values of approximately 67 mN/m. OFX, OFR, and SoloCare Aqua exhibited low ST values in the 30 to 35 mN/m range. The remaining solutions exhibited intermediate ST values of approximately 40 mN/m. These three groupings were significantly different (p < 0.001). The average viscosity of most solutions at room temperature was between 0.95 and 1.26 cP, except for COM (3.02 cP; p < 0.001). At 34°C, the average viscosity of most solutions was between 0.70 and 0.83 cP, except for COM, which had a viscosity of 1.92 cP (p < 0.001). The un-neutralized peroxide solutions had very different pH and osmolality values from all the solutions that would directly contact the eye (p < 0.001). Their viscosity and ST values were similar (p = NS).
Conclusions. This study detailed many physical properties of soft lens solutions that are not readily available and indicated that certain properties vary significantly among these products.

Dumbleton,K. A., Woods,C. A., Jones,L. W., Fonn,D. Comfort and adaptation to silicone hydrogel lenses for daily wear Eye and Contact Lens 2008;34(4):215-223 [ Show Abstract ]

Objectives. To investigate initial comfort and adaptation of currently successful low oxygen transmissibility soft lens wearers refitted with silicone hydrogel (SH) lenses for daily wear. Methods. Fifty-five subjects were enrolled in a subject-masked 5-month clinical trial in which they wore 5 SH lenses in a randomized, crossover design. Comfort, burning, and dryness were rated on scales of 0 to 100 immediately on insertion and the time for lens settling was recorded. Symptoms were then rated at various times, using BlackBerry wireless communication devices (Research in Motion, Waterloo, Canada), during the day for 2 cycles of 2 weeks wear for each lens type. Results. Comfort immediately on insertion varied between lens types (P=0.002). All lens types were reported by the subjects to have settled within 30 to 45 sec of insertion (P=0.14) and "settled" comfort was greater than comfort immediately on insertion (P<0.001). Comfort within the first hour of wear also varied between lens types (P=0.02). Comfort during the day decreased significantly for all lenses (P=0.001), but there was no difference between lenses (P=0.19) and no effect of lens age (P=0.15). The wearing times were greater with the SH lenses than the habitual lenses worn before study commencement (P=0.001). Overall performance of the lenses after 4 weeks was high, with no difference between lenses (P=0.45). Conclusions. Initial comfort and adaptation to all SH lenses were good and no differences in the overall ratings were found between the 5 SH lenses investigated. Decreased comfort was noted later in the day with all lens types, but longer wearing times were reported with the SH lenses than previous hydroxyethyl methacrylate-based lenses. © 2008 Contact Lens Association of Ophthalmologists, Inc.

Glasier,M. -A, Keech,A., Sheardown,H., Subbaraman,L. N., Jones,L. Conformational and quantitative characterization of lysozyme extracted from galyfilcon and senofilcon silicone hydrogel contact lenses Current eye research 2008;33(1):1-11 [ Show Abstract ]

PURPOSE: To compare two solvents for retrieval of lysozyme deposited on a silicone hydrogel (SH) contact lens material galyfilcon A (GA; Acuvue Advance). METHODS: Two buffers used were 50:50 acetonitrile/0.02% trifluoroacetic acid (buffer 1) and 50:50 acetonitrile/50 mM NaOH (buffer 2). RESULTS: Extraction efficiency from GA lenses was 74% (buffer 1) and 83% (buffer 2). Buffer 2 decreased lysozyme activity > buffer 1. Ex vivo GA lenses showed total protein deposition of 2-16 microg/lens with total lysozyme deposition of 0.3-3.9 microg/lens. CONCLUSIONS: We have developed a low acid strength extraction buffer that can be used to efficiently extract active lysozyme protein from novel siloxane-based contact lens materials.

Glasier,M. -A, Subbaraman,L. N., Senchyna,M., Jones,L. A solid-phase assay for the quantitation of total protein eluted from balafilcon, lotrafilcon, and etafilcon contact lenses Current eye research 2008;33(8):631-640 [ Show Abstract ]

PURPOSE: To compare two variations of a membrane-based protein assay utilizing Amido black (AB) detection with a commercially available 3-(4-carboxybenzoyl) quinoline-2-carboxaldehyde (CBQCA) assay for use in the quantitation of individual tear proteins, pooled human tear proteins, and protein extracted from ex vivo lotrafilcon A, balafilcon A, and etafilcon A contact lens materials. METHODS: Ex vivo contact lens extracts, pooled human tears, and individual tear proteins (human serum albumin (HSA), bovine lactoferrin, human secretory immunoglobulin A (sIgA), human lysozyme) were subjected to three solid-phase assays: AB on polyvinylidene difluoride (AB on PVDF) and AB on nitrocellulose (AB on NC) and the CBQCA assay. Micro-bicinchonic acid (micro-BCA) assay was also employed with lens extracts to determine total protein concentration. Individual and pooled tear proteins were referenced to a micro version of the quantitative ninhydrin protein assay. RESULTS: The CBQCA demonstrated the greatest overall sensitivity and lowest intra- and inter-assay variability. AB on NC demonstrated the most accurate ability to quantify total protein in pooled human tear samples, although it also displayed the greatest protein-to-protein variation using individual tear proteins. The CBQCA assay displayed the greatest cross-reactivity with unworn balafilcon and lotrafilcon lens extracts, whereas AB on NC demonstrated the least. AB on NC measured similar amounts of total protein in extracted ex vivo lenses as the CBQCA assay if background interference was subtracted from CBQCA values. AB on PVDF measured the lowest amount of deposited protein from ex vivo lenses. CONCLUSION: Both the AB on NC and CBQCA assays can be used to measure protein in extracts of lotrafilcon, balafilcon, and etafilcon lens materials.

Haque,S., Fonn,D., Simpson,T., Jones,L. Epithelial thickness changes from the induction of myopia with CRTH RGP contact lenses Investigative Ophthalmology and Visual Science 2008;49(8):3345-3350 [ Show Abstract ]

PURPOSE. To investigate changes in epithelial thickness after overnight wear of CRTH rigid gas-permeable (RGP) lenses (Paragon Vision Sciences, Mesa, AZ) for the correction of hyperopia. METHODS. Twenty subjects wore a +3.50 D hyperopia-correcting CRTH lens on one eye for a single night in an attempt to induce myopia (first study). The untreated eye served as the control. Corneal and epithelial thickness was measured at nine points across the horizontal meridian by OCT. Measurements were obtained the night before lens wear, immediately after lens removal the next morning, and 1, 3, 6, and 12 hours after removal. Measurements were obtained 28 hours later, to observe recovery. Then, the attempted hyperopic corrections of +1.50 and +3.50 D were evaluated, using CRTH lenses in both eyes of 20 subjects for a single night (second study). RESULTS. All values were compared to baseline unless otherwise stated. In the first study, the treated eye's central and midperipheral epithelial thickness increased by 21.5% ± 8.6% and 13.3% ± 7.6%, respectively, after lens removal (P < 0.001). The control eye's central epithelial thickness (CET) increased by 7.1% ± 6.0% (P < 0.05). In the second study, CET increased by 17.6% ± 8.5% (P < 0.001) in the +3.50 D-treated eye and by 13.3% ± 4.8% (P < 0.001) in the +1.50 D-treated eye. Midperipheral epithelial thickening was 5.9% ± 4.7% (P < 0.05) in the +3.50 D-treated eye and 6.0% ± 6.3% (P < 0.05) in the +1.50 D-treated eye. CONCLUSIONS. CRTH lenses, designed to correct hyperopia, when worn overnight, caused an increase in CET. The amount of epithelial change seemed to differ with modified lens design. Copyright © Association for Research in Vision and Ophthalmology.

Hui,A., Boone,A., Jones,L. Uptake and release of ciprofloxacin-HCl from conventional and silicone hydrogel contact lens materials. Eye & contact lens 2008;34(5):266-271 [ Show Abstract ]

OBJECTIVES: To investigate the uptake and release characteristics of the antibiotic ciprofloxacin-HCl in conventional and silicone hydrogel lenses, and evaluate their potential as therapeutic drug delivery devices. METHODS: Nine differing soft contact lens materials were soaked in a 0.3% ciprofloxacin-HCl solution at 34 degrees C. The uptake of the drug into the lenses was measured by the change in concentration over 24 hours using fluorescence spectrophotometry. The lenses were then placed in a buffered saline solution, and the release of the drug from the lenses was also measured using spectrophotometry. RESULTS: The release of drug varied from 0.016 +/- 0.004 mg/lens for lotrafilcon A lenses to 0.42 +/- 0.03 mg/lens for etafilcon A lenses, with an average of 0.133 mg/lens. The 3 conventional lenses used in the study released a statistically significantly different amount of drug when compared with the silicone hydrogels. The release of drug was very rapid, with drug release reaching a plateau after no more than 10 minutes for the majority of the lenses. The majority of the lenses were able to release enough drug to achieve minimum inhibitory concentration 90 for most resistant ocular pathogens. Ciprofloxacin was found to heavily precipitate on the etafilcon A lenses during the release phase at physiologic pH. CONCLUSION: While balafilcon A released the most drug from the silicone hydrogel materials, all materials released the drug too quickly to be effective as drug delivery devices.

Lu,F., Simpson,T., Sorbara,L., Fonn,D. Malleability of the ocular surface in response to mechanical stress induced by orthokeratology contact lenses Cornea 2008;27(2):133-141 [ Show Abstract ]

PURPOSE: To determine the malleability of the ocular surface by examining the acute effects of local mechanical stress on optical performance, corneal shape, and corneal/epithelial thickness after corneal refractive therapy for myopia and hyperopia (CRT and CRTH). METHODS: Twenty ametropes (spherical equivalent: -2.08 ± 2.31 D) wore CRT and CRTH lenses in a random order on 1 eye (randomly selected). The lenses were worn for 15, 30, and 60 minutes (randomly ordered, with each period taking place on a different day). Refractive error, aberrations, corneal topography, and corneal/epithelial thickness (using OCT) were measured before and after lens wear. The measurements were performed on the control eyes at the 60-minute visit only. RESULTS: With both CRT and CRTH lens wear, significant changes occurred in many parameters from the 15-minute time point. The refractive error and defocus decreased after CRT lens wear (all P 0.05). Higher-order aberrations, including coma and spherical aberration (SA), increased after CRT and CRTH lens wear (all P 0.05). Higher-order aberrations, including coma and spherical aberration (SA), increased after CRT and CRTH lens wear (all P 0.05). Higher-order aberrations, including coma and spherical aberration (SA), increased after CRT and CRTH lens wear (all P 0.05). Higher-order aberrations, including coma and spherical aberration (SA), increased after CRT and CRTH lens wear (all P 0.05). Higher-order aberrations, including coma and spherical aberration (SA), increased after CRT and CRTH lens wear (all P 0.05). Higher-order aberrations, including coma and spherical aberration (SA), increased after CRT and CRTH lens wear (all P 0.05). Higher-order aberrations, including coma and spherical aberration (SA), increased after CRT and CRTH lens wear (all P 0.05). CONCLUSIONS: CRT lenses for myopia and hyperopia induce significant structural and optical changes in as little as 15 minutes. The cornea, particularly the epithelium, is remarkably malleable, with rapid steepening and flattening possible in little time. © 2008 Lippincott Williams & Wilkins, Inc.

Luensmann,D., Jones,L. Albumin adsorption to contact lens materials: A review Contact Lens and Anterior Eye 2008;31(4):179-187 [ Show Abstract ]

During contact lens wear, tear film components such as lipids, mucins and proteins tend to deposit on and within the lens material and may cause discomfort, reduced vision and inflammatory reactions. The tear film protein that has attracted most interest when studying contact lens deposition is the small (14 kDa), positively charged protein lysozyme. Albumin, which is a much larger protein (66 kDa) with an overall net negative charge is also of interest, and shows very different adsorption patterns to lysozyme. The concentration of albumin in the tear film is relatively low compared to the concentration in blood serum, but this value increases markedly under various conditions, including when the eye is closed, during contact lens wear and in various dry eye states. Gaining an understanding of the manner in which albumin deposits on biomaterials is of importance for contact lens wear, as well as for other medical applications where HEMA-based materials are used for implants, artificial blood vessels or drug delivery devices. This review paper summarizes the impact of individual material compositions, water content, hydrophobicity and electrostatic attraction on the adsorption behavior of the protein albumin.

Schulze,M. M., Hutchings,N., Simpson,T. L. The use of fractal analysis and photometry to estimate the accuracy of bulbar redness grading scales Investigative Ophthalmology and Visual Science 2008;49(4):1398-1406 [ Show Abstract ]

Purpose. To use physical attributes of redness to determine the accuracy of four bulbar redness grading scales, and to cross- calibrate the scales based on these physical measures. Methods. Two image-processing metrics, fractal dimension (D) and percentage of pixel coverage (% PC), as well as photometric chromaticity were selected as physical measures, to describe and compare grades of bulbar redness among the McMonnies/Chapman-Davies scale, the Efron Scale, the Institute for Eye Research scale, and a validated scale developed at the Centre for Contact Lens Research. Two sets of images were prepared by using image processing: The first included multiple segments covering the largest possible region of interest (ROI) within the bulbar conjunctiva in the original images; the second contained modified scale images that were matched in size and resolution across scales, and a single, equally-sized ROI. To measure photometric chromaticity, the original scale images were displayed on a computer monitor, and multiple conjunctival segments were analyzed. Pearson correlation coefficients between each set of image metrics and the reference image grades were calculated to determine the accuracy of the scales. Results. Correlations were high between reference image grades and all sets of objective metrics (all Pearson's r ≥ 0.88, P ≤ 0.05); each physical attribute pointed to a different scale as being most accurate. Independent of the physical attribute used, there were wide discrepancies between scale grades, with almost no overlap when cross-calibrating and comparing the scales. Conclusions. Despite the generally strong linear associations between the physical characteristics of reference images in each scale, the scales themselves are not inherently accurate and are too different to allow for cross-calibration. Copyright © Association for Research in Vision and Ophthalmology.

Simpson,T. L., Situ,P., Jones,L. W., Fonn,D. Dry eye symptoms assessed by four questionnaires Optometry and Vision Science 2008;85(8):E692-E699 [ Show Abstract ]

PURPOSE.: To establish the relationships between commonly used questionnaires including Dry Eye Questionnaire, McMonnies Questionnaire, and Ocular Surface Disease Index, and to test the construct and face validity of the simple Subjective Evaluation of Symptom of Dryness. METHODS.: Ninety-seven non-contact lens wearing subjects were enrolled in the study and classified into either a "dry" and "non-dry" group using a single score from an initially applied subjective evaluation of symptom of dryness. The four questionnaires were then completed in a random order. The unidimensionality and accuracy of the responses was assessed using Rasch and receiver (or relative) operating characteristics curve analysis and the characteristics of and association between symptoms were compared using non-parametric statistics. RESULTS.: The responses from the Dry Eye Questionnaire, McMonnies Questionnaire, and Ocular Surface Disease Index met the Rasch analysis criterion of unidimensionality. Each test separated the symptomatic and asymptomatic groups well [all receiver (or relative) operating characteristics area-under-the-curve statistics at least 0.88] and there were significant associations between the results from each questionnaire (all Spearman ρ at least 0.64). CONCLUSIONS.: The results illustrate that different questionnaire-based instruments examining symptoms in controls and symptomatic subjects derive unidimensional data that are similar inasmuch as the overall scores are highly correlated. The data also point to the utility of a quick, three-question screening tool in dry eye research. © 2008 American Academy of Optometry.

Simpson,T., Fonn,D. Optical coherence tomography of the anterior segment Ocular Surface 2008;6(3):117-127 [ Show Abstract ]

Perhaps no diagnostic technology has emerged as rapidly in ophthalmology as optical coherence tomography (OCT). A single clinical device for this noninvasive imaging technique was first released in 1996, and now at least ten clinical devices are available. Although the first clinical anterior segment OCT was marketed only 2 years ago, a substantial amount of work has been done using modified retinal imagers or prototype laboratory-based imagers. In this review, we discuss OCT imaging primarily of the cornea. We also highlight previous and current publications on nonclinical and clinical uses of the device to illustrate how anterior segment OCT can be used to understand corneal structure and function in health and disease. © 2008 Ethis Communications, Inc.

Situ,P., Simpson,T. L., Fonn,D., Jones,L. W. Conjunctival and corneal pneumatic sensitivity is associated with signs and symptoms of ocular dryness Investigative Ophthalmology and Visual Science 2008;49(7):2971-2976 [ Show Abstract ]

PURPOSE: To investigate the relationships of dry eye symptoms and corneal and conjunctival sensitivity to pneumatic stimulation, tear film stability, and clinical ocular surface characteristics in symptomatic and asymptomatic subjects. METHODS: Ninety-seven subjects were enrolled and grouped by a questionnaire-based single score for symptoms of ocular dryness (none to trace, non-dry group; mild to severe, symptomatic group); 43 were symptomatic and 54 were non-dry. Corneal (K) and conjunctival (C) sensitivities were measured with a computer-controlled Belmonte pneumatic (room temperature) stimulus. Symptoms were assessed according to the Ocular Surface Disease Index (OSDI). Ocular surface staining with fluorescein (FL) and lissamine green (LG), noninvasive tear film break-up time (NIBUT), and the phenol red thread test (PRT) were assessed. RESULTS: The symptomatic group showed lower K and C thresholds (P < 0.01), greater corneal FL and conjunctival LG staining, and shorter NIBUT than did the non-dry eye group (all others P < 0.05). The OSDI scores were higher in the symptomatic group (P < 0.001). K and C thresholds and NIBUT were inversely correlated with the OSDI and corneal and conjunctival staining (all P < 0.05). The K and C threshold and NIBUT (all P < 0.01) correlated positively. Step-wise multiple regression analysis showed that ocular surface sensitivity and NIBUT were significant predictors of the OSDI. CONCLUSIONS: Ocular irritation assessed with the OSDI is associated with ocular surface hyperesthesia to cooling, corneal epitheliopathy, and tear film instability. Although cause and effect are unclear, the analysis showed that altered corneal and conjunctival sensory processing and tear film attributes are essential aspects of what characterizes dry eye.

Situ,P., Simpson,T. L., Jones,L. W., Fonn,D. Conjunctival and corneal hyperesthesia in subjects with dryness symptoms Optometry and Vision Science 2008;85(9):867-872 [ Show Abstract ]

PURPOSE.: To compare conjunctival and corneal sensitivity in noncontact lens wearing subjects with and without symptoms of ocular dryness, stratified by age and gender. METHODS.: Ninety-seven subjects were enrolled, 54 of whom were asymptomatic and 43 of whom were symptomatic of ocular dryness. A single score for the symptom of dryness was used to classify nondry eye (scores of none to trace) and dry eye symptomatic (scores of mild to severe) groups. The subjects were further stratified into "younger" (19 to 49 years) and "older" age groups (50 to 80 years). Conjunctival and corneal sensitivity of the right eye was measured at the central cornea and temporal conjunctiva, using a computer-controlled pneumatic esthesiometer with stimulus temperature set at 20°C. The ascending method of limits was used to determine the thresholds. RESULTS.: Conjunctival and corneal thresholds were significantly lower in the dry eye symptomatic than in the nondry eye group (both p 0.05). Conjunctival threshold in the nondry eye women was lower than the men (p 0.05). CONCLUSIONS.: Conjunctival and corneal sensitivity to pneumatic cool stimulation is increased in subjects with symptoms of ocular dryness. This hyperesthesia seems to be more significant in the conjunctiva. © 2008 American Academy of Optometry.

Teichroeb,J. H., Forrest,J. A., Jones,L. W., Chan,J., Dalton,K. Quartz crystal microbalance study of protein adsorption kinetics on poly(2-hydroxyethyl methacrylate) Journal of colloid and interface science 2008;325(1):157-164 [ Show Abstract ]

The interaction of macromolecules with artificial biomaterials may lead to potentially serious complications upon implantation into a biological environment. The interaction of one of the most widely used biomaterials, polyHEMA, with lysozyme, bovine serum albumin (BSA), and lactoferrin was investigated using quartz crystal microbalance (QCM). The concentration dependence of adsorption was measured for the aforementioned proteins individually as well as for lysozyme-BSA, and lysozyme-lactoferrin combinations. An extension of Voinova's viscoelastic model to n layers was used to create thickness-time graphs for adsorption. For each of lactoferrin and lysozyme, two distinctly different timescales of adsorption could be differentiated. However, the mechanisms of adsorption appeared to differ between the two. Negative dissipation shifts were measured for low concentrations of lysozyme, trending to positive dissipation at higher concentrations. This suggested that lysozyme was adsorbed initially into the matrix, stiffening the hydrogel, and later onto the surface of polyHEMA. Additionally, trials with commercial no-rub cleaning solutions indicated little added effectiveness over buffer solutions. Mixtures of proteins showed behaviour which differed in some cases from the simple combination of single protein adsorption experiments. Crown Copyright © 2008.

Van Beek,M., Jones,L., Sheardown,H. Hyaluronic acid containing hydrogels for the reduction of protein adsorption Biomaterials 2008;29(7):780-789 [ Show Abstract ]

Recently, new contact lens materials have been introduced which are reported to improve comfort by incorporating wetting agents either in a releasable or nonreleasable form. In the present work, model lens materials based on poly(2-hydroxyethyl methacrylate) (pHEMA) were developed which incorporate releasable or crosslinked and therefore physically entrapped hyaluronic acid (HA) of various molecular weights as a wetting agent. Crosslinked HA, despite being only present in very small amounts, resulted in consistently lower water contact angles over 4 h in comparison to controls, indicating that HA is present at the interface and was not being released over time. The presence of HA in the material was further confirmed by increases in the glass transition temperature measured by differential scanning calorimetry (DSC), and small increases in the stiffness as measured by Instron testing. This crosslinking procedure appeared to have no effect on optical transparency using 35 kDa HA, whereas small decreases in optical transparency at higher wavelengths were noted for the 169 kDa HA crosslinked material, as measured by UV spectrophotometry. Most importantly, protein adsorption results indicated that the adsorption of all proteins studied was considerably decreased by the presence of the small amount of crosslinked HA. The results provide insight into the mechanisms of comfort improvement with commercially available lens materials and suggest that HA containing materials may have significant potential for use in contact lens applications. © 2007 Elsevier Ltd. All rights reserved.

Varikooty,J., Srinivasan,S., Jones,L. Atypical manifestation of upper lid margin staining in silicone hydrogel lens wearers with symptoms of dry eye Contact Lens and Anterior Eye 2008;31(1):44-46 [ Show Abstract ]

Purpose: To report an atypical manifestation of upper lid margin staining (ULMS) that occurred in adapted silicone hydrogel (SH) contact lens wearers who complained of ocular surface dryness. Methods: Sequential staining with sodium fluorescein (FL) and lissamine green (LG) strips was performed in 38 SH lens wearers. The "wiper area" of the upper lid was examined with the slit lamp, at 8× and 12× magnifications. Results: Four out of 38 subjects (10.5%) showed fimbriated or "feathery" extensions from the superior margin of the subtarsal fold onto the upper tarsal plate. The extent of these feathery extensions varied between subjects, with a mean (±S.D.) length of 2 ± 0.8 mm. In all cases a broad band of staining with both FL and LG was demonstrated, which extended along the entire length of the lid margin. Conclusion: The staining patterns shown on the subjects' upper lid margins and tarsal plates suggest that ULMS may include more complex variants. The putative tissue damage revealed through the staining, points to a mechanism not simply restricted to the upper lid margin. © 2007 British Contact Lens Association.

2007

Bitton,E., Keech,A., Simpson,T., Jones,L. Variability of the analysis of the tear meniscus height by optical coherence tomography Optometry and Vision Science 2007;84(9):E903-E908 [ Show Abstract ]

PURPOSE. Tear meniscus height (TMH) is an established parameter indicative of tear film volume and has recently been determined using an optical coherence tomographer (OCT). The purpose of this study was to evaluate the inter and intra observer variability in TMH assessment using OCT. METHODS. Ten subjects (6 M, 4 F; aged 32.5 ± 6.4 years) had 10 consecutive scans taken of their inferior central tear meniscus (5 scans originating at 90° and 5 origination at 270°) using the OCT2 (Humphrey-Zeiss). Images were analyzed by two observers using custom software on three separate occasions. Following a training session among observers, the images were reevaluated to assess differences in variability. Data were analyzed for differences within and across examiners, for the effect of examiner training and between scan directions. RESULTS. The mean TMH and tear volume collapsed across subjects were between 0.24 and 0.25 mm and 25 to 27 nL/mm, respectively. No difference was noted within observers. An interobserver mean volume difference (p = 0.044) was present but was eliminated post training (p = 0.167). Variability was less with scans originating at 90°. CONCLUSIONS. The values of the TMH and tear volume are similar to those reported in the literature. Due to the interobserver differences observed, a training session between examiners may prove to be valuable, especially in a large or multicenter study. © 2007 American Academy of Optometry.

Dracopoulos,A., Dixon,D. G., Jones,L. W., Sivak,J. G., Bantseev,V. In vitro assessment of medical device toxicity: Interactions of benzalkonium chloride with silicone-containing and p-HEMA-containing hydrogel contact lens materials Eye and Contact Lens 2007;33(1):26-37 [ Show Abstract ]

PURPOSE. To analyze the interactions of benzalkonium chloride (BAK) with silicone-containing (lotrafilcon A and galyfilcon A) and p-HEMA-containing (etafilcon A and vifilcon A) hydrogel contact lenses and to examine the possibility of using sodium fluorescein permeability assay (SFPA), 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the bovine lens assay in conjunction with confocal laser scanning microscopy (CLSM) as a battery of in vitro alternatives to evaluate the potential toxicity of soft contact lenses. METHODS. Four soft contact lens types (Focus Monthly [vifilcon A], Focus NIGHT & DAY [lotrafilcon A], ACUVUE Advance With Hydraclear [galyfilcon A], and SUREVUE [etafilcon A]) were soaked for 24 hours in various concentrations of BAK (1%, 0.1%, 0.01%, and 0.001%) in 20-mL glass vials. After 24 hours, the lenses were gently washed in Hanks' Balanced Salt Solution (HBSS), placed in 5 mL of HBSS, and incubated for a total of 7 days at 37°C, 5% CO2. BAK released into HBSS (i.e., the extract) was recovered from the vials and used as the test chemical in the SFPA (epithelium integrity), MTT assay (cellular viability), and the bovine lens assay with CLSM (mitochondrial metabolism and optical properties). The amount of BAK extracted from the various contact lenses was measured using an Abbe refractometer. Negative controls consisted of HBSS and contact lenses subjected to the same conditions as the treated contact lenses, but without BAK. RESULTS. Extracts obtained from soaking Focus Monthly lenses in BAK caused the most damage to the epithelium and mitochondrial metabolism. However, at 0.1% BAK extraction, all lens extracts showed increased levels of back vertex distance variability of the cultured bovine lens. CONCLUSIONS. Unexpectedly, lenses extracted with HBSS showed SFPA and MTT assay responses and an observed effect on the bovine lens epithelium visualized by CLSM, indicating that unknown chemical agents may be leached from contact lens polymers. © 2007 Lippincott Williams & Wilkins, Inc.

Duench,S., Simpson,T., Jones,L. W., Flanagan,J. G., Fonn,D. Assessment of variation in bulbar conjunctival redness, temperature, and blood flow Optometry and Vision Science 2007;84(6):511-516 [ Show Abstract ]

PURPOSE. To assess the diurnal variation in bulbar conjunctival redness, conjunctival temperature, and conjunctival blood flow. METHODS. Bulbar redness was quantified by CIE u' chromaticity using a SpectraScan PR650 spectrophotometer. Conjunctival temperature was measured using a Tasco-Thi 500 infrared thermometer. Measurements of conjunctival blood flow were obtained using a modified Heidelberg Retinal Flowmeter (HRF). Measurements on 10 subjects were made on a periodic basis over the day and on waking. RESULTS. For each factor measured a cyclical pattern was observed, with highest values on waking, a reduction in values towards mid-day, and then a gradual increase over the remainder of the day. There was a significant effect of time for redness, temperature, and conjunctival blood flow (p < 0.001 for all three variables), with no significant difference in the cyclical pattern between eyes being observed (p = NS). CONCLUSIONS. Diurnal bulbar redness, temperature, and conjunctival blood flow variation may be objectively quantified and all three are lowest during the middle of the day and maximal at the start of the day. This information should be considered when undertaking studies in which redness, temperature, and ocular surface blood flow are important outcome variables and time of day is a potential confounding factor. © 2007 American Academy of Optometry.

Fonn,D., Simpson,T., Woods,J., Woods,C. New technologies to assess lens-mediated effects of the cornea Eye and Contact Lens 2007;33(6 PART 2 OF SUPPL 2):364-370 [ Show Abstract ]

Contact lenses can affect the cornea in a variety of ways. Corneal structure can be altered so that its thickness changes to involve the epithelium and the stroma. As a result, the curvature may be affected, but whether it is the front or the back surface that is affected depends on the type of lens used. If thickness increases sufficiently, corneal transparency may decrease. Contact lenses can also affect cellular structure of all layers of the cornea through mechanical trauma, hypoxia, or toxicity from solutions that are used in association with lenses. More serious complications, such as inflammation and infection, can arise. All these changes can be detected by clinicians using slitlamp biomicroscopes and keratometers if the changes are significant enough. Since the development of computers, optical instruments have become more sophisticated and have enabled the detection of subtle changes but have also facilitated more precise measurement of these conditions along with the ability to capture images of the alterations or defects. This article describes some of the newer techniques and, specifically, the application of optical coherence tomography, confocal microscopy, and esthesiometry. © 2007 Lippincott Williams & Wilkins, Inc.

Haque,S., Fonn,D., Simpson,T., Jones,L. Corneal refractive therapy with different lens materials, Part 1: Corneal, stromal, and epithelial thickness changes Optometry and Vision Science 2007;84(4):343-348 [ Show Abstract ]

PURPOSE. To assess the corneal swelling response to two myopic correction corneal refractive therapy (CRT) lenses of varying Dk/t values, worn for a single night. Change in thickness of the total cornea, stroma, and epithelium was measured across the horizontal meridian using optical coherence tomography (OCT). METHODS. In this double-masked, randomized study, twenty subjects wore a CRT design lens in each eye, manufactured from Menicon Z (MenZ; Dk/t = 91) and Equalens II (EqII; Dk/t = 47) materials. Baseline corneal thickness was measured centrally and at four points either side of the central cornea using OCT, the night before sleeping at the Centre for Contact Lens Research. The next morning, lenses were removed, and thickness measurements were repeated 1, 3, 6, and 12 h after removal. RESULTS. On lens removal, the MenZ eye had central and paracentral corneal swelling (mean ± SD) of 4.1 ± 2.0% and 5.6 ± 2.4%, and the EqII eye had 5.8 ± 2.6% and 7.0 ± 2.6%. These values were significantly different from baseline (ReANOVA; p 0.05). Stromal swelling values on lens removal were 5.7 ± 2.2% centrally and 5.5 ± 3.0% mid-peripherally (MenZ) and 7.7 ± 3.1% centrally and 6.6 ± 2.9% mid-peripherally (EqII) (all p < 0.001 from baseline). Central stromal swelling was different between eyes at lens removal (p < 0.001). Stromal thickness in both eyes returned to baseline values within 3 h. CONCLUSION. The higher-Dk/t MenZ material caused significantly less overnight corneal and stromal swelling than the Eqll material, which reinforces the need to prescribe lenses with high Dk/t for overnight wear. Neither central epithelial thinning nor paracentral thickening are significantly affected by Dk/t. © 2007 American Academy of Optometry.

Klenkler,B., Sheardown,H., Jones,L. Growth factors in the tear film: Role in tissue maintenance, wound healing, and ocular pathology Ocular Surface 2007;5(3):228-239 [ Show Abstract ]

Numerous biologically active growth factors are secreted by the lacrimal gland and distributed via the tears over the ocular surface where they affect cellular proliferation, migration, differentiation, and survival. The role of growth factors and their receptors in maintenance of tissue homeostasis and wound healing continues to be elucidated, and the effect of growth factor imbalances In ocular surface diseases is just beginning to be understood. For Instance, in eyes with ocular surface diseases, Including conjunctivitis, corneal erosion, keratitis, and corneal ulcers, epidermal growth factor release rates have been shown to be significantly lower than in normal eyes during reflex tearing. Future research into the mechanisms of dry eye disease will focus on reasons for decreased tear and growth factor production in the neuronal reflex loop or the acinar lacrimal gland cells. Animal models to test therapeutic approaches must be developed. © 2007 Ethis Communications, Inc.

Lorentz,H., Jones,L. Lipid deposition on hydrogel contact lenses: How history can help us today Optometry and Vision Science 2007;84(4):286-295 [ Show Abstract ]

The tear film is a complex fluid that is precisely maintained and which is essential to the health of the ocular surface. One of the major components of the tear film is lipid, which is produced by the meibomian glands and serves many important functions on the ocular surface. It is estimated that there are more than 45 individual lipids within the tear film, which vary greatly in their structure and properties. The composition of the lipid within the tear film has an enormous influence on the stability of the tear film, with a subsequent impact on the occurrence of dry eye and the ultimate success of contact lens wear. The purpose of this review article is to describe the composition of the tear film lipids and their interaction with contact lens materials, with a particular emphasis on how the chemistry of novel silicone hydrogel materials has resulted in clinicians needing to understand the deposition of lipids onto contact lenses and how they may best manage this complication.

Lorentz,H., Rogers,R., Jones,L. The impact of lipid on contact angle wettability Optometry and Vision Science 2007;84(10):946-953

Lu,F., Simpson,T., Sorbara,L., Fonn,D. The relationship between the treatment zone diameter and visual, optical and subjective performance in Corneal Refractive Therapy™ lens wearers Ophthalmic and Physiological Optics 2007;27(6):568-578 [ Show Abstract ]

Purpose: To investigate the stability of the treatment zone (TZ) size during Corneal Refractive Therapy (CRT™) over 4 weeks of lens wear, and to determine the relationship between TZ diameter and visual, optical and subjective performance. Methods: Twenty-three myopic subjects wore CRT™ lenses overnight and removed their lenses on awakening. Visual Acuity (VA), subjective vision, refractive error, aberrations and corneal topography were measured at baseline, immediately after lens removal on the first day and 14 h later, and these measurements were repeated on days 4, 10 and 28. The TZ including the central flattened zone (CFZ) and the annular steepened zone (ASZ) was demarcated by the change in corneal curvature from negative to positive and vice versa, using the tangential difference map from the Atlas corneal topographer. Results: After overnight CRT™ lens wear, the central cornea flattened and the mid-periphery steepened (both p < 0.001). After 4 weeks of lens wear, the CFZ (±SE) increased from 3.41 ± 0.09 mm on day 1 morning to 3.61 ± 0.07 mm on day 28 morning and the diameter of the ASZ increased from 8.17 ± 0.16 mm (day 1 morning) to 8.85 ± 0.14 mm (day 28 morning) (both p < 0.001). From day 10 onwards, the CFZ and ASZ diameter were stable in the morning (p ≥ 0.404). Throughout the day, the CFZ became smaller during the first 10 days (all p ≤ 0.022), whereas the ASZ diameter remained constant (all p ≥ 0.079). There were positive correlations between the CFZ or ASZ and residual refractive error, subjective vision and spherical aberration. The CFZ was also correlated with astigmatism and higher order aberrations, and the ASZ was positively correlated with coma (r = 0.726 to 0.961, all p ≤ 0.042). In addition, there were negative correlations between the CFZ or ASZ and total aberration and defocus and between the ASZ and VA (r = -0.707 to -0.953, all p ≤ 0.050). Conclusion: The TZ changed during the first 10 days. Its size was associated with VA, residual refractive error, aberrations and subjective vision. The concept of a TZ is a useful metric of visual, optical and subjective performance in CRT™ lens wearers. © 2007 The Authors.

Lu,F., Simpson,T., Sorbara,L., Fonn,D. Corneal Refractive Therapy™ with different lens materials, Part 2: Effect of oxygen transmissibility on corneal shape and optical characteristics Optometry and Vision Science 2007;84(4):349-356 [ Show Abstract ]

PURPOSE. To compare the effects of two different oxygen transmissible (Dk/t) lenses on corneal shape and optical performance after one night of corneal refractive therapy (CRT®) for myopia. METHODS. Twenty myopic subjects were fit with Menicon Z (MZ) (Dk/t = 90.6, Paragon CRT® lenses) on one eye and an Equalens II (EII) CRT® lens (Dk/t = 47.2) on the contralateral eye (eye randomized). Corneal topography, refractive error and aberrations were measured before lens insertion (baseline), and the following day after overnight lens wear, on lens removal and 1, 3, 6, 12 h later. Root mean square wavefront errors were measured using 4.5 mm pupils. RESULTS. Averaged over position and time, the horizontal corneal curvature was statistically different between the MZ and EII lens-wearing eyes (p = 0.011). The central cornea flattened similarly (p = 0.886) and the mid-periphery steepened in both eyes (p = 0.061) from baseline. The EII lens-wearing eyes were steeper in the mid-periphery than the MZ eyes immediately after lens removal and at the 1-h visit (p ≤ 0.032). Central corneal flattening and mid-peripheral corneal steepening regressed over time (all p < 0.001) but did not recover to baseline by 12 h (all p < 0.004). Myopia was reduced equally by 0.84 ± 0.83 D for the MZ-lens wearing eyes and 0.84 ± 0.87 D for the EII eyes (p = 0.969). Coma increased from baseline 1.85X (0.056 ± 0.081 μm) for the MZ-lens wearing eyes and 1.72X (0.048 ± 0.084 μm) for the EII eyes (both p < 0.001). Spherical aberration increased from baseline 4.55X (0.101 ± 0.077 μm) for the MZ-lens wearing eyes and 4.31X (0.085 ± 0.076 μm) for the EII eyes (both p < 0.001), but there were no differences between the MZ and EII eyes (all p ≥ 0.308). Coma and spherical aberration did not return to baseline by 12 h (both p ≤ 0.007). CONCLUSIONS. After one night of CRT® lens wear, changes in corneal shape were slightly different, with more mid-peripheral steepening in the EII eyes compared to the MZ eyes. Change in central corneal curvature and optical performance were similar in both eyes. © 2007 American Academy of Optometry.

Lu,F., Sorbara,L., Simpson,T., Fonn,D. Corneal shape and optical performance after one night of Corneal Refractive Therapy™ for hyperopia Optometry and Vision Science 2007;84(4):357-364 [ Show Abstract ]

PURPOSE: To investigate the corneal shape and optical performance following one night of Corneal Refractive Therapy for hyperopia (CRTH). METHODS: Twenty subjects (spherical equivalent: -2.14 +/- 2.54 D) were fit with a Paragon CRTH lens (Dk = 100) on one eye randomly. The other eye served as the control. Aberrations, refractive error, and corneal topography at various locations along the horizontal meridian were measured at baseline prior to lens insertion, and immediately after lens removal and at 1, 3, 6, 12, and 28 hours later. Root mean square wavefront errors were measured using a 4.5 mm pupil size. RESULTS: After one night of CRTH lens wear, the central cornea steepened and paracentral region flattened in the experimental eyes (p < 0.001), whereas no significant location effect was found in the control eyes (p = 0.139). Refractive error (mean +/- SE) changed by 1.23 +/- 0.21 D (p < 0.001). The defocus increased by 0.58 +/- 0.09 microm (p < 0.001). Higher-order aberrations, coma, and spherical aberrations increased by factors of 2.69, 2.58, and 4.07, respectively (all p < 0.001). Spherical aberrations shifted from positive to negative. Astigmatism did not change over time (p = 0.771). All parameters returned to baseline by 28 hours (all p > or = 0.808). Aberrations and refractive error did not change in the control eyes (all p > or = 0.082). CONCLUSIONS.: The CRTH lens steepens the central cornea and flattens the paracentral region, which alters the ametropia by inducing a myopic shift. It appears to be effective for correcting hyperopia and also is reversible.

Luensmann,D., Glasier,M. -A, Zhang,F., Bantseev,V., Simpson,T., Jones,L. Confocal microscopy and albumin penetration into contact lenses Optometry and Vision Science 2007;84(9):839-847 [ Show Abstract ]

Purpose. To develop a novel in vitro method to detect the depth of penetration of the tear film protein albumin into contact lens materials using confocal laser scanning microscopy (CLSM).
Methods. A poly-HEMA-based hydrogel (etafilcon A) and a silicone hydrogel material (lotrafilcon B) were examined. In vitro, bovine serum albumin (BSA) was labeled with 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein hydrochloride (DTAF). The lenses were incubated in this protein solution (0.5 mg/ml) at 37°C. After 1 and 7 days incubation, the lenses were examined using CLSM (Zeiss 510, config. META 18) and the location of the fluorescently labeled BSA was identified.
Results. BSA adsorption on the surface and penetration into the lens matrix occurred at a higher concentration for etafilcon compared to lotrafilcon (p < 0.001). For both materials, BSA was detected on the surface after 1 day of incubation. Significant levels of BSA were detected within the matrix of etafilcon after as little as 1 day (p < 0.001), but no BSA was detected in the matrix of lotrafilcon at any time (p > 0.05).
Conclusion. CLSM can be successfully used to examine the depth of penetration of fluorescently labeled proteins into various hydrogel polymers. Our results show that etafilcon lenses both adsorb BSA on the surface and absorb BSA within the matrix, whereas lotrafilcon B adsorbs small amounts of BSA on the surface only.

Schulze,M. M., Jones,D. A., Simpson,T. L. The development of validated bulbar redness grading scales Optometry and Vision Science 2007;84(10):976-983 [ Show Abstract ]

PURPOSE: To develop a perceptually and physically based bulbar redness grading scale. METHODS: Digital conjunctival hyperemia photographs were taken using a photo-slit lamp at controlled exposures. Nine participants arranged 25 images on a tabletop over a range of 1.5 m, using separation to represent changes in redness. The position of each image was recorded and normalized for a 0 to 100 scale, and compared to chromaticity of each image obtained using a spectrophotometer. The performance of two versions of the scale (5 and 10 images) and a continuous grading scale was evaluated based on repeatability data collected from nineteen observers who used each scale twice to grade 30 randomly presented images of bulbar redness. RESULTS: Psychophysical scaling was highly correlated between single observers (Pearson's r >or= 0.92, p < 0.05). The averaged subjective grades significantly correlated with chromaticity (r = 0.95 and r = 0.99, p < 0.001 for CIE u* and log u*, respectively). Across all observers, test and retest ratings were highly correlated with either scale (r >or= 0.98), and showed high levels of repeatability expressed by intraclass correlation coefficients (ICC >or= 0.98), correlation coefficients of concordance (CCC >or= 0.96), and coefficients of repeatability (COR <or= 5.64). Despite single unit increment options, the majority of grade values assigned using the discrete scales were distributed in multiples of 5. CONCLUSIONS: Combining psychophysical and physical attributes is a promising method for the development of novel anterior segment scales; the newly developed scales performed well in a clinical setting.

Situ,P., Simpson,T. L., Fonn,D. Eccentric variation of corneal sensitivity to pneumatic stimulation at different temperatures and with CO2 Experimental eye research 2007;85(3):400-405 [ Show Abstract ]

The purpose was to measure corneal sensitivity at multiple corneal positions using pneumatic stimuli, at room temperature and at ocular surface temperature (with and without CO2 added), in 15 healthy participants. Sensitivity of central, mid-peripheral, and peripheral cornea was measured using a computer-controlled modified Belmonte esthesiometer to deliver pneumatic cool (air at 20 °C), mechanical (air at 50 °C), and chemical stimuli (air at 50 °C with CO2 added). The ascending method of limits and method of constant stimuli were adopted to determine the threshold to these stimuli at each location. Sensitivity across the cornea using pneumatic stimuli at different temperatures and chemical stimuli varied only slightly. These patterns of variation are different to what has been previously reported using Cochet-Bonnet esthesiometry. © 2007 Elsevier Ltd. All rights reserved.

Sorbara,L., Simpson,T., Duench,S., Schulze,M., Fonn,D. Comparison of an objective method of measuring bulbar redness to the use of traditional grading scales Contact Lens and Anterior Eye 2007;30(1):53-59 [ Show Abstract ]

Purpose: The primary objective was to compare measures of bulbar redness objectively using a photometric method with standard grading methods. Measures of redness were made on 24 participants wearing a silicone hydrogel contact lens in one eye for overnight wear. This report compares hyperaemia after 1 week of daily wear (baseline) with redness measured after 6 months of overnight wear. Method: A new method of objectively measuring bulbar conjunctival redness was performed using the Spectrascan650® Photometer by Photo Research® under fixed illumination. Photometric measures in CIEu* chromaticity values involve the measurement of chromaticity, a physical analogue of redness, greenness and blueness in the image. This method was validated in Part 1 of the study using repeated measurements on the photographic CCLRU scale. In Part 2 of the study, the photographic grading scale (CCLRU) from 0 (none) to 100 (extreme) was used to make the comparison. Results: Part 1 indicated that the photometer provides a repeatable and reliable measure of bulbar redness (CCC = 0.989). A moderately strong and significant correlation was found between the CIEu* chromaticity values and the analogue data (R = 0.795, p = 0.000) at each measurement session (from baseline to 1 day, 1 week, and 1, 3 and 6 months of overnight wear). Conclusions: This new standardized and objective method of measuring bulbar redness has great potential to replace subjective grading scales, especially with multi-centre studies, where variability between investigators occurs. This method may also detect smaller changes between visits or between eyes. Crown Copyright © 2007.

Srinivasan,S., Chan,C., Jones,L. Apparent time-dependent differences in inferior tear meniscus height in human subjects with mild dry eye symptoms Clinical and Experimental Optometry 2007;90(5):345-350 [ Show Abstract ]

PURPOSE: The aim of the study was to track the volume of tears contained in the inferior tear meniscus over the course of the day in subjects with symptoms of mild dry eye and a control asymptomatic group. METHODS: Forty non-contact lens-wearing subjects (aged 27 +/- 6 years) were enrolled in this investigator-masked study. They were divided into 'dry eye' (DE) and 'non-dry eye' (NDE) individuals based on their responses to the Allergan Subjective Evaluation of Symptoms of Dryness (SESOD) questionnaire. Measurement of the tear meniscus height (TMH) was undertaken on the centre of the right eye at 9:00 am, noon, 3:00 pm, 6:00 pm and 9:00 pm on the lower lid using a non-contact, non-invasive optical coherence tomographer (OCT). The TMH was determined from scanned images using customised software. RESULTS: A monotonous and significant reduction in the central TMH occurred over the course of the day in both groups (p < 0.05), with the values constantly decreasing (NDE = 0.162 to 0.125 mm; DE = 0.154 to 0.121 mm). While the TMH values in the DE group were always lower than the NDE group, these were not significantly different at any time (p > 0.05). CONCLUSIONS: A diurnal reduction in tear volume, as assessed by evaluation of the inferior TMH, may be one of the reasons responsible for the common increase in end-of-day ocular dryness symptoms reported by many patients in clinical practice.

Srinivasan,S., Joyce,E., Jones,L. W. Tear osmolality and ferning patterns in postmenopausal women Optometry and Vision Science 2007;84(7):588-592 [ Show Abstract ]

PURPOSE: To compare tear osmolality and ferning patterns in postmenopausal women (PMW) with and without dry eye symptoms. METHODS: Thirty-seven healthy PMW (>50 years of age), not on hormone replacement therapy, were categorized as being symptomatic or asymptomatic of dry eye based on their responses to an Allergan "Single-Item Score Dry Eye Questionnaire" (SIDEQ). They subsequently completed the Allergan "Ocular Surface Disease Index" (OSDI) questionnaire. Tear samples were collected from participants to evaluate osmolality and ferning patterns. A novel freezing point depression osmometer (Advanced Instruments Inc., Model 3100 Tear Osmometer), was used to measure the osmolality of the tear film. The tear ferning test was performed and evaluated for the quality of ferning based on the Rolando grading system. RESULTS: SIDEQ responses revealed 21 symptomatic and 16 asymptomatic participants. The OSDI total score was 6.5 +/- 5.9 for the non-dry-eyed (NDE) group and 25.7 +/- 12.4 for the dry-eyed (DE) group. The subscores for the DE group were significantly greater than the NDE group (p < 0.001). Osmolality values in DE individuals were significantly different from NDE (328.1 +/- 20.8 vs. 315.1 +/- 11.3 mOsm/kg; p = 0.02). Fifty percent of the DE participants showed type II ferning patterns and 29% of the DE participants showed type III ferning patterns, whereas the NDE participants showed either type I (44%) or II (66%) ferning patterns. There was a significant difference between the DE and NDE participants for the ferning patterns (p = 0.019). There was no significant correlation between tear osmolality and tear ferning (DE: r = 0.12; p > 0.05, NDE: r = -0.17; p > 0.05). CONCLUSIONS: Osmolality in mild and moderately DE PMW is higher than in NDE PMW and tear ferning is a rapid, simple, noninvasive laboratory procedure that indicates altered tear quality in PMW with symptoms of dry eye.

Subbaraman,L. N., Glasier,M. A., Senchyna,M., Sheardown,H., Jones,L. Extraction efficiency of an extraction buffer used to quantify lysozyme deposition on conventional and silicone hydrogel contact lens materials Eye and Contact Lens 2007;33(4):169-173 [ Show Abstract ]

PURPOSE: Extracting lysozyme from Food and Drug Administration group IV etafilcon lenses by using 0.2% trifluoroacetic acid and acetonitrile (TFA/ACN) is a well-established procedure. TFA/ACN has been the extraction buffer of choice for extracting proteins from silicone hydrogel contact lenses. The purpose of this study was to determine the efficiency of TFA/ACN in extracting lysozyme from silicone hydrogel and etafilcon lenses by using an in vitro model. METHODS: ACUVUE 2, Focus NIGHT & DAY, O2 Optix, PureVision, and ACUVUE Advance lenses were incubated in simple lysozyme solution and a complex artificial tear solution consisting of multiple tear components containing lysozyme labeled with iodine 125. All the silicone hydrogel lenses were incubated for 28 days, whereas the ACUVUE 2 lenses were incubated for 7 days at 37 degrees C with constant rotation. After the incubation period, radioactive counts were determined, and the lenses were placed in an appropriate volume of the buffer for 24 hours in darkness. The lenses were removed from the buffer, and radioactive counts were determined again. RESULTS: Extraction efficiencies for lysozyme from the artificial tear solution were 97.2% +/- 1.2% for ACUVUE 2, 64.3% +/- 6.2% for Focus NIGHT & DAY, 62.5% +/- 5.6% for O2 Optix, 53.5% +/- 5.8% for PureVision, and 89.2% +/- 3.4% for ACUVUE Advance. Results were similar for the lysozyme extracted after incubating in the simple lysozyme solution. CONCLUSIONS: TFA/ACN is extremely efficient at extracting lysozyme deposited on etafilcon lenses. However, it does not extract all the lysozyme deposited on silicone hydrogel lenses, and alternative extraction procedures should be sought.

Suwala,M., Glasier,M. -A, Subbaraman,L. N., Jones,L. Quantity and conformation of lysozyme deposited on conventional and silicone hydrogel contact lens materials using an in vitro model Eye and Contact Lens 2007;33(3):138-143 [ Show Abstract ]

PURPOSE: To determine the activity of hen egg lysozyme (HEL) deposited on conventional and silicone hydrogel contact lens materials by using an in vitro model. METHODS: ACUVUE 2 (etafilcon A), PureVision (balafilcon A), ACUVUE Advance (galyfilcon A), Focus NIGHT & DAY (lotrafilcon A), O2 Optix (lotrafilcon B), Proclear (omafilcon A), and ACUVUE OASYS (senofilcon A) contact lenses were deposited in vitro in a phosphate-buffered solution (PBS) containing 2 mg/mL HEL. Lenses were briefly rinsed in PBS to remove unbound material and extracted in a mixture of acetonitrile and trifluoroacetic acid. After lyophilization, extracts were examined for lysozyme activity by micrococcal assay and total protein by Western blot. RESULTS: In terms of total protein accumulation, ACUVUE 2 showed the most, with 1,800 microg per lens. Proclear was next, with 68 microg per lens, and Focus NIGHT & DAY showed the least, with 2 microg per lens. ACUVUE Advance, ACUVUE OASYS, and O2 Optix accumulated similar amounts of lysozyme, at approximately 6 microg per lens. Lysozyme deposited on ACUVUE 2 showed the greatest activity (91% +/- 5%), and this result was statistically different from all other lens types (P<0.001). Lysozyme deposited on Focus NIGHT & DAY (24% +/- 5%) and O2 Optix (23% +/- 11%) showed the lowest activity. Lysozyme deposits on other lens materials showed intermediate activity (ACUVUE Advance, 60% +/- 15%; ACUVUE OASYS, 51% +/- 9%; PureVision, 58% +/- 8%; and Proclear, 38% +/- 3%). CONCLUSIONS: Silicone hydrogel lenses acquire less lysozyme deposit than conventional group II (Proclear) or group IV (ACUVUE 2) lenses do, and the levels of activity of the lysozyme are highly variable between materials.

Woods,C. A., Jones,D. A., Jones,L. W., Morgan,P. B. A seven year survey of the contact lens prescribing habits of Canadian optometrists Optometry and Vision Science 2007;84(6):505-510 [ Show Abstract ]

PURPOSE: Little is known about the contact lens prescribing habits of optometrists in North America. The purpose of this survey was to obtain data on the types of lenses and solutions prescribed by Canadian optometrists. METHODS: One thousand Canadian optometrists were surveyed annually over seven consecutive years (2000 to 2006; n = 7000) on their contact lens prescribing preferences. Each survey requested a range of information about the contact lenses prescribed to the first 10 patients after its receipt. RESULTS: Over this time period, 1008 (14.4%) of the surveys were returned, providing data on 9383 fits. During the seven-year period, the ratio of male:female fits was 1:2 (3123:6217, 43 not reported), with a mean age of 31.3 +/- 13.6 years (range 2 to 82 years). The ratio of new fits to refits was 2:3 (3780:5518, 85 not reported), with 91.3% of all fits being soft contact lenses (SCL). Of the SCL fits, 59.5% were spherical, 28.5% toric, 9.7% multifocal, and 2.3% cosmetic tints. Gas permeable (GP) fits were 46.6% spherical, 18.6% toric, 19.5% multifocal, and 6.6% were for orthokeratology (OK). Over the seven-year period, SCL prescribed for continuous wear (CW) increased from 3.2% to 14.3% between 2000 and 2004 and reduced to 8.1% in 2006, for all fits. The use of mid-water content (MWC) materials decreased from 34.6% to 2.7% and the use of silicone hydrogel (SH) lenses increased from 61.4% to 96.2%, for all CW fits. GP lens continuous wear increased from 0.7% to 30.6% of all GP lens fits by 2006. Daily wear (DW) of SH lenses decreased from 49.6% (2000) to 33.7% (2004) and then increased to 86.1% in 2006, for SH fits. MWC SCL fit on a monthly planned replacement (PR) basis reduced in popularity over the seven-year period (75.0% to 39.9%) and in 2006 more patients were fit overall with SH lenses (42.9%). The use of non-PR SCL declined from 20.5% to 4.5% of all fits. Fitting of low-water content lenses also declined (15.1% to 7.0%). High-water content (5.4% to10.2%) and SH lenses (5.4% to 42.9%) both increased. By 2006, the majority of GP lenses fit were with high Dk (HDK) materials (50.3%). CONCLUSIONS: The preferred contact lens modality for Canadian optometrists appears to be DW SCL, which are replaced monthly. The proportion of lenses used for CW peaked in 2004, with SH SCL being the preferred material. The market share for GP lenses remains relatively unchanged, with an increasing proportion used for OK and CW. The launch of DW SH lenses in 2004 resulted in a marked increase in their reported fits, with a similar effect following the launch of a HDK GP lens material for CW.

2006

Begley,C. G., Himebaugh,N., Renner,D., Liu,H., Chalmers,R., Simpson,T., Varikooty,J. Tear breakup dynamics: A technique for quantifying tear film instability Optometry and Vision Science 2006;83(1):15-21 [ Show Abstract ]

PURPOSE: The purpose of this study was to develop a novel, quantitative measurement of tear film breakup dynamics (TBUD) to study the phenomenon of tear breakup in dry eye and control subjects and its impact on dry eye symptoms. METHODS: Ten control and 10 dry eye subjects completed the Dry Eye (DEQ) and other questionnaires. After the instillation of sodium fluorescein, subjects kept the tested eye open for as long as possible, similar to a staring contest, while tear film breakup was videotaped (S-TBUD). The maximum blink interval (MBI) and tear breakup time (TBUT) were measured from digital movies by a masked observer. Individual frames of movies were converted to gray-scale images, maps of relative tear film fluorescence were generated, and the total area of tear breakup (AB) of the exposed cornea was quantified. RESULTS: On average, dry eye subjects demonstrated a higher AB and shorter TBUT and MBI, but only the AB was significantly different (p = 0.023). Subjects most often used the descriptors stinging and burning to describe their sensations during staring trials. The AB showed a high correlation between eyes and with some DEQ symptom measures. CONCLUSIONS: These methods allow objective quantification and tracking of the phenomenon of tear breakup. Our results suggest that tear breakup stresses the corneal surface, resulting in stimulation of underlying nociceptors. The tear film of dry eye subjects was less stable than controls. They had a larger AB measured from the last video frame before MBI (i.e., just before blinking) than did controls. This perhaps reflects adaptation to the repeated stress of tear instability in dry eye.

Dumbleton,K., Keir,N., Moezzi,A., Feng,Y., Jones,L., Fonn,D. Objective and subjective responses in patients refitted to daily-wear silicone hydrogel contact lenses Optometry and Vision Science 2006;83(10):758-768 [ Show Abstract ]

PURPOSE. Silicone hydrogel (SiH) lenses offer many physiological advantages for daily wear (DW) in addition to the continuous-wear modality for which they were originally developed. The purpose of this study was to investigate the clinical performance and physiological responses in a group of successful long-term wearers of conventional hydrogel lenses when refitted with DW SiH contact lenses. METHODS. Eighty-seven successful soft lens wearers (8.4 ± 4.7 years of prior lens wear) participated in this study. Bulbar and limbal hyperemia were subjectively graded and digitally photographed for subsequent masked objective evaluation. Subjective symptoms were scored using visual analog scales. In addition, refractive error, corneal curvature, and corneal thickness were measured. All subjects were refitted with Focus Night & Day (lotrafilcon A) SiH lenses; however, to reduce the potential for bias, they were informed that they were being randomly assigned to wear either low oxygen permeability (Dk) lenses or high Dk SiH lenses and were "masked" as to their lens assignment. Subjects returned after 1 week, 1 month, and 2 months of DW, at which time all gradings, photographs, and measurements were repeated. End-of-day subjective symptoms were also graded periodically during the study. RESULTS. Ninety-three percent of subjects were successfully refitted. Both objective and subjective evaluations showed that bulbar and limbal hyperemia decreased significantly in all quadrants during the study (p < 0.001), particularly for those subjects with greater baseline hyperemia (p < 0.001). Subjects reported a concurrent reduction in end-of-day dryness and improved end-of-day comfort compared with their habitual lenses (p < 0.001). No significant changes in refractive error, tarsal papillary response, corneal curvature, or corneal thickness were found during the study. CONCLUSIONS. Hyperemia in contact lens wearers may be attributed to a number of factors, including hypoxia. Refitting existing low Dk lens wearers with SiH lenses on a DW basis can result in a decrease in hyperemia, which may be significant for some subjects and also results in improvements in symptoms of dryness and discomfort. © 2006 American Academy of Optometry.

Haque,S., Simpson,T., Jones,L. Corneal and epithelial thickness in keratoconus: A comparison of ultrasonic pachymetry, Orbscan II, and optical coherence tomography Journal of Refractive Surgery 2006;22(5):486-493 [ Show Abstract ]

PURPOSE: To compare corneal thickness measurements in individuals with keratoconus using optical coherence tomography (OCT), Orbscan II, and ultrasonic pachymetry and to measure epithelial and stromal thickness in these individuals using OCT. METHODS: Twenty individuals with keratoconus and 20 controls (without keratoconus) were enrolled. The Orbscan II was used to locate the steepest area of the cornea, which was taken to represent the cone apex. Each instrument was used to obtain four total corneal thickness measurements-from the cone apex, corneal center, mid-nasal, and mid-temporal cornea. Optical coherence tomography scans were analyzed to provide epithelial and stromal thickness readings. RESULTS: In individuals with keratoconus, mean central corneal thickness (CCT) measured by ultrasonic pachymetry, Orbscan, and OCT was 494.2±50.0 μm, 438.6±47.7 μm, and 433.5±39.7 μm, respectively. The central keratoconic cornea was 57.7 μm thinner than the normal cornea (post-hoc P.05). CONCLUSIONS: Ultrasonic pachymetry produced the highest corneal thickness readings in the center and apex, compared to Orbscan II and OCT. Centrally, the total cornea, epithelium, and stroma were thinner in individuals with keratoconus than in normal individuals.

Lu,F., Simpson,T., Fonn,D., Sorbara,L., Jones,L. Validity of pachymetric measurements by manipulating the acoustic factor of Orbscan II Eye and Contact Lens 2006;32(2):78-83 [ Show Abstract ]

PURPOSE. To assess the validity of pachymetric measurements by examining the constancy of the acoustic factor (AF) of the Orbscan II (Orbtek, Bausch & Lomb, Rochester, NY) after overnight rigid gas-permeable (RGP) contact lens wear. METHODS. Twenty participants wore CRT (Paragon Vision Sciences, Mesa, AZ) HDS 100 contact lenses on one eye and control lenses on the contralateral eye for one night while sleeping. Another 24 participants wore CRT lenses on both eyes for one night. Central corneal thickness was measured using optical coherence tomography and Orbscan II on the night before lens use, immediately after lens removal on the following morning, and 1, 3, 6, and 12 hours later. By using optical coherence tomography as a reference, the adjusted AF was calculated by using a least squares method over time. RESULTS. The adjusted AF depended on the corneal thickness in normally hydrated corneas. The adjusted AF and the percentage change of the adjusted AF varied before and after overnight lens wear. There was a strong and significant correlation between the corneal swelling and the percentage change of the adjusted AF (all r at least 0.91, P<0.05). CONCLUSIONS. The adjusted AF is a variable, not a constant. The AF is a function of the corneal thickness and its alteration with, for example, corneal swelling. The validity of the adjusted Orbscan II pachymetric measures using a single AF is untenable. © 2006 Lippincott Williams & Wilkins, Inc.

Moezzi,A. M., Fonn,D., Simpson,T. L. Overnight corneal swelling with silicone hydrogel contact lenses with high oxygen transmissibility Eye and Contact Lens 2006;32(6):277-280 [ Show Abstract ]

PURPOSE. To compare central corneal swelling after 8 hours of sleep in eyes wearing 2 different silicone hydrogel lenses with high oxygen transmissibility. METHODS. Twenty neophyte subjects were randomly assigned to wear a comfilcon A lens (CooperVision Inc) in one eye and a lotrafilcon A lens (CIBA Vision) in the contralateral eye for an 8-hour overnight period. The study was repeated with another 20 neophyte subjects wearing comfilcon A in one eye only and no lens in the contralateral control eye. Central corneal thickness was measured with optical pachometry before lens insertion, immediately after lens removal on waking, at 20 and 40 minutes, 1 hour, 2 hours and 3 hours. RESULTS. There was no significant difference between the amount of overnight central corneal swelling induced by the 2 lenses (4.1% ± 1.9% with comfilcon A vs. 4.0% ± 1.7% with lotrafilcon A; P>0.05). The swelling of the comfilcon A lens-wearing eyes was significantly higher than that found in the non-lens-wearing contralateral eyes (4.5% ± 2.1% vs. 3.0% ± 1.7%; P<0.05). CONCLUSIONS. The same amount of overnight corneal swelling was induced by the 2 study lenses. The higher overnight swelling observed with the comfilcon A lenses compared to the non-lens-wearing eyes is similar to that reported in the literature for studies using lotrafilcon A lenses. © 2006 Lippincott Williams & Wilkins, Inc.

Moezzi,A. M., Sin,S., Simpson,T. L. Novel pachometry calibration Optometry and Vision Science 2006;83(6):E366-E371 [ Show Abstract ]

PURPOSE: The purpose of this study was to develop a simple method for cross-calibrating instruments that measure corneal thickness. METHODS: Fourteen rigid lenses of different thicknesses were manufactured using a material with refractive index of 1.376. Center thickness of the lenses (CT) was measured using a computerized optical pachometer (OP), two optical coherence tomographers (OCTs), and a confocal microscope (CM). Accuracy of measurements was compared between the four instruments. RESULTS: Before calibrating the machines, there was a significant effect of the measurement device (p < 0.05). The differences between instruments were eliminated (p > 0.05) after applying calibration equations for each device. In addition, after each instrument was calibrated with lenses of 1.376 refractive index, there was no significant difference (p > 0.05) between measured values of lens center thickness by OP, each OCT, CM, and the physical center thickness of the lenses. CONCLUSIONS: Using calibration lenses with the same refractive index as the cornea (1.376) allows rapid and simple calibration of the pachometers so that corneal thickness measurements from different devices can be used interchangeably.

Sin,S., Simpson,T. L. The repeatability of corneal and corneal epithelial thickness measurements using optical coherence tomography Optometry and Vision Science 2006;83(6):360-365 [ Show Abstract ]

PURPOSE.: The purpose of this study is to examine within and between session repeatability of clinical optical coherence tomography (OCT) imaging for anterior segment morphometry. METHODS.: Images of the corneal apex of each eye in 18 subjects were obtained using a Humphrey Zeiss OCT imager. Subjects viewed a target positioned to ensure that scans were orthogonal to the ocular surface and each image, consisting of 100 adjacent sagittal scans, analyzed using custom software. Repeatability data were analyzed using intraclass correlation coefficients (ICCs), correlation coefficient of concordance (CCC, perfect test-retest agreement ICC or CCC = 1.0), and coefficients of repeatability (COR, 95% confidence interval of test-retest differences). To account for each eye, the multivariate repeatability statistic Iota was estimated. RESULTS.: Mean central corneal and epithelial thickness of 32 eyes (OD and OS combined) is 536 ± 26 μm (standard deviation [SD]) and 52 ± 3 μm (SD) with 5th and 95th percentile thicknesses of 507 and 591 μm for central cornea and 48 and 57 μm for central epithelial. Worst case within session repeatability was defined as repeatability between images with greatest differences in mean thickness within a session. Corneal thickness worst case ICC was 0.95 and COR was ± 9.98 μm. Epithelium worst case ICC was 0.36, CCC was 0.12, and COR was ± 11.11 μm. First image between session corneal thickness had an ICC = 0.98 and a COR = 10.83 μm, whereas epithelium ICC = 0.38, CCC = 0.37, and COR was ± 12.84 μm. When we compared the average of the first three tests with the first three retest images, corneal ICC was 0.98 and COR was ± 10.64 μm and epithelium ICC = 0.73, CCC = 0.72, and COR was ± 6.53 μm. Iota (multivariate repeatability, using eye as a factor) for the cornea was at least 0.96 (worst case) and increased to at least 0.98 when within-session image data were averaged. Iota for epithelium measures ranged from 0.29 when first images were compared with 0.57 when within-session image data were averaged. CONCLUSIONS.: There is very good repeatability of corneal thickness measurement using OCT; even the worst case measurements are similar between sessions. On the other hand, this is not the case for epithelium measurements, and if multiple images within a session are acquired, the worst case results demonstrate how important it is to optimize each OCT scan and also average multiple scans to maximize intersession repeatability. Copyright © 2006 American Academy of Optometry.

Subbaraman,L. N., Bayer,S., Glasier,M. -A, Lorentz,H., Senchyna,M., Jones,L. Rewetting drops containing surface active agents improve the clinical performance of silicone hydrogel contact lenses Optometry and Vision Science 2006;83(3):143-151 [ Show Abstract ]

PURPOSE: The purpose of this study was to investigate the impact of using a rewetting drop (RWD) containing surface active agents (OPTI-FREE RepleniSH; Alcon, Fort Worth, TX) on the clinical performance and protein deposition when using a continuous-wear (CW) silicone hydrogel (SH) contact lens. METHODS: Subjects wore lotrafilcon A SH lenses on a 30-day CW basis for two consecutive 1-month periods while inserting either 0.9% unpreserved unit-dose saline (control) or multidose OPTI-FREE RepleniSH (test RWD). Subjective comfort and symptoms were assessed after 2 and 4 weeks with each product. After 1 month of wear with each product, lenses were collected and analyzed in the laboratory for total protein, total lysozyme, and percentage of denatured lysozyme. RESULTS: Symptoms of dryness and comfort varied across the day regardless of drop type (p < 0.001) with dryness being maximal on waking, least in the middle of the day, and increased towards the evening. The test RWD provided greater comfort on insertion (p = 0.02), better visual quality (p < 0.01), and less mucous discharge on waking (p = 0.02) than the control product. Lysozyme deposition was significantly reduced after the use of the test RWD as compared to saline (0.73 +/- 0.5 microg/lens vs. 1.14 +/- 0.7 microg/lens; p < 0.001) as was total protein deposition (1.17 +/- 0.7 microg/lens vs. 1.86 +/- 0.8 microg/lens; p < 0.001). Lysozyme denaturation was also reduced with the use of the test RWD compared with the control (76 +/- 10% vs. 85 +/- 7%; p < 0.01). CONCLUSIONS: The use of a RWD containing surface active agents provided greater subjective satisfaction, reduced lysozyme and total protein deposition, and reduced denatured lysozyme than a RWD containing saline alone.

Subbaraman,L. N., Glasier,M. -A, Senchyna,M., Sheardown,H., Jones,L. Kinetics of in vitro lysozyme deposition on silicone hydrogel, PMMA, and FDA groups I, II, and IV contact lens materials Current eye research 2006;31(10):787-796 [ Show Abstract ]

We sought to compare the kinetics of in vitro lysozyme deposition on silicone hydrogel (SH), polymethyl methacrylate (PMMA), and FDA groups I, II, and IV contact lenses. Lenses were incubated in 125I-labeled lysozyme for time periods ranging from 1 hr to 28 days, and radioactive counts were determined. SH lenses and PMMA deposited less lysozyme than conventional hydrogel lenses (p < 0.05). Lysozyme accumulation on group IV lenses reached a maximum on the seventh day and then plateaued, whereas on groups I, II, and SH lenses, deposition continued to increase across all time periods, reiterating that kinetics of lysozyme deposition is highly material dependent.

Teichroeb,J. H., Forrest,J. A., Ngai,V., Jones,L. W. Anomalous thermal denaturing of proteins adsorbed to nanoparticles European Physical Journal E 2006;21(1):19-24 [ Show Abstract ]

We have used localized surface plasmon resonance (LSPR) to monitor the structural changes that accompany thermal denaturing of bovine serum albumin (BSA) adsorbed onto gold nanospheres of size 5nm-60nm. The effect of the protein on the LSPR was monitored by visible extinction spectroscopy. The position of the resonance is affected by the conformation of the adsorbed protein layer, and as such can be used as a very sensitive probe of thermal denaturing that is specific to the adsorbed protein. The results are compared to detailed calculations and show that full calculations can lead to significant increases in knowledge where gold nanospheres are used as biosensors. Thermal denaturing on spheres with diameter > 20 nm show strong similarity to bulk calorimetric studies of BSA in solution. BSA adsorbed on nanospheres with d ≤ 15nm shows a qualitative difference in behavior, suggesting a sensitivity of denaturing characteristics on local surface curvature. This may have important implications for other protein-nanoparticle interactions. © EDP Sciences, Società Italiana di Fisica and Springer-Verlag 2006.

2005

Chalmers,R. L., Begley,C. G., Edrington,T., Caffery,B., Nelson,D., Snyder,C., Simpson,T. The agreement between self-assessment and clinician assessment of dry eye severity Cornea 2005;24(7):804-810 [ Show Abstract ]

Purpose: The purpose of this analysis was to measure the degree of agreement between clinicians' assessment and subjects' self-assessment of dry eye severity in a cross-sectional, observational dry eye study. A secondary purpose was to identify the role of gender and age in that concordance. Methods: In a cross-sectional observational study, 162 dry eye subjects and 48 controls were recruited from clinical databases of ICD-9 codes in 6 clinical sites. Before examination, subjects gave a global self-assessment of the severity of their dry eye from "none" to "extremely severe." After a clinical examination that included dry eye tests, the clinician discussed the subjects' symptoms and then gave global clinician assessment of dry eye from "none" to "severe." We measured the degree of agreement in these global measures. Results: Although the correlation and agreement between clinician and self-assessment was significant (r = 0.720, P = 0.000; weighted K = 0.471; 95% CI = 0.395, 0.548; P = 0.000), the clinician assessment underestimated the severity in 40.9% of the subjects by at least 1 grade compared with the subjects' self-assessment. Over 54% of subjects over age 65 and 43% of the female subjects had their condition underestimated by the clinician (P < 0.05). Conclusions: Clinicians often relatively underestimated the severity of the subjects' self-assessment of dry eye in this clinical study, especially among the elderly and women. Eye care practitioners need better, more quantitative tools for the assessment of ocular surface symptoms to improve the concordance in severity assessment and to meet the needs of this symptomatic patient population by offering them appropriate treatments. Copyright © 2005 by Lippincott Williams & Wilkins.

Feng,Y., Simpson,T. L. Comparison of human central cornea and limbus in vivo using optical coherence tomography Optometry and Vision Science 2005;82(5):416-419 [ Show Abstract ]

Purpose. The purpose of this study was to compare central corneal and limbal total and epithelial thickness using a commercially available optical coherence tomographer. Methods. A Humphrey-Zeiss Optical Coherence Tomographer (OCT [Carl Zeiss, Meditec, Dublin, CA]) was used to obtain corneal images from 10 subjects. Central corneal and limbal total and epithelial thickness of both eyes were measured using the OCT. Each OCT image comprised 100 measurements, 10 nasal, 10 central, and 10 temporal measurements from each image were analysed. Results. The central corneal and epithelial thickness of the right and the left eyes were 507.9 ± 35.8 μm, 58.4 ± 2.5 μm, 506.9 ± 37.4 μm, and 58.5 ± 2.5 μm, respectively. There were no differences between eyes (p > 0.05). The nasal and temporal limbal total and epithelial thickness of the right and left eyes were 703.8 ± 32.1 μm, 704.9 ± 31.0 μm, 76.8 ± 3.5 μm, 77.9 ± 2.9 μm, 704.4 ± 31.8 μm, 706.3 ± 32.5 μm, 77.5 ± 2.8 μm, and 77.8 ± 2.5 μm, respectively. There were no differences between the nasal and temporal total and epithelial thickness of both eyes (p > 0.05). However, there was a statistical difference between the central corneal and limbal total and epithelial thickness (both p < 0.05). Conclusions. Central cornea and limbus are measurably different using OCT. Central cornea is thinner than limbus for both total thickness and epithelial thickness. There is no difference between eyes of central corneal and limbal total and epithelial thickness. Optical Coherence Tomography is a useful instrument for in vivo human limbal morphometry. Copyright © 2005 American Academy of Optometry.

Feng,Y., Simpson,T. L. The inhibitory interaction between human corneal and conjunctival sensory channels Investigative Ophthalmology and Visual Science 2005;46(4):1251-1255 [ Show Abstract ]

PURPOSE. To explore human corneal and conjunctival sensory channels at suprathreshold level. METHODS. Ten healthy human subjects participated in the study. The Belmonte pneumatic esthesiometer was used to apply mechanical and chemical stimuli to the central cornea and temporal conjunctiva of the left eye. Stimuli were applied in a paired and unpaired way for conjunctival stimulation. A 100-point visual analog scale (VAS) was used to rate the intensity of the stimulus. RESULTS. The magnitudes of the sensation evoked from the conjunctiva were different when using different methods for presenting stimuli to the ocular surface. When stimuli were applied to the conjunctiva alone, the magnitude of the sensation was stronger than when the stimuli were applied in pairs to the cornea and conjunctiva for both mechanical (P = 0.04) and chemical (P = 0.02) stimulation. CONCLUSIONS. The relatively strong discomfort evoked from the cornea appears to suppress partially the relatively weaker conjunctival stimulation. This manifested as the conjunctival sensory transducer function being shallower (less intense sensation) when immediately preceded by corneal stimulation than when the conjunctival sensory transducer functions were measured alone (unpaired). The underlying mechanism could be adaptation or some other inhibitory effect, such as diffuse noxious inhibitory control. At some level therefore, corneal and conjunctival sensory channels are not independent. Copyright © Association for Research in Vision and Ophthalmology.

Fonn,D., Bruce,A. S. A review of the Holden-Mertz criteria for critical oxygen transmission Eye and Contact Lens 2005;31(6):247-251 [ Show Abstract ]

Purpose. Holden and Mertz established the foundations for the new generation of silicone hydrogel contact lenses for daily and extended wear in 1984. Absence of lens-induced corneal swelling was their premise and although this was possible with daily wear, the goal with extended wear seemed almost impossible because of the limitation of hydrogel materials. Experience with extended and daily wear of disposable contact lenses during the last 2 decades and, more recently, with silicone hydrogels has led to the reconsideration of the validity of the findings of Holden and Mertz. Results. A pivotal influence on the Holden and Mertz critical Dk/t value for closed-eye lens wear was exerted by two numbers: the no-lens wear corneal edema level (4%) and the silicone lens data point (Dk/t of 182 × 10-9, closed-eye edema level of 2.6%). Subsequent publications appear to give a more accurate assessment of the no-lens closed-eye corneal edema level, and there are also more recent measurements of silicone hydrogel lens Dk/t and corneal edema responses. Conclusions. It now appears that the Holden and Mertz criteria for extended-wear critical Dk/t should be revised upwards to at least 125 × 10 -9. © 2005 Contact Lens Association of Ophthalmologists, Inc.

Fonn,D., Sweeney,D., Holden,B. A., Cavanagh,D. Corneal oxygen deficiency Eye and Contact Lens 2005;31(1):23-27 [ Show Abstract ]

Objectives. To compare the ocular effects of low Dk hydrogel and high Dk silicone hydrogel contact lenses. Methods. A review of recent literature was conducted to determine the effects of wearing low and high Dk soft lenses on corneal swelling, vascular response, refractive error and the corneal epithelium. Results. High Dk silicone hydrogel contact lenses became available for research and clinical practice almost 10 and 5 years ago respectively. During that time many studies have been conducted and it has been demonstrated repeatedly how much improvement there has been to the physiological response of the eye particularly when wearing the lenses on an overnight basis. Conclusions. Although silicone hydrogels only constitute about 2% of current wearers, their positive effects on the eye compared with low Dk hydrogel lenses should make them the most dominant lenses in the near future. © 2005 Contact Lens Association of Ophthalmologists, Inc.

Henderson,L., Bond,D., Simpson,T. The association between eye color and corneal sensitivity measured using a Belmonte esthesiometer Optometry and Vision Science 2005;82(7):629-632 [ Show Abstract ]

Purpose. The purpose of this study is to determine the association between corneal sensitivity measured using a pneumatic esthesiometer and eye color quantified objectively. Methods. Twenty subjects had ocular surface sensitivity measured using a Belmonte esthesiometer. An ascending method of limits followed by the method of constant stimuli were used to estimate 1) cold detection thresholds, 2) discomfort detection thresholds (both using pneumatic stimuli at 20°C, 3) mechanical detection thresholds using pneumatic stimuli at 50°C (ocular surface temperature approximately 33°C), and 4) percent CO2 chemical detection thresholds using 50°C pneumatic stimuli at flow rates set at half of each subject's pneumatic detection threshold (therefore detected by the chemical content and not the mechanical content). Eye color was estimated 1) clinically by two observers ranking the color (light to dark) of digital images of each subject's iris, 2) photometrically by measuring iris luminance, and 3) using chromaticity obtained from a Photo Research 650 spectroradiometer with controlled illumination. Correlation and linear and nonlinear regression analyses were used to examine relationships between variables. Results. There were no associations between eye color (determined clinically or objectively) for mechanical and chemical detection thresholds (best r2 = 0.15, all p > 0.05). There was a significant linear association between 20° detection thresholds and eye color (r2 = 0.39), which was substantially improved with a two-line function (part level and part increasing linearly, r2 = 0.65). Conclusions. We were generally unable to demonstrate the relationship between eye color and sensitivity reported previously using a Cochet-Bonnet esthesiometer. However, for a subset of subjects with palest irises, there appears to be a linear association between eye color and sensitivity to cooling stimuli. Copyright © 2005 American Academy of Optometry.

Mertzanis,P., Abetz,L., Rajagopalan,K., Espindle,D., Chalmers,R., Snyder,C., Caffery,B., Edrington,T., Simpson,T., Nelson,J. D., Begley,C. The relative burden of dry eye in patients' lives: Comparisons to a U.S. normative sample Investigative Ophthalmology and Visual Science 2005;46(1):46-50 [ Show Abstract ]

PURPOSE. To assess the relative burden of dry eye in daily life by comparing Short Form-36 (SF-36) responses from individuals with and without dry eye against U.S. norms. METHODS. Assessment of 210 people, 130 with non-Sjögren's keratoconjunctivitis sicca (non-SS KCS), 32 with Sjögren's Syndrome (SS), and 48 control subjects. The study population data and published normative SF-36 data were compared. Dry eye severity was assessed by recruited severity (control, non-SS KCS, SS), patient self-report (none, very mild/mild, moderate, severe/extremely severe), and clinician-report (none, mild, moderate, severe). Age- and gender-matched norms were compared with all defined severity groups. RESULTS. Compared with the norms, control subjects scored higher on all SF-36 scales. Effect size (ES) ranged from 0.15 to 0.52. Non-SS KCS patients had lower Role-Physical (ES = -0.07), Bodily Pain (ES = -0.08), and Vitality (ES = -0.11) scores, indicating more dry eye impact on those areas versus the norm. All SF-36 scale scores except Mental Health (ES = 0.12) were lower in the SS group than the adjusted norm (ES range: -0.16 to -0.99). Regardless of severity classification, mild patients consistently had lower Role-Physical and Bodily Pain scores than the norm, suggesting impact on daily roles (ES < 0.2). Patients with moderately severe disease also experienced less vitality and poorer general health. The group with severe disease scored lower than the norm across all domains (ES range: -0.14 to -0.91) except Role-Emotional (ES = 0.13) and Mental Health (ES = 0.23). CONCLUSIONS. These results indicate dry eye's negative impact on everyday life, particularly in daily activities. Further research using disease-specific measures to examine dry eye's impact is underway.

Sorbara,L., Fonn,D., Simpson,T., Lu,F., Kort,R. Reduction of myopia from corneal refractive therapy Optometry and Vision Science 2005;82(6):512-518 [ Show Abstract ]

Purpose. The purpose of the study was to monitor the efficacy of corneal refractive therapy (CRT) lenses to reduce myopia over a 4-week period. Refractive error, keratometry, high and low contrast acuity, and subjective vision after 28 days of using CRT contact lenses were measured. Methods. Twenty-three myopes wore CRT HDS lenses, Dk = 100. The Nikon autokefractor/keratometer was used to measure the refractive error and keratometric changes. Visual acuity was measured using computerized high and low contrast charts and the subjects completed visual analog scales characterizing their vision on a daily basis. Measurements were performed at baseline (before lens insertion before sleep), immediately after lens removal the next morning and at 1, 3, 7, and 14 hours after eye opening. Measurements were made on the days following 1, 4, 10, and 28 nights of lens wear. After 72 hours of no lens wear, these parameters were again measured to assess corneal recovery. Results. The pretreatment manifest refraction (mean of OD and OS ± standard deviation [SD]) was -2.72 DS ± 1.06 and -0.55 DC ± 0.40. Myopic spherical equivalent refractive error (± SD) decreased by 1.30 DS ± 0.53 (range 0-3 D) immediately after lens removal on day 1 and by 2.59 DS ± 0.77 by day 28 (range 1.25-3.88 D). The cylinder remained unchanged. Uncorrected visual acuity improved by 5 lines after one night and reached 0.00 LogMAR (6/6) by day 4. Visual acuity was maintained throughout the day by day 10. The day and time effect of the spherical equivalent change and the central corneal radius of curvature were statistically significant (p < 0.01) up to day 10 and remained the same until day 28. Central (autokeratometer) Ks flattened by 1.28 D ± 1.35 after one night and 2.33 D ± 1.30 by day 28. The subjective vision improved significantly from day 1 to day 28 (p < 0.01) and was maintained throughout the day from day 4 to day 28 (p < 0.01). All measures did not recover completely to baseline after 72 hours of no lens wear. Conclusions. CRT lenses significantly reduced myopia, improved visual acuity and subjective vision, and flattened central corneal curvature. Maximal effect was achieved after 10 days and was maintained for the rest of the study period. Copyright © 2005 American Academy of Optometry.

Srinivasan,S., Joyce,E., Jones,L. W., Senchyna,M. Subconjunctival cyst-like formations following impression cytology Contact Lens and Anterior Eye 2005;28(4):181-184 [ Show Abstract ]

Purpose: To report a case of an unusual adverse event subsequent to undertaking Conjunctival Impression Cytology (CIC). Methods: CIC was un dertaken on a 54-year-old healthy Caucasian female, using a 10 mm Millipore™ membrane on the bulbar conjunctiva. Prior to the CIC procedure, two drops of topical proparacaine (Alcaine®) were instilled and following the procedure two drops of artificial tears (GenTeal®) were administered. Results: The subject reported excessive bulbar conjunctival hyperaemia in the left eye 5 min postprocedure, with no marked pain or discomfort. Slitlamp biomicroscopic evaluation revealed several "bubbles" or cystic formations trapped underneath the conjunctival tissue, in association with moderate to severe bulbar conjunctival redness. These cysts began to regress fairly rapidly and completely disappeared within 1 h. Conclusion: CIC is a useful tool for studying the ocular surface; however, care should be taken while performing this mildly invasive procedure. This is the first report of bubble formation in the conjunctiva following CIC. Subjects should be advised about the short term redness and discomfort that could occur following CIC. © 2005 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Subbaraman,L. N., Glasier,M. -A, Senchyna,M., Jones,L. Stabilization of lysozyme mass extracted from lotrafilcon silicone hydrogel contact lenses Optometry and Vision Science 2005;82(3):209-214 [ Show Abstract ]

PURPOSE: Lysozyme deposits extracted from lotrafilcon silicone hydrogel (SH) contact lens materials demonstrate a loss in total mass as a function of storage time when assessed by Western blotting. This loss represents a potential source of error when quantifying total lysozyme deposition on SH lenses. The purpose of this study was to devise a method whereby lysozyme mass would be preserved over time to allow for its accurate quantitation after its removal from SH lenses. METHODS: Lysozyme deposits from 12 human worn lotrafilcon lenses were extracted using a 50:50 mixture of 0.2% trifluoroacetic acid and acetonitrile. Extracts were lyophilized to dryness, then resuspended in either reconstitution buffer (10 mM Tris-HCl, 1 mM EDTA) or modified reconstitution buffer (reconstitution buffer + 0.9% saline). BIOSTAB Biomolecule Storage Solution (Sigma-Aldrich) was added to one half of the samples from each buffer group. One microliter of each of the samples was immediately subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blotting, whereas the remaining volume was aliquoted and stored at -20 degrees C or -70 degrees C and subjected to the same procedures after 48 h of storage. Comparison of lysozyme band intensity in stored vs. fresh samples enabled calculation of percentage mass loss of lysozyme. RESULTS: Samples stored at -20 degrees C in reconstitution buffer with no BIOSTAB demonstrated a 33% loss in mass over 48 h of storage. Identical samples stored at -70 degrees C in modified reconstitution buffer with BIOSTAB added demonstrated <1% loss in mass. Statistical analysis indicated that buffer composition (p < 0.001), storage temperature (p = 0.04), and addition of BIOSTAB (p < 0.001) were all important in controlling loss of mass over time. CONCLUSION: We have optimized a procedure whereby the extracted mass of lysozyme deposits found on lotrafilcon SH lenses can be preserved, thus enabling accurate quantitation after extraction and resuspension.

Walline,J. J., Holden,B. A., Bullimore,M. A., Rah,M. J., Asbell,P. A., Barr,J. T., Caroline,P. J., Cavanagh,H. D., Despotidis,N., Desmond,F., Koffler,B. H., Reeder,K., Swarbrick,H. A., Wohl,L. G. The current state of corneal reshaping Eye and Contact Lens 2005;31(5):209-214 [ Show Abstract ]

Purpose. The application of contact lenses to alter the shape of the cornea and temporarily reduce or eliminate myopia is known as orthokeratology, corneal refractive therapy, or corneal reshaping. It was first introduced in the 1960s, but high oxygen permeable materials and more sophisticated designs allow patients to wear contact lenses only during sleep, while dramatically improving the predictability and rate of myopia reduction. Many studies have shown that most corneal reshaping patients achieve uncorrected visual acuity of 20/25 or better that lasts all day long in one to two weeks of nighttime wear. 1-3 Treatment is primarily effective through central epithelial thinning and midperipheral epithelial and stromal thickening. Much remains to be learned about corneal reshaping contact lenses and their effects on the cornea. Methods. The authors reviewed existing knowledge and determined what needs to be learned in order to provide patients with appropriate informed consent prior to corneal reshaping contact lens wear. Results. While corneal reshaping contact lenses are effective at temporarily reducing or eliminating myopia, claims about the progress of myopia being controlled with corneal reshaping contact lenses should not be made until further studies are published in peer-reviewed literature. The incidence and prevalence of microbial keratitis related to corneal reshaping contact lens wear is not known. Any overnight wear of contact lenses increases the risk of infection, but it is not known whether the risks of microbial keratitis are greater for corneal reshaping overnight contact lens wearers than other form of overnight contact lens wear. It is also not known whether the risk of microbial keratitis is greater for children than adults, but we must determine if children are at greater risk than adults because many children are wearing corneal reshaping contact lenses. Conclusions. Finally, it is recommended that ongoing education be provided to practitioners and staff regarding safety, informed consent, and prevention of potential problems, with special emphasis on the critical need to properly and thoroughly disinfect lenses that will be worn overnight. © 2005 Contact Lens Association of Ophthalmologists, Inc.

Woods,C. A. Working better with GPs: Lessons to be learned from a study of health care networks in the management of diabetes Clinical and Experimental Optometry 2005;891-2

2004

Haque,S., Fonn,D., Simpson,T., Jones,L. Corneal and epithelial thickness changes after 4 weeks of overnight corneal refractive therapy lens wear, measured with optical coherence tomography Eye and Contact Lens 2004;30(4):189-193 [ Show Abstract ]

Purpose. To investigate thickness changes of the total cornea and epithelium across the horizontal corneal meridian after 4 weeks of overnight corneal refractive therapy (CRT) rigid contact lens (Paragon Vision Sciences, Mesa, AZ) wear. Methods. Thirty subjects were fitted with CRT contact lenses (Dk/t = 67), which were worn overnight for 4 weeks. Corneal thickness was measured at nine locations along the horizontal meridian by using optical coherence tomography (OCT) before lens insertion in the evening. Corneal thickness was measured the next morning immediately after lens removal and 1, 3, 7, and 14 hours later. This was repeated on days 4, 10, and 28 of the study and then 3 days after discontinuing lens wear. Results. Twenty-three subjects completed the study. At lens removal on day 1, the central and paracentral cornea swelled by 4.9% and 6.2%, respectively (both P = 0.000). The central epithelium thinned by 7.3%, and the mid peripheral epithelium thickened by 13% (both P = 0.000). Corneal swelling recovered throughout the day, with most of the deswelling taking place within the first 3 hours after lens removal. Maximal central epithelial thinning reached 13.5% by day 4. Three days after the study completion, corneal and epithelial thickness had recovered to baseline values. Conclusions. This study shows that CRT lenses induce differential overnight swelling across the cornea, with rapid deswelling during the day. Central epithelial thinning and paracentral thickening occurs, with recovery 3 days after discontinuation of lens wear. © 2004 Contact Lens Association of Ophthalmologists, Inc.

Karlgard,C. C. S., Sarkar,D. K., Jones,L. W., Moresoli,C., Leung,K. T. Drying methods for XPS analysis of PureVision™, Focus® Night&Day™ and conventional hydrogel contact lenses Applied Surface Science 2004;230(1-4):106-114 [ Show Abstract ]

The surface composition of hydrogel contact lenses that contain silicon-based monomers, PureVision™ (balafilcon A) and Focus® Night&Day™ (lotrafilcon A), were investigated by X-ray photoelectron spectroscopy (XPS). Conventional and daily disposable hydrogel lenses based on hydroxyethyl methacrylate (HEMA) were also studied, with the commonly prescribed 1-day Acuvue® lens (etafilcon A) used as a control. All the lenses were pre-washed and dehydrated by three different methods, including drying in air, drying in nitrogen or freezing with subsequent freeze-drying, before the XPS analysis. The lenses dried in air had more impurities on the surface, and the lenses that were freeze-dried lost transparency, suggesting that drying lenses in nitrogen is the preferred preparation method for XPS analysis. Surface compositions for all lens materials were obtained and this data can be used as a control/base-value for future analysis of the interactions of soft contact lens materials with chemicals such as drugs or tear components. © 2004 Elsevier B.V. All rights reserved.

Moezzi,A. M., Fonn,D., Simpson,T. L., Sorbara,L. Contact lens-induced corneal swelling and surface changes measured with the Orbscan II corneal topographer Optometry and Vision Science 2004;81(3):189-193 [ Show Abstract ]

Purpose. The purpose of this study was to measure central and topographical corneal swelling in response to contact lens wear and eye closure, to determine whether the swelling induced by soft and polymethyl methacrylate (PMMA) lenses is different, and to determine whether the anterior and/or posterior corneal shape alters with corneal swelling. Methods. An Orbscan II corneal topographer was used to measure corneal swelling and the shape of the anterior and posterior corneal surfaces of 16 neophytes before and after wearing soft and PMMA contact lenses with near-zero oxygen transmissibility. The lens-wearing eye was patched for 3 h. Results. The mean 15.1% ± 3.8% (±SD) central corneal swelling with soft lenses was significantly > 12.6% ± 4.1% with PMMA lenses. Topographical corneal swelling was significantly greater with soft vs. PMMA lenses. However, the difference between central and peripheral corneal swelling was much greater with PMMA lenses. With both lenses, the cornea swelled significantly more in the center than the periphery. The anterior best-fit sphere radius remained unchanged in response to soft lenses (0.00 ± 0.04 mm) and steepened slightly but significantly with PMMA lenses (-0.04. ± 0.05 mm). The posterior best-fit sphere radius flattened significantly with both lenses (0.12 ± 0.07 mm with soft and 0.14 ± 0.08 mm with PMMA lenses). Conclusions. Corneal swelling (greater centrally than peripherally) flattens the posterior surface of the cornea and is independent of lens type. Although the anterior best-fit sphere radius steepened with PMMA, the magnitude is probably clinically unimportant. Both lens types produced greater central vs. peripheral corneal swelling. However, the soft lens induced significantly greater overall swelling than PMMA. Because their oxygen transmission was the same, these results suggest that there is lateral diffusion of oxygen from the peripheral area of the cornea (that is not covered by the lens) toward the center.

Sorbara,L., Simpson,T., Vaccari,S., Jones,L., Fonn,D. Tear turnover rate is reduced in patients with symptomatic dry eye Contact Lens and Anterior Eye 2004;27(1):15-20 [ Show Abstract ]

Purpose: Tear turnover rate (TTR) is defined as the percent decrease of fluorescein concentration in the tears per minute after the instillation of fluorescein. The purpose of this study was to examine differences in TTR in a sample with symptoms of dry eye and an asymptomatic control sample using the Fluorotron Master™ Fluorophotometer. Methods: TTR was measured using the OcuMetrics Fluorotron Master™. It measures the decay of the fluorescence of high molecular weight fluorescein FITC Dextran instilled into the tear film. Twenty participants (post-menopausal women) were enrolled in the study (10 asymptomatic (age 64.7±6.99) and 10 symptomatic (age 61.5±7.98)). Participants were grouped according to either a positive (symptomatic) or negative (asymptomatic) McMonnies Dry Eye Questionnaire, i.e., an indication of self-reported ocular dryness and the use of rewetting/lubricating drops (questions 4 and 5). TTR was measured in the afternoon only. Measurements were made on the right eye with a controlled blink rate (15 blinks/min), for up to 30 min, post-insertion of 2 μl of 2% FITC Dextran (MW 9500). The scan data were used to construct a graph of log fluorescein concentration (ng/ml) as a function of time and the TTR calculated (%/min=(1-ln (slope))×100). Results: There was a significant difference in the TTR between symptomatic and asymptomatic subjects. Mean TTR (symptomatic) was 4.89±2.74%/min (range, 2.04-11.81) and mean TTR (asymptomatic) was 11.85±3.31%/min (range, 5.76-16.45) (P<0.0001). Conclusions: Fluorophotometry may be used to demonstrate differences in the tear turnover rate in this post-menopausal group of women, with patients experiencing symptoms of dry eye having a lower TTR than the normals. © 2003 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

2003

Begley,C. G., Chalmers,R. L., Abetz,L., Venkataraman,K., Mertzanis,P., Caffery,B. A., Snyder,C., Edrington,T., Nelson,D., Simpson,T. The relationship between habitual patient-reported symptoms and clinical signs among patients with dry eye of varying severity Investigative Ophthalmology and Visual Science 2003;44(11):4753-4761 [ Show Abstract ]

PURPOSE. To investigate symptom profiles and clinical signs in subjects with dry eye and normal subjects in a cross-sectional multicenter study. METHODS. Subjects aged 35 to 65 were recruited according to dry eye diagnostic codes and telephone interview and completed the Dry Eye Questionnaire 2001, among others, and underwent dry eye clinical tests. RESULTS. Subjects (122) included 28 control subjects (C), 73 with non-Sjögren's keratoconjunctivitis sicca (non-SS KCS) and 21 with Sjögren's syndrome (SS). Subjects with SS or non-SS KCS reported discomfort and dryness most frequently and that many symptoms worsened over the day and were quite bothersome. Groups were significantly different in corneal fluorescein staining, conjunctival lissamine green staining, Schirmer 1 tear test, and tear break-up time (TBUT; X2 and Kruskal-Wallis, P 0.0001). CONCLUSIONS. Subjects with SS or non-SS KCS reported frequent and intense ocular surface symptoms in the evening, some of which correlated moderately with clinical test results. The global clinician grade of dry eye correlated more highly with patient symptoms than did clinical signs, suggesting that patient symptoms influence dry eye diagnosis and grading of dry eye more than clinical test results.

Du Toit,R., Vega,J. A., Fonn,D., Simpson,T. Diurnal variation of corneal sensitivity and thickness Cornea 2003;22(3):205-209 [ Show Abstract ]

Purpose. To measure the diurnal variation of central corneal sensitivity and thickness over 24 hours. Methods. A noncontact pneumatic esthesiometer to measure central corneal sensitivity and an optical pachymeter to measure central corneal thickness were used on 20 noncontact lens wearers. These measurements were performed at 22:00 before 8 hours of sleep and on the following day on eye opening and at hourly intervals between 7:00 and 22:00. Results. Central corneal sensitivity varied by 35% over the 24 hours. Sensitivity was significantly lower by 17.1 ± 2.1% on eye opening and recovered to the level of the previous night after 4 hours. Corneal sensitivity continued to increase throughout the day but was not significantly higher. Central corneal thickness varied by 3.9% over the 24 hours. The mean overnight corneal swelling was 2.9 ± 0.31%, and 2 hours after eye opening, the cornea had deswelled to the same thickness as the previous night. The cornea thinned further throughout the day, but there were no statistically significant differences between the values after 14:00. There was a high correlation between corneal sensitivity and thickness over time (r = 0.8; p < 0.05). Discussion. Corneal sensitivity correlated with corneal thickness: both were higher on awakening and then decreased and remained below the levels measured the previous night. This may be due to physiological and/or environmental factors. The lack of significant differences between the values after 14:00 suggests that baseline may be measured at any time from 7 hours after eye opening.

Dumbleton,K. Noninflammatory silicone hydrogel contact lens complications. CLAO Journal 2003;29(1 Suppl):S186-189; discussion S190-191, S192-194 [ Show Abstract ]

High Dk silicone hydrogel lenses have overcome many of the hypoxic problems associated with traditional extended wear, and the popularity of continuous wear with these lens types is increasing. Despite the elimination of hypoxia, several noninflammatory clinical complications have been reported to occur as a result of mechanical disturbances or trauma when wearing silicone hydrogel lenses. This article reviews the origin and presentation of mucin balls, superior epithelial arcuate lesions, contact lens papillary conjunctivitis, and corneal erosions in silicone hydrogel lens wearers. A number of management strategies and approaches to minimize the occurrence of these clinical complications are also discussed.

Feng,Y., Simpson,T. L. Nociceptive sensation and sensitivity evoked from human cornea and conjunctiva stimulated by CO2 Investigative Ophthalmology and Visual Science 2003;44(2):529-532 [ Show Abstract ]

PURPOSE. To compare sensation and sensitivity evoked from human cornea and conjunctiva stimulated by CO2. METHODS. Twenty healthy participants were recruited for the study. Central corneal and temporal conjunctival chemical sensation and sensitivity of only one eye of each subject were evaluated. Air mixed with different concentrations of CO2 was delivered by a modified Belmonte pneumatic esthesiometer. The ascending method of limits was used to determine the sensitivity and subjects were required to characterize the sensation at threshold. RESULTS. The sensations evoked by CO2 in the cornea and conjunctiva were stinging or burning. The sensation evoked by mechanical stimulation was that of irritation. The corneal and conjunctival chemical thresholds were 31% ± 2% and 54% ± 5% CO2 (mean ± SE), respectively. The corneal and conjunctival mechanical thresholds were 80 ± 6 and 140 ± 10 mL/min (mean ± SE), respectively. The corneal sensitivity was significantly higher for both mechanical and chemical stimuli (P < 0.05). CONCLUSIONS. The results suggest that CO2 stimulates similar corneal and conjunctival nociceptors in that the interpretations were the same (i.e., nociceptive). The central cornea had a higher sensitivity to CO2 than the temporal conjunctiva, which may reflect a different peripheral innervation, such as different nerve density or different receptor characteristics. Sensations evoked by mechanical and chemical stimulation were different, which suggests that at the peripheral level, the two modalities stimulate two different kinds of molecular receptors or channels and that this information is somehow retained within the nociceptive system.

Fonn,D., Dumbleton,K. Dryness and discomfort with silicone hydrogel contact lenses. Eye & contact lens 2003;29(1 Suppl):S101-104; discussion S115-118, S192-194 [ Show Abstract ]

PURPOSE: The purpose of this study was to determine whether symptoms of dryness and discomfort are experienced differently with silicone hydrogel lenses compared to conventional hydrogels, in symptomatic and asymptomatic subjects. METHODS: Thirty-nine symptomatic and asymptomatic subjects wore four types of lenses: Focus NIGHT & DAY (CIBA Vision), Focus DAILIES (CIBA Vision), ACUVUE 2 (Johnson & Johnson Visioncare) and Proclear Compatibles (CooperVision) contralaterally for 7 hours and rated comfort and dryness on a zero-to-100 point visual analog scale at 0, 1, 3, 5 and 7 hours. RESULTS: In both groups, no lens differences were found for comfort and dryness, but the comfort and dryness ratings of the symptomatic group decreased significantly (became worse) over the 7-hour period. CONCLUSIONS: These results demonstrate that dryness and comfort is the same over time with silicone hydrogel as with the other three lenses.

Hrynchak,P., Hutchings,N., Jones,D., Simpson,T. A comparison of cup-to-disc ratio evaluation in normal subjects using stereo biomicroscopy and digital imaging of the optic nerve head Ophthalmic and Physiological Optics 2003;23(1):51-59 [ Show Abstract ]

The cup-to-disc (CD) ratio evaluated using stereoscopic biomicroscopy was compared with that evaluated by viewing a non-stereo digital image of the optic nerve head. Twenty normal subjects (mean age 26 +/- 4 years) were evaluated by two observers. The average CD ratio was 0.29 with a range of 0-0.80. The intra-class correlations between the observers ranged from 0.82 to 0.96, when comparing horizontal and vertical CD ratios for both evaluation techniques. The mean CD ratio was significantly smaller when viewing the digital image (0.25 +/- 0.01) compared with stereoscopic observation (0.33 +/- 0.03, p < 0.0001). Although the mean differences between the two techniques were small, the percentage of CD ratios that differed by >or=0.2 were between 5 and 25% of evaluations. Caution should be exercised when using stereoscopic and non-stereo digital evaluations of CD ratio interchangeably to assess longitudinal progression in a multi-clinician setting.

Jones,L., Senchyna,M., Glasier,M. A., Schickler,J., Forbes,I., Louie,D., May,C. Lysozyme and lipid deposition on silicone hydrogel contact lens materials. Eye Contact Lens 2003;29(1 Suppl):S75-79; discussion S83-84, S192-194 [ Show Abstract ]

PURPOSE: We sought to determine whether there were differences in lysozyme (quantity and conformation) and lipid deposition on in vivo worn conventional (etafilcon) and silicone hydrogel (balafilcon and lotrafilcon) contact lenses. METHODS: After extraction, lysozyme concentration in each extract was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Lysozyme activity was determined by the rate of lysis of Micrococcis lysodeikticus cells. Lipid deposition was determined by high-performance liquid chromatography. RESULTS: Lysozyme deposition on etafilcon lenses was significantly greater than that measured on silicone hydrogel (SH) lenses (985 microg per lens versus 10 and 3 microg per lens for balafilcon and lotrafilcon materials, respectively; P<0.001). The degree to which lysozyme was denatured was influenced by the lens material, with the lowest degree of denaturation (22%) seen on the conventional lens material, as compared with 50% for balafilcon and 80% for lotrafilcon (P<0.001). Lipid deposition was greatest on the SH materials, with up to 600 microg per lens of certain lipid classes being deposited on balafilcon, as compared with 20 microg per lens on etafilcon (P<0.001). CONCLUSION: The quantity and conformation of lysozyme and the quantity of lipid deposited on hydrogel contact lenses is significantly influenced by the composition of the lens material. SH contact lens materials deposit low levels of lysozyme and high levels of lipid deposition compared with ionic contact lens materials. Although SH materials deposit only small amounts of lysozyme, the degree of lysozyme denaturation that occurs is higher relative to that seen on ionic lens materials.

Karlgard,C. C. S., Jones,L. W., Moresoli,C. Ciprofloxacin interaction with silicon-based and conventional hydrogel contact lenses Eye and Contact Lens 2003;29(2):83-89 [ Show Abstract ]

Purpose. Hydrogel contact lenses can be used as bandage lenses to protect the corneal surface after injury. The use of novel silicon-based hydrogel lens materials as bandage lenses has not gained widespread acceptance. As a first step toward advocating their usefulness as bandage lenses, their interaction with ocular pharmaceuticals must be understood because topical agents are often administered in conjunction with bandage lenses. Methods. The in vitro uptake and release of ciprofloxacin from silicone-based hydrogel (SH) and conventional pHEMA-based (CH) hydrogel contact lenses was examined by spectrophotometric evaluation of the drug concentration in saline solution. Results. The hydrogel contact lenses tested showed similar drug uptake (average 1800 μg/lens) but different levels of drug release. Multiphoton laser microscopy indicated that ciprofloxacin was distributed throughout the lens thickness, with higher levels of drug at the surface owing to drug precipitation. The drug adsorption onto the lenses was partially reversible. The SH lenses released a lower amount of drug than CH lenses (72 vs. 168 μg/lens). Ionic lenses released less drug than non-ionic lenses (127 vs. 151 μg/lens). Conclusions. The differences in ciprofloxacin uptake and release between SH and CH materials may not be clinically significant because the amount of drug released from all lenses would be above the MIC90 of ciprofloxacin for common ocular pathogens. These results indicate that material properties have a significant impact on drug-lens interactions. © 2003 Contact Lens Association of Ophthalmologists, Inc.

Karlgard,C. C. S., Wong,N. S., Jones,L. W., Moresoli,C. In vitro uptake and release studies of ocular pharmaceutical agents by silicon-containing and p-HEMA hydrogel contact lens materials International journal of pharmaceutics 2003;257(1-2):141-151 [ Show Abstract ]

The in vitro uptake and release behaviour of cromolyn sodium, ketotifen fumarate, ketorolac tromethamine and dexamethasone sodium phosphate with silicon-containing (lotrafilcon and balafilcon) and p-HEMA-containing (etafilcon, alphafilcon, polymacon, vifilcon and omafilcon) hydrogel contact lenses indicated that both drug and material affected the uptake and release behaviour. Rapid uptake and release (within 50min) was observed for all drugs except ketotifen fumarate which was more gradual taking approximately 5h. Furthermore, the maximum uptake differed significantly between drugs and materials. The highest average uptake (7879±684μg/lens) was cromolyn sodium and the lowest average uptake (67±13μg/lens) was dexamethasone sodium phosphate. Partial release of the drug taken up was observed for all drugs except dexamethasone sodium phosphate where no release was detected. Sustained release was demonstrated only by ketotifen fumarate. Drug uptake/release appeared to be a function of lens material ionicity, water and silicon content. The silicon-containing materials released less drug than the p-HEMA-containing materials. The lotrafilcon material demonstrated less interactions with the drugs than the balafilcon material which can be explained by their different bulk composition and surface treatment. © 2003 Elsevier Science B.V. All rights reserved.

Situ,P., Du Toit,R., Fonn,D., Simpson,T. Successful monovision contact lens wearers refitted with bifocal contact lenses Eye and Contact Lens 2003;29(3):181-184 [ Show Abstract ]

Purpose. Should successful monovision contact lens wearers be refitted with bifocal lenses? Methods. Fifty current monovision lens wearers were fitted with ACUVUE Bifocal contact lenses (Johnson & Johnson Vision Care, Jacksonville, FL). Visual function and subjective vision ratings were assessed with habitual monovision lenses at the first visit and then were repeated at the end of 6 months while wearing bifocal lenses. Lens preference was determined at the end of the 6-month study, and the subjects were called 1 year later to repeat the lens preference questionnaire. Results. Forty (80%) subjects completed the 6-month study; nine discontinued for visual reasons. At the end of 6 months of wear, 68% preferred bifocal lenses and 25% preferred monovision. Of the subjects who were contacted a year later, 53% were still wearing bifocal lenses. High-contrast visual acuity and letter contrast sensitivity at distance was the same for monovision and bifocal lenses, but low-contrast acuity was better with monovision. Intermediate low- and high-contrast acuity and 3-meter and near stereoscopic acuity were better with bifocal lenses. Near high- and low-contrast acuity were better with monovision. All subjective ratings, except near vision in poor lighting, were significantly greater with bifocal lenses. Conclusions. It is possible to refit successful monovision lens wearers with simultaneous vision bifocal lenses, and these lenses should be considered as an alternative method for the correction of presbyopia. In addition, subjective responses to bifocal lenses may not be reflective of visual function measurements. © 2003 Contact Lens Association of Ophthalmologists, Inc.

Wang,J., Fonn,D., Simpson,T. L. Topographical thickness of the epithelium and total cornea after hydrogel and PMMA contact lens wear with eye closure Investigative Ophthalmology and Visual Science 2003;44(3):1070-1074 [ Show Abstract ]

PURPOSE. To determine changes in topographical thickness of the epithelium and total cornea after hydrogel (2-hydroxyethyl methacrylate; HEMA or soft lens) and PMMA rigid contact lens wear with eyes closed, as measured by optical coherence tomography (OCT). METHODS. Epithelial and total corneal thickness in 18 neophyte eyes was measured with OCT at intervals of 10° across a 10-mm zone of the horizontal meridian of the cornea, before and after 3 hours of soft and rigid contact lens wear with the eye closed. These measurements were repeated 20 minutes after removal of the lenses. RESULTS. Lens type, time, and location were found to be significant main influences (P < 0.0001) on corneal swelling in patched eyes, by three-way ANOVA, and there was a significant three-way interaction among lens type, time, and location (F(16,272) = 1.78, P = 0.033). However, there was no significant main effect and interaction of epithelial thickness (F(16, 272) = 0.33, P = 0.99). Immediately after removal of the lenses, total corneal thickness in the horizontal meridian was significantly greater with both soft and PMMA lenses (P < 0.001) at each location with each lens, compared with the baseline measurements. With both lenses, the increase in actual thickness and percentage of corneal swelling at the center was greater than at each peripheral point (excluding the first 10° points; P < 0.005). HEMA lenses caused greater corneal swelling than the PMMA lenses at each location immediately after removal of the lenses (P < 0.005). CONCLUSIONS. This study shows that corneal swelling is dependent on lens type and corneal location when eyes are closed, but epithelial thickness across the horizontal corneal meridian does not change during lens wear with eyes closed. OCT is an efficient method of measuring topographical corneal and epithelial thickness in response to contact lens wear.

Wang,J., Fonn,D., Simpson,T. L., Jones,L. Precorneal and pre- and postlens tear film thickness measured indirectly with optical coherence tomography Investigative Ophthalmology and Visual Science 2003;44(6):2524-2528 [ Show Abstract ]

PURPOSE. To demonstrate the feasibility of indirectly measuring the precorneal tear film thickness and pre- and postlens tear film (PLTF) thickness using optical coherence tomography (OCT). METHODS. Central corneal thickness (C1) which includes the tear film (T) of both eyes of 40 non-contact lens wearers was measured using OCT after calibration. The mean age of the 40 subjects was 31.2 ± 9.3 years with a mean horizontal K-reading of 7.87 mm. Rigid contact lenses with base curves 0.3- to 0.5-mm steeper than the flattest K of the eye were fitted to measure real corneal thickness (C2), independently of the postlens tear film. T was calculated by T = C1 - C2. To measure pre- and postlens tear film thickness, Focus Night & Day and Acuvue lenses (Vistakon, Johnson & Johnson Vision Care, Jacksonville, FL) were fitted on both eyes. Central soft lens thickness (L1), which includes the prelens tear film (P), was measured by OCT in situ and in saline in a wet cell (L2). P was calculated by P = L1 - L2. Thickness of the central cornea plus the postlens tear film (C3) was measured during lens wearing. Postlens tear film (PLTF) was calculated by PLTF = C3 - C2. RESULTS. The mean ± SD precorneal tear film thickness was 3.3 ± 1.5 μm (range, 0-6.9) before lens insertion and 4.7 ± 2.3 μm (range, 0.7-11.0) after lens fitting, which was significantly thicker (paired t-test: P < 0.01). The prelens tear film thickness was 3.9 ± 2.6 and 3.6 ± 2.1 μm (mean ± SD; paired t-test: P = 0.52) and the postlens tear film thickness was 4.5 ± 2.3 and 4.7 ± 3.1 μm (paired t-test: P = 0.08) on and under Focus Night & Day and Acuvue lenses, respectively. Post hoc tests showed that precorneal (baseline) and prelens tear films were equivalent, and each was different (thinner; Tukey honestly significant difference P < 0.05) from the postlens tear film. CONCLUSIONS. OCT can noninvasively measure the thickness of the precorneal and prelens tear film as well as the postlens tear film. The thickness of the normal precorneal tear film is approximately 3 μm and becomes thicker after lens fitting. The postlens tear film is thicker than the precorneal and prelens tear films with soft contact lenses. The thickness of both preand postlens tear films appears to be independent of the investigated lens types.

2002

Du Toit,R., Pritchard,N., Heffernan,S., Simpson,T., Fonn,D. A comparison of three different scales for rating contact lens handling Optometry and Vision Science 2002;79(5):313-320 [ Show Abstract ]

Purpose. To compare the validity, responsiveness, and reliability of three subjective rating scales applied to soft contact lens (SCL) handling. Methods. Fifty-four adapted SCL wearers handled three different types of lenses on two occasions and rated the handling with each scale: visual analogue scales (VAS), 20-interval visual analogue scales with descriptors (VAD) and Likert rating scales with five intervals (LRS). Results. There were significant differences between the scales (p < 0.01) and between the subjective ratings of lens handling (p < 0.001). VAS showed the least variability, exhibited the highest construct validity, were the most responsive, and were the most reliable: interclass correlations (0.63), coefficient of repeatability (27.5), and correlation between test and retest (Spearman r = 0.65, [all p < 0.05]). Higher repeatability, because of the fewer intervals of LRS, was not demonstrated and, generally, LRS was the least satisfactory scale. Handling was rated as easiest using VAD and most difficult using LRS. Conclusions. Although all three scales can be used to provide measures of lens handling, VAS may provide a simple and repeatable tool for measuring subjective responses.

Dumbleton,K. A., Chalmers,R. L., McNally,J., Bayer,S., Fonn,D. Effect of lens base curve on subjective comfort and assessment of fit with silicone hydrogel continuous wear contact lenses Optometry and Vision Science 2002;79(10):633-637 [ Show Abstract ]

Purpose. To study the effect of base curve on subjective comfort of silicone hydrogel extended wear lenses. Methods. Ninety-five subjects were first trial fitted with 8.6-mm base curve lotrafilcon A (Focus Night & Day) lenses and then with 8.4-mm lenses only if poor subjective comfort or poor fit was present. Comfort and fit were assessed after 15 min. Subjects with discomfort or signs of poor fit were then trial fitted with 8.4-mm lenses. Results. Of 190 eyes, 74.2% were fitted with 8.6-mm lenses, and 23.7% required 8.4-mm lenses. Two (2.1%) subjects could not be fitted with either base curve. Mean steep keratometry (K) reading for eyes dispensed with 8.6-mm lenses was 43.88 D and 45.56 D for eyes dispensed in the 8.4-mm lenses (p < 0.001). Conclusions. A clinically useful criterion showing the need for 8.4-mm lenses was steep K of ≥45.50 D; 77% of these eyes required the steeper lens for good comfort and fit. Subjective discomfort with 8.6-mm lenses was also a useful signal for the need of a steeper lens; mean comfort scores for those subjects rose from 6.33 with 8.6-mm lenses to 9.44 with the 8.4-mm lenses for eyes requiring the steeper lens (p < 0.001).

Fieguth,P., Simpson,T. Automated measurement of bulbar redness Investigative Ophthalmology and Visual Science 2002;43(2):340-347 [ Show Abstract ]

PURPOSE. To examine the relationship between physical image characteristics and the clinical grading of images of conjunctival redness and to develop an accurate and efficient predictor of clinical redness from the measurements of these images. METHODS. Seventy-two clinicians graded the appearance of 30 images of redness on a 100-point sliding scale with three referent images (at 25, 50, and 75 points) through a World Wide Web-based survey. Using software developed in a commercial computer program, each image was quantified in two ways: by the presence of blood vessel edges, based on the Canny edge-detection algorithm, and by a measure of overall redness, quantified by the relative magnitude of the redness component of each red-green-blue (RGB) pixel. Linear and nonlinear regressors and a Bayesian estimator were used to optimally combine the image characteristics to predict the clinical grades. RESULTS. The clinical judgments of the redness images were highly variable: The average grade range for each image was approximately 55 points, more than half the extent of the entire scale. The median clinical grade was chosen as the most reliable measure of "truth." The median grade was predicted by a weighted linear combination of the edgeness and redness features of each image. The strength of the predicted association was r = 0.976, exceeding the strength of association of all but one of the 72 individual clinicians. CONCLUSIONS. Clinical grading of redness images is highly variable. Despite this human variability, easily implemented image-analysis and statistical procedures were able to reliably predict median clinical grades of conjunctival redness.

Fonn,D., MacDonald,K. E., Richter,D., Pritchard,N. The ocular response to extended wear of a high Dk silicone hydrogel contact lens Clinical and Experimental Optometry 2002;85(3):176-182 [ Show Abstract ]

Purpose: A four-month extended wear clinical trial was conducted to compare the ocular effects of a high Dk Balafilcon A silicone hydrogel lens and a low Dk HEMA 38.6 per cent H2Osoft lens. Method: Twenty-four subjects who were adapted to daily wear of soft lenses wore a high Dk lens in one eye and a low Dk HEMA lens in the other eye for four months on an extended wear basis after one week of daily wear. Thirteen progress evaluations were conducted using standard clinical procedures. Results: Eighteen subjects (75 per cent) completed the study. The high Dk lens induced significantly less bulbar and limbal injection and corneal vascularisation than the low Dk HEMA lens (p < 0.05). Epithelial microcysts were observed only in the eyes wearing the low Dk lens. A significant increase in myopia was found in the eyes wearing the low Dk HEMA lens (mean = 0.50 D, p < 0.01) compared to the insignificant myopic increase of 0.06 D in the eyes wearing the high Dk lens. Three subjects developed small infiltrates in the high Dk lens wearing eyes and significantly more post-lens debris was observed under the high Dk lens. Six subjects developed papillary conjunctivitis in the eye wearing silicone hydrogel lenses but only two of those were discontinued from the study. Conclusion: No hypoxia-related effects were observed with extended wear of the high Dk Balafilcon A silicone hydrogel lens.

Jones,L., Macdougall,N., Sorbara,L. G. Asymptomatic corneal staining associated with the use of balafilcon silicone-hydrogel contact lenses disinfected with a polyaminopropyl biguanide-preserved care regimen Optometry and Vision Science 2002;79(12):753-761 [ Show Abstract ]

PURPOSE: To compare subjective symptoms and signs in a group of individuals who wear silicone-hydrogel lenses on a daily wear basis while they sequentially used two differing care regimens. METHODS: Fifty adapted soft-lens wearers were fitted with a silicone-hydrogel lens material (PureVision, Bausch & Lomb). The lenses were worn on a daily wear basis for two consecutive 1-month periods, during which the subjects used either a Polyquad (polyquaternium-1) -based system or a polyaminopropyl biguanide (PHMB) -based system, using a double-masked, randomized, crossover experimental design. RESULTS: Significant levels of relatively asymptomatic corneal staining were observed when subjects used the PHMB-based system, with 37% of subjects demonstrating a level of staining consistent with a classical solution-based toxicity reaction. Only 2% of the subjects exhibited such staining when using the Polyquad-based system. These results were significantly different (p < 0.001). Significant symptoms were not correlated with the degree of staining, with no differences in lens comfort or overall preference being reported between the regimens (p = NS). The only statistically significant difference in symptoms related to minor differences in stinging after lens insertion being reported, with the Polyquad-based system demonstrating less stinging (p < 0.008). CONCLUSIONS: Practitioners who fit silicone-hydrogel contact lenses on a daily wear basis should be wary of the potential for certain PHMB-containing multipurpose care systems to invoke corneal staining. Switching to non-PHMB based regimens will eliminate this complication in most instances.

Jones,L., May,C., Nazar,L., Simpson,T. In vitro evaluation of the dehydration characteristics of silicone hydrogel and conventional hydrogel contact lens materials Contact Lens and Anterior Eye 2002;25(3):147-156 [ Show Abstract ]

Purpose: This study investigated the in vitro dehydration performance of silicone hydrogel and conventional hydrogel contact lens materials. Methods: In vitro dehydration was assessed using a gravimetric method. The mass loss over time of Focus Night&Day, PureVision, Optima, Acuvue and Proclear Compatibles was measured as the ambient temperature increased from room temperature to 34°C under varying airflow and humidity conditions. Results: Dehydration data demonstrated a typical ogival form. The results were best fitted with a double exponential, non-linear regression model, which accounted for at least 99% of the variance. Regardless of material, increased airflow had a greater impact on dehydration rate than increased humidity (P < 0.05). Relative dehydration amounts were strongly correlated with initial water content (r2 = 0.92), with higher water content materials dehydrating to a greater extent. Conclusions: In vitro dehydration studies of conventional and novel silicone-containing hydrogel materials indicated that evaporation rates from materials are predominantly water content related, with only subtle differences between materials of similar water contents being seen. Environmental conditions have a significant impact on in vitro dehydration, with increased airflow having a greater impact than reduced humidity on increasing dehydration rates. In vitro dehydration is closely related to bulk water diffusion rates and, as a result of their low water content, silicone-containing hydrogel materials exhibit low levels of dehydration compared with high water content hydrogel contact lens materials. Further, in vivo studies are necessary to see if the in vitro dehydration behaviour of silicone hydrogel materials is predictive of in-eye performance. © 2002 British Contact Lens Association. Published by Elsevier Science Ltd. All rights reserved.

Mann,A. M., Jones,L. W., Tighe,B. J. The application of counter immunoelectrophoresis (CIE) in ocular protein studies. Part I: Time dependent deposition patterns of immunoregulatory proteins on anionic hydrogel contact lenses Contact Lens and Anterior Eye 2002;25(2):73-80 [ Show Abstract ]

This paper focuses on the effects of wear regime on the deposition pattern of important immunoregulatory proteins on FDA Group IV etafilcon-A lenses. Specifically, the aim was to assess the extent to which the daily disposable wear modality produces a different deposition of proteins from the conventional daily wear regime which is coupled with cleaning and disinfection. Counter immunoelectrophoresis (CIE) was employed to detect individual proteins in lens extracts from individual patients and focused on the analysis of five proteins, IgA, IgG, lactoferrin, albumin and kininogen. Deposition was monitored as a function of time; significantly lower deposition was detected on the daily disposable lenses. cr 2002 British Contact Lens Association. Published by Elsevier Science Ltd. All rights reserved.

Pritchard,N., Young,G., Coleman,S., Hunt,C. Subjective and objective measures of corneal staining related to multipurpose care systems Contact Lens and Anterior Eye 2002;363-9 [ Show Abstract ]

An objective, digital-imaging method of measuring corneal staining was evaluated in 24 subjects wearing soft contact lenses. The method was used to compare the clinical performance of common multipurpose care systems (MPS) for soft contact lens care. Subjects used three different MPS, one containing polyquaternium-1 (PQ) and two containing polyhexanide (PX1 and PX2), for 2 weeks in a randomised, single-masked (investigator) crossover study. Corneal staining induced with the three MPS was analysed using an image-processing program (ImageTool, UTHSCSA Version 2, University of Texas, USA). Conjunctival hyperaemia and papillae were also evaluated. The intraclass correlation coefficient was similar with image analysis to that of investigator grading (0.876, 0.879, respectively). Significant differences in staining response were detected using the objective method. There was significantly less staining area with polyquaternium-1 (PQ) than polyhexanide (PQ: 0.12 mm2, PX2:0.91 mm2). Inferior palpebral papillae were significantly greater with PX2 than with PQ (1.0, 0.7 (0-4), respectively). The technique was shown to be an effective method of evaluating different corneal staining responses. Bilateral corneal staining in three or more quadrants is useful in the diagnosis of MPS-related staining. © 2003 British Contact Lens Association. Published by Elsevier Science Ltd. All rights reserved.

Wang,J., Fonn,D., Simpson,T. L., Jones,L. Relation between optical coherence tomography and optical pachymetry measurements of corneal swelling induced by hypoxia American Journal of Ophthalmology 2002;134(1):93-98 [ Show Abstract ]

PURPOSE: To determine the relation between optical coherence tomography (OCT) and optical pachymetry (OP) measurements of corneal swelling induced by hypoxia. DESIGN: Experimental study. METHODS: One randomly selected eye of 20 noncontact lens wearers (10 males and 10 females, age 35.6 ± 9.6 years) was patched during 3 hours of soft contact lens (SCL) wear while the contralateral eye acted as control. Central corneal thickness of both eyes was measured before and after SCL wear using OCT and OP in randomized order. RESULTS: Baseline central corneal thickness was 523.6 ± 33.0 μm (mean ± standard deviation [SD]) measured with OCT and 490.6 ± 25.5 μm with OP. Immediately after contact lens removal, corneal thickness measured with OCT increased by 13.8 ± 2.3% compared with 12.1 ± 1.8% (paired t test: P < .001) measured with OP. Thereafter, corneal thickness decreased at the rate of 5.6% per hour for OCT and 5.4% per hour for OP. The difference in thickness between instruments before lens insertion, which was 33 μm compared with the difference after lens removal (edematous cornea), which ranged from 46 to 41 μm. The difference between instruments decreased during the corneal deswelling period after lens removal. The correlation coefficient between OCT and OP was 0.914 before lens insertion and 0.932 after lens removal. CONCLUSION: This study has demonstrated the difference of corneal thickness measured with OCT and OP. Although both instruments are correlated highly in all conditions tested, OCT may overestimate corneal thickness in normal and edematous corneas. © 2002 by Elsevier Science Inc. All rights reserved.

Wang,J., Fonn,D., Simpson,T. L., Jones,L. The measurement of corneal epithelial thickness in response to hypoxia using optical coherence tomography American Journal of Ophthalmology 2002;133(3):315-319 [ Show Abstract ]

PURPOSE: To determine if corneal epithelial thickness increases in association with corneal edema induced by wearing soft contact lenses during eye closure. DESIGN: Experimental study. METHODS: One eye (randomly selected) of twenty noncontact lens wearers (10 males and 10 females, age 35.6 ± 9.6 years) was patched during 3 hours of soft contact lens (SCL) wear and the contralateral eye acted as a control. Corneal and epithelial thickness of both eyes was measured before and after SCL wear using optical coherence tomography (OCT). RESULTS: Immediately after contact lens removal, total corneal thickness was increased significantly by 13.8 ± 2.3% (mean ± SD) compared with baseline (P .05, paired t test). Immediately after contact lens removal, corneal epithelial thickness was increased by 1.7 ± 4.8%, but this change was not statistically significant (P > .05, paired t test). Following contact lens removal, epithelial thickness changed significantly (Repeated measure analysis of variance [Re-ANOVA]: F(7,133) = 4.91, pH-F < 0.001) over the next 100 minutes with thinning recorded at 60, 80, and 100 minutes (P < .05, paired t test). There was no significant change over time in epithelial thickness of the control eyes (Re-ANOVA: F(4, 76) = 0.91, pH-F = 0.464). CONCLUSION: OCT demonstrated that corneal epithelial thickness does not increase in response to hypoxia from SCL wear and eye closure, in contrast to a significant increase in total corneal thickness. © 2002 by Elsevier Science Inc. All rights reserved.

Young,G., Veys,J., Pritchard,N., Coleman,S. A multi-centre study of lapsed contact lens wearers Ophthalmic and Physiological Optics 2002;22(6):516-527 [ Show Abstract ]

Purpose: Discontinuation from contact lens wear has been identified as a contributing factor in the lack of growth of contact lens use in Europe. The purpose of this study was to determine the proportion of lapsed contact lens wearers that can be refitted successfully with contact lenses and to evaluate the reasons for discontinuation from contact lens wear. Methods: This was a multi-site clinical study involving 15 UK investigators and 236 lapsed contact lens wearers who had previously tried contact lenses and discontinued. The reasons for discontinuation were assessed by subjects, who were then refitted with contact lenses. Investigators subsequently evaluated factors associated with their initial discontinuation. Short-term success was defined as the successful completion of 1 month of contact lens wear with absence of complications that would prevent further wear. Subjects were interviewed by telephone 6 months after being refitted to determine whether they were still wearing contact lenses. Those who were not wearing lenses were questioned about the reasons for discontinuation and their likelihood of resuming lens wear. Results: A majority of subjects (51%) cited discomfort as the principal reason for having previously given up contact lens wear. Problems with vision were the second most common reason (13%), either with reading (6%) or general vision (7%). The most common type of discomfort was dryness (40%). In almost all cases (97%), the investigator's assessment of the reasons for discontinuation agreed with the subject's own assessment but investigators also cited product-related and practitioner-related factors as contributing to previous failure. The short-term success rate for refitting lapsed wearers was found to be 77% (CI: 70-82%). The highest short-term success rates were for 2-weekly/monthly soft spherical lenses (91%) and daily disposable lenses (89%). Lower success rates were found for soft toric (69%) and soft bifocal (53%) lenses. At the 6-month stage, 73% of those who continued in lenses after the 1-month visit were still wearing contact lenses and a further 18% indicated that they were either 'very likely' or 'likely' to resume lens wear. Conclusions: A high proportion of lapsed contact lens wearers can be successfully refitted with contact lenses. The prime reason for previous discontinuation from contact lenses is discomfort and, in particular, dryness-related discomfort. In many cases, previous contact lens failure is product or practitioner-related rather than because of patient-specific problems. Once refitted with contact lenses, lapsed wearers cite vision problems rather than discomfort as the most common reason for discontinuing. This finding suggests that recent advances in contact lens material, design, replacement frequencies and care systems have improved the prospects for avoiding lens-related discomfort and for continuing contact lens wear. © 2002 The College of Optometrists.

2001

Begley,C. G., Chalmers,R. L., Mitchell,G. L., Nichols,K. K., Caffery,B., Simpson,T., DuToit,R., Portello,J., Davis,L. Characterization of ocular surface symptoms from optometric practices in North America Cornea 2001;20(6):610-618 [ Show Abstract ]

Purpose. This study characterized ocular symptoms typical of dry eye in an unselected optometric clinical population in the United States and Canada. Methods. Self-administered dry eye questionnaires, one for non-contact lens wearers (dry eye questionnaire) and one for contact lens wearers (contact lens dry eye questionnaire), were completed at six clinical sites in North America. Both questionnaires included categoric scales to measure the prevalence, frequency, diurnal severity, and intrusiveness of nine ocular surface symptoms. The questionnaires also asked how much these ocular symptoms affected daily activities and contained questions about computer use, medications, and allergies. The examining doctors, who were masked to questionnaire responses, recorded a nondirected dry eye diagnosis for each patient, based on their own diagnostic criteria. Results. The dry eye questionnaires were completed by 1,054 patients. The most common ocular symptom was discomfort, with 64% of non-contact lens wearers and 79% of contact lens wearers reporting the symptom at least infrequently. There was a diurnal increase in the intensity of many symptoms, with symptoms such as discomfort, dryness, and visual changes reported to be more intense in the evening. The 22% percent of non-contact lens wearers and 15% of contact lens wearers diagnosed with dry eye (most in the mild to moderate categories) reported symptoms at a greater frequency than those not diagnosed with dry eye. Conclusions. Our results show that symptoms of ocular irritation and visual disturbances were relatively common in this unselected clinical population. The intensity of many ocular symptoms increased late in the day, which suggested that environmental factors played a role in the etiology of the symptoms.

Du Toit,R., Simpson,T. L., Fonn,D., Chalmers,R. L. Recovery from hyperemia after overnight wear of low and high transmissibility hydrogel lenses Current eye research 2001;22(1):68-73 [ Show Abstract ]

Purpose. To measure the limbal vascular response after 8 hours of eye closure while wearing high and low permeability lenses compared to control eyes without lenses. Method. Twenty neophyte participants wore lotrafilcon A silicone hydrogel lenses (HDk; Dk = 140) or etafilcon A hydrogel lenses (LDk; Dk = 18). On two different nights the lenses were randomly worn for 8 hours during sleep in the right eyes only. Left eyes were non-lens wearing controls. Biomicroscopic images of the temporal limbal area were videotaped at baseline, on eye opening and every 20 minutes for 3 hours. A masked observer graded digitized images of the limbal area. Results. On waking and after lens removal there were no differences in hyperemia between the HDk and LDk lens wearing eyes. There were also no differences at any time between the HDk lens wearing eyes and their control eyes (p > 0.05). On waking the eyes wearing the LDk lens were more hyperemic compared to baseline (p < 0.001) and compared to their control eyes at 20 (p < 0.001) and 180 minutes (p = 0.01), indicating slower recovery from hyperemia. The HDk lens wearing eyes recovered to their baseline levels by 180 minutes (p = 0.99), compared to the LDk lens wearing eyes, which had not recovered to baseline levels by 180 minutes (p = 0.04). Conclusion. The reduction in hyperemia over time of the HDk lens wearing eyes was the same as the controls. The LDk lens wearing eyes were more hyperemic than the controls on waking and the reduction in hyperemia over time was slower. This suggests that the slower recovery from hyperemia may be affected by the lower oxygen transmissibility of the LDk lens.

Du Toit,R., Situ,P., Simpson,T., Fonn,D. The effects of six months of contact lens wear on the tear film, ocular surfaces, and symptoms of presbyopes Optometry and Vision Science 2001;78(6):455-462 [ Show Abstract ]

Purpose. To assess the tear film, ocular surfaces, and symptoms of ocular discomfort in a presbyopic population before and after contact lens wear. Methods. A total of 150 presbyopes (49% were previous soft contact lens wearers) participated in a clinical trial in which they wore either monovision (single vision Acuvue lenses) or Acuvue Bifocal contact lenses. Clinical measurements of tear film, biomicroscopy, and corneal sensitivity as well as subjective ratings using the Dry Eye Questionnaire were collected at the initial visit and repeated after 6 months. Comparisons were made between age groups (40 to 51 years and 52 to 71 years) and genders before and after contact lens wear. Associations between objective and subjective tests were sought. Results. After 6 months of contact lens wear, clinical signs had worsened by less than one-half of a grade, and tear break up time (TBUT) worsened by 3 s. Only TBUT was lower for the older age group. Females had less bulbar hyperemia, more sensitive eyes, more lissamine green staining, and lower TBUT and phenol red thread measurements (all p lt; 0.04). Twenty-eight percent experienced dryness before contact lens wear, but this figure increased to 68% when wearing contact lenses. There were no age differences, but almost twice as many females as males reported dryness. Reporting symptoms of dryness was associated with gender, corneal sensitivity, and type of corneal staining. Conclusions. These results provide a representation of the ocular surface condition and symptoms of ocular discomfort in the middle-aged population and seem similar to reports of younger populations. Wearing contact lenses seems to influence dry eye symptoms more than age or gender. Therefore, presbyopes should not be excluded from consideration for contact lens fitting.

Dumbleton,K. A., Chalmers,R. L., Richter,D. B., Fonn,D. Vascular response to extended wear of hydrogel lenses with high and low oxygen permeability Optometry and Vision Science 2001;78(3):147-151 [ Show Abstract ]

Purpose. The purpose of this study was to determine the impact of extended wear of high and low oxygen permeability (Dk) lenses on the development or resolution of limbal hyperemia and corneal neovascularization in a randomized prospective clinical trial. Methods. Adapted daily-wear contact lens wearers were randomly assigned to one of two groups. The low-Dk group (N = 23) wore etafilcon A lenses (Dk/t = 40) for up to 7 days and 6 nights, and the high-Dk group (N = 39) wore lotrafilcon A lenses (Dk/t = 175) for up to 30 days and nights. Limbal hyperemia and neovascularization were assessed and graded during 9 months of extended wear. A stratified analysis to determine how change in ocular redness depended on initial presentation was also conducted. Results. On a 0 to 100 scale, extended wear of low-Dk lenses resulted in a 16-point increase in limbal hyperemia (p < 0.0001); no significant change occurred with the high-Dk lenses. The difference was greatest for low-Dk participants who initially presented with lower levels of hyperemia (N = 18). There was a slight resolution of redness in participants who initially presented with higher levels of hyperemia (N = 10) after wearing the high-Dk lenses. Neovascularization increased by an average of 0.5 on a scale of 0 to 4 in low-Dk lens wearers (p < 0.0001) but remained unchanged in the high-Dk lens wearers. The increase was most marked for the low-Dk group with lower levels of neovascularization at baseline. Conclusions. Subjects who wore lenses with higher oxygen permeability for 9 months of extended wear exhibited a lower vascular response of the ocular surface compared with subjects who wore lenses of lower oxygen permeability for the same period. This result was found both for the surface limbal vessels and in the deeper neovascular stromal vessels. Moderate neovascularization also developed after 3 months of extended wear of low-Dk hydrogels, whereas high-Dk lenses caused no neovascularization.

Feng,Y., Varikooty,J., Simpson,T. L. Diurnal variation of corneal and corneal epithelial thickness measured using optical coherence tomography Cornea 2001;20(5):480-483 [ Show Abstract ]

PURPOSE: To determine the feasibility of optical coherence tomography (OCT) measurement of overnight corneal swelling and de-swelling and, specifically, to examine overnight changes in the corneal epithelium and recovery during the day. METHODS: Ten healthy volunteers were recruited. Corneal OCT imaging was performed at 10:00 PM (baseline), 8:30 AM, and every 2 hours thereafter until 4:30 PM. Either the right or left eye was taped shut (using a gauze pad and surgical tape) until the 8:30 AM session of the next day. Measurements were made along a 1-mm strip centered on the visual axis. RESULTS: At baseline, there were no differences in corneal or epithelial thickness between control and experimental eyes (all p > 0.05). Immediately after patch removal, corneal and epithelial thicknesses of patched eyes were higher than the baseline (all p < 0.05). In patched eyes, the cornea and epithelium swelled 5.5% and 8.1% overnight, respectively (p > 0.05). Two hours later, the epithelial thickness of the experimental eyes recovered to baseline level (p > 0.05), but corneal thickness did not reach to baseline level until 4 hours after patch removal. For control eyes, there were no differences compared with baseline (all p > 0.05). CONCLUSION: Both cornea and corneal epithelium experience proportionately similar amounts of overnight swelling. Recovery of overnight swelling may be slower for the cornea than for the epithelium. OCT provides valuable information about anterior segment morphometry.

Jones,L. W., Jones,D. A. Non-inflammatory corneal complications of contact lens wear Contact Lens and Anterior Eye 2001;24(2):73-79 [ Show Abstract ]

Contact lenses can induce changes in the epithelium, stroma and endothelium of the cornea, all of which can be observed clinically using the slit-lamp biomicroscope. These complications include epithelial microcysts, vacuoles and staining, stromal oedema and vascularization, and endothelial polymegethism and blebs. Each complication can be attributed to one or more aetiological factors such as hypoxia, hypercapnia, tissue acidosis, trauma, hypersensitivity and toxicity. This review outlines the way in which these complications manifest clinically, and consideration is given to management strategies and likely prognoses. Early detection of these conditions and appropriate action can usually prevent more serious ocular complications.

Lu,F., Tang,S., Zhu,X., Zhang,J., Zheng,H. Experimental study on the effect of perfluorodecalin on rabbit corneas. Eye science 2001;17(1):16-20 [ Show Abstract ]

PURPOSE: To study the effects of perfluorodecalin on the cornea of the rabbit eyes. METHODS: Perfluorodecalin (0.05 ml/each) was injected into the anterior chambers of eighteen rabbit eyes. Corneal morphology and endothelial cells were monitored clinically by slit-lamp biomicroscope and specular microscope for 26 weeks. Animals were sacrificed in 1st, 2nd, 4th, 10th, 16th, 22nd, and 26th week after injection, respectively, and the corneas were examined under the light microscope. RESULTS: Perfluorodecalin droplets looking like "fish eggs" were found at about 1/4-1/2 of the corneal height in the inferior anterior chamber. Corneal opacification on the area contacted with perfluorodecalin was observed in five eyes five weeks after injection, and all in the 22nd week. Mutton fat KPs in one eye were seen in the 6th week firstly, and in all eyes in the 7th week. Corneal pannus formation in one eye was present in the 4th week, two eyes in the 5th week and three eyes in the 6th week. Retrocorneal fibrous membrane in one eye was detected at the 6th week and 3 eyes at the 7th week respectively. After injection of perfluorodecalin, endothelial cell density was significantly decreased (2,789 +/- 192 vs. 2,341 +/- 658, P < 0.01) and corneal thickness was increased. CONCLUSIONS: Perfluorodecalin injected into anterior chamber can lead to corneal damage and inflammatory reaction.

Tonge,S., Jones,L., Goodall,S., Tighe,B. The ex vivo wettability of soft contact lenses Current eye research 2001;23(1):51-59 [ Show Abstract ]

Purpose. To investigate the ex vivo wettability of Etafilcon A contact lenses over an eight hour period of wear and observe the influence of surfactant pre-treatment. Methods. Etafilcon A hydrogel lenses, comprising poly[2-hydroxyethyl methacrylate-co-methacrylic acid] and 58% water, were soaked for 12 hours in either 0.9% saline (control) or a 1% aqueous solution of poloxamine 1107 (treated). The advancing and receding contact angles were subsequently determined ex vivo after various periods of wear in six adapted contact lens wearers using a single-blind, randomised protocol. Contact angles were measured with a dynamic contact angle tensiometer, using the Wilhelmy plate technique. Patient comfort scores were recorded and the static surface tensions of the probe fluids assessed. Results. Control lenses exhibited no change in wetting angles over time, indicating a lack of surface modification by components within the tear film. Treated lenses exhibited a significantly reduced advancing angle (p > 0.001) and hysteresis angle (p < 0.001) when compared with control lenses. In addition, treated lenses were consistently rated as being more comfortable than control lenses (p = 0.04). Conclusions. This study has shown clearly that new Etafilcon A lenses do not exhibit significant changes in wettability during the initial four hour wearing period. Pre-treatment of such lenses with a polymeric surfactant results in wetting of the lenses due to the adsorption of surfactant. The surfactant is retained by the lens for at least eight hours of wear, resulting in significant improvements in subjective comfort, especially over the first 30 minutes of wear.

2000

Chen,H., Ge,J., Liu,X., Lu,F. The clinical analysis of 260 combined surgery of glaucoma and cataract Yan ke xue bao = Eye science / "Yan ke xue bao" bian ji bu 2000;16(2):102-105 [ Show Abstract ]

PURPOSE: To evaluate the efficacy of the combined surgery of glaucoma and cataract. METHODS: We reviewed 260 consecutive cases (279 eyes) who underwent the combined procedure of glaucoma and cataract. The patients were divided into three groups: group 1: extracapsular cataract extraction combined with trabeculectomy; group 2: extracapsular cataract extraction and intraocular lens implantation combined with trabeculectomy; group 3: cataract phacoemulsification and intraocular lens implantation combined with trabeculectomy; We analyzed and compared the postoperative visual acuity (VA), intraocular pressure(IOP) and complications among three groups. RESULTS: 16.2%, 32.4% and 43.5% of patients in three groups achieved 0.3 or better VA. The VA improved rate were 46.6%, 70.4% and 78.3% respectively. The mean postoperative IOP of three groups were 12.72 +/- 6.66 mmHg(1 mmHg = 0.133 kPa), 13.01 +/- 5.26 mmHg, 12.63 +/- 4.66 mmHg(compared with preoperative IOP, P < 0.01). The complications of group 3 were much less than those of the other two groups. CONCLUSION: The combined surgery can control the IOP effectively; The triple procedure can improve the VA rapidly and the phacoemulsification technique can decrease the complications.

Chong,T., Simpson,T., Fonn,D. The repeatability of discrete and continuous anterior segment grading scales Optometry and Vision Science 2000;77(5):244-251 [ Show Abstract ]

Purpose: To investigate the repeatability of three anterior segment clinical grading scales: 1) verbal descriptors scale (VDS), 2) photographic matching scale (PS), and 3) continuous matching scale (CS). Methods: Five optometrists graded 30 slides each of 3-9-o'clock staining, bulbar redness, and palpebral conjunctival roughness twice, separated by at least a day. VDS and PS were five-point scales (0-4.) with half grades permitted. The CS was a 5-second, 240-frame video movie generated using morphing software. PS and CS grading was done with references presented on a computer screen. Results: Averaged across observers, the test-retest intraclass correlation, correlation coefficient of concordance, and Pearson's r ranged from 0.95 to 0.99 (all p < 0.001). Coefficients of repeatability using CS to grade all three ocular conditions ranged between 0.31 and 0.49. The corresponding PS and VDS coefficients of repeatability ranged between 0.37 and 0.49; PS generally had better repeatability than VDS. Conclusions: Each of the clinical grading scales was reliable. The coefficients of repeatability showed that bulbar redness and palpebral conjunctival roughness were graded with higher precision using CS.

Dumbleton,K., Jones,L., Chalmers,R., Williams-Lyn,D., Fonn,D. Clinical characterization of spherical post-lens debris associated with lotrafilcon high-DK silicone lenses CLAO Journal 2000;26(4):186-192 [ Show Abstract ]

Purpose: Experience with high Dk silicone hydrogel lenses has revealed post-lens debris, which is characterized by the appearance of spherical, translucent particles referred to as 'mucin balls.' The objectives of this analysis were to characterize the presence of mucin balls, determine whether any ocular characteristic predicts the development of mucin ball debris, and determine whether there is any association between mucin balls and the ocular response to contact lens wear. Methods: Ninety-two subjects wore lotrafilcon A lenses on an extended wear basis for up to 30 nights and were followed for 6 months. Mucin balls were graded on a 0 to 4 scale at three visits. Subjective ratings and biomicroscopic appearance were recorded at all visits. Results: Mucin balls were observed in 70% of subjects at one or more visits, and 29% of subjects at all three visits. There was no change in the mean grade of mucin balls over time. Mucin balls were graded > 1 in 20% of eyes, > 2 in 6% of eyes, and > 3 in 2% of eyes. Subjects who exhibited mucin balls at each clinical visit had significantly steeper keratometry readings along the flatter meridian (44.3 D) than those who never exhibited mucin balls (42.9 D, P<0.0001). The percentage of subjects who 'never' use lubricating drops was higher in the subjects with mucin balls (P=0.0014). No association was found between mucin ball observation and biomicroscopic appearance, inflammatory responses, or subjective responses. Conclusions: The presence of mucin balls does not appear to be detrimental to contact lens wear. Eyes with steeper corneal curvature were significantly more likely to present with mucin ball debris, indicating they may be a function of lens fit. Clinical factors that may be modified in order to menage the more severe presentation of mucin balls are the use of lubricating drops and the number of nights extended wear schedule.

Hrynchak,P., Simpson,T. Optical coherence tomography: An introduction to the technique and its use Optometry and Vision Science 2000;77(7):347-356 [ Show Abstract ]

This report describes the new optical imaging technique of optical coherence tomography (OCT). OCT is capable of high-resolution, micrometer-scale, cross-sectional imaging of biological tissue. The OCT for ophthalmic application uses 843-nm, near-infrared light, which produces a longitudinal resolution of 10 to 20 μm and a penetration depth of a few millimeters. The scans are displayed in a false color representation scale on which warm colors represent areas of high optical reflectivity and cool colors represent areas of minimal or no reflectivity. A cross-sectional view similar to a histology section is obtained. The cornea, iris, and lens may be visualized as well as the retina and optic nerve. OCT has been used to investigate several ocular diseases. These include macular disease, genetic retinal disease, retinal detachment and retinoschisis, choroidal tumors, optic nerve disorders, and glaucoma.

Pritchard,N., Jones,L., Dumbleton,K., Fonn,D. Epithelial inclusions in association with mucin ball development in high-oxygen permeability hydrogel lenses Optometry and Vision Science 2000;77(2):68-72 [ Show Abstract ]

Debris trapped behind contact lenses may be associated with adverse reactions in extended wear. Although streaks and clumps of cellular material have been reported after overnight wear of conventional materials, recent experience with several high-oxygen permeability (Dk), silicone-containing hydrogel lenses indicates that certain participants are prone to the development of a unique back surface debris. This debris forms as spherical, translucent entities and results in depressions within the ocular surface after lens removal. Little information is known about these spherical bodies, particularly with respect to their composition and development. In this report, we provide photographic evidence of this debris (sometimes termed 'mucin balls' or 'lipid plugs'), discuss its differential diagnosis and describe a case in which material seems to be embedded in the epithelium as a direct consequence of their presence.

Situ,P., Elliott,D. B. The detection of change in stereoacuity Chinese Journal of Optometry and Ophthalmology 2000;2(4):216-218 [ Show Abstract ]

Objective: To compare the repeatability of the Frisby, Randot and Howard-Dolman stereotests, and to determine the 95% confidence limits for the change of each test. Methods: Stereoacuity using the three clinical stereoacuity tests was measured in 26 healthy adult subjects with normal binocular vision. The subjects were retested approximately one week later. Results: The coefficients of repeatability for the three tests were ±2.7" (Frisby) ±8.0" (Randot) and ±9.3" (Howard-Dolman) and test-retest correlation coefficients were 0.91 (Frisby), 0.56 (Randot), and 0.60 (Howard-Dolman). Conclusion: The Frisby test showed the best repeatability and smallest range of normal values. For young adults, the 95% confidence limits for change were calculated to be ±2.7". If a young adult's stereoacuity measured with the Frisby test changes by more than this amount, then this should be considered a significant clinical change.

Sorbara,L., Chong,T., Fonn,D. Visual acuity, lens flexure, and residual astigmatism of keratoconic eyes as a function of back optic zone radius of rigid lenses Contact Lens and Anterior Eye 2000;23(2):48-52 [ Show Abstract ]

The purpose of this study was to determine whether the visual acuity of keratoconic eyes was affected by alteration of back optic zone radii (BOZRs) of rigid gas permeable lenses (RGP) contact lenses. Visual acuity, spherical and sphero-cylindrical over-refraction and keratometry of the front surface of the RGP lenses of nine keratoconic eyes were measured. The BOZR of the five lenses varied from steeper to flatter than that habitually worn by the subjects. The steepest lenses produced significantly greater lens flexure and residual astigmatism (P<0.002) and worse high and low contrast visual acuity with the spherical over-refraction (P<0.05). There was no statistical difference in visual acuity across the range of BOZR when a sphero-cylindrical over-refraction was applied. Thus reduced visual acuity in keratoconus with steep lenses is likely due to uncorrected residual astigmatism from a combination of several possible sources. © 2000 British Contact Lens Association.

1999

Dumbleton,K. A., Chalmers,R. L., Richter,D. B., Fonn,D. Changes in myopic refractive error with nine months' extended wear of hydrogel lenses with high and low oxygen permeability Optometry and Vision Science 1999;76(12):845-849 [ Show Abstract ]

Background: A small but significant increase in myopia after extended wear of low oxygen permeability (Dk) hydrogel lenses has been previously reported; however, the specific impact of hypoxia on refractive status and corneal curvature with extended wear are not well documented. The purpose of this study was to compare the refractive changes induced over a period of 9 months' extended wear with high-Dk fluorosiloxane hydrogel lenses and low-Dk hydrogel lenses. Methods: Adapted daily wear contact lens wearers were randomly assigned to one of two groups. The low-Dk group wore etafilcon A (Dk = 28) for up to 7 days and 6 nights and the high-Dk group wore Iotrafilcon A (Dk = 140) for up to 30 days and nights. Refractive error and corneal curvature were measured at 3-month intervals over 9 months of extended wear. Results: The etafilcon A group demonstrated an average increase in myopia of 0.30 D over the 9-month period; however, no change in spherical myopic correction was measured in the Iotrafilcon A group. The cylindrical component did not change in either group. A stratified analysis revealed a greater increase in myopia for low myopes than moderate myopes in the etafilcon A group but no difference in the Iotrafilcon A group. Keratometric analysis revealed no change in the etafilcon A group and a small degree of central corneal flattening in both major meridians of 0.35 D in the Iotrafilcon A group. Conclusions: Nine months of extended wear of low-Dk lenses is associated with a small degree of myopic progression in adult myopes that appears to be reversible. Wearing fluorosiloxane-hydrogel lenses of high-Dk had no impact on refractive error and may be associated with a small degree of central corneal flattening.

Fonn,D., Du Toit,R., Simpson,T. L., Vega,J. A., Situ,P., Chalmers,R. L. Sympathetic swelling response of the control eye to soft lenses in the other eye Investigative Ophthalmology and Visual Science 1999;40(13):3116-3121 [ Show Abstract ]

PURPOSE. To compare central corneal swelling and light scatter after 8 hours of sleep in eyes wearing high- and low-Dk hydrogel lenses and to the contralateral control eyes. METHODS. Twenty neophyte subjects wore a Lotrafilcon A (Dk, 140; Ciba Vision, Duluth GA) silicone hydrogel lens and an Etafilcon A (Dk, 18; Acuvue; Vistakon, Jacksonville, FL) 58% water content hydrogel lens of similar center thickness in random order in the right eye only, for overnight 8-hour periods. The contralateral nonwearing left eyes served as controls. Central corneal thickness was measured using an optical pachometer and light scatter using a Van den Berg stray-light meter before lens insertion, after lens removal on waking, and every 20 minutes for the next 3 hours. RESULTS. Central corneal swelling induced by the Etafilcon A lens on eye opening was significantly higher than with the Lotrafilcon A lens (8.66% ± 2.84% versus 2.71% ± 1.91%; P < 0.00001). Light scatter induced by the Etafilcon A lens on eye opening was significantly higher than with the Lotrafilcon A lens (46.09 ± 5.62 versus 42.78 ± 6.07 Van den Berg units, P = 0.0078). The swelling of the control eyes paired with the Etafilcon A lens- wearing eyes was also slightly but significantly higher than that of the control eyes paired with the Lotrafilcon A lens-wearing eyes (2.34% ± 1.26% versus 1.44% ± 0.91%; P = 0.0002). Light-scatter measurements were not significantly different between control sets of eyes but showed the same trend. CONCLUSIONS. In neophyte subjects, corneal swelling of the contralateral control eyes appears to be influenced by the swelling of the fellow lens-wearing eyes - that is, the swelling of the contralateral control eye was significantly lower when there was less swelling of the fellow eye wearing the high-Dk lens. Although there was no statistically significant difference in light-scatter measurements between the control sets of eyes, a trend similar to the corneal swelling results was observed, which could be used to support the suggestion that this may he a sympathetic physiological response rather than an unusual sampling coincidence.

Fonn,D., Situ,P., Simpson,T. Hydrogel lens dehydration and subjective comfort and dryness ratings in symptomatic and asymptomatic contact lens wearers Optometry and Vision Science 1999;76(10):700-704 [ Show Abstract ]

Purpose. To determine whether lens dehydration correlates with discomfort, dryness, and noninvasive tear break-up time in symptomatic and asymptomatic contact lens wearers and whether dehydration of the two lens types varies. Method. Twenty hydrogel contact lens wearers with dryness- related symptoms and 20 asymptomatic wearers wore an Etafilcon A lens (Acuvue; Vistakon, Inc., Jacksonville, Florida) in one eye and an Omafilcon A lens (Proclear; Biocompatibles, Norfolk, Virginia) in the contralateral eye for 7 h in a randomized, double-masked study. Lens water content was measured before and after 7 h of lens wear and prelens noninvasive tear film break-up time (NIBUT) was measured immediately after insertion and after 5 h of lens wear. Subjective comfort and dryness were rated at 0, 1, 3, 5, and 7 h of lens wear. Results. The symptomatic group had significantly reduced prelens NIBUT, decreased comfort, and increased dryness, but there was no difference between lenses for these variables. The Omafilcon-A lenses dehydrated significantly less than the Etafilcon A lenses, but there was no significant difference in lens dehydration between two subject groups. Conclusion. No correlation was found between lens dehydration and subjective dryness and comfort. Symptomatic hydrogel contact lens wearers with decreased wearing time had measurably decreased comfort, increased dryness ratings, and reduced NIBUT.

Fonn,D., Situ,P., Simpson,T. L. Oxygen and contact lens wear Chin J Optom and Ophthalmol 1999;1(3):185-189

Mathur,A., Jones,L., Sorbara,L. Use of reverse geometry rigid gas permeable contact lenses in the management of the postradial keratotomy patient: Review and case report International Contact Lens Clinic 1999;26(5):121 [ Show Abstract ]

Radial keratotomy (RK) is a well-known procedure for reducing myopia. However, the complications associated with the procedure and the development of newer technologies, such as photorefractive keratectomy and laser-assisted in situ keratomileusis, has resulted in the technique of RK falling out of favor. A number of patients who received RK during the 1980s are now experiencing a shift in their prescription and are presenting to primary care practitioners for contact lens fitting. These patients pose a significant challenge to the contact lens practitioner, and novel methods frequently are required to fit corneas that exhibit such abnormal topography. This article reviews the potential problems associated with fitting patients who have received RK and describes a case in which a novel lens design was used to achieve a successful lens fit.

Vega,J. A., Simpson,T. L., Fonn,D. A noncontact pneumatic esthesiometer for measurement of ocular sensitivity: A preliminary report Cornea 1999;18(6):675-681 [ Show Abstract ]

Purpose. The aim of this investigation was to evaluate a prototype noncontact pneumatic esthesiometer for measuring sensitivity of the eye. Methods. To evaluate the instrument's repeatability, central corneal sensitivity was recorded on two separate occasions with a 24-h interval between the two measures. In a separate experiment, corneal edema was induced with a thick hydrogel lens, and the eye was closed and patched. Corneal sensitivity was measured before wearing the lenses for 3 h, immediately after lens removal, and 15 min later. Corneal sensitivity also was measured before the instillation of a single drop of proparacaine (Alcaine, 0.5%) and at 2 and 18 min later. Sensitivity was measured at the corneal apex and at a temporal conjunctival location 3 mm from the limbus. Results. A high correlation was found between clays 1 and 2 (r = 0.90; p = 0.0001). The coefficient of repeatability (COR = 0.87 mm Hg) showed that 95% of the difference between test and retest measures were between ±0.87 mm Hg. Corneal sensitivity decreased by 55% after lens-induced corneal swelling and by 159% after instillation of the topical anesthetic. Central corneal sensitivity was found to be significantly higher than that of the temporal conjunctiva (p = 0.0001). Conclusion. We conclude that this pneumatic esthesiometer provides repeatable and reliable measures of ocular-surface sensitivity.

1998

Dengis,C. A., Simpson,T. L., Steinbach,M. J., Ono,H. The Cyclops effect in adults: Sighting without visual feedback Vision research 1998;38(2):327-331 [ Show Abstract ]

When asked to look through a tube, younger children place it at the bridge of the nose, and not over one eye: the Cyclops effect. This is a natural response to a median plane egocenter. With maturity, the Cyclops effect disappears as we learn to overcame the consequences of an egocenter between the two eyes, and instead, to use the 'preferred' eye. We videotaped adults (n = 14) and children with normal vision (n = 30), children with comitant strabismus (n = 14), and adults and children (n = 14) with one eye enucleated as they attempted to look through a plastic tube. Immediately in front of the face was a liquid crystal window that could be either transparent or opaque. As the tube was raised, the window was made opaque-blocking sight of the target, their hands, and the tube. Most binocular observers placed the tube approximately at the bridge of the nose. This was significantly different from the response of the enucleated observers who put the tube 75% of the way to the remaining eye (P = 0.0001). All observers align, on average, with the measured location of their egocenter when asked to perform a monocular task without visual cues. Deprived of visual feedback, binocular observers show the Cyclops effect, regardless of age.

Elliott,D. B., Situ,P. Visual acuity versus letter contrast sensitivity in early cataract Vision research 1998;38(13):2047-2052 [ Show Abstract ]

Large and small letter contrast sensitivity and visual acuity were assessed in 37 elderly eyes (mean VA -0.01 logMAR, Snellen 6/6) and their lens opacities were categorised and graded using the LOCS III system. Large letter contrast sensitivity was often not reduced in cataract from age-matched normal values and provided limited information. Small letter contrast sensitivity was shown to be a more sensitive measure of early cataract than visual acuity and large letter contrast sensitivity. Its usefulness may be limited by its strong correlation with visual acuity (r2 = 0.70), which is the standard and traditional measure of vision in cataract.

Elliott,M., Fandrich,H., Simpson,T., Fonn,D. Analysis of the repeatability of tear break-up time measurement techniques on asymptomatic subjects before, during and after contact lens wear Contact Lens and Anterior Eye 1998;21(4):98-103 [ Show Abstract ]

This study assessed the repeatability of various methods of measuring tear break-up time (TBUT) with and without soft contact lenses (CLs).TBUT was measured on 22 subjects with the tearscope, videokeratoscope and slit-lamp before and after 30 min of soft CL wear, and immediately after CL removal. Slit-lamp corneal TBUT was measured with fluorescein and without fluorescein while wearing CLs. TBUT was measured three times on the right eye only, using each technique in randomised order. TBUT measurements on CLs were repeated a second day. TBUT measurements were highly variable under all conditions and our results indicated a lack of correlation between techniques. The videokeratoscope was the least repeatable; while the tearscope was the most repeatable technique.

Elliott,M., Simpson,T., Richter,D., Fonn,D. Repeatability and comparability of automated keratometry: The Nikon NRK-8000, the Nidek KM-800 and the Bausch and Lomb keratometer Ophthalmic and Physiological Optics 1998;18(3):285-293 [ Show Abstract ]

This study assessed the repeatability of the Nikon NRK-8000, the Nidek KM-800 and the Bausch and Lomb keratometer. In addition, the comparability of the Nikon NRK-8000 and the Nidek KM-800 are evaluated relative to the Bausch and Lomb keratometer. Measurements were taken with all three techniques on two separate occasions with a test-retest separation of at least 24 hr. The right eyes of 30 normal subjects were used. Repeatability and comparability statistics and plots were generated using matrix representations of dioptric power. The Nidek KM-800 coefficient of repeatability values were found to be 0.345, 0.187, and 0.321 in the vertical, torsional, and horizontal meridians while the Nikon NRK-8000 values were 0.346, 0.232, and 0.276 respectively.

Pritchard,N., Fonn,D. Post-lens tear debris during extended wear of hydrogels Canadian Journal of Optometry 1998;60(2):87-91 [ Show Abstract ]

Debris entrapment after overnight wear of hydrogel lenses has been implicated as a cause of adverse ocular responses. We conducted two short-term pilot studies to determine if post-lens debris is related to the duration of lens wear, lens binding after overnight wear, movement of the lens prior to sleep or lens type. Debris and lens movement patterns upon waking were examined after one night (1N), one day and one night (1D+N) and one week of extended wear (6N). Three lens types were used on 10 subjects for the 1N experiment, and one lens type was used on 6 different subjects for the 1D+N and 6N experiment. Debris did appear to increase with duration of wear and was observed in approximately 60% of subjects after 1N. The appearance of debris observed ranged from light grey streaks to small clumped patches. Acuvue was bound more frequently than Medalist and NewVue. Movement was re-established after approximately 4 minutes of eye opening; however, the lenses appeared more adherent after 6N of overnight wear than after 1N or 1D+N. Debris dissipated after approximately 15 minutes (range 9 to 24 minutes) following eye opening. No statistical association was made between debris, lens binding, movement and lens type in this small group of subjects. These experiments demonstrated that debris appears to increase with duration of wear, may be associated with lens binding in a larger group and is quite difficult to view and quantify.

Sorbara,L., Richter,D., Chong,T. Evaluation and comparison of videokeratoscopic simulated fluorescein programs 1998;60(3):158-163 [ Show Abstract ]

Software for designing rigid gas permeable contact lenses has been developed for a number of corneal topography systems. There are some common and some unique features in the fitting programs of these instruments. Three currently available instruments are compared and contrasted to traditional contact lens fitting. These instruments are the EyeSys (EyeSys Technologies), the EyeMap (Alcon) and the TMS (Computed Anatomy, Tomey).

1997

Doughty,M. J., Fonn,D., Richter,D., Simpson,T., Caffery,B., Gordon,K. A patient questionnaire approach to estimating the prevalence of dry eye symptoms in patients presenting to optometric practices across Canada Optometry and Vision Science 1997;74(8):624-631 [ Show Abstract ]

Objective. To collect questionnaire data from patients in a large clinical population that would allow for an estimate of the prevalence of self-reported symptoms of dry eyes. Methods. A 13-point questionnaire (The Canada Dry Eye Epidemiology Study, CANDEES) was mailed to all optometric practices in Canada in October 1994, with the request that it be completed by 30 successive nonselected patients. Results. Four hundred fifty sets of questionnaires (total, 13,517) were analyzed (a 15.7% return rate) from patients aged from 80 years; 55% were in the 21- to 50-year age group; 60.7% were female; and 24.3% were contact lens wearers. A total of 28.7% reported dry eye symptoms, of whom 24.2% reported concurrent dry mouth, 24.5% had worse symptoms in the morning, 30.3% reported concurrent lid problems, and 35.7% reported a history of allergies. Of the 3716 patients reporting symptoms, 62 (1.6%) were in the 'severe' category and 290 (7.8%) were in the 'constant but moderate' category. Contact lens wear, concurrent allergies, dry mouth, lid problems, or use of medications increased the chance of a patient reporting dry eye symptoms. Conclusions. The prevalence of patients reporting any level of symptoms of dry eyes was approximately 1 in 4; severe symptoms were reported by 1 in 225 patients.

Elliott,M., Simpson,T., Richter,D., Fonn,D. Repeatability and accuracy of automated refraction: A comparison of the Nikon NRK-8000, the Nidek AR-1000, and subjective refraction Optometry and Vision Science 1997;74(6):434-438 [ Show Abstract ]

This study assessed the repeatability of the Nikon NRK-8000, the Nidek AR-1000, and subjective refraction. In addition, the accuracy of the Nikon and the Nidek were evaluated in comparison to subjective refraction. Measurements were taken with all 3 techniques on 2 separate occasions with a test-retest separation of at least 24 h. The right eyes of 30 normal subjects were used. Repeatability and accuracy statistics and plots were generated using matrix representations of dioptric power. Subjective refraction was the most repeatable method, with the coefficient of repeatability (COR) found to be 0.611, 0.224, and 0.490 in the vertical, torsional, and horizontal meridians. The autorefractors' COR was found to range from 0.712 to 0.826 for the vertical and horizontal meridians, whereas the torsional meridian ranged from 0.224 to 0.319.

1996

Barton,J. J. S., Rizzo,M., Nawrot,M., Simpson,T. Optical blur and the perception of global coherent motion in random dot cinematograms Vision research 1996;36(19):3051-3059 [ Show Abstract ]

We evaluated the effect of +3.25 dioptres of optical blur on the discrimination of motion direction in random dot cinematograms. Dot displacement between frames varied from 2.1 to 63' of visual angle while the temporal interval was held constant. Optical blur worsened discrimination in three normal subjects at displacements below 16', but improved discrimination at displacements of 21' or more. In a second experiment, two subjects viewed equivalent velocity stimuli constructed with different combinations of temporal interval and spatial displacement. Results showed that the effect of blur was specific to displacement and not velocity. Furthermore, varying the dot density of the display showed that the effect of blur correlated with dot displacement and not the probability of dot mismatches. Since optical blur attenuates high spatial frequencies, this suggests that high spatial frequencies are important for motion perception when dot displacements are less than 16' to 21', but reduce motion perception at larger dot displacements. The use of random dot cinematograms in populations must take into account stimulus displacement and optical causes of reduced spatial acuity.

Barton,J. J. S., Simpson,T., Kiriakopoulos,E., Stewart,C., Crawley,A., Guthrie,B., Wood,M., Mikulis,D. Functional MRI of lateral occipitotemporal cortex during pursuit and motion perception Annals of Neurology 1996;40(3):387-398 [ Show Abstract ]

We performed functional imaging with a conventional 1.5-T magnetic resonance scanner in 9 normal subjects. We used a gradient-echo technique to examine changes in signal between periods when subjects viewed a stationary black-and-white grating, a moving grating, and when they followed a moving spot. We located image pixels with significant differences between the viewing conditions. In 7 subjects, these occurred in the lateral occipitotemporal cortex, a region previously identified as a putative human homologue of the motion-sensitive middle temporal area (MT, or V5) of monkeys. Signal intensity was greater during pursuit of the moving dot than during viewing of the moving grating with the eyes still, despite the fact that the moving grating generated more retinal image motion. In contrast, signal intensity in striate cortex was least during pursuit of the moving dot. These findings suggest that the lateral occipitotemporal cortex has extraretinal signals during pursuit. Such signals may include attentional input, corollary eye movement information, or even a pursuit command. Extraretinal signals suggest that the lateral occipitotemporal cortex may contain a human homologue not only of MT but also of other components of the monkey V5 complex, such as the medial superior temporal area.

Fonn,D., Pritchard,N., Garnett,B., Davids,L. Palpebral aperture sizes of rigid and soft contact lens wearers compared with nonwearers Optometry and Vision Science 1996;73(3):211-214 [ Show Abstract ]

Previous studies have shown that contact lens wear may affect palpebral aperture size (PAS). In this study, 74 wearers of rigid lenses were matched for sex and age with soft lens wearers and nonwearers. Partial face photographs were taken of all subjects, in the case of contact lens wearers, after lens removal. PAS was determined by measuring the resulting 35-mm transparencies on a Mitutoya profile projector. The mean PAS of the rigid lens wearers (9.76 ± 0.99 mm) was found to be significantly smaller than that of the soft lens wearers (10.24 ± 0.94 mm) and the nonwearers (10.10 ± 1.11 mm) (p = 0.0154, analysis of variance). There was no significant difference between the PAS of soft lens wearers and nonwearers. This study supports the hypothesis that rigid lens wear causes a decrease in PAS.

Pritchard,N., Fonn,D., Weed,K. Ocular and subjective responses to frequent replacement of daily wear soft contact lenses CLAO Journal 1996;22(1):53-59 [ Show Abstract ]

Purpose: A significant number of soft contact lens wearers develop complications as a result of lens contamination. We conducted a single-blind 2 year clinical trial to determine if scheduled frequent replacement of lenses decreases complications. Methods: One hundred nineteen non-contact lens wearers were fit with soft contact lenses and randomly assigned to 1 or 3 month replacement schedules or a non-replacement (control) group. All subjects were fit with 0.04 mm thick HEMA (water content: 38%) lenses to be worn on a daily wear basis only. A single multipurpose solution was prescribed for cleaning and disinfection. Results: The 2-year results showed a significantly greater number of subjects in the non-replacement group exhibited microcysts, infiltrates, clinically significant corneal staining, and limbal and bulbar injection. As a result of lens deposition and damage, approximately twice the number of unscheduled lens replacements per subject were necessary in the non-replacement group compared with the 1 and 3 month replacement groups. Overall subject satisfaction with lens wear decreased in the non-replacement group and increased in the 1 and 3 month replacement groups over the 2-year period. Conclusions: Frequent replacement of soft lenses for daily wear as compared to non-replacement daily wear: 1) is less likely to cause contact lens induced complications; 2) reduces the number of unscheduled lens replacements; and 3) improves satisfaction with lens wear.

Sorbara,L., Fonn,D., Holden,B. A., Wong,R. Centrally fitted versus upper lid-attached rigid gas permeable lenses. Part I. Design parameters affecting vertical decentration International Contact Lens Clinic 1996;23(3):99-104 [ Show Abstract ]

The purpose of this study was to develop rigid gas permeable lens designs that would facilitate upper lid attachment and central (interpalpebral) positions. A pilot study was conducted with trial lenses of varying back surface designs and axial edge lifts (AELs) with and without lenticulated front surface designs. From this study, the final upper lid attachment lens was designed to have high AELs (150–300 mm) and a minus carrier lenticulation. The centered lenses had an AEL of 110 mm, with thin edges. Forty-one neophyte subjects were fitted with these two designs to be worn contralaterally for an 8-month period during which the consistency of the lens position was examined. We were unable to achieve upper lid attachment on 6 subjects, and a further 10 were discontinued for other reasons. Of the remaining 25 subjects who completed the study, 80% had consistent upper lid attachment in the one eye and a centered lens in the other, over the eight visits. The balance of the subjects demonstrated correct lens positioning for at least 50% of the visits. The lens design factors that correlated with vertical decentration of the lenses were AEL (r = 0.614), edge thickness (r = 0.751), and front surface carrier radius (r = 0.654).

1995

Doughty,M. J., Potvin,R., Pritchard,N., Fonn,D. Evaluation of the range of areas of the fluorescein staining patterns of the tarsal conjunctiva in man Documenta Ophthalmologica 1995;89(4):355-371 [ Show Abstract ]

Fluorescein dye is commonly used to highlight the tarsal conjunctiva in man to facilitate diagnosis of papillary conjunctivitis. A quantitative analysis of the fluorescein-highlighted features could be useful in both assignment of severity grades as well as for objective comparisons but no data is available on the distributions of sizes (areas) of these features. An exploratory, range-finding study was undertaken to provide data on feature areas that might be encountered. After application of fluorescein, 35 mm photographs were taken at a fixed distance with zone 1/zone 2 (Allansmith) of the tarsal plate aligned perpendicular to the camera. The photographs were projected, an overlay of 150 to 180 contiguous features outlined by fluorescein made and planimetry used to assess the areas and area distributions of the features on tarsal plates clinically graded with stages 1 to 4 papillary hypertrophy. For zone 1 of the tarsal plate in asymptomatic subjects, a fluorescein solution highlights the limits of features that enclose an area averaging 30,000 μm2 (range 8000 to 120,000; median area of close to 35,000 μm2). The areas of these features were generally normally distributed and there was little variation in feature areas across the zone. At different stages of clinical papillary conjunctivitis, the areas of the negative staining patterns are larger. Averages of 60,000 to 90,000 μm2, median values of close to 70,000 μm2 and individual feature areas up to 350,000 μm2 were seen in mildly symptomatic patients. These distributions were generally heterogeneous and showed a skewed distribution. Areas averaging up to 0.755 mm2 (range 0.6 to 3.2 mm2) were measured in moderate to severe papillary hypertrophy.

Fonn,D., Gauthier,C. A., Pritchard,N. Patient preferences and comparative ocular responses to rigid and soft contact lenses Optometry and Vision Science 1995;72(12):857-863 [ Show Abstract ]

Patient preferences and ocular responses were compared between rigid and soft contact lenses by randomly fitting 32 neophyte subjects with a rigid lens in 1 eye and a soft lens in the contralateral eye. Twenty-seven of 32 subjects completed the 3-month study and 16 subjects were willing to continue for an additional 3-month extension. Subjects preferred the comfort and handling of the soft lens but preferred the vision provided by the rigid lens and initially its ease of maintenance. There was also a marked preference for the soft lens when all aspects of lens wear were compared. Objectively, the rigid lenses were responsible for more ocular changes than the soft lenses. Palpebral aperture sizes of the rigid gas permeable (RGP) wearing eyes decreased significantly (0.5 mm; p < 0.05) compared to the soft lens wearing eyes. The incidence of corneal staining was significantly greater in the rigid lens wearing eye (50% RGP vs. 22% soft) but limbal injection was greater in the soft lens wearing eye (18% soft vs. 6% RGP). Refractive sphere, cylinder, and corneal astigmatism decreased in the rigid lens wearing eye after 3 months. This daily wear clinical trial has shown a marked subjective preference for wearing soft lenses with fewer short-term ocular effects.

Potvin,R. J., Fonn,D., Sorbara,L. Comparison of polycarbonate and steel test surfaces for videokeratography Journal of Refractive Surgery 1995;11(2):89-91 [ Show Abstract ]

BACKGROUND: Assessing video imaging systems for measuring corneal topography often requires test surfaces. Steel bearings have been employed, but manufacturers caution that high reflectance (>90%) relative to the eye (<10%) may compromise test findings. The differences between steel and polycarbonate test surfaces are quantified in this study. METHODS: Images of a steel and a polycarbonate sphere of known radius of curvature were obtained with the Tomey/Computed Anatomy Topographic Modeling System (TMS, Cambridge, Mass). Analysis was performed on the raw video data files and the resultant surface curvature estimates. RESULTS: The raw video images differed sufficiently to affect image processing. Polycarbonate yielded consistently better images. Many steel images (approximately 25%) contained data points that could not be processed; calculated surface contour was more variable for these. Differences were less obvious when these images were removed from the pool. CONCLUSIONS: Results support the manufacturer's caution against the use of steel surfaces for testing or calibration of the TMS instrument. Problems appear due to the fundamental differences in the intensity distributions of video images captured from high- and low-reflectance surfaces.

Pritchard,N., Fonn,D. Dehydration, lens movement and dryness ratings of hydrogel contact lenses Ophthalmic and Physiological Optics 1995;15(4):281-286 [ Show Abstract ]

Previous studies have shown that soft lenses dehydrate during lens wear. The purpose of this study was to determine the dehydration time course of 38% water content non-ionic Medalist(®), 58% ionic Acuvue(®) and 74% non-ionic Permaflex(®) lenses, and the relationship between dehydration and in vivo diameter, movement and symptoms of dryness. Nineteen subjects randomly wore three pairs of lenses, each for 7 h. Lens movement and diameter were measured in vivo and hydration after lens removal at 1, 3 and 7 h. Dryness was rated by the subjects using a visual analogue scale. A separate experiment was conducted to measure hydration changes after 7 continuous hours of lens wear. The water content of all three lens types decreased significantly over 7 h with Acuvue decreasing more than the Permaflex and Medalist(®) lenses in the interrupted and continuous experiments (ANOVA P < 0.05). Dehydration of Acuvue was significantly greater in the 7 h continuous experiment (9.0 ± 2.6% H2O, ANOVA P = 0.0062) compared to the interrupted experiment. Hydration levels measured for Acuvue lenses on subjects for control purposes at 0, 1, 3 and 7 h showed no difference over time (ANOVA P = 0.0711). Movement of Permaflex lenses decreased 0.60 ± 0.57 mm (ANOVA P = 0.0005) over 7 h and the in vivo diameter of Acuvue lenses decreased by 0.12 ± 0.16 mm (ANOVA P = 0.0569). Dryness ratings increased significantly and equally for all three lenses over 7 h (ANOVA P = 0.9833). No correlation was found between lens dehydration, movement, diameter and dryness with the exception of a weak significant (r = 0.5, P < 0.05) correlation between dehydration and dryness for Permaflex. The results of the study suggest that dehydration of soft lenses over a 7 h period does not significantly affect the clinical performance (dryness and movement) of the three lens types.

Regan,D., Simpson,T. Multiple sclerosis can cause visual processing deficits specific to texture-defined form Neurology 1995;45(4):809-815 [ Show Abstract ]

We performed the following tests in 25 patients with multiple sclerosis (MS) and 25 age-matched control subjects: recognition of texture-defined (TD) letters; recognition of motion-defined (MD) letters; and recognition of luminance-defined (LD) letters of 96% and 11% contrasts. Six patients with normal visual acuity were abnormal on recognizing TD letters, of whom one gave normal results on all other tests. Eleven patients were abnormal on MD letter recognition, of whom four gave normal results on all other tests. Visual acuity for letters of 11% contrast were abnormally low in seven patients, of whom two gave normal results on all other tests. We conclude that the neural mechanisms underlying recognition of TD, MD, and low-contrast LD letters in subjects with normal visual acuity are sufficiently different that they can be differentially damaged by MS. Therefore, TD, MD, and LD letter tests provide complementary information. We suggest that the detection of TD letters can be disrupted by demyelination of long-range horizontal connections between orientation-tuned neurons in the striate cortex.

Simpson,T. L. A comparison of six methods to estimate thresholds from psychometric functions Behavior Research Methods Instruments & Computers 1995;27(4):459-469 [ Show Abstract ]

There are many ways in which to estimate thresholds from psychometric functions. However, almost nothing is known about the relationships between these estimates. In the present experiment, Monte Carlo techniques were used to compare psychometric thresholds obtained using six methods. Three psychometric functions were simulated using Naka-Rushton and Weibull functions and a probit/logit function combination. Thresholds were estimated using probit, logit, and normit analyses and least-squares regressions of untransformed or z-score and logit-transformed probabilities versus stimulus strength. Histograms were derived from 100 thresholds using each of the six methods for various sampling strategies of each psychometric function. Thresholds from probit, logit, and normit analyses were remarkably similar. Thresholds from z-score- and logit-transformed regressions were more variable, and linear regression produced biased threshold estimates under some circumstances. Considering the similarity of thresholds, the speed of computation, and the ease of implementation, logit and normit analyses provide effective alternatives to the current ''gold standard''-probit analysis-for the estimation of psychometric thresholds.

Simpson,T. L. Vision thresholds from psychometric analyses: Alternatives to probit analysis Optometry and Vision Science 1995;72(6):371-377 [ Show Abstract ]

Vision scientists and clinicians regularly obtain measures of vision and determine a person's vision threshold by choosing one of numerous methods of analysis. Analytical methods differ in their presumptions about the measures, in their complexity and in the ease of obtaining the threshold estimate. In light of these differences among so-called methods of psychometric analysis, the question is, "Do various analytical methods provide essentially equivalent vision threshold estimates or are there consequential differences that require consideration?" Measures of visual acuity, motion processing, and texture processing were obtained from 20 subjects. Each set of measures was analyzed by five psychometric methods: Logit Analysis, Normit Analysis, and linear regression of z-score transformed, logit transformed and untransformed probabilities vs. stimulus strength. The resulting thresholds were compared to the threshold obtained from Probit Analysis, which was used as a reference or "gold standard." Thresholds from the procedures were remarkably similar to those from Probit Analysis. In addition, examination of the speed of the procedures revealed that Probit Analysis was up to 10 times slower than some of the others. Considering the similarity of thresholds, the speed of computation, and the ease of implementation, Logit and Normit Analyses especially provide effective alternatives to the current gold standard, Probit Analysis, for the estimation of psychometric thresholds. In addition, z-score, logit, and linear regressions also produced unbiased threshold estimates under many circumstances, but the latter method should be applied with some caution.

Simpson,T. L., Regan,D. Test-retest variability and correlations between tests of texture processing, motion processing, visual acuity, and contrast sensitivity Optometry and Vision Science 1995;72(1):11-16 [ Show Abstract ]

PURPOSE: To compare the test-retest variability (reliability) and the relations among clinical tests of texture and motion processing, visual acuity for high- and low-contrast letters, and the Pelli-Robson contrast sensitivity test. METHODS: In 20 normally sighted subjects, monocular visual acuity for letters of 96% and 11% contrast, Pelli-Robson contrast sensitivity, and motion-defined and texture-defined letter recognition thresholds were measured on each of two different days. RESULTS: Test-retest correlation coefficients were 0.75, 0.91, 0.61, 0.90, and 0.84 and bivariate test-retest regression slopes were 1.0, 1.1, 0.8, 1.0, and 1.2 for high- and low-contrast acuity, contrast sensitivity, and motion and texture processing, respectively. The inter-test correlations with both test and retest significant were as follows: visual acuity for high-contrast letters vs. visual acuity for low-contrast letters; and recognition threshold for texture-defined letters vs. acuity for letters of both high and low contrast. CONCLUSION: Test-retest variability for the tests of motion and texture processing were at least as low as for established clinical tests of high and low contrast acuity and contrast sensitivity. We conclude that these new tests offer a reliable means of obtaining clinical information which complements that provided by conventional tests with luminance-defined letters.

Sivak,J. G., Herbert,K. L., Fonn,D. In vitro ocular irritancy measure of four contact lens solutions: Damage and recovery CLAO Journal 1995;21(3):169-174 [ Show Abstract ]

We measured the potential toxicity of four contact lens solutions using an in vitro approach in which the optical quality of the cultured bovine lens was measured as a function of exposure to each substance tested. This approach uses an automated scanning laser to measure the focal variability of lenses contained in special culture cells and maintained under long-term culture conditions. The products tested included three rigid gas permeable contact lens conditioning solutions (Boston Conditioning Solution(TM), Boston Advance Conditioning Solution(TM), and a new formulation of Boston Advance Conditioning Solution(TM) [Polymer Technology]) and one soft contact lens disinfecting system (OptimEyes(TM); Core Technologies). The results indicate a wide range of toxicologic potential that corresponds, on a relative basis, with published in vivo evaluation of the same substances. Moreover, the results demonstrate that this in vitro system can be used to evaluate the potential for recovery from damage caused by the four solutions tested.

Skaff,A., Cullen,A. P., Doughty,M. J., Fonn,D. Corneal swelling and recovery following wear of thick hydrogel contact lenses in insulin-dependent diabetics Ophthalmic and Physiological Optics 1995;15(4):287-297 [ Show Abstract ]

Thick, 0.34 mm, 38% water hydrogel lenses were fitted, under a pressure patch, to one eye of 18 type I diabetic patients (aged 18-40 years) to assess the acute response to hypoxia and hypercapnia; the response was compared with that in 18 healthy, aged-matched nondiabetic subjects; the closed-eye lens wear was started mid-morning. Pre-lens wear assessments were made of acuity, intraocular pressure (IOP), central corneal thickness (CCT) and corneal appearance by biomicroscopy. The mean duration of the diabetes was 13±7 years and the Baseline CCT values were marginally greater in diabetic patients (600±33μm) compared with a group of non-diabetic control subjects (584±26μm; P>0.5). A 7.7±2.1% increase in CCT was measured after 3h lens wear in the diabetic patients while an average 10.6±2.4% increase in CCT was measured in the control subjects (P<0.05). The recovery of corneal thickness to baseline values in diabetic patients was slower (at 44.8±2.0% per hour) than the control subjects (53.9±2.1 per hour; P<0.05) although recovery of corneal thickness occurred in both groups within 2.5-3h, IOP values (non-contact tonometry) were higher in the diabetic patients than in the controls (14.5±2.9 vs 12.4±1.7mmHg; P<0.01). Overall, those corneas with greater baseline CCT values tended to swell less than those with lower baseline CCT values (r = 0.582). Positive correlations were also found between corneal thickness and IOP and blood glucose. The diabetic patients thus tended to have slightly thicker corneas (but this could be related to blood glucose or IOP rather than true corneal disease) and also had corneas that tended to swell less with a contact lens stress test (but this could be constitutively due to the slight oedema already present). The different corneal response in diabetic patients may thus be the result of physical determinants such as initial oedema and IOP and not the result of a disease of the cornea itself.

1994

Potvin,R. J., Doughty,M. J., Fonn,D. Tarsal conjunctival morphometry of asymptomatic soft contact lens wearers and non-lens wearers International Contact Lens Clinic 1994;21(11-12):225-231 [ Show Abstract ]

Soft contact lens wear is known to induce changes in the tarsal conjunctiva; qualitative grading is the current standard for recording such changes. This project was designed to investigate the usefulness of quantitatively assessing the morphometry of the tarsal conjunctiva, through a comparison of eight asymptomatic long-term soft contact lens wearers and eight nonwearers. The right tarsal plates were photographed after staining with fluorescein. A subjective assessment and grading of the fluorescein-highlighted tarsal plates was not able to distinguish the wearers and nonwearers. However, morphometry of the fluorescein-highlighted features across zone 1 of each tarsal plate revealed two basic patterns to the histograms of the areas of these features in both contact lens wearers and nonwearers. The analyses suggest that there are at least two types of "features" highlighted by fluorescein, evident in both wearers and nonwearers. Asymptomatic long-term soft lenswear appears to reduce the size of "small features" and increase the size and variability of "large features". These differences could be shown to be statistically significant. Further refinement of these quantitative assessment techniques should be useful in defining contact lens wear-related changes in the tarsal conjunctiva. © 1994.

1993

Doughty,M. J., Fonn,D. Pleomorphism and endothelial cell size in normal and polymegethous human corneal endothelium International Contact Lens Clinic 1993;20(5-6):116-123 [ Show Abstract ]

The normal human corneal endothelium is composed of a tessellated mosaic of cells with different numbers of sides. A number of published studies indicate that while six-sided cells predominate (58-74%), significant numbers of five-sided (13-22%) and seven-sided (11-18%) are present along with occasional four-, eight-, nine- and even 10-sided cells. In polymegethous endothelia (associated with polymethyl methacrylate [PMMA] lenses and extended wear soft contact lenses [EW SCL]), the decline in the percentage of six-sided cells is associated with increases in the percentage of four-, five-, seven-, or eight-sided cells. Our analysis of photo slit-lamp micrographs revealed that the four- or five-sided cells tend to be smaller than the six-sided cells, whereas the seven-sided or larger cells are larger than six-sided cells. As a result, analyses of the average areas of each cell type indicate that the greater the pleomorphism (associated with polymegethism) the steeper the slope of a plot relating cell areas to the number of cell sides. The relationship is not necessarily linear (as suggested in previous reports), but does indicate that the remodeling of the endothelium (when significant cell loss is not evident) may follow some formal ordered process. © 1993.

Doughty,M. J., Fonn,D., Nguyen,K. T. Assessment of the reliability of calculations of the coefficient of variation for normal and polymegethous human corneal endothelium Optometry and Vision Science 1993;70(9):759-770 [ Show Abstract ]

In endothelial morphometry, uncertainty exists concerning how many cells should be measured. A study was undertaken to calculate mean cell area and coefficient of variation (COV) of cell areas using different numbers of cells from photo-slitlamp pictures and published micrographs. Groups of 65, 95, or 165 tesselated cells were measured and area and COV values calculated in progressive sets of 5 cells; each pair of values was compared to that obtained using all cells in each group. The results show that, for both normal (homomegethous) and irregular (polymegethous) endothelia, even cell counts as low as 50 cells can usually provide average cell area values that are within 1 to 2% of the values estimated from larger groups of cells. A similar reliability was observed for estimates of COV for normal endothelia. However, for polymegethous endothelia, even with 100 cells analyzed, the estimates of COV generally only approached a +/- 4% reliability. This uncertainty in COV estimates should be considered in both comparative studies and in regression analyses of COV changes over time or other variables.

Elliott,D. B., Fonn,D., Flanagan,J., Doughty,M. Relative sensitivity of clinical tests to hydrophilic lens-induced corneal thickness changes Optometry and Vision Science 1993;70(12):1044-1048 [ Show Abstract ]

The relative sensitivity of the van den Berg Straylightmeter, slitlamp biomicroscopy, a modified optical pachometer, Bailey-Lovie logMAR visual acuity (VA), and two glare tests (The Brightness Acuity Tester used with 10% contrast VA and Pelli-Robson contrast sensitivity) to hydrophilic contact lens-induced edema was assessed in 19 subjects (mean age 25.9 +/- 4.5 years). After baseline assessments, subjects wore thick hydrogel lenses on one eye which was patched tightly for 3 h. Assessments were repeated at frequent intervals after lens removal to assess recovery. None of the pachometer measurements returned to baseline within the 2-h monitoring period, although the majority were within 2% of baseline corneal thickness. The average time for the Straylightmeter scores to recover to baseline values after the lens removal was 90 min, which was similar to the time when visible edema at the slitlamp disappeared. The average time for return to baseline of logMAR VA and the two glare tests was consistently two to three times shorter than the time for the Straylightmeter score. The Straylightmeter therefore provided assessments of corneal edema similar to slitlamp examination and was more sensitive than VA or glare testing.

Elliott,D. B., Yang,K. C. H., Dumbleton,K., Cullen,A. P. Ultraviolet-induced lenticular fluorescence: Intraocular straylight affecting visual function Vision research 1993;33(13):1827-1833 [ Show Abstract ]

Ultraviolet radiation (UVR) excitation of fluorophores within the crystalline lens results in intraocular straylight. These fluorescent emissions are known to increase with age. The visual effect of this increase in fluorescent straylight has not previously been published. In this study, the visual deficit associated with UV-induced lenticular fluorescence was measured for 61 normal subjects between the ages of 21 and 80 yr of age using the Regan visual acuity charts at varying levels of contrast. UVR was shown to decrease low contrast acuity and this loss increased linearly with age.

Simpson,T. L. Effect of asymmetry on calculations of convergence in prism diopters Optometry and Vision Science 1993;70(3):201-204 [ Show Abstract ]

Calculations of convergence in units of prism diopters are based on an assumption that convergence is symmetrical, that is, the visual axes intersect on the median plane. The effect of departure from symmetrical convergence is shown to produce systematic errors in calculations of convergence distance, if the convergence angle is constrained to be constant. On the other hand, if the convergence distance is constrained to be constant, departure from symmetry results in a systematic reduction in the convergence angle. Because these errors are disregarded in the specification of convergence in prism diopters, care should be taken in using these units for larger amounts of asymmetrical convergence.

1992

Simpson,T. Monocular acuity in the presence and absence of fusion Optometry and Vision Science 1992;69(5):405-410 [ Show Abstract ]

Because little is known about monocular acuity during binocular fusion, acuity of the right eye was measured in binocularly normal subjects, with the fellow eye open or fully occluded. The target was flashed for 65 ms or presented sinusoidally for 1 s. Subjects had both eyes optimally focused, or the right eye defocused by +3.00 D. Monocular acuities were equivalent during fusion or occlusion when both eyes were optimally focused. Acuity of the defocused eye was reduced when the fellow eye was open compared to when it was occluded. Suppression of the blur, therefore, produced a measurable reduction in recognition thresholds. As monocular acuity was not measurably affected by the fellow eye when each eye was in focus, the finding that monocular vision is improved with the fellow eye occluded should be ascribed to something other than suppression or more sensitive spatial measures of the suppression should be obtained.

Sorbara,L., Fonn,D., MacNeill,K. Effect of rigid gas permeable lens flexure on vision Optometry and Vision Science 1992;69(12):953-958 [ Show Abstract ]

The flexure of spherical rigid lenses (various materials) and a soft lens was measured using automated over-keratometry on 6 adapted rigid lens wearers (12 eyes) whose corneal toricity ranged from 1.37 to 3.87 D. The results showed: (1) that there was no significant difference in flexure between polymethyl methacrylate (PMMA), silicone acrylate, and the fluorosilicone acrylate lenses (whose Dks ranged from 0 to 115). However, Advent (fluoropolymer) did flex significantly more than the other rigid lenses, and significantly less than the soft lens (Bausch & Lomb U4) and (2) that lens flexure of the rigid lenses did not alter over a 2-h period. We also measured high and low contrast visual acuity (HCVA and LCVA), and the results from subjects wearing Advent and the soft lens were significantly worse than with the other rigid lenses. Finally, the results of this study showed no correlation between rigid lens flexure and permeability and between rigid lens flexure and visual acuity when Advent was excluded from the linear regression analysis.

1991

Fonn,D., Gauthier,C. Prevalence of superficial fibrillary lines of the cornea in contact lens wearers and nonwearers Cornea 1991;10(6):507-510 [ Show Abstract ]

Superficial corneal epithelial striations described as fibrillary lines have been documented as a common finding in normal and keratoconic eyes. We first noticed these fine white structures in both soft and rigid contact lens wearers. This prompted us to investigate whether the prevalence of these lines was greater in contact lens wearers than in non-lens wearers. Our results indicated that although the lines were more frequently observed in lens wearers (35.7% of 42 patients) than in the controls (19.0% of 42 patients), the difference was not statistically significant (p = 0.0867, χ2 analysis). We speculate that lens wear makes fibrillary lines more visible but is not responsible for their presence.

1990

Fonn,D., Anderson,R., Sorbara,L., Callender,MGE A survey of optometric contact lens use in Canada Canadian Journal of Optometry 1990;52(3):90-95 [ Show Abstract ]

A questionnaire was mailed to all optometrists in Canada for the purpose of conducting a national survey on the habits of prescribing contact lenses and care products. Optometrists were requested to complete the survey for each practice for the time period of April 1, 1987 - April 1, 1988. The results of the survey revealed a response from slightly more than 10% (221) of the optometric practices. The vast majority of patients fitted with contact lenses (81%) were in the 17-44 year age group and 50% of the patients fitted with contact lenses in that period had never worn lenses previously or had not worn lenses for five years prior to the survey period. A high proportion of soft lenses (85%) were prescribed compared to rigid lenses (14%). Hydrogen peroxide was the preferred method of disinfection and extended wear was moderately popular.

1988

Fonn,D., Holden,B. A. Rigid gas-permeable vs. hydrogel contact lenses for extended wear American Journal of Optometry and Physiological Optics 1988;65(7):536-544 [ Show Abstract ]

A clinical trail was conducted to compare the extended wear performance of rigid gas-permeable (RGP) contact lenses with that of soft lenses. Subjects were fitted with a RGP lens (Boston IV) in one eye and a soft lens (Bausch & Lomb 'O' series) in the other eye, and wore them on an extended wear basis for up to 3 months. No subjects developed any acute adverse reactions in the RGP lens-wearing eye. After the initial adaptation period, subject acceptance of RGP extended wear in terms of vision and comfort was superior. The RGP lenses also induced less chronic hypoxic stress than hydrogel lenses of comparable Dk/L, as evidenced by the presence of epithelial microcysts. Several complications of RGP extended wear were observed including lens binding, blepharoptosis, transient pupil size increases, and corneal staining. As hypoxia-induced corneal changes, such as microcysts and striae, were observed in the RGP lens-wearing eyes, we consider that these particular RGP lenses do not have adequate oxygen transmissibility for successful long-term extended wear. However, if RGP lens materials of higher oxygen transmissibility and better designs can be attained, the potential of RGP extended wear would appear promising.

Sorbara,L., Talsky,C. Contact lens wear in the dry eye patient predicting succes and achieving it
Canadian Journal of Optometry 1988;50(4):234-241 [ Show Abstract ]

Clinical diagnosis of dry eye and its implications in successful contact lens wear has not been well defined. Two thousand patient files from the University of Waterloo, School of Optometry, Contact Lens Clinic were surveyed and 54 patients, diagnosed as having dry eye, were fit with contact lenses and were included in a retrospective prevalence study. Diagnostic procedures commonly used in the detection of dry eye were evaluated in terms of their ability to accurately predict successful lens wear in the dry eye patient. The Tear Break Up Time was found to be the most valid in identifying those patients who are less likely to achieve success. Schirmer`s Test was found to be of little predictive value. Possible correlations between lens type and successful lens wear were investigated. Dry eye patients fit with low water content, thin (0.06-0.10 mm) hydrogel lenses of differing water content or rigid gas permeable lenses. Additional factors which may serve to increase successful lens wear are briefly discussed.

Scientific Presentations

2024

Fadel D, Wong S, Luensmann D, Guthrie S, Seo J, Woods J, Voltz K, Vega J. The use of Scleral Lenses to Manage Dry Eye Symptoms in Habitual Soft Lens Wearers Global Specialty Lens Symposium, Las Vegas, Jan 20, 2024 [ Show Abstract ]

PURPOSE: To determine if scleral lenses (SLs) with and without Hydra-PEG coating can improve ocular comfort and reduce dryness in symptomatic soft lens wearers.

METHODS: This prospective, randomized, double masked, 1-month bilateral cross over, daily wear study recruited symptomatic soft lens wearers who presented with healthy eyes and a CLDEQ-8 score ≥12 with their habitual contact lens (hab-CL). Eligible participants were fit with SLs (Onefit MED, CooperVision, Inc.) and wore these with and without HydraPEG coating (coated (C-SL) / uncoated (U-SL)) in a randomized order for 1 month per pair. Participants completed a CLDEQ-8 and rated comfort, vision clarity, dryness and handling after each 1-month wear period using a 0-10 scale (10=best) and these data were compared between study SLs and to their hab-CL.

RESULTS: Twenty participants (16F:4M), mean age 29.3±12.4 years [18-64 years] completed the study. The mean refraction of the right eye was Sph -4.69±3.42DS [-15.25 to -0.50DS] and Cyl -0.84±0.79DC [0.00 to -2.75DC]. At 1 month, the CLDEQ-8 score improved with both study SLs in comparison to hab-CL (p0.05) and both were rated better compared to hab-CL (p0.05). At study exit, 9 of the 20 participants requested the SL details to be shared with their eye care professional because they wanted to continue wearing these SLs in future.

CONCLUSIONS: Switching symptomatic soft lens wearers into scleral lenses improved comfort and reduced dryness symptoms after 1 month of wear, with little reduction in ease of lens handling. Subjective ratings were similar with uncoated and HydraPEG coated scleral lenses, with the latter providing slightly better visual clarity.

Fadel D, Wong S, Luensmann D, Guthrie S, Woods J, Jones L, Voltz K, Vega J. Evaluation of Scleral Lenses in the Management of Dry Eye Symptoms American Academy of Optometry Meeting, Indianapolis, Nov 8, 2024

Fromstein S, Guthrie S, Acs M, Caffery B, Di Marco A, Pal S, Ramdass S, Thakrar V, Zeidenberg M, Jones D, Chow A. Clinical Practice Patterns for the Initial Management of Young Myopic Patients in Canada American Academy of Optometry Meeting, Indianapolis, Nov 7, 2024

Garg P, Shokrollahi P, Phan CM, Jones L. 3D printing of PVA loaded ocular inserts for ocular drug delivery The Association for Research in Vision and Ophthalmology, Seattle, WA, May 9, 2024 [ Show Abstract ][ PDF ]

Purpose: To develop ocular inserts comprised of polyvinyl alcohol (PVA) and gelatin methacrylate (GelMA), using 3D printing technology.

Methods: Inserts were synthesized using a bioink formulation consisting of 10% (w/v) GelMA, 5% (w/v) and 7.5% (w/v) PVA, 0.6% (w/v) lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP), and 5% (v/v) yellow dye as a light absorbing agent to improve print resolution. They had a 4mm diameter, 1mm thickness and were fabricated using a commercial masked-stereolithography (mSLA) 3D printer at 95% humidity and 37°C temperature. Morphology of the inserts was investigated by freeze-drying samples and imaging them using a scanning electron microscope (SEM). Release of PVA over 5 hours was studied by incubating at 35°C in PBS in an incubator shaker at 50rpm. The hydrogel samples were freeze dried and their equilibrium swelling was studied in PBS using gravimetric method.

Results: The PVA-loaded ocular inserts were 3D printed within 30 minutes. SEM images showed that 7.5% PVA loaded inserts had more uniform pore size distribution compared to the gels with no PVA. Approximately 37% of PVA was released within the first 2 hrs from the inserts containing PVA, and the release continued up to approximately 4 hrs before reaching a plateau. The release kinetics can be attributed primarily due to passive diffusion. The swelling curves of these hydrogels suggest that they reach equilibrium swelling within 24hr. From the slope of the swelling curve in the first hour, it can be inferred that swelling happens at a slower rate for GelMA/PVA compared to GelMA alone. This slower swelling rate helps to control the release and supports a sustained release of PVA from the combination.

Conclusions: This study showed that a GelMA-PVA based bioink can be used to 3D print ocular inserts that can release PVA for up to 4 hours. Future work will focus on designing 3D scaffolds to increase the release duration of PVA from these gels.

Ho B, Phan CM, Garg P, Shokrollahi P, Jones L. A screening platform for simultaneous evaluation of biodegradation and therapeutic release from an ocular hydrogel and its effect on human corneal epithelial cells The Association for Research in Vision and Ophthalmology, Seattle, WA, May 7, 2024 [ Show Abstract ][ PDF ]

Purpose: To integrate human corneal epithelial cells (HCECs) into a millifluidic screening platform that quantifies biodegradation and release of an entrapped therapeutic from an ocular hydrogel.

Introduction: Biodegradable hydrogels are novel drug delivery methods designed to release entrapped drugs or therapeutics as the gel degrades in situ. The primary challenge in developing biodegradable hydrogels for drug delivery lies in accurately measuring their degradation over time, while simultaneously being able to evaluate the drug release kinetics, which is typically a cumbersome procedure. To properly evaluate the biodegradation of a hydrogel, it is also essential to simulate key factors of the target tissue environment. In the context of the eye, this includes ocular temperature, tear flow, and low tear volume. Recent advances in organ-on-a-chip technologies have made it possible to emulate the human corneal environment. This will allow more accurate measurements of hydrogel degradation rates, subsequent drug or therapeutic release, and ultimately the overall effect on human corneal epithelial cells.

Methods: Gelatin Methacrylate (GelMA) ocular inserts with polyvinyl alcohol (PVA) (10% GelMA 7.5% PVA) were placed inside a custom-designed millifluidic device. Ocular inserts were degraded with up to 200 μg/mL of matrix metallipeptidase 9 (MMP9) for 24 hours at 37oC in PBS. Biodegradation of the ocular insert was quantified using a computational image analysis pipeline. The eluates containing the degradation products were collected to measure PVA released using a spectrophotometric assay, and its toxicity on human corneal epithelial cells (HCECs) was determined by alamarBlueTM assays.

Results: There was significant biodegradation of the GelMA-PVA inserts with increasing concentration of MMP9 in the millifluidic device, which was accurately quantified using a custom computational analysis. Degradation products in the eluate were collected, and there was a ~2-fold increase of PVA released in samples treated with MMP9 compared to the control. The same eluates were non-toxic to HCECs, and interestingly protected HCECs from hyperosmotic conditions mimicking dry eye disease.

Ho B, Phan CM, Jones L, Hui A, Ketelson H. Evaluating Protective Effects of Hyaluronic Acid Containing Ophthalmic Lubricants on an in Vitro Dry Eye Model American Academy of Optometry Meeting, Indianapolis, Nov 6, 2024

Jabeen A, Luensmann D, Woods J, Hill J, Jones L. Short-term effect of DOT spectacle lenses on choroidal thickness in emmetropic children The Association for Research in Vision and Ophthalmology, Seattle, WA, May 9, 2024 [ Show Abstract ][ PDF ]

Purpose: To investigate regional changes in choroidal thickness (ChT) following short-term wear of Diffusion Optics Technology™ (DOT) spectacle lenses, designed to control myopia by lowering retinal contrast.

Method: Emmetropic children (SER +1.00 to -0.75 D) aged 8 to 14 years wore plano DOT spectacle lenses without central apertures and +3.00D spectacle lenses in a two-visit, prospective, randomized, subject-masked crossover study. High-resolution OCT (Triton DRI-OCT, Topcon) evaluated central, parafoveal (3 mm from the fovea) and perifoveal (6 mm from the fovea) ChT after 0, 30 and 60 minutes of viewing a high contrast video at each visit.

Results: A total of 30 participants (17F, 13M) with a mean (± SD) age of 10.9 (1.7) years completed the study. After 30 minutes of spectacle lens wear, a significant increase in ChT was observed with DOT spectacle lenses compared to +3.00D spectacle lenses in 4 of the 9 macula regions evaluated (p<0.05 for all). DOT spectacles showed a significant ChT thickening in the central (+7.69 ± 4.19 μm), parafoveal regions at nasal (+9.01 ± 2.77 μm) and temporal (+6.20 ± 5.46 μm) and inferior perifoveal (+9.79 ± 2.31 μm) compared to myopic defocus with +3.00D lenses. After 60 minutes, ChT remained higher only in the inferior parafoveal region (+3.96 ± 8.33 μm, p=0.03), while all other regions returned to baseline levels.

Conclusion: After short-term DOT spectacle lens wear, emmetropic children experienced macula ChT thickening, similar or greater than the response observed with +3.00D spectacle lens wear. These results indicate the choroid is able to respond to contrast reduction. Further research is required to investigate the long-term impact of contrast modulation on ChT.

Jones D, Guthrie S, Acs M, Caffery B, Di Marco A, Fromstein S, Pal S, Ramdass S, Thakrar V, Zeidenberg M, Chow A. Initial Clinical Management of Myopic and Pre-Myopic Patients in Ontario, Canada – how has this changed over time? International Myopia Conference, Sanya, Hainan, China, Sep 25 , 2024 [ Show Abstract ]

Purpose: To determine how optometrists in Ontario, Canada are changing their management of myopic and pre-myopic pediatric patients at their initial visit over time

Methods: In a retrospective chart review, charts for 2920 patients aged 6-10 with presenting refraction of ≤-0.50D (myopes) or ≤ +0.75D (pre-myopes) were reviewed. All patients had eye examinations between 2017-2021 at optometry practices in Ontario. A maximum of five unique charts were selected for each age (6, 7, 8, 9, 10) and visit year (2017 to 2021) for each group (myopes, pre-myopes), for up to 250 files per practice. Demographic information, refraction and recommended interventions (categorized as standard myopia correction with single vision (SV) spectacles or contact lenses; myopia control treatment with myopia control spectacles or contact lenses, ortho-K, atropine, bifocals/progressives; and lifestyle changes (increasing outdoor time and reducing screen time)) were recorded. A two-way ANOVA with post-hoc Bonferroni-corrected t-tests were used to determine whether visit year and discussion type differed across myopic and pre-myopic groups at their initial visit.

Results: Optometrists in Ontario, predominantly recommended SV spectacles at the initial visit across the 5 years (89.56% in 2017 to 48.88% in 2021), some optometrists increased the incorporation of myopia control treatments in their discussions over time (increasing from 8.84% in 2017 to 44.84% in 2021, F2,8=31.33, p=0.0002). Patients recommended myopia control are on average 0.58D more myopic than those prescribed standard myopia correction (mean spherical equivalent  standard error for myopia control treatment -1.890.09 DS vs standard myopia correction -1.310.05 DS, F1,1147 = 62.08, p0.05). 95% of optometrists monitor pre-myopic children with no treatment. A small group of optometrists, 0.85%, prescribed bifocals/progressives as an attempt at preventative myopia control, the sole modality employed. Awareness of parental history of myopia increased the likelihood of discussing myopia control with myopic patients (2.63x more likely if one parent was myopic and 4.68x more likely if both parents were myopic). Age and gender did not appear to be factors impacting recommendations for myopia control or lifestyle changes, this was unchanged over the years.

Conclusions
While optometrists in Canada are increasingly integrating evidence-based practices in the clinical management in myopic children and children at risk of myopia, this study reveals knowledge gaps that should be the focus of continuing education programs. Recommendations include: initiating myopia control earlier instead of waiting for further progression of myopic refractive error and discussing lifestyle changes with pre-myopic children for optimal efficacy in delaying the onset of myopia.

Jones L. New materials and emerging techniques Minisymposium: Contact lens is not a piece of plastic: Back to the future. The Association for Research in Vision and Ophthalmology, Seattle, WA, May 8, 2024 [ Show Abstract ]

Recent advancement and diversification in contact lenses are remarkable. Today, contact lenses are not merely correcting tools for refractive errors, but can be used as therapeutic modalities for various diseases. With new materials and technologies entering the market, several options, such as lenses with internal wetting agents and silicone hydrogel lenses, have become available for wearers seeking relief from contact lens discomfort. Custom-made contact lenses can address irregular astigmatism and improve the vision in eyes with irregular corneas. Myopia has become increasingly prevalent worldwide over the past century. Contact lenses such as orthokeratology lenses or multifocal soft contact lenses are commonly used for myopia control. Numerous studies and clinical experience show that we can prescribe interventions that significantly slow the rate of myopia progression. Contact lenses can be used as biosensors and medication depots. Intraocular pressure monitoring is essential in the diagnosis and management of glaucoma patients. Currently, continuous ocular monitoring contact lens sensor is available in clinical use, which helps clinicians personalize glaucoma treatment according to the patient’s intraocular pressure profiles. Drug-eluting contact lenses can be used for ocular drug delivery with widespread therapeutic applications. Future development of both types of lenses are of great interest. This symposium will cover some of the hottest topics in contact lenses today. Attendees will learn about exciting new lens technologies and how these lenses can help their patients.

Jones L. TFOS Dry Eye Workshop III - Management and therapy of dry eye disease Tear Film & Ocular Surface Society Conference, Venice, Italy, Nov 1, 2024

Jones L, Schallhorn J, Ng AY, Alster Y, Bosworth C. Sign and Symptom Improvements Rates Among MGD Patients Following Treatment with AZR-MD-001 for 6 Months Tear Film & Ocular Surface Society Conference, Venice, Italy, Nov 2, 2024

Jones L, Schallhorn J, Stapleton F, Alster Y, Bosworth C. AZR-MD-001 Opens Meibomian Glands, Improves Meibum and Tear Quality Resulting in Increased Wear Time and Desired Lens Use in Patients With CLD The Association for Research in Vision and Ophthalmology, Seattle, WA, May 6, 2024 [ Show Abstract ][ PDF ]

Purpose: Contact lens discomfort (CLD) is a common problem for practitioners and wearers. Individuals with CLD experience episodic or persistent ocular discomfort symptoms related to lens wear, including visual disturbances, decreased wear time, or discontinuation overall. AZR MD 001 (AZR) is an ophthalmic keratolytic, keratostatic, and lipogenic ointment containing selenium sulfide, developed to improve signs and symptoms of MGD. This study evaluated if biweekly AZR can open meibomian glands and improve comfortable wear time, allowing patients with CLD who continue to challenge their ocular surface, tear film, and meibomian glands with contact lens use, to wear their contact lenses as desired.

Methods: Adults with CLD and evidence of meibomian gland obstruction (n=67) were randomized (1:1) to AZR 0.5% (n=34) or vehicle (n=33) applied twice weekly at bedtime for 3 months in a Phase 2, multi-center, single-masked parallel-group study (NCT05548491). Key efficacy endpoints evaluated were the change from baseline (CFB) at month 3 compared to vehicle in meibomian gland secretion score (MGS), Tear film stability (TBUT) post lens removal, and total and comfortable wear time.

Results: At month 3, AZR 0.5% significantly improved signs (MGS; TBUT) and lens wear time vs vehicle. Mean [SE] CFB in MGS was 13.8 [0.67] vs vehicle 3.8 [0.68], p<0.0001; TBUT was +3.31 s [0.70] vs vehicle 0.65 s [0.72], p<0.0001; and total comfortable wear time was +192 min [38.07] vs vehicle +2.9 min [38.01], p<0.0001. Significantly more patients, who were unable to comfortably wear contact lenses as desired at baseline, were able to wear them as long as desired by month 3 (42.5% vs vehicle 6.2%, p=0.0015). Improvements over vehicle were first seen on Day 14 in MGS (Mean [SE] CFB 3.2 [0.97] vs vehicle 0.8 [0.91], p<0.0007) and at Month 1 for comfortable wear time +41.6 minutes [24.04] vs vehicle -14.2 minutes [24.04], p=0.0111. All treatment-emergent adverse events (TEAEs) (47/47, 100%) in the 0.5% group were mild to moderate. There were no discontinuations due to a TEAE.

Conclusion: AZR MD 001 significantly improved the meibum and tear film quality, resulting in improved wear time in patients with CLD compared to vehicle starting as early as 8 doses of treatment. AZR demonstrated efficacy, safety, and tolerability, with no major adverse events observed.

McKinney M, Irving E, Jones D, Christian L. Parental Compliance in Response to Vision Screenings in Waterloo, Canada American Academy of Optometry Meeting, Indianapolis, Nov 7, 2024

Moezzi A, Moghadas M, Laachiri K, Lamrani M, Woods J, Jones L, Ngo W. Dry Eye Diagnostic Efficacy of Novel Ocular Thermography Metrics American Academy of Optometry Meeting, Indianapolis, Nov 8, 2024

Nagaarudkumaran N, Ngo W. Impaired Autophagy Dysregulates the Immune Response of the Corneal Epithelium under Hyperosmolar Stress American Academy of Optometry Meeting, Indianapolis, Nov 6, 2024

NG AY, Jones L, Woods J, Basuthkar S, Keir N. Diurnal changes in corneal dendritic cell density and morphology in symptomatic and asymptomatic contact lens wearers The Association for Research in Vision and Ophthalmology, Seattle, WA, May 6, 2024 [ Show Abstract ][ PDF ]

Purpose: To explore corneal dendritic cell (DC) density and morphology in soft contact lens (CL) wearers using in vivo confocal microscopy (IVCM) after different wear times, imaging with and without CLs in situ.

Methods: This was a prospective study involving hydrogel and silicone hydrogel CL wearers (17F, 3M; 29.5±10.5 years): 10 symptomatic (S-CL) and 10 asymptomatic (A-CL), by Young’s criterion and comfortable wear time. Eligible participants attended a baseline day (no CL wear, IVCM conducted in the morning (AM) and 8 hours later (PM), three separate CL wearing days (IVCM after 1, 4 or 8 hours [randomized] with CLs removed immediately before imaging and topical anesthesia), and a day where CLs were worn all day (IVCM after 1, 4 and 8 hours of CL wear, with CLs in situ during imaging and no anesthesia). At least five non-overlapping sequence scans were taken at the central and inferior cornea with the Heidelberg Retina Tomograph III with Rostock Cornea Module. Up to five images per location were analyzed with automated DC counting software. A linear mixed model was applied for all statistical analyses.

Results: At the central cornea, DC density was greater in the AM/1 hour compared to PM/8 hours (p<0.001), and for the A-CL group compared to the S-CL group (p=0.041). There was no effect of imaging with CLs in situ on DC density; DC density with and without CLs in situ strongly correlated across all time points at both corneal locations (r=0.694 to 0.843, all p≤0.01). For cell morphology, immature dendritic cells were the dominant cell type in both groups at both locations (S-CL ≥77%, A-CL ≥78%). Mature cells made up 8-15% of all DCs. The A-CL group had 5% more mature cells than the S-CL group at the inferior cornea only (p=0.034). At both locations, 5% more mature cells were observed on lens wearing days (central p=0.043, inferior p=0.027). Time of imaging was not a significant effect on the proportion of immature or mature cells at either location.

Conclusions: This study shows subtle differences in DC density and morphology between symptomatic and asymptomatic CL wearers and over the course of the day in different corneal regions. The clinical significance of these results requires further investigation. This study supports the imaging of DCs with CLs in situ, which could simplify monitoring these cells during CL wear.

Schulze M, Guthrie S, Ho B, Woods J, Jones L. Do Symptomatic Contact Lens Wearers Benefit from Using Lifitegrast Tear Film & Ocular Surface Society Conference, Venice, Italy, Nov 1, 2024

Schulze M, Guthrie S, Woods J, Jones L. Does Lifitegrast Improve Symptoms of Discomfort and Dryness in Symptomatic Contact Lens Wearers American Academy of Optometry Meeting, Indianapolis, Nov 8, 2024

Shukla M, Jones L, Hui A.. Poly (vinyl alcohol) elution from commercial contact lenses . Controlled Release Society Annual Meeting and Expo, Bologna, Italy, Jul 10, 2024 [ Show Abstract ]

Introduction: Contact lenses (CL) are a common form of refractive error correction, with approximately 140 million contact lens wearers across the world and 40 million in the US. Unfortunately, wearing contact lenses can cause discomfort and dryness, with almost half of all wearers experiencing these type of symptoms during use. (2) (1) Polyvinyl alcohol (PVA) is a lubricant which is effective against CL discomfort when used as an eye drop.(3) The purpose of this study was to investigate PVA elution from commercial contact lenses for a one-day wear modality. This study hypothesizes that by incorporating freezing as part of PVA loading into contact lenses, hydrogen bonding of PVA to lens materials will be enhanced, enabling the formation of a surface layer on contact lenses and increased PVA elution.

Methods: Commercial contact lenses (1-Day Acuvue® Moist® (etafilcon A, Johnson and Jonson), Acuvue® Oasys (senofilcon A, Johnson and Johnson), and DAILIES® AquaComfort PLUS® (nelfilcon A, Alcon)) were soaked in 2.5% w/v high molecular weight (avg. - 166 kDa) PVA solutions at 37°C for 48 hours. This was followed by 1 hour at either room temperature or freezing at -80°C. Total PVA release from lenses was determined in a vial containing 2 mL PBS on an orbital shaker at 50 RPM for 24 h. PVA was quantified using UV at 630 nm. All experiments were performed with n=6.

Results: A significant (p0.05) change in the amount of PVA released after freezing. Etafilcon A lenses released 17.03 ± 3.03 μg and 20.21 ± 2.51 μg (p>0.05), and senofilcon A showed 20.33 ± 6.60 μg and 24.14 ± 2.58 μg (p>0.05) at room temperature and after freezing at -80°C for one hour, respectively. However, nelfilcon A did not show significant (p>0.05) effect after 5 free-thaw cycles.

Conclusions/Implications: The findings suggest that the freezing technique has potential applications in enhancing the release of PVA from nelfilcon A contact lenses, which contains PVA internally. This provides insights into optimizing contact lens design for improved comfort by utilizing PVA release. The impact of freezing on nelfilcon A lenses releasing PVA indicates a promising potential avenue for enhancing the release of other comfort agents. Learning Objective 1: Understand the impact of freezing on enhancing the release of PVA from different contact lenses

Spafford M, Jones D, Christian L, Labreche T, Furtado N, MacIver S, Irving E. Public Perspectives on Eye Educational Videos and Posters American Academy of Optometry Meeting, Indianapolis, Nov 7, 2024

Vega J, Woods J, Guthrie S, Luensmann D, Orsborn G. Ease of Success Refitting Habitual Multifocal Soft Lens Wearers with a New Progressive Multifocal Lens System American Academy of Optometry Meeting, Indianapolis, Nov 8, 2024

Wang T, Jones L, Semp D, Trave-Huarte S, Wolffsohn J and TFOS Ambassadors. Clinical Practice Patterns in The Diagnosis of Dry Eye Disease: A TFOS International Longitudinal Survey Tear Film & Ocular Surface Society Conference, Venice, Italy, Nov 1, 2024

Wong S, Fadel D, Seo J, Luensmann D, Guthrie S, Woods J, Voltz K, Vega J. Dry eye management with scleral lenses in non-lens wearers NCC, Veldhoven, Netherlands, Mar 10, 2024 [ Show Abstract ]

PURPOSE: To assess the benefits of scleral lenses (SLs) with and without Hydra-PEG in non-lens wearers with dry eye symptoms.

METHODS: This prospective, randomised, double-masked, 1-month bilateral cross-over study recruited symptomatic non-wearers with healthy eyes and an OSDI score ≥13. Participants were fitted with SLs (hexafocon A, Onefit MED, CooperVision, Inc.) with and without Hydra-PEG coating (Tangible Science) (coated (C-SL)/uncoated (U-SL)) for 1-month daily wear per pair. LogMAR visual acuity was measured, and participants rated overall satisfaction with ocular comfort, dryness and vision clarity using a 0-10 scale (10=best) at baseline (BL) and after each 1-month wear period with the two SLs.

RESULTS: In total, 22 participants were eligible and 18 completed the study (18F:0M, mean age 34.9±13.4 years [20-66], OSDI score 39.8±18.0 [14-80], reason for discontinuation: n=3 handling, n=1 comfort). Mean refraction of the right eye was -3.28±1.13DS [-12.00 to +1.00] and -1.11±0.90DC [0.00 to -3.25]. At 1-month, satisfaction with ocular comfort and dryness was similar between study SLs (p>0.05), and both were rated better than BL (p0.05) (BL: 7.6±19, C-SL: 7.8±2.3, U-SL: 7.8±2.9), which was confirmed by LogMAR visual acuity with no clinically relevant differences noted (BL: -0.14±0.07, C-SL: -0.17±0.07, U-SL: -0.18±0.08). At study exit, 44% asked to share their SL details with their eye care professional to continue wear in the future.

CONCLUSIONS: Symptomatic non-lens wearers were successfully fit with SLs, which improved ocular comfort and reduced dryness after 1 month of wear. Although no difference was noted between Hydra-PEG-coated and uncoated lenses, participants with a wide range of dryness symptoms benefited from SL wear and almost every second participant indicated an interested to continue SL wear.

Woods J, Guthrie S, Luensmann D, Vega J, Orsborn G. Evaluating the Success of Habitual Multifocal Soft Lens Wearers when Refit with a Progressive Multifocal Lens System NCC, Veldhoven, Netherlands, Mar 11, 2024 [ Show Abstract ]

PURPOSE: To evaluate the ease and predictability of fit and success when switching habitual, multifocal (MF) wearers from a somofilcon A (som-A) multifocal 2-Add system to a som-A 3-Add system.

METHODS: Presbyopic habitual MF wearers were recruited to a crossover, daily wear, subject-masked study. At first, participants were fit and dispensed bilaterally with som-A 2-Add (CooperVision) lenses and power optimizations were permitted at the fitting visit and the 1-week visit. The optimal lens powers were worn for 2-weeks. Next, som-A 3-Add (CooperVision) was fit and worn following the same visit schedule. Visual acuity and subjective ratings (0–10 scale;10=best) were collected after each lens wear period and preference ratings were completed at study exit (5-point Likert).

RESULTS: Fifty-eight participants (mean age 53.5±6.2 years, 46F:12M) completed the study. Mean refraction OD: Sph -1.11±2.44D [-4.75D to +3.50D], Cyl -0.27±0.25D [-0.75D to 0.00D], near addition +2.05±0.36D [+1.25D to +2.50D]. There was no difference between lenses for satisfaction with comfort (p=0.76), vision quality (p=0.78), or overall satisfaction (p=0.94). The only statistical difference among preferences related to vision clarity for near tasks, where som-A 3-Add was preferred (p=0.03). After 2-weeks, LogMAR acuity was significantly better with som-A 3-Add for distance vision (p<0.01) and near vision (p=0.02), but not different for intermediate vision (p=0.10). When strictly following the fitting guides, som-A 2-Add was successful with the first pair of lenses in 59% of participants, whereas som-A 3-Add was successful with the first pair in 80% of participants (p=0.03).

CONCLUSIONS: The performance of som-A 3-Add either matched or exceeded that of som-A 2-Add based on visual acuity, participant ratings and participant preferences. The 3-Add lens system had a higher rate of success with the first lens pair than the 2-Add system. Results indicate that switching som-A 2-Add wearers to the updated som-A 3-Add lens system was successful and well accepted.

Woods J, Richards J, Guthrie S, Kollbaum P. Can Optical Modelling Predict Clinical Vision Outcomes of Myopia Control Contact Lenses? NCC, Veldhoven, Netherlands, Mar 11, 2024 [ Show Abstract ]

PURPOSE: To understand if optical metrology and computational modelling can predict the clinical visual performance of two myopia control contact lenses which employ different optical designs: non-coaxial senofilcon A (NC) (Acuvue Abiliti 1-Day, Johnson & Johnson Vision) and dual-focus omafilcon A (DF) (MiSight 1 day, CooperVision).

METHODS: For clinical assessments, children aged 8-15 years with no history of contact lens wear or recent myopia control intervention completed a randomised, non-dispensing, contralateral double-masked trial. After 1-hour of wear, participants rated their lens preference (Likert) and subjective vision (0-100 scale, 100=best), then distance visual acuity (VA) was measured.
For optical metrology and modeling, wavefront errors were measured with an aberrometer (Optocraft GmbH). Custom software was used to compute point spread functions, image quality and simulated retinal images for 3-6mm pupils by combining the lens optics with the optics of a model young eye, assuming centred and decentred lens positions.

RESULTS: Twenty-six participants completed the clinical study: 17M; mean age 11.6yrs [8-15yrs]; mean OD refraction: -1.96DS [-0.25 to -3.50DS], -0.34DC [0.00 to -1.00DC]. Ratings of distance vision at 1-hour were better with DF (88±14) versus NC (79±18), p<0.01. Distance logMAR VA was better with DF (0.02±0.04) versus NC (0.09±0.08), p<0.01. A higher number of participants indicated overall preference for DF, with vision the most common reason (DF:14 vs NC:6, p=0.17).
Optical modelling of well-centred lenses showed reduction in image quality for both lenses as the pupil increased. Lens decentration degraded image quality for both designs, but more for the NC design. Differences in add power zone geometry and NC optics may account for these differences.

CONCLUSIONS: Both optical modelling and clinical subjective results support better image quality with the dual-focus design. These results suggest that optical modelling techniques may be valuable in evaluating and comparing myopia control lens designs prior to on-eye testing.

2023

Chan V, Drolle E, Phan CM, Hui A, Shi C, Subbaraman L, Wu J, Jones L. Evaluating the activity of lysozyme deposited on contemporary reusable silicone hydrogel contact lenses using an in vitro eye model The Association for Research in Vision and Ophthalmology, New Orleans, LA, USA, 2023 [ Show Abstract ][ PDF ]

Purpose: To evaluate lysozyme activity (LA) on five contemporary reusable silicone hydrogel contact lens (CL)materials over their proposed wear period using an advanced in vitro blink model.

Methods: Five CL materials (lotrafilcon B, samfilcon A, comfilcon A, senofilcon A, and serafilcon A) were cycled daily for 16h on an eye model, followed by 8h of soaking in OPTI-FREE PureMoist, to mimic a typical wear cycle. An artificial tear solution containing physiologically representative proteins and lipids was delivered to the model at a rate of 1.2-2.1μl/min. The model includes an artificial eyelid that blinks at a rate of 6blinks/min, which was kept at room temperature and humidity above 50%. Serafilcon A and senofilcon A were tested over 14 days, whereas the other CLs were evaluated for 30 days. At specified time intervals, including after 1, 7, 14 and 30 days, CLs were removed from the model and lysozyme extracted using a solvent containing acetonitrile and trifluoroacetic acid. The LA from the extracts were then evaluated using a micrococcal absorbance assay.

Results: Overall, LA decreased over time, reaching non-detectable levels by day 30 (p<0.05). Serafilcon A (13.9 ± 7.8μg/lens), and samfilcon A (9.6 ± 2.3μg/lens), had the highest LA after 1 day, followed by comfilcon A (4.7 ± 1.8μg/lens), lotrafilcon B (3.3 ± 1.6μg/lens), and senofilcon A (2.2 ± 3.7μg/lens). By day 7, LA for the weekly replacement lens, serafilcon A, decreased to 0.5 ± 0.6μg/lens. By day 14, LA for the biweekly replacement lens, senofilcon A, decreased to 0.6 ± 0.7μg/lens. Lotrafilcon B, samfilcon A, and comfilcon A, all monthly replacement lenses, decreased in activity by day 30 (0.1 ± 0.2μg/lens, 0.5 ± 0.7μg/lens, 0.0 ±0.0μg/lens respectively).

Conclusions: Deposition of biologically active lysozyme has been proposed to be an important factor for biocompatible CL wear. A decline in activity over time as the deposited protein becomes denatured may impact overall CL performance and has been linked to reduced comfort. LA decreases over time and reaches near zero for all lens types by the end of their proposed wearing period, confirming that they should be replaced within their specified replacement intervals. Compared to simple in vitro vial models, using an advanced blink model for CL deposition testing aims to provide more physiologically relevant results prior to clinical testing.

Garg P, Wulff D, Phan CM, Jones L. Evaluation of a biodegradable bioink for the fabrication of ophthalmic devices using 3D printing The Association for Research in Vision and Ophthalmology, New Orleans, LA, USA, April, 2023 [ Show Abstract ][ PDF ]

Purpose: To develop a degradable bioink for fabricating ophthalmic devices using 3D printing.

Methods: The bioink formulation consisted of 10% gelatin methacrylate (GelMA), 0.6% lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP), and 5% yellow dye as a light absorbing agent to improve print resolution. The bioink was used to 3D print square sheets (7x7x1 mm) using a commercial masked-stereolithography (mSLA) 3D printer at 95% humidity and 37°C temperature. The degradation of printed sheets was evaluated with different concentrations (0,25,50,100 μg/ml) of matrix metalloproteinase (MMP9) enzyme 37°C. MMP9s are naturally found in the tear film and elevated in various diseased states such as in corneal wounds and dry eye disease. The weights of the sheets were measured at t = 0,4,6,8,12,16,24 hrs. Another set of cubes (1x1x1 cm) was autoclaved and kept sealed in storage at different temperatures (4°C, 25°C, and 37°C) in phosphate buffered saline (PBS) and their weight was measured on day 10. An attempt was made to fabricate a contact lens using this bioink.

Results: Samples that were exposed to MMP9 enzymes showed a time-dependent degradation with increasing enzyme concentration. The samples incubated with 100 and 50 μg/ml of MMP9 were completely degraded by the end of 12 and 16 hrs, respectively. At the end of 24 hrs, the samples incubated at 25 μg/ml enzyme showed 72.8% degradation whereas the control samples did not show any signs of degradation. Interestingly, samples that were autoclaved and kept in storage also did not show any signs of degradation at all temperatures. A 3D-printed CL with overall diameter 14mm and thickness 1mm was printed without any support structures within 1 hour.

Conclusion: This study showed GelMA-based bioink can be used to fabricate biodegradable devices such as contact lenses. The biomaterials degrade in the presence of MMP-9 and future work will work on tuning the degradation kinetics of these materials, as well as incorporating ocular drugs.

Garg P, Wulff D, Phan CM, Jones L. Fabrication of a degradable ocular drug delivery system using 3D printing CBB 2023 Conference: Waterloo for Health, Technology and Society, March, 2023 [ PDF ]

Guthrie S, Chow T, Luensmann D, Woods J, Lumb E, Orsborn G. Short term visual performance of two myopia control soft contact lenses British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 9-11, 2023 [ Show Abstract ]

PURPOSE: To gain insights into the short-term visual performance of two myopia control contact lenses which employ different optical designs.

METHODS: Children aged 8 to 15 years, with no history of contact lens wear or recent myopia control intervention, participated in a non-dispensing, single visit, double masked trial where the study lenses were fit and worn contralaterally in randomised eyes. The myopia control study lenses were senofilcon A (AA1D, Johnson & Johnson Vision) and omafilcon A (M1D, CooperVision). After participants had worn the lenses for 1 hour, they rated their subjective experience with vision using a 0-100 scale (100 is best) and distance visual acuity (LogMAR (VA)) was measured. Lens preference was determined at the end of the wear period using a 5-point Likert scale and reasons for preference were provided.

RESULTS: Twenty-six participants completed the study (9F:17M; mean age 11.6 ± 2.1 years). Mean refraction was OD Sph -1.96 ± 0.93D (-0.25 to -3.50D), Cyl -0.34 ± 0.35D (0.00 to -1.00D) and OS Sph -1.77 ± 0.97D (-0.25 to -3.50D), Cyl -0.38 ± 0.38D (0.00 to -1.00D). Subjective ratings of distance vision at 1 hour were better (Wilcoxon matched pairs, p<0.01) with M1D (88 ± 14) versus AA1D (79 ± 18). Distance VA was also significantly better (Wilcoxon matched pairs, p<0.01) with M1D (0.02 ± 0.04 logMAR) over AA1D (0.09 ± 0.08 logMAR). When asked to provide an overall lens preference after 1 hour of wear, more participants preferred M1D than AA1D, and vision was reported as the main reason for their preference (M1D:14 vs AA1D:6, No preference:6; p=0.17).

CONCLUSIONS: When worn contralaterally for 1 hour, the different optical designs of M1D and AA1D performed significantly differently. M1D resulted in better distance vision ratings and visual acuity, and both of these differences would also be considered clinically relevant.

Guthrie S, Woods J, Luensmann D, Chow T, Lumb C, Orsborn G. Subjective Vision Experience in Soft Myopia Control Contact Lenses by Age American Academy of Optometry, New Orleans, October 12, 2023 [ Show Abstract ]

PURPOSE: To compare the short-term vision experience of preteens (PT) and teens (T) with two myopia control (MC) contact lenses of different optical designs: senofilcon A, with a noncoaxial ring-focus design (AA1D, Johnson & Johnson Vision) and omafilcon A, with a dual-focus design (M1D, CooperVision, Inc.).

METHOD: Children aged 8-15 years who had no prior history of contact lens wear or recent MC intervention were recruited for a single-visit, double-masked trial with study lenses randomly fit and worn contralaterally. Participants were separated into two age groups: PT: 8-12 years and T:13-15 years. After wearing the lenses for 1 hour, participants rated their subjective visual experience on a 0-100 scale (where 100 indicated the best experience), and distance visual acuity was measured using LogMAR (VA). At the end of the wear period, lens preference was determined using a 5-point Likert scale, and participants provided reasons for their preference.

RESULTS: Twenty-six participants completed the study (9F:17M; mean age 11.6 ± 2.1 years), 16 PT and 10 T. Mean refraction was OD Sph -1.96 ± 0.93D (-0.25 to -3.50D), Cyl -0.34 ± 0.35D (0.00 to -1.00D) and OS Sph -1.77 ± 0.97D (-0.25 to -3.50D), Cyl -0.38 ± 0.38D (0.00 to -1.00D). When participants rated their subjective experience with vision at 1 hour, both age groups reported better distance vision with M1D compared to AA1D (PT:M1D: 90 ± 15, AA1D: 82 ± 17, p<0.01; T:M1D: 85 ± 13, AA1D: 73 ± 18, p=0.02). Distance visual acuity (VA) was also better with M1D over AA1D in both groups, with the difference in the PT group being statistically significant (PT:M1D: 0.03 ± 0.04, AA1D: 0.09 ± 0.08, p<0.01; T:M1D: 0.02 ± 0.04, AA1D: 0.08 ± 0.09, p=0.07). For near VA, M1D performed better than AA1D in PT (PT:M1D: 0.07 ± 0.08, AA1D: 0.12 ± 0.08, p<0.05; T:M1D: 0.05 ± 0.05, AA1D: 0.06 ± 0.06, p=0.29). When asked to provide an overall lens preference after 1 hour of wear, more PT preferred M1D than AA1D (M1D:8 vs AA1D:4, No preference:4) and more T preferred M1D than AA1D (M1D:6 vs AA1D:2, No preference:2), with both groups reporting vision as the main reason for their preference.

CONCLUSION: When worn contralaterally for 1 hour, the different optical designs of M1D and AA1D performed significantly differently. The preteen and teen groups responded similarly, with M1D preferred by both groups for better distance vision. In addition, while teens had an equivalent vision experience to the preteens, they were overall more likely to rate that experience lower than preteens, indicating a potential difference in subjective experience between the groups and a more critical assessment of vision in teenagers.

Ho B, Phan CM, Ramasamy M, Hui A, Jones L. PDMS microfluidic devices fabricated from commercial 3D printers support growth of viable HCECs and enable cell biological assays for low-cost high-throughput screening The Association for Research in Vision and Ophthalmology, New Orleans, LA, USA, April, 2023 [ Show Abstract ]

Purpose: To integrate human corneal epithelial cells (HCECs) into a PDMS microfluidic chip fabricated from a novel 3D printing method to perform cell biological assays.
Introduction: The advent of microfluidic devices has enabled tight control over the physical and chemical cellular environment in vitro, while allowing for large-scale imaging and biochemical reactions at single-cell resolution. These devices are capable of miniaturizing assays to the microliter and nanoliter range, thereby increasing assay throughput with high sensitivity, a feature that is highly advantageous in high-throughput cell-based screens. Polydimethylsiloxane (PDMS) has been widely used in microfluidics devices due to its optical clarity and non-toxicity to cells, among other desirable features. However, the fabrication of PDMS devices traditionally requires specialized facilities and instruments. Additionally, PDMS itself is highly hydrophobic and does not support mammalian cellular viability and growth.

Methods: PDMS devices were cured in 3D-printed moulds generated using the FormLabs stereolithography (SLA) printer (FormLabs 3B+, FormLabs, Somerville, MA). These devices were sterilized by autoclaving, and coated with 0.01% polydopamine (PDA) and 20μg/mL collagen. HCECs were seeded onto the device, and allowed to grow for 18-36 hours in DMEM/F12 media at 37oC. HCECs were imaged by light microscopy, and viability was assessed by alamarBlue assays.

Results: Here, we present a novel and simple method of generating PDMS microfluidic devices suitable for mammalian cell biology assays using commercial 3D printing. We show that PDMS devices coated with polydopamine (PDA) support the growth of human corneal epithelial cells (HCECs) that are metabolically active (~60-90% viability) and are comparable to HCECs cultured in standard tissue culture plastic consumables. Finally, HCECs cultured in our devices are capable of growth with fluid flow rates of up to 1mm/s.

Conclusion: Our study shows that PDMS devices manufactured through the aid of a novel 3D printing pipeline support the growth of HCECs. We aim to utilize these microfluidic devices as a tool to screen different compounds and formulations while assessing cellular viability and acquiring high resolution microscopic and fluorescence images of HCECs.

Hui A. Commercialized Ocular Drug Delivery Devices XXV Biennial Meeting of the International Society for Eye Research, Feb 21, 2023 [ Show Abstract ]

The goal of creating a sustained drug delivery device for the anterior or posterior segment has been approached from numerous avenues, from inserts to contact lenses and punctal plugs. The utility of a device which can sustain drug release allows for the potential to increase patient compliance as well as improve clinical outcomes, as agents are able to be maintained at appropriate concentrations for desired periods with less administration. This presentation will discuss drug releasing devices for the eye which have reached commercialization. The indications for these devices, their reported effectiveness and known adverse reactions will be discussed. The experience on the use of the devices after they have been released on to the market will also be discussed, as well as their current clinical usage in contemporary eye care management.

Hui A, Heynen M, Chan V, Mirzapour P, Enstone D, Saad M, George M, Ngo W, Jones L. The impact of RGP care solutions on ISO measured lens parameters and the protein deposition on RGP lenses when managed with a hydrogen peroxide care solution Global Specialty Lens Symposium, Las Vegas, Jan 20, 2023 [ PDF ]

Jin Y, Jones L, Gorbet M. Investigation of the Circadian Recruitment of Tear Neutrophils to the Ocular Surface and Their Phenotypes  The Association for Research in Vision and Ophthalmology, New Orleans, LA, USA, April, 2023 [ Show Abstract ]

Purpose: Hundreds of thousands of leukocytes (with approximately 60% of the population being polymorphonuclear neutrophils (PMNs)) can be collected from the ocular surface immediately on waking, while only a few are harvested during the daytime. To better understand their role in ocular surface homeostasis and inflammation, this study aimed to investigate potential factors contributing to the circadian infiltration of tear PMNs and changes in phenotype across different time points in a 24-hour cycle.

Methods: Tear leukocytes were collected from 30 participants using a gentle eyewash after 2-hr and 7-hr of sleep at night, after 2-hr sleep during the day, and towards the end of the day (around 5 pm). Cell count and morphology were determined using a Moxi Z cell counter and May-Grunwald stain, respectively. Cells were stimulated by fMLP. Changes in the degranulation (lactoferrin, CD66b, CD63) and cell aging state (CD184) of PMNs were measured via flow cytometry. Neutrophil extracellular traps (NETs) were also identified by flow cytometry and microscopy following staining with myeloperoxidase, citrullinated histones, and CD15.

Results: Significantly more cells were collected from the nighttime compared to the daytime (p<0.001). There was a positive correlation between IL-8 concentrations and PMN numbers, but not with C5a, suggesting that the recruitment of tear PMNs to the ocular surface may be driven mainly by IL-8. 2hr-sleep-derived tear PMNs were less degranulated than 7hr-sleep-derived tear PMNs (p<0.03) and possessed a larger functional activation potential in response to stimulus (p<0.03). Furthermore, 7hr-sleep-derived tear PMNs exhibited hyper-segmented nuclei and were prone to aggregation, when compared to 2hr-night-derived tear PMNs, suggesting an aged and activated phenotype. A significantly increased number of NETs were present in 7hr-night-derived tear samples (p<0.05).

Conclusions: The diurnal-nocturnal recruitment pattern of tear PMNs may be driven by the increase in IL-8 in nighttime tears. Higher levels of degranulation and NETs indicate that tear PMNs become more activated on the ocular surface during prolonged eye closure at night. This PMN inflammatory response must then be balanced by other anti-inflammatory processes to prevent ocular surface damage.

Jones D, Guthrie S, Woods J, Nguyen M, Chamberlain P, Hammond D. . Young Adult Acceptance of Dual Focus Myopia Control Soft Contact Lenses British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 10, 2023 [ Show Abstract ]

Purpose: Myopia can continue to progress during early adulthood and previously observed acceptance of dual focus contact lenses in adolescents does not verify that progressing young adult myopes will similarly accept potential minor vision compromises when achieving the desired myopia control effect. This study assessed acceptance of dual focus myopia control contact lenses by myopic young adults.

Methods: Habitual single vision (SV) contact lens wearers (age 17-25) were dispensed MiSight 1 day (M1d, omafilcon A, CooperVision, Inc.) for 3 months. The Quality of Vision (QoV) questionnaire (McAlinden, 2010) was performed at baseline, 2 weeks, 1, 2 & 3 months. Frequency, severity and bothersome scores were summed for each vision symptom (e.g. glare) to give a combined metric (Best:0/Worse: 9). Non-parametric repeated measure ANOVA with Wilcoxon post-hoc analysis was used to determine how visual experience in M1d changed over the duration of the study and compared to SV at baseline.

Results: 27/29 of participants completed the study (23F:4M; age 22.5±1.7; SERE -3.55D±1.55D). Subjects self-reported that M1d was worn at least 6 days per week and this wear pattern was sustained over three months, averaging >12h per day (2w: 12.5±1.9h, 1M: 12.6±2.0h, 3M: 12.2±1.7h). Perception of starbursts, hazy vision, blurred vision, distortion, and fluctuating vision were not significantly different in M1d than SV. While glare, haloes, focusing difficulties, depth perception and double vision summed symptom scores at all timepoints were significantly increased compared to SV (range between 2-4 points higher, p<=0.002), 70% of subjects responded that they were likely to continue M1d wear given the likely myopia control benefits.

Conclusion: Full day wear of MiSight 1 day soft contact lenses was well tolerated in young myopic adults with mild increases in a limited number of vision symptoms that had no impact on wear time.

Jones D, Luensmann D, Alton K. The prevalence of refractive error in children in a Canadian rural, First Nation Community 4th World Congress of Optometry O=MEGA23, Melbourne, Sep 8, 2023

Jones L. Osmolarity: Gold Standard for Dry Eye Disease Determination or Random Number Generator? XXV Biennial Meeting of the International Society for Eye Research, Feb 23, 2023 [ Show Abstract ]

The potential impact of osmolarity on dry eye symptoms dates back to the early 1970’s. The concept that tear film instability leads to hyperosmolarity and that this is a key factor in the development of dry eye disease (DED) is described in the 2017 TFOS Reports. Both aqueous deficient and evaporative DED can lead to tear hyperosmolarity, which stimulates ocular surface inflammation through increased expression and production of proinflammatory cytokines and chemokines, resulting in corneal epithelial cell death by apoptosis. Ocular surface disease and tear hyperosmolarity have also been associated with goblet cell loss, which can lead to altered mucin expression and tear film instability, further exacerbating inflammatory processes. These changes may stimulate sensory nerve fibers innervating the ocular surface, generating sensations of ocular discomfort. Although osmolarity has gained fairly widespread acceptance as a DED diagnostic, findings suggest that tear osmolarity measurements do not possess the very high sensitivity and specificity claimed by some studies and it may have limited value in the diagnosis of DED. A key factor in determining the relationship between DED and osmolarity relates to the ability to measure osmolarity, a process that is not without its challenges. The low volume of tears on the ocular surface necessitate using techniques that can estimate osmolarity using micolitre or nanolitre volumes of fluid. Clinical assessment methods typically occur through estimation of the osmolarity of the inferior tear meniscus. However, calculations using fluorescence assessments and hyperosmolar drops suggest that hyperosmolar levels in the tear film overlying the ocular surface may transiently spike during tear instability to levels far greater than that determined in the inferior tear meniscus, resulting in corneal inflammation and triggering sensory neurons. This may explain the relative disconnect between DED symptoms and osmolarity measurements.
Additonally, variability in results obtained between instruments, within-visit measures, differences between eyes and the impact
of treatments on osmolarity values over time require further examination.
In addition to DED, this review will examine other factors that may impact osmolarity values, including contact lens wear, cataract
and refractive surgery and systemic drugs. Finally, the osmolarity of ocular lubricants and contact lens blister packs and their
clinical relevance will be discussed.

Jones L, Craig J, Hinds M, Alster Y, Bosworth C, Ng A.. Sign and Symptom Improvement Rates Among MGD Patients Following 6 Months of Treatment With AZR MD 001 American Academy of Optometry, New Orleans, October 12, 2023 [ Show Abstract ]

Purpose: AZR MD 001, a topical ophthalmic ointment consisting of selenium sulfide as an active ingredient (either 0.5% or 1.0% concentration), was investigated in a Phase 2 clinical trial as a new treatment for meibomian gland dysfunction (MGD). Treatments for MGD seek to demonstrate strong efficacy, restore gland function, and improve patient symptoms. The aim of this study was to determine the responder rates for signs and symptoms in patients with MGD following 6 months of treatment with AZR MD 001.

Methods: For this multicenter, double-masked, vehicle-controlled, parallel-group trial (NCT03652051), randomized patients (1:1:1) received AZR MD 001 (0.5% [n=82] or 1.0% [n=83]) or vehicle (n=80) twice weekly before bed for 6 months. Eligible patients were ≥18 years of age, exhibited meibomian gland obstruction (Meibomian Gland Secretion [MGS] score ≤12 for 15 lower lid glands), and were required to discontinue topical prescription ocular surface treatments for ≥2 weeks and topical ophthalmic preparations (including artificial tear substitutes). Predefined responder criteria, based on literature thresholds, were: Meibomian Glands Yielding Liquid Secretion (MGYLS) change from baseline ≥5, MGS score >12, and Ocular Surface Disease Index (OSDI) score <13. Analyses included all data through month 6.

Results: AZR MD 001 showed a higher percentage of patients with a clinically meaningful improvement of ≥5 more glands yielding meibum compared with vehicle (MGYLS: 60%, p12) as early as 14 days (20%, p=0.0380 for AZR MD 001 0.5%; 19%, p=0.0949 for AZR MD 001 1.0%; 7.6% for vehicle). Patients continued to demonstrate normal meibum at month 6 (74%, p=0.0017 for AZR MD 001 0.5%; 63%, p=0.1273 for AZR MD 001 1.0%; 48% for vehicle). By month 6, significantly more patients treated with AZR MD 001 were asymptomatic for disease (OSDI <13: 48%, p=0.0333 for AZR MD 001 0.5%; 50%, p=0.0205 for AZR MD 001 1.0%; 30% for vehicle).

Conclusion: Over 6 months, a statistically significant proportion of patients applying AZR MD 001 demonstrated a clinically meaningful response, with normalization of their meibomian gland function and the achievement of asymptomatic status for disease.

Luensmann D, Guthrie S, Woods J, Voltz K, Vega J.. Software Guided Orthokeratology Fitting Success American Academy of Optometry, New Orleans, October 12, 2023 [ Show Abstract ]

PURPOSE: To evaluate the ease of fit and success rate of the recommended orthokeratology lens parameters as determined by the Visavyä software (CooperVision Inc.).

METHOD: This four-site prospective study recruited participants aged 6-35 years and fit them bilaterally with Paragon CRT® or Paragon CRT Dual Axis® orthokeratology lenses (CooperVision Inc.), worn every night for 1 month. Four different topographers were used in the study: Medmont E300, Oculus Keratograph 5, Oculus Pentacam or Topcon CA-800. Topography data were uploaded into the software and together with subjective refraction and white-to-white corneal diameter data, the software calculated the recommended lens parameters for the first trial lens. If fit and/or vision was not acceptable, lens modifications were permitted at the dispense visit, after the first night or after one week of wear. Best-corrected visual acuity was determined at baseline and unaided acuity was measured after one month of overnight lens wear.

RESULTS: 54 participants (33F:21M), mean age 17.5±7.4 years [7 to 35 years] were included in the analysis. An additional 8 participants were successfully screened and dispensed but exited the study early for lens related and other reasons, they are not included in the analysis. The mean subjective refraction (OU) of all completed participants was Sph -2.60±1.30DS [-5.75 to 0.00] and Cyl -0.50±0.47DC [-1.75 to 0.00]. The software recommended either CRT or CRT Dual Axis lenses depending on the corneal toricity: • Medmont: 13 CRT, 17 Dual Axis • Oculus Keratograph 5: 10 CRT, 28 Dual Axis • Oculus Pentacam: 11 CRT, 9 Dual Axis • Topcon CA-800: 13 CRT, 7 Dual Axis Only four eyes (<4%) involving 3 different participants required a lens parameter change from the initial lens recommendation by the fitting software (all CRT Dual Axis) and involved two different topographers. For the cohort, the best-corrected visual acuity (logMAR) prior to lens wear was -0.07±0.11 (-0.30 to 0.14) and unaided vision after 1 month of lens wear was -0.03 ± 0.15 (-0.30 to +0.38) (p<0.01). Remaining refraction after 1 month was Sph –0.04 ± 0.34 DS. (-1.25 to +0.75). The 1-month unaided vision by lens type was: • CRT: -0.07 ± 0.12 (-0.30 to 0.14) • CRT Dual Axis: -0.01 ± 0.16 (-0.30 to 0.38) There were no significant or serious ocular adverse events in this study.

CONCLUSION: The Visavy™ software successfully integrated data from four different topographers and provided a >96% first fit success rate for Paragon CRT® and Paragon CRT Dual Axis®. This predictable outcome makes the Visavy™ software a valuable tool for eye care professionals when fitting these lenses to minimize chair time and optimize wearer satisfaction.

Luensmann D, Guthrie S, Woods J, Voltz K, Vega J.. Orthokeratology fitting success using a new software British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 9-11, 2023 [ Show Abstract ]

PURPOSE:
To determine vision outcome after orthokeratology (Ortho-K) lens wear when using the new Visavy software (CooperVision Specialty EyeCare) to determine the recommended lens parameters.

METHODS:
This multisite (3) prospective study recruited participants aged 6-35 years and fit them with Paragon CRT or Paragon CRT Dual Axis Ortho-K lenses (CooperVision Specialty EyeCare), worn every night for 1 month. Topography images (Oculus Keratograph 5, Medmont E300, or Topcon CA-800) were uploaded in the software and together with entries for subjective refraction and white-to-white corneal diameter, the software provided the recommended lens parameters. If fit and/or vision was not acceptable, lens modifications were permitted at the dispense visit, after the first night or after one week of wear. Best-corrected visual acuity was determined at baseline and unaided after one day, one week and one month of Ortho-K wear. Subjective comfort was collected after the first lens application and after one month (0-10 scale, 10=very comfortable).

RESULTS:
Thirty participants (19F:11M), mean age 13.6±5.9 years [7 to 35 years] were included in the analysis. The mean refraction of all 60 eyes was Sph -2.98±1.27DS and Cyl -0.54±0.43DC. Best-corrected visual acuity (logMAR) prior to lens wear was -0.01±0.04 and unaided vision was +0.30±0.33 after the first night, +0.05±0.13 after 1 week and +0.06±0.10 after 1 month of Ortho-K lens wear. Remaining subjective refraction after 1 month was Sph –0.37±0.82DS. Only two eyes (<3%) required a lens parameter change after the initial lens recommendation by the fitting software. Comfort ratings were significantly better after 1 month (7.8±1.6) compared to the dispense visit (5.6±2.2)(p<0.01). There were no ocular adverse events in this study.

CONCLUSIONS:
The software provided a 97% first fit success rate for Paragon CRT and Paragon CRT Dual Axis. This predictable outcome makes the Visavy software a valuable tool for ECPs when fitting Ortho-K lenses.

Luensmann D, Schulze M, Guthrie S, Woods J, Jones L. Evaluating the change in symptoms when symptomatic daily disposable lens wearers are refit with delefilcon A Optometry's Meeting ePosters Virtual Event, Jun 13, 2023

Luensmann D, Schulze M, Guthrie S, Woods J, Jones L. Early lens handling experience of neophyte wearers fitted contralaterally with a hydrogel and a silicone hydrogel daily disposable contact lens Optometry's Meeting ePosters Virtual Event, Jun 13, 2023

Luensmann D, Tucker AW, Voltz K, Guthrie S, Woods J, Vega J. Orthokeratology Lens Fit Success Using a New Software Global Specialty Lens Symposium, Las Vegas, Jan 20, 2023 [ Show Abstract ][ PDF ]

Purpose: To determine orthokeratology (Ortho-K) lens parameters in as few steps possible is beneficial for the eye care professionals (ECPs) and patient and this study investigated how the new Visavy software can help to inform the initial lens parameters.

Methods: This prospective study recruited participants aged 6-35 years and fit them with Paragon CRT or Paragon CRT Dual Axis Ortho-K lenses (CooperVision Specialty EyeCare), worn every night for 1 month. Topography images (Oculus Keratograph 5) were uploaded in the software and together with additional entries for subjective refraction and white-to-white corneal diameter, the software populated the initial lens parameters. Lens modifications for fit and/or vision were permitted at any of the following three timepoints: the dispense visit, after the first night or after one week of wear. Visual acuity (LogMAR) was determined with subjective refraction at baseline and unaided after one month of Ortho-K wear. Subjective comfort was collected after the first lens application and after one month (0-10 scale, 10=very comfortable). Subjective vision clarity was collected via home ratings just after lens application on the first night and after one month (0-10 scale, 10=Sharp, clear/ very good vision).

Rresults: Sixteen participants (12F:4M), mean age 11.3±3.2 years [7 to 18 years] were included in the analysis. The mean refraction of all 32 eyes was Sph -2.80±1.38DS [-1.00 to -5.75DS] and Cyl -0.56±0.46DC [0.00 to -1.25DC]. Best-corrected visual acuity prior to lens insertion was 0.00±0.01 logMAR and unaided vision after 1 month was +0.09±0.11 logMAR. Remaining correction after 1 month was Sph -0.12±0.46DS [+0.75 to -1.25DS]. Almost all lens designs predicted by the software were considered acceptable (fit and vision) by the investigator with just one lens requiring a modification after the first night due to corneal staining. Comfort ratings were significantly better after 1 month (7.8 ± 1.4) compared to the dispense visit (5.2 ± 2.2)(p<0.01). Vision clarity ratings were also better after 1 month (8.4 ± 1.5) compared to after the first night (7.0 ± 3.2)(p=0.02).

Conclusions: The Visavy software could help determine acceptable lens parameters for the Paragon CRT or Paragon CRT dual axis Ortho-K lenses in 97% of eyes (31 of 32 eyes). This high initial success rate has the potential to reduce chair time and assist ECPs to confidentially fit these lenses to their patients.

Ng A, Tan J, Read S, Alster Y, Bosworth C, Jones L. AZR-MD-001 Improved Tear Film Stability and Symptoms of Meibomian Gland Dysfunction in a 6-Month Study American Academy of Optometry, New Orleans, October 12, 2023 [ Show Abstract ]

Purpose: Abnormalities of the tear film and subsequent ocular surface disease symptoms can be caused by meibomian gland dysfunction (MGD). In a Phase
2 clinical trial, AZR-MD-001 topical ointment (selenium sulfide, 0.5% or 1.0% concentration) was investigated as a new treatment for MGD.
Changes in tear film stability, meibomian gland secretion and ocular surface symptoms were monitored in adults with signs and symptoms of
MGD.

Methods: For this multicenter, double-masked, vehicle-controlled, parallel-group trial (NCT03652051), 245 adults were randomized to receive treatment
(AZR-MD-001 0.5% [n=82] or AZR-MD-001 1.0% [n=83]) or vehicle (n=80) twice a week before bed. Eligible patients were ≥18 years old, had a
Meibomian Gland Secretion (MGS) score ≤12 in both eyes, and an Ocular Surface Disease Index (OSDI) score from 13 to 33, and TBUT <10
seconds. Prespecified co-primary endpoints were change from baseline in Meibomian Glands Yielding Liquid Secretion (MGYLS) and OSDI score at
month 3. Tear film stability was considered improved if tear breakup time (TBUT; with 2% fluorescein sodium) increased by more than 2 seconds
from month 3 onward. Patients were defined as asymptomatic if their OSDI score was <13. Statistical differences from baseline were calculated
for visit days 14, 45 (1.5 months), 90 (3 months), 135 (4.5 months), and 180 (6 months). Co-primary endpoints were evaluated using a
hierarchical approach that controlled for family-wise Type I error, using an ANCOVA model. Responder endpoints were evaluated via Cochran-
Mantel-Haenszel test using Wilson-Hilferty transformation.

Results: AZR-MD-001 0.5% achieved statistically significant improvements vs vehicle for both co-primary endpoints, MGYLS (p=0.0004) and OSDI score
(p=0.0438), at month 3, which continued through to month 6 (MGYLS: p=0.0002; OSDI: p=0.0135). Tear film stability (TBUT) significantly
increased from baseline in both treatment groups compared with vehicle at month 3 (AZR-MD-001 0.5% mean change=2.2 s, p<0.0001 vs
vehicle; AZR-MD-001 1.0%=1.5 s, p=0.0187 vs vehicle; vehicle=0.5 s), with increases generally sustained at month 6 but no longer significant vs
vehicle (0.5%=2.3 s; 1.0%=1.3 s; vehicle=1.6 s; p>0.05 vs vehicle for both concentrations). Many patients treated with AZR-MD-001 were
considered asymptomatic for disease (OSDI 0.05 vs vehicle; vehicle=28%),
which was sustained for the 0.5% concentration and improved for 1.0% concentration at month 6 (0.5%=48%, p=0.0333 vs vehicle; 1.0%=50%
p=0.0205 vs vehicle; vehicle=30%).

Conclusion: Compared to vehicle, AZR-MD-001 significantly improved meibomian gland secretions and tear film stability, which resulted in clinically significant
improvements in ocular symptoms after 6 months of treatment.

Phan C-M, Chan V, Walther H, Pereira da Mota A, Lorenzo CA, Jones L. Developing a High-throughput in vitro Eye Model for Evaluating Ocular Drug Delivery with Contact Lenses XXV Biennial Meeting of the International Society for Eye Research, Feb 21, 2023 [ Show Abstract ]

Purpose: To develop a high-throughput in vitro eye model for evaluating ocular drug delivery with contact lenses (CLs).
Method: The eye model was designed using CAD software and manufactured using a combination of fabrication methods, including moulding, CNC machining, laser cutting, and 3D printing. The model consists of an eyeball, an upper and lower eyelid, and a collection tray to collect flow-through fluid. The portion of the upper eyelid that comes into contact with the eyeball is moulded with a highly wettable and durable polyvinyl alcohol hydrogel. The centre of the eyeball is designed with a 300 µm thick, 15 mm diameter cut-out that allows for a contact lens to be mounted. Simulated tear fluids can be delivered through an inlet located on the upper eyelid using a pump. During each blink cycle, the eyelid slides and flexes across the eyeball to create an artificial tear film layer. The blink distance, speed and rate are actuated using a motor controlled by an Arduino board and software. The release of a red dye from two CLs (etafilcon A and senofilcon A) and the release of two drugs (resveratrol and pravastatin sodium) from drug-loaded CLs were evaluated using the model and compared to the traditional vial testing method. Phosphate buffered saline (PBS) was used as the simulated tear fluid and infused into the model at 5 µL/min, at a blink rate of 1 blink/10 s.
Results: The fluid flows from the inlet, spreads across the eye, accumulates in the lower eyelid and then flows into the collection tray via gravity. During this process, approximately 25% of the fluid originally injected into the model was lost due to evaporation, nonspecific absorption, and residual dead volume. Overall, the release of the dye and drugs from the CLs was higher in a vial compared with the eye model. Interestingly, the drug release profiles from the drug-loaded CLs on the eye model were similar to in vivo results previously collected from a rabbit study, although the total amount of drugs released was significantly less. 9 or 24 CLs can be tested with one syringe or peristaltic pump, respectively.
Conclusion: The current eye model developed from this study could be used to measure the release of ophthalmic drugs or comfort agents from CLs in a high-throughput manner. However, further work is required to fine-tune the parameters of the model, such as the composition of the tear fluid, blink rate, tear flow rates, and temperature, to better simulate in vivo conditions.

Phan CM, Ramasamy M, Ho B, Hui A, Jones L. Fabrication of a microfluidic chip using 3D printing for evaluating ocular cytotoxicity The Association for Research in Vision and Ophthalmology, New Orleans, LA, USA, April, 2023 [ Show Abstract ][ PDF ]

Purpose: To develop a PDMS (polydimethyl siloxane) microfluidic chip to evaluate ocular cytotoxicity with ophthalmic formulations and materials.

Methods: The microfluidic chip was designed using CAD software (FreeCAD), and the moulds of the chips were printed using (1) a stereolithography (SLA) and (2) digital light processing (DLP) 3D printer. The printed moulds were washed with isopropyl alcohol (IPA), UV-cured for 1-hour at 60oC, followed by heating in an oven at 120oC for 2 hours to remove any unreacted polymers. The surface of the chips was smoothed with sandpaper with increasing grit, followed by an application of nail polish. The moulds were then cast with PDMS, a gas-permeable and clear polymer commonly used for the fabrication of microfluidic chips. The moulds and chips were imaged using SEM (scanning electron microscopy). The light transmittance of the chips was also measured. The PDMS top half of the chip was adhered to a microscope slide using medical-grade double-sided tape. For a pilot study, the PDMS chips were sterilized via autoclaving, coated with 0.1% polydopamine to improve their surface wettability, and then seeded with immortalized human corneal epithelial cells (HCEC). After 2 days of incubation in a nutrient media broth (no flow), cell adhesion and growth were evaluated using light microscopy.

Results: Both 3D printers were able to print moulds with high resolution, with channel dimensions as low as 50 µm, and with faster print times for the DLP printer. SEM images revealed that moulds that were both sanded and had a nail coating were significantly smoother than the original 3D-printed moulds. The chips cast from the polished moulds were transparent, with >85% transmittance from 450-700 nm, and could be used to image cells through a microscope. The microfluidic chips were able to handle flow rates up to 1 mL/min for 24 hours without any signs of leakage. HCEC cells were able to adhere and grow on the coated PDMS microfluidic chip after 2 days.

Conclusion: This study showed that SLA and DLP printers could be used to fabricate PDMS microfluidic chips as a low-cost rapid prototyping approach. The fabricated chips were clear and could be used to incorporate HCEC cells. Future work will examine the viability of cells under different flow rates and shear stress conditions on these chips.

Ramasamy M, Ho B, Phan CM, Jones L. Fabrication of a microfluidic chip for ophthalmic drug delivery studies using 3D printing The Association for Research in Vision and Ophthalmology, New Orleans, LA, USA, April, 2023 [ Show Abstract ]

Purpose: To develop a microfluidic chip for testing the release of ocular drugs from soft contact lenses using 3D printing.

Methods: The microfluidic chips were designed using CAD (computer-aided design) software consisting of a top and bottom portion. The top portion comprised of inlet, outlet, and channels for fluid flow. The lower portion contained a dome-shaped mount to mount a contact lens. The chips were printed using clear resin on a commercial stereolithography (SLA) 3D-printer. The printed chips were washed in isopropyl alcohol (IPA) for 30 minutes, air dried and UV cured for 30 minutes. The top and bottom portions of the chip were fused by applying a thin layer of resin, followed by UV-curing for 10 minutes. In another design iteration, moulds for the chips were 3D printed and casted with polydimethylsiloxane (PDMS). The two halves of the PDMS chips were fused using double-sided adhesive tape. In a preliminary study, two commercial contact lenses, etafilcon A and senofilcon A, were soaked in 2 ml of red food dye for 2 hours. The release of the dye was measured using the PDMS chip with phosphate-buffered saline at a flow rate of 1.5 L/min over 24 hours via absorbance at 520 nm. The dye extraction from both lenses was
performed by incubating the dye-soaked lenses in 1:1 acetonitrile/water solution for 24 hours with gentle shaking.

Results: Both the chip and moulds were printed in less than 5 hours, with a minimum resolution of 50 μm. The resulting resin and PDMS chips can also be sterilized by autoclaving. The top and bottom parts of the chips were completely sealed such that no leakage was detected at a flow rate of up to 100 μL/min for 24 hours. The release kinetics of the dye was linear throughout the 24 h period for both lens types under the current parameters. The total amount of dye released after 24 h was higher for etafilcon A (26.26 mg/lens) than senofilcon A (18.41 mg/lens), which corresponded to approximately 83.1% and 40.01% release, respectively. Both the lens types were still visibly red after 24 hours. The output of the microfluidic chip could be used as an input for subsequent analyses.

Conclusions: This study showed a cost- and time-efficient approach to fabricate a microfluidic chip for evaluating drug release from contact lenses. Future work will examine the release profile of various ocular drugs from contact lenses using different flow conditions.

Woods J, Guthrie S, Luensmann D, Vega J, Orsborn G. Task-based Evaluations of Two Daily Disposable Soft Multifocal Lenses American Academy of Optometry, New Orleans, October 12, 2023 [ Show Abstract ]

Purpose: Drop-outs from contact lens (CL) wear remains problematic across the entire sector, however for presbyopes it has been reported to be higher
and largely related to comfort and vision problems. Many practitioners use daily disposable (DD) CLs to improve comfort, therefore it is of high
interest to evaluate two recently launched DD multifocal (MF) CLs with a particular emphasis on evaluating subjective comfort and situational or
task-related vision performance: stenfilcon A (stenA) DDMF (CooperVision, Inc.) and senofilcon A (senoA) DDMF (Johnson & Johnson Vision).

Methods: Habitual MFCL wearers were recruited for this randomized, subject masked, cross-over study. After a successful screening both lenses were fit
following manufacturers’ fitting guides. Lens 1 was dispensed and optimized 3-8 days later, prior to entering a 2-week optimized lens wear period,
after which Likert ratings were completed for comfort, vision and everyday tasks. Then, Lens 2 was dispensed and the same power optimization
and data collection schedule were followed. Likert ratings used 4-point forced choice, with strongly or slightly agree considered positive responses
and strongly or slightly disagree considered negative responses.

Results: 54 subjects, 43F/11M, completed the study with demographic means [range]: age 53yrs [42-75]; OD: sphere -1.72D [+4.00 to -5.50], cyl -0.29D [0.00 to -0.75] near addition +1.94D [+1.00 to +2.50]. At the end of each optimized lens wear period, Likert data showed no differences between lenses (p>0.05). Each lens showed statistically higher counts of positive versus negative responses for each statement (all p<0.05). Percentage of positive responses were:
• These CLs feel good on my eyes: stenA 93%; senoA 89%
• These CLs gave me all day comfort: stenA 87%; senoA 87%
• These CLs give me crisp clear vision at all distances: stenA 81%; senoA 69%
• These CLs give me crisp clear vision in different lighting conditions: stenA 89%; senoA 74%
• These CLs give me crisp clear vision even in dim/dark light conditions: stenA 80%; senoA 69%
• These CLs give me crisp clear vision when driving: stenA 90%; senoA 81%
• These CLs give me crisp clear vision when using a laptop: stenA 88%; senoA 92%
• These CLs give me crisp clear vision when reading text on my phone: stenA 91%; senoA 85%
• These CLs give me crisp clear vision when reading up close: stenA 83%; senoA 80%
• These CLs give me reliable vision: stenA 93%; senoA 87%
• I do not experience halos and starbursts in my vision: stenA 94%; senoA 94%

Conclusion
The high percentage of positive responses to these task specific reports of lens performance suggests that both lenses largely met or exceeded the needs of these subjects for those tasks. It seems plausible to assume that if a MFCL is reported as comfortable and it also performs well in frequent everyday vision tasks and situations, then it is likely to help minimise future drop-out.

Woods J, Guthrie S, Luensmann D, Vega J, Orsborn G. Investigation of Ease of Fit to a Different Daily Disposable Multifocal Soft Lens American Academy of Optometry, New Orleans, October 12, 2023 [ Show Abstract ]

PURPOSE: Eye care professionals (ECPs) regularly need to decide whether to switch their multifocal contact lens (MFCL) patients to new products. Common reasons for switching are visual or comfort performance, prescription availability, new optical designs, or lens material benefits. This study evaluated the visual and comfort impacts of switching habitual MFCL wearers from somofilcon-A MF 2 add design (somA) into stenfilcon-A MF 3 add system (stenA) (both 1-day, CooperVision, Inc.) and collected information about the ease of fit.

METHOD: In this crossover, subject-masked study, subjects were first fit and dispensed with somA; power adjustments were permitted at the fit visit and also 1-week later. Optimal lens powers were worn for 2 weeks. After this adaptation period to optimized somA MFCLs, subjects were refit with stenA MFCLs which were worn and optimized following the same schedule. Fitting guides were followed for both. Subjects used diaries on days 6 and 13 to report whether stenA performance exceeded or met their needs (positive response) or whether they failed to meet their needs (negative response). Likert ratings were collected at the end of the stenA wear period.

RESULTS: Sixty participants (mean age 52.6±6.9; 50F:10M) completed. Mean OD refraction: sph -1.97D [-5.00D to +2.75D], cyl -0.50D [0.00 to -0.75], near addition: +1.95D [+1.00D to +2.50D]. All achieved successful fit with both MFCLs. 78% subjects achieved optimal fit with the first pair of trial stenA, the remaining 22% required just one adjustment. Lenses were worn on average >13hrs/day, ≥5 days/week. Diary responses showed stenA resulted in statistically more positive responses vs negative responses for various comfort and vision criteria (all p<0.01): • Comfort on lens application: Day 6 & 13: 98% & 100% positive responses • Comfort at time of removal: Day 6 & 13: 90% & 95% • Dryness at time of removal: Day 6 & 13: 90% & 92% • Vision stability throughout the day: Day 6 & 13: 93% & 95% • Overall speed & ability to change focus between distances: Day 6 & 13: 95% & 92% Through Likert questions, statistically more subjects agreed than disagreed with the following statements: • I could see clearly right away with these [stenA] contact lenses, and it was easy to adapt (p<0.01) • My vision improved when I switched from somA to stenA (p<0.01) • The transition from somA to stenA was easy (p<0.01)

CONCLUSION: Success was high with the first trial lens pair for stenA 3 add system lenses. Subjects reported the transition to be easy, resulting in clear vision straight away and through the wear period most reported that comfort and vision experiences met or exceeded their needs. These results should reassure ECPs when considering refitting their presbyopic patients from somA 2 add to stenA 3 add system; these subjects reported transitioning was easy and performance improvements were recognized within 2-weeks.

Wulff D, Phan C-M, Jones L. Development of a 3D-printed hydrogel eye model for evaluating ocular drug delivery The Association for Research in Vision and Ophthalmology, New Orleans, LA, USA, April, 2023 [ Show Abstract ][ PDF ]

Purpose: To 3D-print a soft hydrogel eye model using a novel bioink for evaluating ocular drug delivery.

Methods: The eye model was designed using CAD software. It includes several key components made from a hydrogel, including an upper and lower eyelid, a frontal surface to mimic the cornea and sclera, and an internal chamber to mimic the interior of the eye. The components were designed to fit with an existing blink model that was developed previously in our laboratory that allows for automated blinking and tear collection. The eyeball and the lower eyelid were 3D bioprinted using a modified commercial mSLA printer (Photon Mono X, AnyCubic, Shenzhen, China). Various bioinks were tested, consisting of 5-15% gelatin methacryloyl, 1-5% polyvinyl alcohol, 5-30% polyethylene glycol diacrylate, 0.4-0.6% lithium phenyl-2,4,6-trimethylbenzoylphosphinate, and 2-3% of a yellow food-grade dye in phosphate buffer solution. Different formulations were evaluated to create prints that were desirable in terms of print quality, stiffness, and flexibility. Printing was undertaken at 40˚C to ensure the ink remained a liquid and at 90% humidity to protect the parts and ink from desiccation.

Results: Both the eye and the lower eyelid were successfully printed in high resolution using 100 µm layer heights without any support structures within 3 hours. The prints are hydrophilic with a 60-80% water content, are soft and flexible, and are fabricated with biocompatible biomaterials. Both components were able to be incorporated into an in vitro blink model which will allow for improved testing that more closely mimics a human ocular system, in particular, drug absorption through the cornea. A port on the eye allows for the sampling of fluid from the interior eye model for testing the diffusion of drugs to the posterior chamber when released by topical ophthalmic formulations or anterior segment devices such as contact lenses.

Conclusion: This study demonstrated that a modified mSLA 3D printer can be used to fabricate soft, hydrophilic ocular model components using a novel biocompatible bioink.

2022

Bitton E, Hurteau G, Laplante A, Jones D, Wittich W. Optometry student debt in Canada American Academy of Optometry, San Diego, October, 2022

Chan V, Phan CM, Walther H, Ngo W, Jones L. Effects of temperature and blinking on contact lens dehydration using an in vitro blink model 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Chan VWY, Phan CM, Walther H, Jones L. Fabrication of an in vitro eye model for practicing corneal foreign body removal 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Christian LW, Rose K, Opoku-Yamoah V, Jones D, Irving EL, McCulloch D, Leat S. Changes in Canadian pediatric optometric vision care in a 14-year period American Academy of Optometry, San Diego, October, 2022

Guthrie S, Luensmann D, Woods J, Vega J, Orsborn G. Acceptability of different lens materials in habitual wearers of frequent replacement lenses American Academy of Optometry, San Diego, 2022 [ Show Abstract ]

Purpose: New soft lens materials frequently enter the market for different lens wear modalities and the question remains as to how these compare to established products. The purpose of this study was to compare the subjective performance of two silicone hydrogel (SiHy) lenses that employ different technologies to improve wearer comfort: the recently introduced lehfilcon A (leh-A)(Alcon) lens employs ‘Water Gradient Technology’ and the established comfilcon A (com-A)(CooperVision) lens employs ‘Aquaform Technology’.

Methods: This study was a prospective, bilateral, double-masked, randomized, cross-over, daily-wear design involving two different monthly replacement SiHy lens types (leh-A and com-A). Young adults who habitually wore frequent replacement spherical lenses were recruited at four clinical sites in the US. Each of the two lens types was worn for one month and participants used their habitual care products. Throughout each month, participants recorded their lens wear comfort on several days at home and during study visits (0-10 scale, 10=can’t feel the lenses) and answered agreement (5-point strongly/slightly agree, neither agree or disagree, strongly/slightly disagree) and preference (5-point strong/slight prefer first/second lens pair, no preference) questions. Statistical differences were determined by Wilcoxon matched pairs and binomial testing.

Results: Sixty-three participants (44F:19M), mean age 27.5 ± 4.8 years [18 to 35 years] were included in the analysis. The mean spherical refraction was -3.12 ± 1.6D [-6.50D to +1.25D]. Overall comfort ratings on Days 1, 14, 27 were 8.5, 8.0, 7.7 for com-A and 8.8, 8.2, 8.1 for leh-A. For both lens types, comfort ratings were higher at the beginning of the month (p0.05). The mean drop in overall comfort after one month of wear was the same for both lens types (com-A: 0.7, leh-A: 0.7, p>0.05). At 1-month, participants rated overall satisfaction with comfort similarly (com-A: 8.0, leh-A: 7.8, p>0.05) and there was no difference in the number of participants preferring each lens when considering comfort on application (26:24), removal (27:24) and overall (29:27)(com-A:leh-A, all p>0.05). For each lens type, a similar number of participants agreed compared to disagreed with the statement “These lenses feel like nothing even after one month of wear” (each lens type p>0.05) and no statistically significant differences were found between the lens types (p>0.05).

Conclusion: Despite significant differences in material composition and surface technologies between com-A and leh-A, the subjective contact lens comfort experience over 1 month was similar. The preference ratings further highlight the importance of providing patients with different options and deciding together which lens type is best for them to help ensure long-term success with lens wear.

Irving EL, Jones DA, Chow A, Christian LW, Furtado NM, Labreche T, MacIver S, Spafford MM. Eye care literacy: How the public wants to learn 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Jones D, Leat S, Rose K, Opoku-Yamoah V, Irving E, McCulloch D, Christian L. Attitudes and practices of pediatric eye care: A survey of Canadian optometrists American Academy of Optometry, San Diego, October, 2022

Jones DA, Christian LW, Rose K, Opoku-Yamoah V, Irving EL, McCulloch DL, Leat SJ. Practices and attitudes toward pediatric eye care 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Jones DA, Luensman D, Alton K. The prevalence of refractive error in children in a Canadian rural, first nation community 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Jones L, Bose S, Phan CP, Rizwan M, Tse JW, Yim EKF. Fabrication of an enzyme-triggered therapeutic releasing biomaterial for bandage contact lenses American Academy of Optometry, San Diego, 2022 [ Show Abstract ]

Purpose: The use of a soft bandage contact lens in combination with a therapeutic could help improve the treatment of corneal injuries. The purpose of this study was to develop an enzyme-triggered therapeutic release platform using a unique gelatin methacrylate formulation (GelMA+) and bovine-lactoferrin (BLF), a model therapeutic.

Methods: Two formulations of GelMA+, 20% and 30% w/v, were prepared using UV polymerization. The properties of the material, including porosity, tensile strain, and swelling were characterized. The degradation of GelMA+ in the presence of matrix metalloproteinase-9 (MMP-9), typically found upregulated at a wounded sight, from 0 – 300 µg/mL of the enzyme was also evaluated. Cell viability, cell growth, and cytotoxicity on the GelMA+ gels were determined using the AlamarBlueTM assay and the LIVE/DEAD™ Viability/Cytotoxicity Kit staining with immortalized human corneal epithelial cells after 5 days. For a preliminary drug release study, the 30% GelMA+ gels were also loaded with 3 µg of BLF, and the release of the therapeutic was evaluated over 5 days at various MMP-9 concentrations (0, 100, 300 µg/mL) in phosphate-buffered saline (PBS 1X) at 37 °C. The gels were washed for 1 hour at room temperature (22 – 24 °C) before the release phase to remove any loosely bound BLF on the surface. The amount of BLF released was measured using an ELISA kit and UV absorbance at 450 nm, n=4.

Results: The 30% w/v GelMA+ had a higher crosslinking density, tensile strength, smaller pore size, and lower swelling ratio than the 20% w/v GelMA+ (p<0.05). The degradation rate of the 20% w/v gel was much faster (p<0.001), degrading almost completely after 48 hours at 300 µg/mL of MMP9. After 5 days, There was no cytotoxicity detected in the live/dead staining for either concentration, but the 30% w/v GelMA+ showed significantly higher cell viability (p<0.05). In the drug release study, there was no burst release of BLF observed for the 30% w/v gel, and the release of the therapeutic was sustained over 5 days. The rate of release from the gel significantly increased with increasing concentrations of MMP-9 (p<0.001), correlated to the rate of degradation of the gels.

Conclusion: The results showed that degradation of GelMA+ can be tuned by modifying the cross-linking density or exposure to different concentrations of MMP-9. The release of BLF from 30% GelMA+ is driven by a combination of diffusion and degradation of the material by MMP-9 enzymes. Future work will focus on optimizing the materials to deliver other therapeutic agents at physiologically-relevant concentrations of MMP enzymes

Luensmann D, Guthrie S, Woods J, Vega J, Orsborn G. Performance evaluation of two toric multifocal contact lenses available in different parameter increments Nederlands Contactlens Congres, Veldhoven, Netherlands, Jun 27, 2022 [ Show Abstract ]

Purpose:
Toric multifocal contact lenses (TMFCLs) offer vision correction to the astigmatic presbyopic population. The vision outcome was determined in existing soft lens wearers when fit with two TMFCLs, available in different parameter steps; 5 vs 10 degree axis increments and 6 vs 2 near adds.

Methods:
In a multisite, prospective, randomised, participant-masked, 1-month crossover, bilateral dispensing study, habitual soft lens wearers ≥42years old with minimum 0.75DC astigmatism were fit with two monthly replacement, silicone hydrogel TMFCLs (comfilcon A (com-A); CooperVision, samfilcon A (sam-A); Bausch & Lomb). The manufacturer’s fitting guides were followed, and lens prescriptions were optimised after 3-7 days of wear, before the 1-month wear period. Vision outcomes included visual acuity (LogMAR), 3-point ratings (met/exceeded or did not meet my needs), and 5-point preference ratings (strongly/slightly prefer lens 1 or 2, no preference).

Results:
Fifty-six participants age 53.6±8.6 years were included in the analysis (OD mean(±SD): sph -2.47D(±2.38), cyl -1.27D(±0.47), add 1.88D(±0.48)). For com-A axes ending in 5 degrees were chosen for 47% of eyes and each add power was prescribed. After one month, LogMAR acuity was similar for both lens types for distance, intermediate and near (p>0.05 for all). On days 7, 14 and 28 participants rated that com-A met their needs better for ‘Overall speed and ability to change focus between distances’, ‘Vision stability throughout the day’ and ‘Overall vision clarity’ (p<0.05 for all); other ratings showed no difference between lenses. A preference was found for com-A for vision clarity for ‘intermediate tasks’ (p=0.03), ‘near tasks’ (p=0.01), ‘during digital device use' (p0.05).

Conclusion:
The higher accuracy of prescribing for com-A due to the 5-degree axis steps and the 6 near adds may have contributed to the better vision outcomes reported with com-A.

Nagaarudkumaran N, Mirzapur P, McCanna DJ, Jones L, Ngo W. The effect of Lifitegrast on cytokine response from immortalized human corneal epithelial cells under hyperosmolar stress American Academy of Optometry, San Diego, 2022 [ Show Abstract ]

Purpose: Lifitegrast is a topical ophthalmic pharmaceutical used to treat moderate to severe dry eye disease. Its mechanism of action occurs by inhibiting the binding between lymphocyte function-associated antigen 1 (LFA-1) and intercellular adhesion molecule 1 (ICAM-1). As an integrin antagonist, lifitegrast binds to LFA-1, preventing the formation of the LFA-1/ICAM-1 complex.
Given that lifitegrast is a small molecule with potential to act on other intracellular targets, this study aimed to examine its effect on the inflammatory response of immortalized human corneal epithelial cells (HCECs) undergoing hyperosmolar stress.

Methods: HCECs were exposed to hyperosmolar media (500 mmol/kg via sodium chloride) and treated with 1% or 3% lifitegrast. A treatment without lifitegrast was used as a control. Following an exposure period of 0.25-hours, 3-hours, 6-hours and 12-hours, the conditioned cell media was collected and cytokines IFN-γ, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, TNF-α and IL-17A were quantified using electrochemiluminescent multiplexing assays.

Results: Cells exposed to 1% lifitegrast exhibited significantly lower IL-1β, IL-6, IL-8, and TNF-α compared to the control (all p < 0.0172) at 6-hours and lower IL-6, IL-8, and TNF-α (all p < 0.0053) at 12-hours. With the 3% lifitegrast exposure, there was a significant reduction in IL-1β, IL-6, IL-8, and TNF-α (all p < 0.0224) at 6 and 12-hours. By the 12-hour mark, IL-10, IL-17A, IFN-γ, and IL-2 were significantly higher in both 1% and 3% lifitegrast compared to the control (all p < 0.0254). IL-12p70 was significantly higher with 3% lifitegrast only at all time points (all p < 0.0146), and IL-4 was significantly higher with 3% lifitegrast only at 0.25 and 3-hours (both p < 0.0249) compared to the control. There was no significant difference in IL-13 concentration between 1% and 3% lifitegrast at any time point.

Conclusion: Lifitegrast reduced IL-1β, IL-6, IL-8, and TNF-α from HCEC exposed to hyperosmotic stress. However, lifitegrast also increased IL-10, IL-12p70, IL-17A, IL-2, IL-4, and IFN-γ. Therefore, in addition to LFA-1/ICAM-1 antagonism, it is possible that lifitegrast may function additionally to inhibit the innate immune response and promote suppressive immune function.

Nagaarudkumaran N, Mirzapur P, McCanna DJ, Jones L, Ngo W. The effect of Lifitegrast on the hyperosmotic stress-induced cytokine response from immortalized human corneal epithelial cells 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Ng AY. Pain and (almost) no stain: exploring corneal neuropathic pain beyond the slit lamp 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Ng AY, Dantam J, Woods J, McEwen B, Jones L.. Examining Symptomatic Relief and Kinetic Tear Film Stability of I-DROP MGD Eye Drops Optometry's Meeting ePosters Virtual Event, Jun 8, 2022 [ Show Abstract ]

Background:
I-DROP MGD is a novel formulation of viscoadaptive hyaluronan, phosphorylcholine and glycerin to support integration, stabilization and enhancement of the tear film lipid layer as well as hydration of the ocular surface. The purpose of this study was to compare the difference in tear film measures after instilling I-DROP MGD (test) compared with another hyaluronic acid-based lubricant, Thealoz Duo (control), and to examine the subjective relief of dry eye symptoms with I-DROP MGD over 1-week.

Methods:
This prospective pilot study (n=10) comprised of two parts. Part 1 was a non-dispensing, doublemasked study involving contralateral application of test and control drops, followed by a two-hour observation period. Non-invasive tear break-up time (NITBUT), tear meniscus height (TMH) and lipid layer thickness (LLT) were measured out to 2 hours. Part 2 was a dispensing study, where one bottle of I-DROP MGD was provided to participants to use bilaterally at least once daily for 7 days. After 7 days, subjective ratings (0-100 scale) of comfort, soothing and quality of vision along with OSDI and SPEED scores were collected and compared with participant's habitual eye drops.

Results:
Part 1: NITBUT and TMH were significantly greater with I-DROP MGD (14.2 ± 5.1s and 0.42 ± 0.22mm) compared to Thealoz Duo (10.5 ± 5.7s and 0.29 ± 0.10mm) after 60 minutes (p =0.037) and 5-minutes of instillation (p =0.022) respectively; LLT was significantly thicker with Thealoz Duo (79.5 ± 15.7nm) compared to I-DROP MGD (68.5 ± 13.8nm) after 5 minutes of instillation (p=0.005). Part 2: Subjective ratings for comfort and soothing were significantly greater with I-DROP MGD (81.6 ± 5.7 and 86.8 ± 8.1) compared to habitual eye drops (73.3 ± 13.7 and 75.3 ± 19.8), p=0.027 and p=0.010 respectively. No significant differences were observed for quality of vision. OSDI and SPEED scores were significantly lower following use of I-DROP MGD (33.2 ± 11.7 and 11.1 ± 3.6) when compared to habitual drops (45.2 ± 14.7 and 14.9 ± 2.7), p=0.017 and p=0.006 respectively.

Conclusion:
When used for 7 days, I-DROP MGD resulted in clinically relevant reductions in dry eye symptoms, measured with OSDI.

Ng AY, Woods J, Jones L. The impact of fluid intake on dry eye symptoms and signs American Academy of Optometry, San Diego, 2022 [ Show Abstract ][ PDF ]

Purpose: Preventing dehydration is essential for optimal bodily function. This study investigated if maintaining the recommended daily fluid intake set out by the Dietitians of Canada affects tear film measures and ocular symptoms in participants with and without dry eye disease (DED).

Methods: This was a prospective, non-randomized interventional pilot study. Twenty participants were enrolled: 10 with DED and 10 healthy controls. At Baseline, symptom questionnaires (Ocular Surface Disease Index [OSDI] and Ocular Comfort Index [OCI]) and habitual fluid intake was documented. Baseline tear film measures (non-invasive tear break-up time [NITBUT], tear meniscus height [TMH], non-anaesthetized Schirmer test) were also assessed. Eligible participants were instructed to attain the recommended daily intake (3.0L for males, 2.2L for females) for 7 days, while keeping a diary to track all fluids consumed during this time. On Day 8, participants returned for follow-up: symptom questionnaires and tear film measures were reassessed and fluid intake diaries were collected.

Results: Twenty participants completed the study; 4/20 (3 DED, 1 control) met the fluid intake recommendation prior to starting the study and were excluded from data analysis. All remaining 16 participants (8 male, 8 females; 7 DED, 9 control) increased their fluid intake for 7 days. There was a statistically significant and clinically relevant improvement in OSDI scores in the DED group after the fluid intake intervention only (Control baseline: 4 ± 3, Day 8: 2 ± 3, p>0.05; DED baseline: 40 ± 12, Day 8: 29 ± 8, p<0.001). Similarly, OCI scores (0-100, where 100=worst level of discomfort) were 5-points better in both groups after maintaining the fluid intake (Control baseline: 26 ± 5, Day 8: 21 ± 9; DED baseline: 40 ± 3, Day 8: 35 ± 4; both p0.05; DED baseline: 0.21 ± 0.09, Day 8: 0.31 ± 0.15, p=0.043. Schirmer Control baseline: 26 ± 12, Day 8: 27 ± 10; DED baseline: 24 ± 14, Day 8: 23 ± 15; both p>0.05). Compared to baseline, a small increase in NITBUT was observed in the control group and a small decrease observed in the DED group, however neither changes were statistically significant (Control baseline: 11.7 ± 6.5, Day 8: 12.9 ± 8.3; DED baseline: 8.1 ± 4.2, Day 8: 6.4 ± 3.1; both p>0.05).

Conclusions: In participants with DED, maintaining increased fluid intake for 7 days significantly improved OSDI and OCI scores and increased tear volume however, there was no change in non-anaesthetized Schirmer tests or NITBUT. In the control group, small changes in tear film measures were found, however these were not clinically or statistically significant.

Ngo W, Nagaarudkumaran N. Prediction and validation of an intracellular target for lifitegrast 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Opoku-Yamoah V, Leat SJ, Kalpana R, Jones DA, Irving EL, McCulloch DL, Christian LW. Is Canadian pediatric optometric vision care changing? 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Phan C-M, Wulff D, Garg P, Jones L.. Developing a novel in vitro eye model using 3D bioprinting for drug delivery studies The Association for Research in Vision and Ophthalmology, Denver, CO, USA, May 1, 2022 [ Show Abstract ]

Purpose: To develop an in vitro eye model using a novel 3D bioprinting method for testing the release of ophthalmic formulations to the posterior ocular region.

Methods: The eye model was designed using CAD software and includes both an anterior aqueous chamber and a posterior vitreous chamber. The vitreous chamber is surrounded by a blood chamber to mimic vessels that can be used to transport a blood-like substance. Three inlet ports control the flow of fluid into the chambers and the blood channels, and the three outlet ports allow fluids to exit these compartments. The eye model was 3D printed on a commercial mSLA printer (Photon Mono X, AnyCubic), which was retrofitted with a humidity and temperature control module to create a printing environment at 37°C and >80% humidity. The bioink formulation consisted of 10% gelatin methacrylate (GelMa). After printing, the models were incubated at 37°C to remove any uncured GelMa within any hollow compartments. For this study, phosphate-buffered saline was used as an aqueous and vitreous humour mimic. To evaluate the diffusion of a small hydrophilic molecule on the eye model, a contact lens (Air Optix) was soaked with a water-soluble red food dye for 1 hour and then placed on the eye model. The amount of dye in the anterior chamber, posterior chamber, and blood channels was measured using UV spectrophotometry after 24 hours.

Results: The entire model can be printed without any support structures within approximately 3 hours. The 3D printed eye model can also be autoclaved for testing that requires sterility. Because there were no diffusion barriers present in the current model, the red dye was detected in all three chambers after 24 hours. The highest concentration of dye was found in the anterior chamber, followed by the blood chamber and then the posterior chamber.

Conclusions: The prototype developed in this study can be used as a starting point to develop enhanced 3D printed eye models to test drug release kinetics of various devices and formulations. Future work will focus on adding the appropriate diffusion barriers to better simulate drug diffusion through ocular tissues.

Layman Abstract: The aim of the study was to create an advanced eye model using commercial 3D printing methods. Current 3D bioprinters are extremely expensive and regular commercial 3D printers do not have the capabilities to print biological materials. We are developing a method to 3D print sophisticated eye models using inexpensive 3D printers. The models from this research can further be refined for studying drug absorption in the eye. This research will also enable researchers to create their own biological models using 3D printing methods.

Phan C-M, Wulff D, Jones L.. Developing bioinks for commercial mSLA printers and a method for quantifying print quality Canadian Biomaterial Society Conference, Banff, AB, May 25, 2022 [ PDF ]

Phan CM, Chan V, Drolle E, Shi C, Subbaraman L, Wu J, Jones L. Evaluating the in vitro wettability of contemporary reusable soft contact lenses using an in vitro blink model American Academy of Optometry, San Diego, 2022 [ Show Abstract ][ PDF ]

Purpose: To evaluate the in vitro wettability of four contemporary reusable soft contact lens materials (serafilcon A, senofilcon A, senofilcon C, lotrafilcon B, comfilcon A) over a 14-day simulated wearing period using a novel, physiologically relevant in vitro eye model.

Methods: The 14-day wearing period was simulated using an in vitro blink model (OcuBlink). A tear mimic solution containing relevant proteins and lipids was delivered to the eye model at a rate of 1.25 -2.25 µL/min. A tear film was created over the lens via an artificial eyelid that slid across an eyeball surface at 6 blinks/minute, with a lens in-situ, at room temperature and humidity above 50%. For each cycling day, the lenses were incubated on the eye model for 16 hours, followed by a 10 second rub-rinse each side with OPTI-FREE PureMoist Solution, and then incubated overnight for 8 hours in the same solution. Lens wettability was quantified at t = 0 (straight from blister pack), 1, 7, and 14 days via two methods, (1) sessile drop contact angle (CA) and (2) non-invasive keratographic tear-break-up time (NIKBUT), n = 4 for each lens type. Contact angles were measured using the Optical Contact Analyzer (DataPhysics, Germany). NIKBUT measurements were assessed on the OcuBlink via the OCULUS Keratograph 5M (OCULUS, Germany).

Results: At t = 0, comfilcon A (24.0 ± 5.3°) had the lowest contact angle, followed by lotrafilcon B (29.6 ± 6.5°), serafilcon A (67.7 ± 16.0°), senofilcon C (89.2 ± 6.0°), and senofilcon A (92.0 ± 3.1°). All contact lens materials had similar CA out of the blister pack compared to 7 days (p >0.05). There was a slight increase in CA between 7-14 days for serafilcon A and lotrafilcon B, but this was not statistically significant (p>0.05). The NIKBUT for all contact lens materials ranged between 4 – 9 seconds, and there were no significant differences between NIKBUT within the same lens type at any time point (p>0.05). NIKBUT at t = 0 was highest for serafilcon A (8.3 ± 1.7 s) (p<0.05), followed by lotrafilcon B (6.3 ± 1.4 s), comfilcon A (6.1 ± 1.5 s), senofilcon A (5.6 ± 1.1 s), and senofilcon C (5.5 ± 0.8 s).

Conclusion: Lenses with a very low CA did not translate into significantly higher NIKBUT. For some lens materials, notably serafilcon A, there was an increase in CA after 7 days of in vitro testing, which warrants further investigation.

Phan CM, Kapadia W, Qin Nm Zhao P, Ren C, Haines L, Jones L. Development of a microfluidic viscometer for measuring microliter-volume fluid samples American Academy of Optometry, San Diego, 2022 [ Show Abstract ][ PDF ]

Purpose: To develop a microfluidic viscometer capable of measuring the viscosity of microliter-volume fluid samples such as human tear fluid.

Methods: The microfluidic chip was designed using CAD software and laser cut from acrylic sheets into the desired shape and sizes. The various parts of the microfluidic chips were assembled and combined together using medical-grade double-sided tape. The micro-channels were coated with a repellant coating to provide a smooth and hydrophobic surface, which provided a straight flow path for a sample to approach flow equilibrium as it moves through the chip. The chip was attached to a syringe pump to control the flow rate. Additional supporting devices, including a high-speed camera and a pressure transducer, were used for analysis. Based on the difference in capillary pressure at the air-liquid interface, channel dimension, sample length, sample velocity, volumetric flow rate and contact angle, the viscosity of the fluid sample can be derived. For a preliminary experiment, the viscosity of an eye drop (Hydrasense, Bayer Inc., Canada) was measured by the developed microfluidic viscometer as well as a commercial cone/plate rheometer (Model: LVDV-III+, Brookfield Engineering Laboratories Inc, MA, USA) at a shear rate between 27.8 – 308 s-1, n=3.

Results: The minimum sample volume that was needed for measurement was 12 microliters, but this volume can be reduced with further optimization. The results showed that the viscosity values obtained for both the commercial rheometer and the microfluidic viscometer were in strong agreement. At a low shear rate (141 s-1), the viscosity of the eye drop was at 8.03 mPa·s, and at higher shear rates (622 s-1), the viscosity decreased to 6.33 mPa·s. The viscosity of the eye drop decreased with increasing shear rate, which reflects its shear-thinning properties. The maximum shear that was tested was 622 s-1 with no signs of fluid leakage.

Conclusion: The developed microfluidic chip and analysis setup can be used to analyze the viscosity of fluids using very low sample volumes and at very high shear rates. Future work will focus on optimizing the system to further reduce the sample volume requirements to permit testing with human tear samples. This device will provide valuable data in clinical studies investigating dry eye and other ocular surface diseases.

Postnikoff C, Woods J, Weiss S, Jones D, Kasthurirangan S, Chamberlain P, McNally J. Preliminary modification and adaptation of quality of vision questionnaire for children American Academy of Optometry, San Diego, October, 2022

Postnikoff C, Woods J, Weiss S, Jones D, Kasthurirangan S, Chamberlain P, McNally J. Preliminary modification and adaptation of a visual ability questionnaire for children International Myopia Conference, Rotterdam, Netherlands, September, 2022

Ramasamy M, Qin N, Phan C-M, Jones L. Developing a microfluidic chip using 3D printing for testing drug release from contact lenses 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Schulze M, Luensmann D, Ng A, Guthrie S, Woods J, Jones L. Performance of verofilcon A daily disposable contact lenses in digital device users American Academy of Optometry, San Diego, 2022 [ Show Abstract ][ PDF ]

Purpose: To evaluate the performance of Precision1 (verofilcon A) daily disposable (DD) contact lenses (CLs) in habitual CL wearers who undertake substantial digital device use.

Methods: CL wearers between 18-40 years of age who reported a daily digital device use of ≥6 hours while wearing their habitual CLs participated in the study. Eligible participants were dispensed with verofilcon A DD CLs for a period of 12-16 days and were asked to wear these for at least 5 days/week and at least 10 hours/day, while continuing their normal routine of ≥6 hours digital device use. At the 2-week follow-up visit, participants rated their experience with the study lenses on a 0 to 100 scale, with 100 being best, and reported their lens wear times and digital device use. Comfort, dryness and clarity of vision ratings with verofilcon A lenses were collected directly after lens insertion, after 6 hours of digital device use, just before removal, and for overall lens performance. Participants also completed a 4-point (strongly agree, slightly agree, slightly disagree, strongly disagree) Likert scale-based questionnaire. Subjective ratings were not normally distributed, therefore non-parametric analysis was conducted and data are reported as median (range). The Likert scale responses were analyzed using binomial testing.

Results: Thirty-two participants completed the study (27F:5M), mean age of 25.8 ± 6.0 years (range 19-40). Participants reported total and comfortable CL wear time of 14 hours (10-17) and 11.6 hours (2.8-16), respectively, and digital device use of 8.5 hours (6-18) on a typical day. Subjective ratings for overall lens performance after 2 weeks of CL wear were high, with median ratings of 90 (68 – 100) for comfort, 90 (52-100) for dryness and 95 (70-100) for clarity of vision. There were no differences in comfort, dryness and clarity of vision ratings over the course of a typical day, with similar ratings at insertion, after 6 hours of digital device use and just before removal (all p≥0.05). The majority of participants agreed that the study lenses provided good comfort (28/32 subjects; p<0.01) and good vision (29/32; p<0.01) all day long. Considering CL performance when using digital devices for 6 hours, the majority of participants were satisfied with CL comfort (27/32; p<0.01) and vision (29/32; p<0.01) and most agreed that the verofilcon A lenses provided good performance (26/32; p<0.01). Most study participants (24/32; p<0.01) agreed that they did not experience any eye strain during digital device use while wearing verofilcon A lenses. No significant lens-related ocular health findings were observed after 2 weeks of wear.

Conclusions: After 2 weeks of wear, most participants rated the performance of verofilcon A DD CLs highly, with median overall performance ratings for comfort, dryness and vision all 90 on a 0 to 100 scale.

Shukla M, Phan CM, Jones L. Effect of methacrylic acid on atropine sulfate loading into model contact lens materials 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Wulff D, Phan C-M, Jones L. 3D printing using a novel bioink with a commercial mSLA printer to fabricate a model contact lens The Association for Research in Vision and Ophthalmology, Denver, CO, USA, May 2, 2022 [ Show Abstract ]

Purpose: To develop a cost-effective and scalable 3D printing method and novel bioinks to fabricate contact lenses.

Methods: The bioink formulations consisted of GelMA (gelatin methacrylate), LAP (Lithium phenyl-2,4,6-trimethylbenzoylphosphinate), and a yellow food-grade dye. The dye minimizes unwanted light leakage during the photopolymerization process. A commercial mSLA (masked stereolithography) printer, the Photon Mono X (AnyCubic, Shenzhen), was retrofitted with a custom temperature and humidity control kit. The printing process was performed at 40 oC and 90% humidity to ensure that the GelMA remained at a liquid state and to prevent the bioink from drying out, respectively. A set of matrix cubes of varying sizes with holes was used as a standard control. Images of the cubes were taken with a camera, top-down and side-review, analyzed with the ImageJ software and compared with the original CAD designs to derive an overall print quality score. Two print variables, exposure time (5 s to 40 s) and yellow dye concentration (1 – 7%), were analyzed in this study.

Results: The best resolution with the highest print scores were obtained at either 5% yellow dye concentration and 30 seconds exposure time, or 3% yellow dye concentration and 20 seconds exposure time. There was an overall optimal range for both print times (20 - 30 s) and yellow dye concentration (3 - 5%). Values above or below this critical value resulted in lower print quality scores of the standard cubes. A prototype contact lens with a 200 µm thickness was able to be 3D printed using the developed print methods and parameters, with a total print time of approximately 20 minutes. Approximately 28 contact lenses can be printed at the same time using the 3D printer. However, the surface and edges of the 3D printed contact lens were still visually very rough.

Conclusions: The current study demonstrated that a low-cost commercial 3D mSLA printer can be used to fabricate model contact lenses using a hydrogel material. Still, further work is necessary to improve the print quality for fabricating ultra-thin devices such as contact lenses. Future work will use this 3D printing method to fabricate contact lenses for drug delivery.

2021

Basuthkar S, Stahl U, Jones L, Keir N. Impact of monocular lens wear on tear film characteristics The Association for Research in Vision and Ophthalmology. San Francisco, May, 2021

Boegel S, Nogueira C, Shukla M, Ngo W, Jones L, Aucoin M. The impact of a rub and rinse step on the removal of an enveloped virus from a contemporary silicone hydrogel contact lens material American Academy of Optometry, Boston, November, 2021

Bose S, Phan CM, Yim E, Jones L. Fabrication of a MMP-9 triggered biomaterial for corneal wound healing The Association for Research in Vision and Ophthalmology. San Francisco, May, 2021

Chamberlain,P., Arumugam,B., Jones,D., Logan N., Peixoto-de-Matos S., Young G.. Myopia progression in children on cessation of dual-focus contact lens wear: MiSight 1 day 7-year findings American Academy of Optometry, Boston, 2021

Guthrie S, Luensmann D, Woods J, Vega J, Orsborn G. Relationships between success factors in daily disposable multifocal lenses American Academy of Optometry, Boston, 2021 [ Show Abstract ]

PURPOSE:
To evaluate relationships between subjective responses to two daily disposable multifocal contact lenses (MFCLs), stenfilcon A (stenA-MF) and delefilcon A (delA-MF).

METHODS:
Habitual MFCL wearers participated in a prospective, randomized, subject-masked, bilateral crossover study at five optometry offices. Subjects wore each study contact lens (SCL) for 2 weeks and answered lens handling (0-10), satisfaction (1-fell short of needs; 2-met needs; 3-exceeded needs) and agreement (4-strongly agree; 3-slightly agree; 2-slightly disagree; 1-strongly disagree) questions. Responses were analyzed using Wilcoxon Matched-Pairs testing for differences between lens types. Spearman correlations were done for each lens type separately.

RESULTS:
Fifty-eight subjects (50F:8M; mean 54.4 ± 7.3 years) were included in the analysis; mean spherical-equivalent refraction OD: -1.10 ± 2.7D [-6.50D to +3.75D], add +2.00 ± 0.4D [+1.00D to +2.50D]. Subjects had greater agreement for stenA-MF compared to delA-MF for “SCL met my needs for vision” (stenA-MF: 3.3; delA-MF: 2.9; p=0.02) and for “I would like to wear SCL in the future” (stenA-MF: 2.9; delA-MF: 2.6; p=0.03). For each SCL there was a significant correlation between responses to these two questions (stenA-MF: rs=0.81; delA-MF: rs=0.84; p<0.05). For stenA-MF, “SCL met my needs for vision” was significantly correlated (p0.05). Similarly, for stenA-MF, “I would like to wear SCL in the future” was significantly correlated (p0.05). There were no statistically significant differences between stenA-MF and delA-MF for D13 EOD satisfaction with comfort (stenA-MF: 2.0; delA-MF: 2.0; p=0.72) or dryness (stenA-MF: 1.9; delA-MF: 1.9; p=0.88). For both SCLs, EOD satisfaction with comfort was significantly correlated (all p<0.05) with EOD satisfaction with dryness (stenA-MF: rs=0.71; delA-MF: rs=0.67), ease of handling for removal (stenA-MF: rs=0.35; delA-MF: rs=0.51) and comfortable wear time (CWT) (stenA-MF: rs=0.30; delA-MF: rs=0.37). CWT was similar for both SCLs (stenA-MF: 11.6 hours; delA-MF: 11.0; p=0.08), but stenA-MF was rated significantly better for ease of handling for removal (stenA-MF: 8.4 vs delA-MF: 7.6, p=0.02).

CONCLUSIONS:
While end-of-day comfort and dryness are important factors in contact lens success, these results suggest that satisfaction with vision for these multifocal lens wearers was a better indicator (both rs>0.80) of their desire to continue wearing the multifocal lenses in the future.

Guthrie S, Luensmann D, Woods J, Vega J, Orsborn G. Comfort and vision correlations in daily disposable multifocal lenses BCLA Virtual Clinical Conference & Exhibition, 2021 [ Show Abstract ][ PDF ]

Purpose: To evaluate the subjective responses to two daily disposable multifocal contact lenses (MFCLs), stenfilcon A (stenA-MF) and delefilcon A (delA-MF), and to see if there is a correlation between preferences based on vision and comfort.
Method: Habitual MFCL wearers participated in a prospective, randomized, subject-masked, bilateral crossover study at five sites. Subjects wore the study MFCLs for 2-weeks each and then responded to preference questions comparing the study lenses for comfort and vision for near, intermediate, distance, digital device use and overall at all distances. A 5-point Likert scale (Strong/slight preference for each lens or no preference) was used.
Results: For the 58 eligible subjects (50F:8M; mean 54.4±7.3 years), preferences were as follows (#stenA-MF:#delA-MF, p-value): subjects favoured stenA-MF for overall comfort (26:9, p=0.03), intermediate vision (25:8, p=0.03), overall vision (34:10, p=0.04) and vision for digital device use (27:10, p=0.03). Preferences were equivocal for near vision (29:14, p=0.06) and distance vision (13:19, p=0.51). Correlation analysis found that the lens preference based on overall comfort was significantly correlated (all p<0.05) with lens preference based on vision at near (rs=0.61), intermediate (rs=0.48), overall (rs=0.65) and for digital device use (rs=0.66). Lens preference based on overall vision was also correlated with lens preference based on vision at near (rs=0.85), intermediate (rs=0.71), and for digital device use (rs=0.87). Lens preference based on vision with digital device use correlated with lens preference based on vision at near (rs=0.85), and intermediate distance (rs=0.69).
Conclusions: Subjects preferred stenA-MF for a range of comfort and distance measures. Preferences for overall comfort and overall vision were both significantly correlated to the same three preferences of near, intermediate and digital device vision, illustrating how comfort and vision are intricately related when evaluating MFCLs and supporting how poor vision could potentially impact comfort.

Jones DA, Luensmann D, Alton K, Werner L. The prevalence of refractive error in children in a Canadian rural, First Nation Community
American Academy of Optometry, Boston, 2021 [ PDF ]

Luensmann D, Schulze M, Woods J, Lazon de la Jara P, Vega J, Orsborn G. Fitting success with stenfilcon A daily disposable multifocal lenses
BCLA Virtual Clinical Conference & Exhibition, 2021 [ Show Abstract ][ PDF ]

Purpose: Multifocal contact lens (MFCL) fitting sometimes raises concerns about the number of fitting attempts required to determine the optimal lens prescription. This study compared the fit process and success rates of stenfilcon A (stenA) MFCL with delefilcon A (delA) MFCL when fitted to existing MFCL wearers in a randomized order.

Method: Successful MFCL wearers with <1.00DC of astigmatism were recruited at five clinical sites in the US. The first trial lenses were determined from current subjective refraction and the respective fitting guides. Prescription changes were reviewed at this first fit visit and also when participants returned for an optimization visit after wearing the lenses for 3-7 days. Multiple lens powers could be trialed at each visit, all were recorded.

Results: Fifty-eight subjects (50F:8M), mean age 54.4±7.3 years [42 to 70 years] were included in the analysis. The spherical-equivalent refraction was OD -1.10±2.7D [-6.50D to +3.75D] with near add +2.00±0.4D [+1.00D to +2.50D]. StenA-MFCL was successfully fit with the first pair of trial lenses in 83% (48) participants, while 10% (6) needed one additional lens and 7% (4) needed an extra two lenses to reach their final power. Regarding count of eyes, 12% (14) needed power optimizations. DelA-MFCL was successfully fit with the first pair of trial lenses in 66% (38) participants, while 17% (10) needed one additional lens, 10% (6) needed two extra lenses and 7% (4) needed three extra lenses to reach their final lens power. Regarding count of eyes, 25% (30) needed power optimizations.

Conclusions: Habitual MFCL wearers were successfully fitted with both MF lens types when following the respective fitting guides. There was a higher success rate with the first lens pair for stenA-MFCL (>8/10 patients) compared to delA-MFCL (<7/10 patients), and no more than one additional fitting lens (per eye) was needed when fitting stenA-MFCL.

Luensmann D, Schulze M, Woods J, Vega J, Orsborn G. Intermediate vision with multifocal contact lenses American Academy of Optometry, Boston, 2021 [ Show Abstract ]

Purpose:
Fitting multifocal contact lenses (MFCL) typically focusses on optimizing distance and near vision, however many presbyopes require good intermediate vision to focus on targets such as desktop screens. This study determined the performance of habitual MFCL (hab-MFCL), stenfilcon A MFCL (stenA-MFCL) and delefilcon A MFCL (delA-MFCL) for intermediate distance vision in existing MFCL wearers.

Methods:
Five clinical sites in the US recruited habitual MFCL wearers with <1.00DC of astigmatism. Habitual MFCL were power optimized and both study lens types were fit following the respective fitting guides. After two weeks of hab-MFCL wear, study MFCL were worn in a masked/randomized order for the same period of time. Intermediate visual acuity (VA) at 0.75m was determined and subjective responses (fell short of needs; met needs; exceeded needs) were collected along with preference ratings (strongly prefer, slightly prefer, no preference). Subjective responses and logMAR VA were analyzed using Wilcoxon Matched-Pairs testing for differences and binomial testing was conducted on preference ratings.

Results:
Fifty-eight subjects (50F:8M), mean age 54.4±7.3 years [42 to 70 years] were included in the analysis. The mean spherical-equivalent refraction was OD -1.10±2.7D [-6.50D to +3.75D]. The average near spectacle Rx add was +2.00±0.4D [+1.00D to +2.50D] and included 18 participants (31%) who required an add of up to +1.75D and 40 (69%) with an add of at least +2.00D. After two weeks of wear, intermediate logMAR VA with stenA-MFCL (0.08±0.10 logMAR) was statistically significantly better compared to hab-MFCL (0.12±0.11 logMAR, p=0.002) and compared to delA-MFCL (0.12±0.12 logMAR, p0.05 for both).

Conclusion:
All MFCL were worn successfully for two weeks, however differences in the intermediate vision clarity were noted between lens types, in favour of stenA-MFCL compared to delA-MFCL. Digital devices are frequently used at work and during leisure time today and form part of the need for optimal intermediate vision. While it may often be overshadowed by distance and near vision assessments, good performance at the intermediate distance can be just as critical to ensure success in MFCL wearers.

Ng AY, Yumori J. Rethinking Eye Cosmetics and Cosmetic Procedures: What Should We be Telling Our Patients? Best of Boston Academy (Virtual), 2021 [ Show Abstract ]

Cosmetics are used widely to enhance our appearance, clean, and maintain the condition of our skin. With face mask-wearing on the rise many cosmetic users are choosing to accentuate their eyes further with eye cosmetics. However, patients might not have considered the effects that some eye cosmetic products and procedures may have on their eyes. This session will explore the complications that can arise from some common products and procedures, and highlight points of discussion where we should be engaging with our patients.

Nogueira CL, Boegel SC, Shukla M, Ngo W, Jones L, Aucoin MG. Antiviral activity of contemporary contact lens solutions against human seasonal coronavirus strains American Academy of Optometry, Boston, November, 2021

Schulze M, Luensmann D, Woods J, Vega J, Orsborn G.. Comfort and vision with two daily disposable multifocal lenses when worn by habitual multifocal contact lens wearers BCLA Virtual Clinical Conference & Exhibition, 2021 [ Show Abstract ][ PDF ]

Purpose: Practitioners can be reluctant to switch successful multifocal soft contact lens (MF) wearers to different materials or replacement frequencies, fearing the new MF will be less accepted. Subjective responses are highly valued in MF fitting and this study investigated subjective responses from habitual MF (hab-MF) wearers after a refit into daily disposable MF; stenfilcon A (stenA-MF) and delefilcon A (delA-MF).

Method: After optimising the lens powers, subjects wore hab-MF and both study-MFs for 2-weeks each. Study-MF brands were masked and randomised. Throughout the study, subjects answered 13 experience questions per lens type, and 6 preference questions (comfort and vision for distance, intermediate, near, digital-device use, overall vision) to compare between hab-MF and each study MF, and also between study MFs.

Results: Fifty-eight subjects (50F:8M), mean age 54.4±7.3 years were included. Mean spherical-equivalent OD refraction: -1.10±2.7D [range -6.50D to +3.75D], mean near add +2.00±0.4D. 44% habitually wore daily disposable MF yet all were naïve to the study-MFs. Hab-MF wear resulted in positive responses for all experience questions (p<0.05); for stenA-MF 12 answers were positive (p<0.05), 1 was equivocal (p=0.90); for delA-MF 6 were positive (p0.05). Preferences between stenA-MF and hab-MF showed no differences (p>0.05). Subjects preferred hab-MF over delA-MF for intermediate vision (p=0.03) but no other preference (p>0.05). Comparing between study MFs, the preference for stenA-MF was stronger than delA-MF for comfort (p=0.03), intermediate vision (p=0.03), digital-device use (p=0.03) and overall vision (p=0.02) with no difference for distance or near vision (p>0.05).

Conclusions: This study showed that even when habitual MF wearers are already successful, refitting with a new design does not necessarily lead to compromised performance; stenA-MF performed comparably to hab-MF, and for some metrics better than delA-MF. These results should give practitioners confidence to recommend newer materials and different replacement frequencies when managing their existing MF wearers.

Wong S, Srinivasan S, Murphy P, Jones L.. Comparison of meibomian gland dropout using two infrared imaging devices Vision Institute of Canada, October, 2021

Woods J, Luensmann D, Schulze M, Vega J, Orsborn G. Subjective lens experience when refit with daily disposable multifocal contact lenses BCLA Virtual Clinical Conference & Exhibition, 2021 [ Show Abstract ][ PDF ]

Purpose: Practitioners can be reluctant to switch successful multifocal soft contact lens (MF) wearers to different materials or replacement frequencies, fearing the new MF will be less accepted. Subjective responses are highly valued in MF fitting and this study investigated subjective responses from habitual MF (hab-MF) wearers after a refit into daily disposable MF; stenfilcon A (stenA-MF) and delefilcon A (delA-MF).

Method: After optimising the lens powers, subjects wore hab-MF and both study-MFs for 2-weeks each. Study-MF brands were masked and randomised. Throughout the study, subjects answered 13 experience questions per lens type, and 6 preference questions (comfort and vision for distance, intermediate, near, digital-device use, overall vision) to compare between hab-MF and each study MF, and also between study MFs.

Results: Fifty-eight subjects (50F:8M), mean age 54.4±7.3 years were included. Mean spherical-equivalent OD refraction: -1.10±2.7D [range -6.50D to +3.75D], mean near add +2.00±0.4D. 44% habitually wore daily disposable MF yet all were naïve to the study-MFs. Hab-MF wear resulted in positive responses for all experience questions (p<0.05); for stenA-MF 12 answers were positive (p<0.05), 1 was equivocal (p=0.90); for delA-MF 6 were positive (p0.05). Preferences between stenA-MF and hab-MF showed no differences (p>0.05). Subjects preferred hab-MF over delA-MF for intermediate vision (p=0.03) but no other preference (p>0.05). Comparing between study MFs, the preference for stenA-MF was stronger than delA-MF for comfort (p=0.03), intermediate vision (p=0.03), digital-device use (p=0.03) and overall vision (p=0.02) with no difference for distance or near vision (p>0.05).

Conclusions: This study showed that even when habitual MF wearers are already successful, refitting with a new design does not necessarily lead to compromised performance; stenA-MF performed comparably to hab-MF, and for some metrics better than delA-MF. These results should give practitioners confidence to recommend newer materials and different replacement frequencies when managing their existing MF wearers.

2020

Chan V, Phan CM, Jones L. Evaluating lysozyme deposition on contemporary daily disposable contact lenses in a novel in vitro blink model The Association for Research in Vision and Ophthalmology, 2020 [ Show Abstract ][ PDF ]

Purpose : To evaluate total lysozyme deposition on daily disposable (DD) contact lenses (CL) using a novel in vitro eye-blink model.

Methods : Three conventional hydrogel (CH) DD CL materials (etafilcon A, omafilcon A, nelfilcon A) and three silicone hydrogel (SH) DD CL materials (delefilcon A, senofilcon A, somofilcon A) were tested. The lenses were removed from their blister packs and placed directly on the eye model. An artificial tear solution (ATS) was flown over the lenses at a flow rate of 1 µl/min. The blink rate was set to 6 blinks per minute and the model was incubated at room temperature (23-26°C) and >45% humidity. After exposure periods of 2, 4 or 8 hours the lenses were removed and the lysozyme was extracted using acetonitrile: 0.2% trifluoroacetic acid (n=3). A separate experiment was conducted with lenses incubated in a vial containing 480 µL of ATS on an orbital shaker at 60 rpm for 8 hours (n=3). The lysozyme activity was measured using a spectrophotometric assay.

Results : Etafilcon A had the highest amount of active lysozyme absorption at all time points (p>0.001). After 8 hours, a cumulative total of 402 ± 102µg/lens of active lysozyme was absorbed on etafilcon A. Delefilcon A had the highest cumulative amount of active lysozyme (26 ± 1µg/lens) for SH materials (p<0.05). Nelfilcon A, senofilcon A and somofilcon A had the lowest amount of lysozyme activity (p0.05). The amount of active lysozyme sorption for certain lens types was different when measured using the eye-blink model as compared to a vial (p<0.05). Etafilcon A had a higher amount of active lysozyme when incubated on the blink model as compared to the vial (p<0.05), whereas somofilcon A and senofilcon A had a higher amount of lysozyme activity in the vial compared to the eye model (p0.05).

Conclusions : The in vitro eye-blink model provides quantitative data that is close to that determined from ex vivo studies and is an excellent model to assess the deposition of lysozyme on DD CL materials.

This is a 2020 ARVO Annual Meeting abstract.

Cheng X, Almaghshi M, Yang M, Shaw A, Brennan NA. Evaluating on-eye wavefront aberrations of a soft contact lens with an optical design simulating orthokeratology Investigative Ophthalmology & Vision Science 2020;61, 7:554 [ Show Abstract ][ PDF ]

Purpose : Orthokeratology (OK) has been shown to be effective in slowing myopia progression. The mechanism of action is hypothesized to be the resultant optical impact to the eye. However, a soft contact lens (SCL) designed to simulate the optical effect of OK (simOK) for myopia control was found to be ineffective in a randomized controlled myopia control trial. The purpose of this study was to evaluate on-eye wavefront aberrations of the simOK lens by comparing to that of successful OK patients.

Methods : Distance (4 m) and near (25 cm) wavefront aberrations were measured with an open-field Shack-Hartmann aberrometer in 8 OK-treated patients (bare eye only) and 20 non-OK subjects with bare eye (simOK-BE) and with simOK lens on-eye (simOK-LOE) between the age of 7 and 25 years. Zernike expansions of wavefront aberration functions to the 6th order were used to determine aberration coefficients for a series of pupil diameters. Zernike coefficient of primary spherical aberration (Z40), Root-Mean-Square (RMS) of 3rd order and total Higher Order Aberrations (HOA, 3rd – 6th orders) at a 5 mm aperture were compared between simOK-BE and SimOK-LOE and between OK and simOK-LOE. A general linear mixed model with a type I error of 0.05 was used for statistical analysis.

Results : Under a 5mm pupil and with a 4-m target, the means (SD) of Z40 were 0.054 (0.050), 0.350 (0.066), and 0.364 (0.212) microns in simOK-BE, simOK-LOE and OK, respectively. Compared to simOK-BE, Z40 was significantly increased with simOK-LOE with least-square-mean (LSM) difference of 0.297 micron (95% CI: 0.255, 0.338, p<0.001). There was no significant difference in Z40 between simOK-LOE and OK (LSM difference (95%CI): -0.034 micron (-0.148, 0.080), p=0.783). Similar results were found between conditions for near wavefront and for total 3rd order aberrations and total HOAs.

Conclusions : This exploratory study demonstrated that wearing SCL designed to simulate the optical impact of OK resulted in a significant increase of HOAs in the eye. The magnitude of HOAs, including primary spherical aberration and 3rd order aberrations, was similar to those of the OK patients. To fully characterize the on-eye optical performance of the simOK lens and understand the mechanism of action of OK, additional analysis of off-axis refraction and accommodative response with the simOK lens will be examined.

This is a 2020 ARVO Annual Meeting abstract.

Craig J, Bitton E, Dantam J, Ngo W, Jones L. Subjective ocular awareness with the use of eyelid cleansing products available for the management of demodex folliculorum Academy at Home, 2020

Craig J, Jones L, Willcox M, James W, Muntz A, Luensmann D, Tan J, Trave-Huarte S, Wang MTM, Xue AL. Evaluating the therapeutic profiles of lipid and non-lipid based dry eye supplements The Association for Research in Vision and Ophthalmology, 2020 [ Show Abstract ][ PDF ]

Purpose : A lack of clinical evidence on how long dry eye treatment is to be administered, before a significant improvement in signs and symptoms may be observed, has been identified in the literature. This study sought to assess the three-month therapeutic profiles of lipid-based and non-lipid-based artificial tear supplements in patients with dry eye disease.

Methods : Ninety-nine participants fulfilling the TFOS DEWS II criteria for dry eye disease (66 females, 33 males; mean±SD age, 44±16 years) were enrolled in a prospective, multi-centre, double-masked, parallel-group, randomised controlled trial. Participants were randomised to receive minimum four times daily application of lipid-based (Systane® Complete) or non-lipid-based tear supplements (Systane® Ultra) for three months. Dry eye symptomology, tear film parameters, and ocular surface characteristics were assessed at days 0, 30, 60 and 90 and compared using a multiplicity-adjusted mixed model analysis of variance.

Results : Baseline measurements did not differ between treatment groups (all p>0.05). Sustained reductions in OSDI, DEQ-5, and SANDE dry eye symptomology scores were observed by day 30 onwards (all p<0.05), and significant improvements in non-invasive tear film breakup time were detected by day 90 (both p0.05).

Conclusions : Improvements in dry eye symptomology preceded tear film stability during the three-month treatment period with both lipid-based and non-lipid-based artificial tear supplements. However, significant changes in lipid layer grade were limited to the lipid-based tear supplement.

This is a 2020 ARVO Annual Meeting abstract.

Craig J, Muntz A, Luensmann D, Tan J, Jones L, Willcox M, Wolffsohn J. Six-month therapeutic profiles of lipid and non-lipid-based artifical tear supplements in managing dry eye disease Academy at Home, 2020

Guthrie S, Woods J, Vega J, Orsborn G, Ng AY, Jones L. Exploring the factors which impact overall satisfaction with contact lenses Academy at Home, 2020 [ Show Abstract ]

Purpose: To evaluate the performance of two spherical lenses, one silicone hydrogel (SiHy) (somofilcon A) and one hydrogel (Hy) (etafilcon A), using subjective evaluations after 1-week and to correlate the relationships between specific subjective evaluations of lens performance and subjective overall satisfaction.
Methods: Fifty-five subjects participated in a prospective, double-masked, bilateral crossover dispensing study, wearing each lens for 1 week in a randomized order. Subjective ratings (0-10 scale) were completed after 1 week based on a typical day experience and a 4-point Likert scale (Strong/slight preference for each lens) was used to determine lens preference.
Results: Data for both lenses were combined and correlation analyses were conducted. Overall satisfaction was found to be significantly correlated (p<0.01) with handling for insertion (r=0.64), overall satisfaction with vision (r=0.64), handling for removal (r=0.50), comfort at insertion (r=0.59), comfort at end of day (r=0.61) and overall satisfaction with comfort (r=0.88). In addition, insertion comfort was significantly correlated with overall satisfaction with comfort (r=0.66). Considering the lenses separately, SiHy was rated significantly higher for handling for lens insertion compared to Hy (9.4 vs 8.1, p<0.01) and correlation strength with overall satisfaction varied greatly with lens material (SiHy: r=0.26, p=0.05 vs Hy: r=0.72, p<0.01). Overall lens preference based on lens handing for insertion also strongly favoured SiHy (37 subjects vs 18, p<0.01). Comfort at insertion was rated significantly higher at insertion with SiHy (9.0 vs 8.1, p<0.01) and similarly at end of day (8.1 vs 7.9, p=0.80). Correlation strength of comfort at insertion/end of day with overall satisfaction again varied with lens material (Insertion: SiHy: r=0.40 vs Hy: r=0.61; End of day: SiHy: r=0.76 vs Hy: r=0.58; all p≤ 0.01). There were no other statistically significant differences in subjective results for SiHy and Hy.
Conclusions: Significant correlations were found between overall satisfaction and the specific subjective evaluations of handling, vision and comfort. Interestingly, handling for insertion had a similar correlation (r) value as vision, suggesting that handling for insertion should not be underestimated when considering overall patient satisfaction. And while insertion and end of day comfort correlated moderately with overall satisfaction, overall satisfaction with comfort highly correlated with overall satisfaction. Separate analysis of SiHy and Hy also indicate that lower handling and comfort scores for Hy at insertion drove a higher correlation, suggesting that dissatisfaction with both handling for lens insertion and comfort upon lens insertion can play major roles in overall dissatisfaction with a lens.

Luensmann D, Schulze M, Ng AY, Woods J, Jones L. Refitting symptomatic daily disposable contact lens wearers with dry eye disease with delefilcon A lenses Academy at Home, 2020 [ Show Abstract ]

Purpose: To refit symptomatic wearers of daily disposable (DD) contact lenses with a confirmed dry eye diagnosis with Dailies Total1 (delefilcon A, Alcon) to evaluate the performance of the new lenses after one month of wear.
Methods: In this prospective, participant-masked study (over-labelled lenses), symptomatic DD lens wearers were recruited who demonstrated symptoms and signs of dry eye disease according to the TFOS DEWS II criteria. The performance of the lenses after one month was evaluated using subjective ratings and comfort scores, and by determining average wear time and comfortable wear time. Lens wear times as well as subjective symptom scores for comfort, dryness and vision (0-100 scale, with 100 being best) with habitual DD were collected at the screening visit and these results were then compared to delefilcon A after 1 month of wear. The data were not normally distributed, therefore non-parametric analysis (Wilcoxon Matched Pairs Test) was conducted. Data are reported as median (range), with delefilcon A data reported first.
Results: In total, 27 symptomatic DD lens wearers (19 female, 8 male) completed the study. Comfort ratings across all participants were significantly higher (p=0.014) for delefilcon A (80 (40-100)) compared to habitual DD lenses (80 (25-90)). Participants reported less dryness (p=0.007) with delefilcon A compared to their own lenses (80 (40-100) vs 70 (20-95)), and no difference in vision (p>0.05, 90 (50-100) vs (85 (60-100)). There were no statistically significant differences in total hours of lens wear per day (p>0.05, 12.5 hours (6.5-17) vs 11 hours (2.5-16)) or for comfortable wearing time (p>0.05, 8 hours (1-17) vs 6 hours (1-14.8). There were no lens-related ocular findings after one month of delefilcon A wear.
Conclusion: In general, participants had a positive lens wear experience with delefilcon A and rated this lens more comfortable and less dry compared to their habitual DD lenses. This suggests that symptomatic DD lens wearers with dry eye disease may benefit when refit into delefilcon A lenses.

Luensmann D, Woods J, McParland M.. Toric lens fitting success supported by an online fitting App Contact Lens Anterior Eye 2020 [ Show Abstract ][ PDF ]

Purpose: To provide eye care professionals quick access to lens parameter availability and to make soft toric lens fitting easier, online tools are now available to calculate and suggest a first choice prescription based on the patient’s subjective refraction. How close the recommended prescription matches the dispensed lens has been investigated in this study.

Method: In clinical studies, two daily disposable toric lenses, stenfilcon A and somofilcon A, and one monthly replacement toric lens, comfilcon A (all CooperVision, Inc.), were fitted and dispensed to 54, 37 and 47 habitual lens wearers respectively, following the manufacturer’s fitting guides. The final lens prescriptions were determined by the clinician based on over-refraction and lens rotation (Final-Rx). In a secondary analysis the subjective refraction data and back vertex distance were entered in the OptiExpert™ app to determine the recommended initial trial lens (App-Rx). The prescription results from both approaches were compared by calculating the mean differences (Bland-Altman) and the percentages of matching prescriptions following predetermined allowances for sphere, cylinder and axis.

Results: The mean differences between OptiExpert™ and the clinician final prescriptions for sphere, cylinder and axis were within ±0.13DS, ±0.01DC and ±1.38 degrees, respectively. For allowance combination sphere ±0.25D, cylinder ±0.00DC, axis ±10 degrees, the lens prescriptions from both methods matched in 75-82% of eyes (82% stenfilcon A, 75% somofilcon A, 79% comfilcon A). For allowance combination of sph ±0.50D, cyl ±0.00DC, axis ±20 degrees the Final-Rx and the App-Rx matched in 86-92% of eyes (91% stenfilcon A, 92% somofilcon A, 86% comfilcon A).

Conclusions: All three toric lens types showed a predictable on-eye performance, resulting in a close agreement between the initial OptiExpert recommended prescription and the lens prescription dispensed by the clinician. The OptiExpert™ app can therefore confidently be used to assist CooperVision toric lens fitting in order to help optimize patient chair time.

Luensmann D, Woods J, McParland M.. The use of a modern web-application to assist reusable toric lens fitting success Contact Lens Anterior Eye 2020 [ Show Abstract ][ PDF ]

Purpose: Increasing numbers of online tools are available to assist ECPs in fitting contact lenses. In this study, the contact lens prescription of a reusable toric silicone hydrogel lens was determined using a traditional fitting guide and the results were compared to the prescription recommended by the lens fitting app OptiExpert™.

Method: Forty-seven habitual lens wearers were fit with monthly replacement toric silicone hydrogel contact lenses (comfilcon A; CooperVision, Inc.).The manufacturer’s fitting guide was followed and the final lens prescription was determined based on the subjective refraction, the over-refraction and lens rotation (Final-Rx). Following this clinical study, the participant’s subjective refraction data and back vertex distance were entered in the OptiExpert online app to determine the recommended initial trial lens prescription (App-Rx). In this secondary analysis, the fitting results from both approaches were compared using Pearson correlation analysis. Different allowances for sph (±0.25, ±0.50D), cyl (±0.00DC) and axis (±10, ±20degrees) were combined to calculate the percentage of matching fitting results between both methods. Additionally, Bland-Altman graphs were plotted.

Results: A high correlation was found in respect to sphere, cylinder and axis between the Final-Rx and the App-Rx (all r ≥0.88). For the allowance combination of sphere ±0.25D / cylinder ±0.00DC / axis ±10, the lens prescriptions from both methods matched in 79% of eyes. For the allowance combination of sphere ±0.50D / cylinder ±0.00DC / axis ±20, the Final-Rx and the App-Rx matched in 86% of eyes. Bland-Altman comparisons between methods determined a mean difference of +0.06D for sph, +0.01D for cyl and 1.38 degrees for axis.

Conclusions: For most participants, the initial trial lens power recommended by the OptiExpert app was in close agreement to the final power dispensed in the clinical setting. The OptiExpert app can confidently be used as a clinical tool to aid comfilcon A toric lens fitting success.

Nagaarudkumaran N, McCanna D, Ngo W, Jones L. In vitro quantification of cytokines adhered to contemporary contact lens materials The Association for Research in Vision and Ophthalmology, 2020 [ Show Abstract ][ PDF ]

Purpose : Contact lenses (CL) may induce a low-level inflammatory response on the ocular surface. Previous studies have quantified the concentration of inflammatory mediators present in the tear film during CL wear. Analyzing the inflammatory mediators loosely adhered to CL materials may provide another perspective on the role that contact lenses play in inflammation. The purpose of this in vitro study was to quantify a variety of cytokines found in the tear film that adhered to various CL materials and to develop a method that could extract them.

Methods : Cytokines IL-1β, IL-6, IL-8, and TNF-α (Meso Scale Diagnostics, Rockville, MD) were combined with 5 mL of Diluent 2 to prepare a cytokine solution with a final concentration of 119.41, 166.05, 101.48 and 40.73 pg/mL, respectively. Contact lenses (etafilcon A, somofilcon A, omafilcon A, delefilcon A) (n=4 each) were each placed into a polypropylene tube containing a volume of 200 μL of the prepared cytokine solution and were incubated at 23°C for 6 hours. The lenses were removed from the tubes using tweezers and placed into a 0.6 mL microcentrifuge tube containing 200 μL of Diluent 2 and were incubated at 23°C for 1 hour. The microcentrifuge tube was then vortexed for 5 seconds and pin sized holes were made at the base of the tube. The tube was then placed into a larger 2.0 mL microcentrifuge tube acting as a carrier and were centrifuged at 604 RCF. The eluent in the 2.0 mL microcentrifuge was then collected and stored at -80°C for cytokine quantification at a later date, using the MESO QuickPlex SQ 120 (Meso Scale Diagnostics, Rockville, MD). Statistical analysis was performed using a one-way ANOVA.

Results : There was no significant difference between cytokine concentrations for all CL materials (p>0.05).

Conclusions : While there were no significant differences between the concentrations of cytokines found loosely adhered to the soft CL materials investigated, the results support this method as a means to quantify such cytokines on soft lens materials. This method may be used to examine human-worn lenses in future studies.

This is a 2020 ARVO Annual Meeting abstract.

Phan CM, Shukla M, Heynen M, Walther H, Jones L. Development of an In Vitro Blink Model for Measuring Drug and Comfort Agent Elutes from Soft Contact Lens Polymers Academy at Home, 2020 [ Show Abstract ]

Purpose: To develop an advanced in vitro blink model that could be used to examine release of a wide variety of components (topical drugs; comfort agents etc) from soft contact lenses.
Methods: The model was designed using CAD software and 3D printed using an SLA printer. A UV-curable resin polymer was used to fabricate the main components of the eye model to ensure water-sealed parts. The eyelid and eyeball were synthesized from a polyvinyl alcohol and a silicone material respectively. Simulated tear fluid is delivered through tubing attached to the eyelid. With each blink cycle (1 blink/10s), the eyelid slides and flexes across the eyeball to create an artificial tear film. The flow-through fluid is collected in a specialized trough. Two contact lenses, etafilcon A and senofilcon A, were incubated in 2 mL of a water-soluble red dye for 24 hours and then placed on the eye model. The release of the dye was measured at t= 0.5, 1, 2, 4, 8, 12, and 24 hours (n=3) in phosphate buffered saline (flow rate = 5 µL/min). The dye release from the lenses was also evaluated in a vial containing 2 mL of PBS over 24 hours (n=3). The amount of dye in the samples was determined using a UV/Vis spectrophotometer at 520 nm.
Results: All of the contact lenses were visibly red after the incubation with the dye. After the release studies, the etafilcon A lenses became transparent with a slight red tint, whereas the senofilcon A lenses retained a moderate red colour. For the vial study, the release of the dye from the contact lenses was rapid within the first 4 hours, which was then followed by a slower release phase. In contrast, dye release from the lenses on the eye model was significantly slower and was sustained over the 24-hour period. The total amounts of dye released in the eye model were also significantly lower compared to the vial (p<0.05), which could be attributed to the absorption of the dye into the eyelid. From the total amount of tear fluid (7.2 mL) that was infused into the eye model, approximately 5.2 ± 0.6 mL of flow-through was collected. The loss of fluid can be attributed to fluid absorption into the eyelid and contact lenses, as well as evaporation.
Conclusion: The blink model developed in this study could be used to measure the release of topical ophthalmic drugs or comfort agents from contact lenses. The results showed that the release kinetics of a dye from contact lenses on the eye model was significantly different than that of a vial. The model also simulated non-specific absorption of the dye into the eyelid. Future work will focus on developing polymers to simulate the absorption of drugs on the eye.

Schulze M, Ng AY, Luensmann D, Guthrie S, Woods J, Jones L. The subjective response to verofilcon A daily disposable contact lenses during extensive digital device use Academy at Home, 2020 [ Show Abstract ]

Purpose: To evaluate the subjective response of habitual lens wearers during extensive digital device use when switched to Precision1 (verofilcon A) daily disposable (DD) contact lenses (CLs).
Methods: Volunteers between 18-40 years of age who used digital devices for at least 6 hours/day while wearing their habitual CLs were recruited for the study. Eligible participants were dispensed with verofilcon A DD CLs for a period of 2 weeks, during which they were required to wear the study CLs for at least 5 days/week and at least 10 hours/day. Participants returned after 142 days for their final visit, where they reported their CL wear time and time spent using digital devices, and rated their typical experience on a 0 to 100 scale, with 100 being best. Comfort, dryness and clarity of vision with verofilcon A were rated directly after insertion, after 6 hours of digital device use, and just before removal, as well as by rating their overall performance. Participants also completed a 4-point (strongly agree, slightly agree, slightly disagree, strongly disagree) Likert scale-based questionnaire. Subjective ratings were not normally distributed, therefore non-parametric analysis was conducted and data are reported as median (range). The Likert scale responses were analyzed using binomial testing.
Results: Twenty participants completed the study (18F:2M), mean age of 25.1 ± 6.0 years (range 19-40). They reported their typical day to include median CL wear time of 13.8 hours (10.5-17), comfortable CL wear time of 12.1 hours (8-16.5) and digital device use of 9 hours (6-12). After 2 weeks of verofilcon A DD CL wear, subjective ratings after 6 hours of digital device use were high, with ratings for a typical day of 93 (68-100) for comfort, 93 (52-100) for dryness and 96 (70-100) for clarity of vision. After 2 weeks of wear, the majority of participants agreed that the study lenses provided good comfort (16/20 subjects; p=0.01) and good vision (18/20; p<0.01) all day long. Similarly, the majority of participants were satisfied with the comfort (16/20; p=0.01), vision (18/20; p<0.01) and overall performance (16/20; p=0.01) they experienced with the study lenses while using digital devices for 6 hours. Additionally, most reported they did not experience any eye strain while using verofilcon A lenses (n=16/20; p=0.01). No significant lens-related ocular findings were observed after 2 weeks of wear.
Conclusions: After 2 weeks of wear, participants rated the performance of verofilcon A DD CLs very highly, with median overall performance ratings for comfort, dryness and vision all 93 on the 0 to 100 scale (with 100 being best). Verofilcon A DD CLs may be a viable alternative for those struggling with their habitual lens performance when spending long hours using digital devices.

Srinivasan S, Jones L, Schulze M, Guillon M, Tauber J, Silverstein S, Yeu E, Venkiteshwar M. Efficacy of a propylene glycol/hydroxypropyl guar-based lubricant eye drop The Association for Research in Vision and Ophthalmology, 2020 [ Show Abstract ][ PDF ]

Purpose : SYSTANE® Complete (propylene glycol/hydroxypropyl guar [PG/HPG]) lubricant eye drop formulation developed using advanced nano-droplet technology, helps replenish a deficient tear film. This study evaluated the improvement in tear film break up time (TFBUT) after 14 days of treatment with PG/HPG lubricant eye drops in patients with dry eye disease (DED).

Methods : This was a Phase IV, multicenter, open-label, single-arm, interventional study. Adult patients with a clinical diagnosis of mild to moderate DED (subtyped into aqueous deficient (ADDE), evaporative dry eye (EDE) and mixed dry eye (MDE)) were included. Eligible patients received one drop of PG/HPG, twice daily. The change from baseline in fluorescein stained tear film break-up time (TFBUT) was assessed at Day 14. Data were analyzed for the overall cohort and by DED subtypes.

Results : Of 134 patients who received the study treatment, 131 completed the study. The median age of the study cohort was 59 (range: 18–87) years, and majority of patients were female (75.4%). Number of patients per subtype were similar (ADE=41; EDE=44; MDE=49). Overall, the median TFBUT increased from 2.68s at baseline to 3.32s at Day 14 (change from baseline= 0.81s; CI for the median = 0.52 -1.18). Subtype analysis showed a median change from baseline in TFBUT of 0.72s for ADDE (CI of median = 0.17-1.22), 1.32s for EDE (CI of median = 0.61-2.26), and 0.55s for MDE (CI of median = 0.07-1.03), at Day 14. The change in TFBUT values were significant overall as well as in the subtypes of DE. The maximum increase in tear film stability was noted in the EDE subgroup (59.2%).

Conclusions : PG/HPG lubricant eye drops increased tear film break up time in patients with DED, with an improvement reported in all dry eye subtypes at Day 14 of treatment. These results show that PG-HPG lubricant eye drops provide an increase in tear film stability in patients with DED.

This is a 2020 ARVO Annual Meeting abstract.

Wolffsohn J, Craig JP, Jones L, Trave-Huarte S, Wang MTM. Global approaches to dry eye diagnosis The Association for Research in Vision and Ophthalmology, 2020 [ Show Abstract ][ PDF ]

Abstract
Purpose : Dry eye is a chronic and often debilitating disease, but understanding the prevalence and the effectiveness of management is hampered by differences in diagnosis and subclassification. This cross-sectional survey of eye care practitioners across the world aimed to identify the current approaches to dry eye diagnosis.

Methods : A Survey Monkey questionnaire was developed in consultation with dry eye specialists. Questions sought to determine the tests practitioners consider essential in the diagnosis of dry eye. Which aid the diagnosis? Which aid the subclassification into evaporative or aqueous deficient dry eye? Descriptive statistics were applied.

Results : 1,139 responses were received from 51 countries, 38% from ophthalmologists and 58% from optometrists, with a median of 11-15years of experience. The main tests reported as critical for a diagnosis of dry eye were verbal symptoms (69%), fluorescein breakup time (67%) and corneal staining (64%). In addition, reports of visual disturbance (57%), symptomology results from a validated questionnaire (48%), ocular redness (54%) and blink/lid closure analysis (54%) were commonly used to aid diagnosis. A median of 7 tests were deemed essential to diagnose dry eye (range 0-28). Tests that proved popular for differentiating dry eye subtypes were Schirmer/Phenol red thread test (32%), meibomian gland expression (32%) and orifice examination (32%) and blink/lid closure analysis (32%); use of verbal (38%) and questionnaire (30%) symptomatology, fluorescein breakup time (39%) and corneal staining (37%), for this purpose, were also noted.

Conclusions : In 2018 when the data were collected, dry eye disease diagnosis among practitioners was not standardised and there was little agreement on subclassification to inform the optimal treatment strategy. Future studies will determine whether recent global consensus reports and position papers unify diagnosis of the disease to improve the quality of epidemiological and treatment efficacy data.

This is a 2020 ARVO Annual Meeting abstract.

Wong S, Murphy P, Jones L. Impact of contemporary contact lens wear on tear evaporation measured using a novel evaporimeter The Association for Research in Vision and Ophthalmology, 2020 [ Show Abstract ][ PDF ]

Purpose : To determine whether a novel binocular evaporimeter is able to detect changes in tear evaporation rate (TER) before and while wearing delefilcon A and nesofilcon A contact lenses (CL).

Methods : The evaporimeter consists of a pair of swimming goggles modified with a temperature and relative humidity (RH) sensor embedded in both the right and left goggle lenses. For each measurement, the evaporimeter goggles were positioned and held tightly over the palpebral aperture of both eyes (to ensure an air-tight seal) for 20 seconds. There were two measurement conditions: Open Eye, during which the participants blinked every 3 seconds, and Closed Eye, when the eyes were closed. The difference between the Open and Closed Eye measurements was used to determine the TER from the ocular surface. TER was calculated as the slope of the change in RH in the period 5 to 13 seconds after the evaporimeter was placed over the eyes. Three repeated measurements were taken and averaged together. Two baseline TER measurements were recorded (15-minute interval) prior to CL insertion. Participants were randomized for delefilcon and nesofilcon CL lens wear in either eye. TER was measured after 15 minutes and ≥6 hours of CL wear. Measurements over time and between CL types were compared using repeated measures ANOVA with Bonferroni correction. (Mean±SD: Ambient temperature, 23.2±1.1°C; RH, 43.9±7.7%).

Results : Twenty habitual CL wearers (mean age: 28 years, range 18-71, 95% female) completed the study. Both evaporimeter sensors were able to detect a significant change in TER over time (right: p=0.003, left; p<0.0001). TER was significantly higher after 15 minutes (right: p=0.035, left: p<0.0001) and 6 hours of CL wear (right: p=0.002, left: p=0.001), compared to second baseline measurement. Both CLs showed a significant increase in TER between 15 minutes and 6 hours of lens wear (p=0.001). No significant difference in TER was observed between delefilcon and nesofilcon (p=0.770).

Conclusions : The novel evaporimeter was able to simultaneously measure TER from both eyes. TER significantly increased when CLs were worn and was highest after ≥6 hours of CL wear. No significant differences in TER were found between delefilcon A and nesofilcon A, which suggests that contemporary daily disposable CL materials behave in a similar manner with regards to their impact on TER, regardless of water content or material.

This is a 2020 ARVO Annual Meeting abstract.

Woods J, Guthrie S, Varikooty J, Jones L. Satisfaction of habitual wearers of reusable multifocal lenses when refitted with a daily disposable, silicone hydrogel multifocal lens Contact Lens Anterior Eye 2020 [ Show Abstract ][ PDF ]

Purpose: Visual performance with multifocal contact lenses (MFCL) can vary with lens design. This study simulated a real-world refit of habitual wearers of reusable MFCL with a silicone hydrogel (somofilcon A), daily disposable multifocal (DDMF) lens to assess visual and overall experience with the new design and modality.

Method: Subjects rated the DDMF and compared it with their habitual reusable MFCL. The habitual MFCL prescription was not reviewed or confirmed as optimal, though all reported having an eye-examination within 2-years. Subjects were masked to the DDMF brand. After 2 weeks of daily wear with the new lens, subjects reported their experience using 0-10 ratings and Likert scales.

Results: Twenty-eight subjects, spanning 14 habitual lens brands, completed the study. Visual acuity with DDMF was statistically better than with habitual MFCL for all four distances measured (all p<0.05); distance (≥6m): -0.04±0.09, long intermediate (1.5m): -0.11±0.11, short intermediate (0.75m): -0.10±0.09, and near (0.4m): 0.02±0.09. Subjective vision clarity was statistically better with the DDMF for distance tasks in the dark, long intermediate tasks, and when considering all visual needs (all p0.05) for vision clarity performing tasks at distance, short intermediate and near. When asked for a preference, the DDMF was significantly preferred over habitual for long intermediate tasks (p=0.03), but not different for tasks at other distances. Ease of insertion was statistically better with the DDMF (p=0.03); ease of removal was not different. End of day comfort was not different from the habitual lenses (p=0.10), however the DDMF was rated better for end-of-day dryness (p=0.01) and overall satisfaction with lenses (p=0.04).

Conclusions: This daily disposable, silicone hydrogel (somofilcon A), multifocal lens provided good vision and overall performance. Many ratings showed it to provide statistically better performance than their habitual reusable MFCL, supporting the benefits of a trial wear period.

Yee A, Phan CM, Heynen M, Walther H, Jones L. The uptake and release kinetics of myristamidopropyl dimethylamine (MAP-D) from contact lenses using radioactive labelling he Association for Research in Vision and Ophthalmology, 2020 [ Show Abstract ][ PDF ]

Purpose : Biocides are an important disinfecting component commonly found in contact lens (CL) multipurpose solutions (MPS). During the disinfection step, the uptake of biocides into CL materials can significantly reduce the efficacy of the MPS to disinfect the lens. An increased release of biocides from the CL can lead to clinical complications such as discomfort and corneal staining. However, detection methods using chromatography and spectrometry can be time-consuming and have low sensitivity. The purpose of this study was to evaluate the uptake and release of myristamidopropyl dimethylamine (MAP-D; ALDOX®) using a radiolabel method.

Methods : Radioactive (14C) MAP-D was purchased from Moravek Inc. (CA, USA). Five soft CL materials (lotrafilcon B, balafilcon A, senofilcon A, etafilcon A, omafilcon A) were tested (N=4). The lenses were incubated in PBS (ISO 18369-3) solution containing 2mL of 14C radioactive MAP-D (5µg/mL) for 8 hours, followed by a release period in PBS for 16 hours. The cycle was continued over a 7-day period with a new replenishing solution for each day. The samples were counted for their radioactive signal (CPM) using the LS6500 Beckman Coulter liquid scintillation beta counter (ON, CA). A standard curve was used to convert CPM to µg of MAP-D.

Results : After 7-days, the silicone hydrogel (SH) lenses, lotrafilcon B (36.21±0.42µg), balafilcon A (36.29±1.15µg) and senofilcon A (35.54±1.37µg) had a significantly greater uptake of MAP-D compared to the conventional hydrogel (CH) lenses, etafilcon A (7.66±1.19µg) and omafilcon A (6.54±0.94µg) (p<0.01). However, the percent of MAP-D released was higher for CH lenses, etafilcon A (80%), omafilcon A (93%) compared to SH lenses, lotrafilcon B (25%), balafilcon A (19%) and senofilcon A (19%) over the 7-days (p<0.01).

Conclusions : Radioactive labelling offers a highly sensitive and accurate way of assessing the uptake and release kinetics of MAP-D to CL materials. Greater uptake of MAP-D occurs to SH materials, and the release of MAP-D is relatively minor. While CH materials take up only low amounts of MAP-D, the majority of it is easily released from these materials.

This is a 2020 ARVO Annual Meeting abstract.

2019

Bitton E, Srinivasan S, Elder M, Luensmann D, Jones L. Dry Eye Disease (DED) in Canada: A retrospective chart review American Academy of Optometry, Orlando, 2019 [ Show Abstract ]

Purpose: Dry eye disease (DED) is a complex and common condition across populations, with an estimated prevalence ranging between 5 and 50%, affecting females more than males. While numerous epidemiological studies exist, few have focused on DED in a Canadian population. The objective of this retrospective study was to describe the demographic and clinical characteristics of DED patients in University-based optometric clinics in Canada.

Methods: Charts of patients with DED were randomly reviewed at the University of Waterloo (UW) using ICD-9 diagnostic codes and at the dry eye clinic, University of Montreal (UM), which only accepts DED referrals. Demographics, health history, symptoms, diagnostic and management options were evaluated.

Results: 200 charts (100/clinic) were reviewed. The cohorts examined were broadly similar, consisting of similar ages (UM 57±15; UW 53±20yrs), were mainly female (76% UM, 72% UW) and used systemic medications frequently (76% UM; 62% UW). Symptom scores (0-100) by OSDI (ocular surface disease index) were: 38 UM; 33 UW. Clinical tests included TBUT (4.9sec UM; 3.9sec UW), cotton thread test (21mm UM; 20mm UW), positive corneal staining (46% UM; 68% UW). Recommended therapies included artificial tears (94% UM; 96% UW), warm compresses (63% UM; 83% UW), lid hygiene (29% UM; 22% UW), and Omega 3 supplementation (47% UM; 42% UW).

Conclusion: This review supports the literature that DED is typically seen with higher age, in females, and patients with systemic disease who use medications which can contribute to iatrogenic DED. No clear association was found between symptoms and signs, underlining the complexity of DED.

Bose S, Phan CM, Rizwan M, Tse J, Yim E, Jones L. Release of FitC-Dextran from a MMP9-triggered material for corneal wound healing ISCLR, Singapore, 2019

Guthrie S, Moezzi A, Varikooty J, Woods J, Jones L. A bilateral dispensing evaluation of two different toric lens geometries
BCLA Conference, Manchester, UK, 2019 [ Show Abstract ][ PDF ]

Purpose: To evaluate the subjective acceptance of two different types of prism ballast toric lens geometries, when worn on a daily wear modality over 1 month.
Methods: The study was a prospective, double-masked, bilateral, randomized, cross-over, 1-month wear, dispensing study where 45 astigmats wore two different soft toric lenses: comfilcon A toric which utilises a uniform horizontal iso-thickness design and samfilcon A toric which utilises a thin-edge design. Assessments were completed at 1-month. Ratings (0-10 scale) were competed at 2-weeks and 1-month.
Results: At 1-month, investigator-rated lens fit acceptance was high for both lens designs (3.65 vs 3.58, p=0.29), as was logMAR visual acuity for high contrast, high illumination (-0.12 vs -0.12, p=0.63) and low illumination (-0.10 vs -0.09, p=0.71). Subjective ratings for ‘overall visual quality’ were significantly higher for comfilcon A at 1-month (8.1 vs 7.4, p=0.04), but not different at 2-weeks (8.2 vs 7,6, p=0.05). ‘Vision stability’ ratings were significantly higher for comfilcon A at 2-weeks (8.2 vs 7.3, p=0.01) and 1-month (8.0 vs 7.2, p=0.03). ‘Overall comfort’ was rated significantly better with comfilcon A at 2-weeks (8.1 vs 7.4, p=0.04) and 1-month (8.1 vs 7.4, p=0.03). ‘End of day comfort’ ratings were similar after 1-month but significantly better with comfilcon A at 2-weeks (7.2 vs 6.5, p=0.03). ‘Overall satisfaction’ was statistically higher for comfilcon A after 2-weeks (8.0 vs 7.0, p<0.01) and 1-month (7.8 versus 7.0, p=0.02). Comfortable wearing time was not different at 2-weeks (9.2 vs 8.8, p=0.12), but was significantly longer with comfilcon A at 1-month (8.9h vs 8.0h, p=0.03).
Conclusions: Although both comfilcon A and samfilcon A use a prism ballast stabilisation principle and both provide excellent acuity and lens fit results, comfilcon A provided better subjective results for vision, vision stability, comfort, comfortable wear time and overall satisfaction.

Guthrie S, Woods J, Moezzi A, Varikooty J, Jones L. Comparing in-office evaluations to subjective evaluations for two toric lenses American Academy of Optometry, Orlando, 2019 [ Show Abstract ][ PDF ]

Purpose: To evaluate the performance of two monthly replacement silicone hydrogel toric lenses, comfilcon A toric and samfilcon A toric, using in-office assessments and subjective evaluations after 1 month.

Methods: A prospective, double-masked, bilateral, cross-over, dispensing study was conducted, where 45 subjects wore each lens type in a reusable, daily wear modality for 1 month, in a randomised order. Both in-office and subjective evaluations (0 [worst]-10 [best] scale) were completed at 1-month.

Results: Comfilcon A and samfilcon A toric lenses both performed well and similarly in all aspects of investigator lens evaluation. At 1-month, there was no significant difference for ‘fit acceptance’ grades (3.65 vs 3.58, p=0.29), ‘overall lens stability’ (3.56 vs 3.42, p=0.09) or for measures of logMAR high contrast acuity under ‘high illumination’ (-0.12 vs -0.12, p=0.63) or ‘low illumination’ (-0.10 vs -0.09, p=0.71). However, subject evaluations did show some significant differences related to comfort and vision. At 1-month comfilcon A toric lenses were rated significantly better for ‘overall comfort’ (8.1 vs 7.4, p=0.03). The difference in the 1-month ratings for ‘end of day comfort’ was not statistically significant (7.1 vs 6.7, p=0.15), however the ‘comfortable wear time’ was significantly longer for comfilcon A toric (8.9h vs 8.0h, p=0.03). For vision, comfilcon A toric was rated significantly better for ‘overall vision quality’ (8.1 vs 7.4, p=0.04) and ‘vision stability’ (8.0 vs 7.2, p=0.03). Subjects were asked to rate their ‘overall satisfaction’ and comfilcon A toric was rated significantly higher (7.8 versus 7.0, p=0.02). Subjects were also asked if they had a lens preference. Of those with a preference, significantly more subjects preferred the comfilcon A toric lens in terms of comfort (32 vs 10, p<0.01), dryness (28 vs 10, p=0.01) and overall (31 vs 13, p=0.01).

Conclusions: Although both comfilcon A and samfilcon A toric lenses both provided similar, high-level results for lens fit, stability and acuity, comfilcon A toric was rated statistically significantly higher in the subjective evaluations, specifically for comfort, vision, vision stability, overall satisfaction and comfortable wear time. These results illustrate that the patient experience cannot always be predicted from in-office evaluations.

Jones L, Jabeen A, Subbaraman L, Heynen M, Keir N, Srinivasan S. Method optimization to quantify four different neuropeptides in the human tear film Global Specialty Lens Symposium, Las Vegas, Nevada, 2019 [ PDF ]

Jones L, Pucker A, Jones-Jordan LA, Marx S, Powell D, Kwan JT, Srinivasan S, Sickenberger W. Clinical factors associated with contact lens dropout ISCLR, Singapore, 2019

Jones L, Pucker A, Jones-Jordan LA, Marx S, Powell D, Kwan JT, Srinivasan S, Sickenberger W. Impact of soft contact lens factors and compliance on contact lens dropout ISCLR, Singapore, 2019

Jones L, Subbaraman L, Dare E, Fung CK. Establishment of optimal culture media in human corneal epithelial wound healing models Global Specialty Lens Symposium, Las Vegas, Nevada, 2019 [ PDF ]

Jones L, Yee A, Jabeen A, Subbaraman L, McCanna D, Phan CM. Novel in-vitro method to study bacterial interaction with contact lenses Global Specialty Lens Symposium, Las Vegas, Nevada, 2019 [ PDF ]

Luensmann D, Woods J, Patel S. Validation of an online lens fitting app for two daily disposable toric lenses BCLA Conference, Manchester, UK, 2019 [ Show Abstract ][ PDF ]

Purpose: With recent increases in online tools to aid lens fitting, it was of interest to compare the prescriptions provided to wearers of two daily disposable silicone hydrogel (DDSH) toric lenses using traditional fitting guides to the prescriptions recommended by the OptiExpert online lens fitting app.

Method: Investigators determined the optimal toric lens prescription (Rx) for two DDSH toric lenses; stenfilcon A and somofilcon A using subjective refraction data (sph/cyl/axis), following the manufacturer’s fitting guide. The final lens prescription (Investigator-Rx) was determined based on the over-refraction and lens rotation. Subjects wore the lenses for one week. Retrospectively, the subjects’ refraction data were entered into the fitting app, which calculated the recommended Rx (App-Rx). Pearson correlation analysis was conducted between the Investigator-Rx and the App-Rx for each lens type. A success matrix for each lens type was further created to show how closely the results matched, using different criteria for sph (±0.25, ±0.50D), cyl (±0.00DC) and axis (±10, ±20degrees).

Results: Data of 54 and 37 subjects were analyzed for stenfilcon A and somofilcon A, respectively. Both lens types showed high correlation for sph, cyl and axis between Investigator-Rx and the App-Rx (stenfilcon A r >0.92, somofilcon A r >0.97). Compared to Investigator-Rx the matrix success rate for the app was 82% and 75% for criteria sph ±0.25D, cyl ±0.00DC, axis ±10 for stenfilcon A and somofilcon A respectively, and the success rate reached 91% and 92% for criteria sph ±0.50D, cyl ±0.00DC, axis ±20.

Conclusion: The OptiExpert app showed close agreement to the investigator prescribed lens in 9 out of 10 eyes for both toric DDSH lens types. Today’s toric lenses are generally stable and predictable in performance and this modern app-based approach can help to make toric lens fitting easy.

Muntz A, Subbaraman L, Jones L. Comparison of LWE grades with histological measures of the lid wiper region in contact lens wearers ISCLR, Singapore, 2019

Muntz A, Subbaraman L, Jones L. LWE grades compared with histological measures of the lid wiper region in contact lens wearers American Academy of Optometry, Orlando, 2019 [ Show Abstract ]

Purpose: The clinical assessment of lid wiper epitheliopathy (LWE) is often considered inconsistent. The number of publications reporting an association between contact lens (CL) wear and LWE is approximately equal to those that report a lack of association. To date, the extent of LWE has not been evaluated using histological techniques. The aim of this study was to histologically evaluate the extent of LWE staining in a diverse CL wearing population.

Methods: Seventy-seven participants were enrolled into four study groups: asymptomatic soft, symptomatic soft, rigid CL, and non-CL wearers. Subjective symptoms and CL wear habits were recorded, and an ocular surface assessment conducted. LWE at both lid margins of both eyes was graded using lissamine green according to the Korb scale. Impression cytology samples were collected from all lid margins, according to a previously optimized technique. Samples underwent histological staining with Papanicolaou dyes for keratinization and up to 100 high-resolution images were captured per sample and stitched into large-scale, panoramic images. The extent of the muco-cutaneous junction and lid wiper conjunctival areas were dimensioned using ImageJ.

Results: The histologically measured width (mean ± SD) of the keratinized lid wiper conjunctiva for samples clinically graded 0, 1, 2 and 3 for sagittal width of LWE staining was 279 ± 169, 406 ± 241, 513 ± 260 and 694 ± 292 µm, respectively. Average clinical grades for LWE sagittal width for asymptomatic, symptomatic, rigid and non-CL wearers were 0.4 ± 0.7, 0.5 ± 0.7, 1.2 ± 1.0 and 0.07 ± 0.2, whereas the histologically measured width of the keratinized lid wiper conjunctiva was 339 ± 218; 314 ± 185; 532 ± 278 and 243 ± 112 µm, respectively. Only 43% of all histologically measured widths (n=159) corresponded to the clinical grading range for LWE staining width proposed by Korb. Clinical LWE grades were overestimated in 25% and underestimated in 32% of cases, compared to objective histological measures.
Both clinical and histological measures of LWE were similar between symptomatic and asymptomatic soft CL wearers (all p>0.05). However, LWE was significantly higher in the rigid lens and significantly lower in the non-lens wear group, both clinically and histologically, versus all other groups. Clinical grades were underestimated by up to three times relative to the histological width in all cases, and particularly in the non-CL group.

Conclusion: We provide a first account of a histologically dimensioned equivalent of clinically observed LWE. The ranges proposed by Korb for grading LWE may not correspond with histological dimensions of the lid wiper width. Knowledge of patients’ habits (such as the lens type worn) may bias clinicians’ clinical appraisal of LWE. These findings lend support to the development and implementation of objective, computerized dimensioning methods for use in clinical settings.

Ng AY, Woods J, Jahn T, Jones L, Ritter J. The effect of a novel oral supplement containing omega-3 and omega-6 fatty acids on the signs and symptoms of dry eye disease American Academy of Optometry, Orlando, 2019 [ Show Abstract ][ PDF ]

Purpose: To determine the effect of daily intake of an essential fatty acid supplement on the signs and symptoms of dry eye disease (DED) in patients with moderate to severe symptoms. The supplement contains omega-3 fatty acids (1200mg eicosapentaenoic acid [EPA] and 300mg docosahexaenoic acid [DHA]) and the novel addition of an omega-6 fatty acid (150mg gamma-linoleic acid [GLA]).

Methods: This was a prospective, double-masked, randomized, parallel group pilot study. Participants were eligible if they had an Ocular Surface Disease Index (OSDI) score ≥ 23 and had not taken omega-3 or -6 supplements in the previous 3 months. Participants were randomized to use one of two liquid supplements: the treatment supplement (EPA, DHA and GLA combination), or the placebo supplement (coconut and olive oil). Participants were instructed to take one teaspoon, once daily for three months. In addition to keeping a diary, an omega-3 index blood test was conducted at baseline and 3 months to confirm compliance of supplement use. At baseline, 1 and 3 months the following assessments were conducted: OSDI questionnaire, non-invasive tear break-up time (NITBUT), tear meniscus height (TMH), tear osmolarity, ocular redness and surface staining, Schirmer test and meibography to assess meibomian gland (MG) dropout.

Results: Fifty participants completed the study: 24 randomized to the treatment group, 26 randomized to placebo. Participants were 95% compliant with daily dosing over the study period. After 3 months of supplement use, a 34% increase in omega-3 index blood values was observed in the treatment group (baseline: 5.3±0.8, 3 months: 8.0 ± 2.1, p50) at baseline demonstrated a clinically significant improvement with the treatment supplement (n=13, 20.8 point reduction, p=0.002) at 3 months compared to the placebo group (n=12, 8.4 point reduction, p=0.066). There were no clinically significant changes in NITBUT, TMH, tear osmolarity, ocular redness and surface staining, Schirmer test or MG dropout, (all p>0.05).

Conclusions: Omega-3 supplementation is an established therapeutic option for DED. This cohort of participants who were predominantly in the severe DED category by OSDI classification, experienced clinically meaningful improvements in their dry eye symptoms associated with supplementation with EPA, DHA and GLA. The addition of the omega-6 GLA in this formulation may have contributed to the significant improvement in dry eye symptoms.

Phan C, Walther H, Jones L.. Development of a blink model for testing contact lenses American Academy of Optometry, Orlando, 2019 [ Show Abstract ][ PDF ]

Purpose: To develop an eye model with a physiological blink mechanism to test contact lenses.

Methods: All parts of the eye model were designed using CAD software. The eyeball moulds were CNC machined to ensure a smooth finish for the corneal surface. A chamber to house the eye model was cut using a laser cutter, assembled, and sealed using methylene chloride. The eyelid consisted of a unique 3D printed structure containing teeth to physically secure a flexible membrane. Both the eyeball and eyelid membrane were synthesized using polyvinyl alcohol (PVA). Four molecular weights of PVA (89-98 kDa, 85-124 kDa, 130 kDa, and 146-186 kDa) were tested at a range of concentrations between 5 – 30 % w/v. The wettability and water content of these materials were compared with the bovine cornea and sclera. The rotational motion of the eyelid was controlled by a stepper motor and an Arduino. The model was connected to a microfluidic pump, which delivers artificial tear solution (ATS) to the eyelid. A corneal topographer was used to evaluate the tear break-up and tear film regeneration.

Results: The eyelid flexes and slides across the eyeball during each blink, which ensures direct contact between the two surfaces. When loaded with an ATS, this mechanism evenly spreads the solution over the eyeball to generate an artificial tear film. The speed, degree of actuation, and rate of blinking can be controlled using the open source Arduino software. The artificial tear film layer in this eye model had a tear break-up time (TBUT) of 5.13 ± 0.09 seconds at 1.4 µL/min flow rate, 6 blinks/min, and <25% humidity.

Conclusion: This model simulates a physiological blink actuation and an artificial tear film layer. Future studies will examine variations in flow rates and ATS composition to simulate clinical values of TBUT. The model could be used to study in vitro TBUT, tear deposition, and drug delivery from contact lenses.

Phan CM, Qiao H, Jones L. A simple method to synthesize PVA hydrogels Canadian Biomaterials Society, Quebec, 2019 [ PDF ]

Phan CM, Qiao H, Shinde R, Jones L. Development of an in vitro eye model with polyvinyl alcohol The Association for Research in Vision and Ophthalmology. Vancouver, British Columbia, 2019 [ Show Abstract ][ PDF ]

Purpose: The purpose of this study was to develop a simple method to synthesize an in vitro eye model using polyvinyl alcohol with similar wettability and water content as the cornea, sclera, and lens.  

Methods: Bovine eyes, donated by an abattoir, were used as the ex vivo eye model for comparison. The eyes were dissected fresh, and the wettability and water content for the cornea, sclera, lens, and vitreous humour were measured. Four molecular weights of polyvinyl alcohol, 89-98 kDa, 85-124 kDa, 130 kDa, and 146-186 kDa, were tested. The monomer was added to a mixed solvent of dimethyl sulfoxide and Milli-Q water to achieve a range of concentrations between 5 – 30 % w/v. The mixture was heated at 120oC for 3 hours, and polymerized at -30o C for 3 hours. The gels were then equilibrated with Milli-Q water for 3 days before characterization. A model eyeball from polyvinyl alcohol was also synthesized using a custom mould.

Results: The bovine cornea had the highest wettability, with the lowest advancing contact angle (28.0 ± 7.2°), followed by the lens (64.0 ± 4.6°) and sclera (56.73 ± 6.5°). The contact angles for the polyvinyl alcohol gels ranged between 40.4 ± 2.5° and 61.6 ± 4.7° for various gels. The vitreous humour had the highest water content (98.7 ± 0.2 %), followed by the cornea (80.9 ± 1.2%), sclera (64.8 ± 0.7%), and lens (59.7 ± 7.5%). The water content for the gels decreased with increasing concentrations of the polyvinyl alcohol (p<0.001), and ranged between 66.1 ± 0.1 % to 91.4 ± 0.2 %. The eye models made from polyvinyl alcohol were translucent, smooth, wettable, lubricous, and pliable.

Conclusion: This study presents a simple method to synthesize hydrogels from polyvinyl alcohol, which can be formulated to closely match the wettability and water content of a bovine cornea, sclera, and lens. The method can be easily modified in future studies to incorporate other reagents. The eye model synthesized from this study could be used as a potential model to study in vitro tear-break up or drug absorption.

Phan CM, Walther H, Jones L. Mass spectrometry detection of phosphatidyl choline from delefilcon A Canadian Biomaterials Society, Quebec, 2019 [ PDF ]

Phan CM, Walther H, Jones L. Development of a polymeric eye model for foreign body removal Canadian Biomaterials Society, Quebec, 2019

Phan CM, Walther H, Qiao H, Jones L. Development of a novel in vitro blink model Canadian Biomaterials Society, Quebec, 2019 [ PDF ]

Phan CM, Walther H, Qiao H, Jones L. The development of an eye model that truly blinks ISCLR, Singapore, 2019

Rangarajan R, Ketelson H, Do R, McCanna D, Suko A, Enstone D, Subbaraman L, Jones L, Meyer A. Characterization of a New Phospholipid Containing Nanoemulsion Lubricant Eye Drop for Dry Eye Invest Ophthalmol Vis Sci 2019;E-abstract 303

Rappon J, Woods J, Jones D, Jones L. Tolerability of novel myopia control spectacle designs Invest Ophthalmol Vis Sci 2019;E-abstract 5845

Rappon JM, Chalberg TW, Neitz M, Woods J, Jones D, Jones L Neitz J. Clinical Development of a Novel Myopia Treatment for Myopia Management The 17th International Myopia Conference, Tokyo, Japan, 2019

Tichenor A, Cofield S, Gann D, Elder M, Ng AY, Walsh K, Jones L, Nichols J. Frequency of contact lens complications between contact lens wearers using multipurpose solutions versus hydrogen peroxide in the United States and Canada American Academy of Optometry, Orlando, 2019 [ Show Abstract ]

Purpose: To retrospectively compare frequency and likelihood of contact lens complications in long-term soft contact lens (CL) users of hydrogen peroxide (PXD) and multipurpose solutions (MPS).

Methods: This was a multicenter, retrospective chart review study of soft CL patient records. The study was conducted at two academic clinic sites, the University of Alabama at Birmingham School of Optometry and CORE, School of Optometry & Vision Science, University of Waterloo, and across five private practice clinical sites (three in the US and two in Canada). Records of established, adult soft CL wearers were reviewed from the three most recent full examination visits. Patients must have used the same CL solution technology (either MPS or PXD) documented at the first and last visit for at least three years. Data collected included demographics, CL solution, and any complications for either eye. Univariate analyses were conducted using Chi-Square or Fisher’s Exact test for categorical measures, as applicable. Covariate adjusted logistic regression models were used for categorical outcomes using Likelihood Ratio Chi-Square Test.

Results: In total, there were 1137 subjects included across the seven clinical locations, with 670 (59%) MPS users and 467 (41%) PXD users. The MPS users were 57% female with a mean (±SD) age of 42.9 (±14.7) years. The PXD users were 43% female with a mean age of 43.2
(±14.2) years. At the academic clinic sites, 428 records (38%) were reviewed of which 244 (57%) were MPS users. At the private practice sites, 709 records (62%) were reviewed and 426 (60%) were MPS users. Of all subjects, 706 (62%) experienced at least one complication over three visits; 409 were MPS users and 297 were PXD users. The most common complication was papillae (n=311, 27%) followed by hyperemia (n=242, 21%) and discomfort (n=240, 21%).There was no difference in the proportion of subjects experiencing at least one complication over the three visits between MPS (61%) and PXD (64%) users (p=0.38). Nonetheless, MPS users were more likely to report discomfort at least one time over the three visits compared to PXD users (p=0.04). Infectious keratitis was experienced by 25 subjects (2%); 19 were MPS users and 9 were PXD users (p=0.60).

Conclusion: While no differences were found in the frequency of contact lens complications between MPS and PXD users, the ocular surface health benefits of PXD should be considered when determining the best lens care option for patients. In addition, MPS users were more likely to report low levels of discomfort at least once over the time period reviewed. Therefore, PXD may be a beneficial solution alternative in CL users who report discomfort.

Varikooty J, Woods J, Jones L. Visual performance with a daily disposable silicone hydrogel center-near progressive design multifocal lens with two independent intermediate zones BCLA Conference, Manchester, UK, 2019 [ Show Abstract ][ PDF ]

Purpose: Multifocal contact lens visual performance can vary with add-power and lens design. This study compared logMAR acuity (VA) and subjective ratings in habitual multifocal lens (HabMF) wearers refitted with a daily disposable multifocal lens (DDMF) of center-near progressive design, with two intermediate zones.

Methods: VA with HABMF was measured at four working distances (WDs) - distance (DV), long-intermediate (LI=1.5m), short-intermediate (SI=0.75m), and near (NV= 0.4m). Subjects were refit with a DDMF (somofilcon A) and after 2 weeks, VA and vision clarity rating (VC-rating) at these four WDs were measured; VC-rating options were ‘Exceeded expectations’, ‘Met expectations’ or ‘Fell-Short of expectations’. For each WD, changes in VA were analysed for the whole group and also for subjects grouped according to their VC-rating.

Results: For the 48 subjects who completed the study, VA was better at every WD with DDMF compared to HabMF (all p<0.032): mean logMAR VA improvement was DV=0.03, LI=0.06, SI=0.04 and NV=0.07. VC-ratings were significantly better for DDMF at LI (p=0.013), SI (p=0.042), NV (p=0.001), but not different at DV (p=0.068). When grouped by subjective VC-ratings into Exceeded and Met expectations, VA was also
better at every WD with DDMF: mean logMAR VA improvement was DV=0.05 (n=42), LI=0.07 (n=44), SI=0.05 (n=41) and NV=0.08 (n=40). Subjects reporting VC-ratings of Fell Short of expectations showed mean logMAR VA improvement with DDMF at SI=0.02 (n=7) and NV =0.05 (n=8) but showed reduction in mean logMAR VA with DDMF at DV=0.03 (n=6) and LI=0.04 (n=4).

Conclusions: While positive subjective responses for all WDs were always associated with improved VA, the negative subjective responses were not always associated with reduced VA. This supports the importance of allowing the wearer to experience the lens in order to determine acceptance, rather than rely solely on VA measures.

Walther H, Chan V, Phan CM, Jones L. Modelling non-invasive tear break-up times of soft lenses using a sophisticated in vitroblink platform Invest Ophthalmol Vis Sci 2019;60, E-abstract 6328 [ Show Abstract ][ PDF ]

Purpose : To evaluate the feasibility of a novel in vitro eye model to determine the pre-lens non-invasive tear breakup times (NIBUT) of two daily disposable (DD) contact lenses (CLs).

Methods : An artificial eyeball synthesized from polyvinyl alcohol (15% w/t, 89-98 kDa) was used on a novel in vitroeye model (OcuBlink), incorporating a blink and constant tear flow. A flat black disc was incorporated into the eyeball for contrast. The OcuBlink’s flexible eyelid design ensures contact with the eyeball, thereby enabling an even spread of the tear solution over the front of the CL. The blink interval was set to 10 seconds, and the flow rate of an artificial tear solution was set to 1.4 µL/min. A silicone hydrogel (SH; delefilcon A), and conventional hydrogel (CH; nelfilcon A) DD were placed over the corneal section and the NIBUT was evaluated after 1 h of blinking. A corneal topographer (Atlas, Zeiss Canada) was used to illuminate the lens surfaces and capture changes of the placido ring images. The humidity during the experiment was between 22-23%.

Results : A stable artificial tear film layer was formed over the artificial eyeball and the CLs. This layer was regenerated after each blink. The NIBUTs for delfilcon A, nelfilcon A, and the artificial eyeball were 7.55 ± 1.59 seconds, 8.16 ± 0.81 seconds, and 5.13 ± 0.09 seconds respectively. There were no significant differences between the two lens types (p>0.05), and between nelfilcon A and the artificial eyeball (p>0.05). However, delfilcon A had a longer NIBUT than the artificial eyeball (p<0.05).

Conclusions : The measured NIBUT values over the artificial eyeball and CLs are similar to those found in vivo. The OcuBlink simulates the blink motion and physiological tear flow rates, and could be used to measure in vitro pre-lens NIBUT values for various CLs.

Walther H, Phan CM, Jones L.. Detection of Phosphatidylcholine from Delefilcon A Contact Lenses using Mass Spectrometry American Academy of Optometry, Orlando, 2019 [ Show Abstract ][ PDF ]

Purpose: The gradual release of phospholipids from contact lenses could potentially stabilise the tear film over the front surface of the lens and increase comfort during wear. Delefilcon A (Dailies Total 1) contact lenses inherently contain phosphatidylcholine (PC), a zwitterionic phospholipid that is a potent wetting agent and lubricant found in the human tear film.Due to its molecular structure, PC is relatively difficult to detect using standard spectrophotometric techniques. However, it has been detected previously at low concentrations using ultra-high performance liquid chromatography mass spectrometry (UHPLC-MS). The aim of this study was to detect the presence of PC from contact lens extracts of delefilcon A lens materials and its blister packaging solution using UHPLC-MS.

Methods: PC was extracted from the contact lens and the blister pack using 3 mL of 2:1 chloroform: methanol and 0.5 mL of monosodium phosphate aqueous buffer. The chloroform layer containing PC was collected, dried down using nitrogen gas, and then resuspended in 100 µL sample buffer. A PC standard, L-α-Phosphatidylcholine (Sigma Aldrich, St. Louis, MO), was prepared at 8 pmol/µL. The samples were analyzed using UHPLC-MS on a Waters and Thermo/Dionex system using a multi-step, reversed-phase gradient consisting of A: 60:40 acetonitrile: water and B: 90:10 isopropanol: acetonitrile, both with 10mM ammonium formate and 0.1% formic acid. The flow was set at 250 uL/min, the column was kept at 45C, sample tray at 4C, and injection volume was 10 uL.

Results: During the electrospray process, L-α-Phosphatidylcholine, also known as 1,2-diacyl-sn-glycero-3-phosphocholine, protonates to form C42H10NO8P+, with a theoretical mass m/z = 758.57. Elution peaks from the UHPLC-MS corresponding to PC were detected in the PC standard at m/z = 758.5-758.6. Other elution peaks for PC were also detected at m/z = 760.58-760.60, 786.60-786.61, and 788.62-788.63. These same peaks, with nearly identical retention times, were detected in both the blister pack solution and contact lens extracts for delefilcon A.

Conclusion: These results indicate that PC is present within the delefilcon A material and also in its blister pack solution. Future studies will determine if PC is released over time from the contact lens using a novel in vitro blink platform.

Wong S, Bhamra T, Jones L, Tighe B. Subjective assessment of contact lens handling: what can we learn from the past? BCLA Conference, Manchester, UK, 2019 [ Show Abstract ]

Purpose: This study examines correlations between clinician-assessed subjective ease of handling of soft contact lenses, and laboratory-assessed physicochemical characteristics. High CL dropout rates caused by handling problems and difficulties in objectively measuring handling performance underline the clinical importance of such studies. The first stage involved assessment of conventional hydrogel lenses widely available in the 1980s, some currently available and some not. This is a platform for assessment of SiHy lenses in which effects of inherently lower coefficients of friction need to be assessed in parallel.

Methods: The prospective, single-masked study involved participants (no previous long-term CL wear history) each asked to rate the ease of handling of 23 different types of soft CLs on a 10-point continuous scale. Primary physicochemical data (e.g. EWC, lens thickness and mass, tensile modulus) were collected and additionally transposed into derived quantities (e.g. stiffness factor, plasticising factor).

Results: The data for the conventional hydrogels revealed:
• The early conventional hydrogels Hydrocurve II and SofLens 38 had lowest mean ± SD handling scores of 6.08 ± 1.56 and 6.08 ± 1.98, respectively.
• Excelens had the highest mean handling score of 8.67 ± 1.78.
• No significant correlation was found between handling and the equilibrium water content (Spearman’s r = -0.34, p = 0.11) or centre thickness (Spearman’s r = 0.33, p = 0.13)
• Handling of hydrogel CLs was strongly correlated with the stated modulus (Spearman’s r = 0.70, p = 0.02), the equilibrium water content (Spearman’s r = 0.64, p = 0.04) and centre thickness (Spearman’s r = 0.76, p = 0.01).

Conclusions: The poster will discuss detailed lens data including graphical presentation of “derived” factors combining thickness and modulus together
with the observations that SiHy CLs had higher mean handling scores than hydrogel CLs. All current CLs had mean handling scores of > 6.0.

Woods J, Varikooty J, Lumb E. Validation of a multifocal contact lens online fitting app BCLA Conference, Manchester, UK, 2019 [ Show Abstract ][ PDF ]

Purpose: Online tools to assist complex contact lens fittings are becoming more commonplace, replacing traditional fitting guides. Data from a daily disposable multifocal lens refit study were used to conduct a post-study comparison of the multifocal lens power recommendations of one such online tool, the OptiExpert app, with those powers determined by investigators who used the traditional fitting guide.

Methods: For 48 habitual multifocal lens wearers, subjective refraction data (sph, cyl, add, ocular-dominance) were determined by investigators who refit them with a somofilcon A lens, using the fitting guide. At an ‘optimization visit’ 3-10 days later, lens power was re-assessed and new powers dispensed if necessary. Subsequent to study completion, subjects’ refraction data was input to the online app, and the
recommended power for each eye (App-Rx) was compared to the power dispensed at the optimization visit (Optimized-Rx). Bland-Altman and correlation analyses were conducted to measure agreement between methods.

Results: The 48 presbyopes (38F:10M) had a mean (±SD) age of 55.6 (±7.3SD, range 41-67) years. Subjective refraction range across all 96 eyes was +5.25 to -6.75DS, all with cylinder ≤-1.00D. Reading add ranged between +1.25 to +2.50D. At the optimization visit, 10% of eyes (10 eyes across 10 subjects) required change in lens power, meaning 100% of eyes were successfully fit with just 1 additional lens. The App-Rx was significantly correlated with Optimized-Rx (r=0.996 and p<0.0001). Bland Altman analysis showed a mean difference (and 95% limits of agreement) between App-Rx and Optimized-Rx of 0.08D (-0.58 to +0.42). The app predicted powers were within 0.25D of the investigatoroptimized lens powers in 82% of eyes, within 0.50D in 96% eyes.

Conclusions: The OptiExpert app recommended CL powers were in close agreement with those determined by investigators. Therefore, OptiExpert multifocal app is a useful tool to aid somofilcon A multifocal fitting success.

Yang M, Moezzi A, Woods J, Jones L. Comparing Strip Meniscometry to Tear Meniscus Height & Schirmer Test American Academy of Optometry, Orlando, 2019 [ Show Abstract ][ PDF ]

Purpose: Evaluation of tear volume is an important parameter for investigating aqueous deficient dry eye disease (DED). Historically, this has been achieved using Schirmer (SCH) strips or non-invasively using estimation of tear meniscus height (TMH). A method using strip meniscometry (SM) (SMTube, Shirakawa Factory, Tokyo, Japan) has recently been developed as a fast (5-second) in-office diagnostic test. The purpose of this study was to determine how tear volume assessed by SM compared to TMH and SCH in a mixed cohort of subjects with and without DED.

Methods: Both eyes of 27 participants (7 males; 20 females) aged between 21 and 64 (mean 40.7 years) underwent all measurements. TMH and non-invasive tear breakup time (NITBUT) were assessed using the Keratograph5M (Oculus, Germany). Subjects completed the ocular surface disease index (OSDI). SM was undertaken, and after a 1 hour delay, SCH (without anesthetic) was measured over five minutes. Subjective preference between SM and SCH was also collected. The correlation between SM and NITBUT, TMH and SCH were analysed.

Results: Only right eye data is presented. The mean (±SD) scores were: SM 5.6 (±3.2) mm; NITBUT 8.82 (±5.35) seconds; TMH 0.23 (±0.07) mm; SCH 22.2 (±10.1) mm. Mean OSDI was 13.1 (±9.3). The linear correlations (Pearson r) with SM were all low: NITBUT (0.479), TMH (0.006), SCH (0.301) and OSDI (0.075). 100% of participants preferred SM to SCH, citing the reasons for their preference as better comfort and shorter test time.

Conclusion: Strip meniscometry (SM) is a more rapid test compared to Schirmer test, and was found to be significantly more comfortable by the participants. However, given the low correlation with standard tear film evaluation tests its ability to discriminate between patients with and without DED requires further evaluation.

Yee A, Chan V, Heynen M, Jones L. A radioactive labelling technique for evaluating the uptake and release of myristamidopropyl dimethylamine (MAP-D) from contact lenses Invest Ophthalmol Vis Sci 2019;E-abstract 6370 [ Show Abstract ][ PDF ]

Purpose: The uptake and subsequent release of biocides from contact lens (CL) materials is of relevance as it has been linked with outbreaks of microbial keratitis and potential cytotoxic responses. Previous uptake and release studies of myristamidopropyl dimethylamine (MAP-D; ALDOX®) have used light-scattering techniques, which are time consuming and have relatively low sensitivity. The purpose of this study was to develop a radioactive labelling technique in order to improve the accuracy and sensitivity of biocide uptake and release to CL materials.

Methods: Four soft CL materials (lotrafilcon A, balafilcon A, senofilcon A, etafilcon A) were tested (N=4). Radioactive (14C) MAP-D was purchased from Moravek Inc. (California, USA). The lenses were incubated in PBS (ISO 18369-3) solution containing radioactive MAP-D (5µg/mL) for 8 hours. After the incubation period of 8 hours, the lenses were placed into the release condition. The release of MAP-D was assessed over 24 hours in 2 mL of PBS. Aliquots were removed at 0.25, 0.5, 1, 2, 4, 8, and 24 hour time points and added to scintillation fluor (PerkinElmer, USA). The samples were counted for their radioactive signal (CPM) using the LS6500 Beckman Coulter liquid scintillation beta counter (Beckman Coulter, ON, CA). The CPM was converted to µg of MAP-D based on a standard curve.

Results: After the incubation period of 8 hours, the uptake of MAP-D by etafilcon A (2.78±0.19µg) was significantly different than lotrafilcon A (4.69±0.1µg, p<0.01), balafilcon A (4.55±0.31µg, p<0.01), and senofilcon A (4.35±0.13µg, p<0.01). The total amount of MAP-D released by etafilcon A (1.41±0.09µg) was significantly greater than lotrafilcon A (0.27±0.02µg, p<0.01), balafilcon A (0.23±0.04µg, p<0.01), and senofilcon A (0.21±0.01µg, p<0.01). The results demonstrate that the uptake of MAP-D was higher for all silicone hydrogel (SH) lenses and lower for the conventional hydrogel lens. The release profile of etafilcon A was greater than the SH lenses, with a burst release of 0.33µg at 0.25 hr.

Conclusions: Radioactive labelling of MAP-D offers a highly sensitive, accurate way of assessing the uptake and release profiles of biocides to CL materials. Future studies using this methodology will investigate the profiles for other biocides, such as polyhexamethylene biguanide (PHMB), a common biocide used in CL solutions.

2018

Chamberlain P, Jones D, Logan N, Peixoto-de-Matos S, Ngp C, Young G. Comparison of myopia progression in new and established myopia control treatment (MiSight) groups BCLA Asia. Singapore, 2018

Jabeen A, Subbaraman L, Heynen M, Srinivasan S, Jones L. Method Optimization to Quantify Four Neuropeptides in the Human Tear Film American Academy of Optometry, San Antonio, USA, 2018 [ Show Abstract ][ PDF ]

Purpose: Ocular surface neuropeptides play a key role in modulating the infiltration and activation of immune cells in both tearing and ocular discomfort. The purpose of this study was to optimize a method to quantify the amount of four neuropeptides - calcitonin gene-related peptide (CGRP), Substance P (SP), Neuropeptide Y (NPY) and Vasoactive Intestinal Peptide (VIP) - in the human tear film

Methods: Basal and flush tears (following instillation of 20 microliters of saline on the ocular surface) of 8 healthy participants were collected from the right and left eyes respectively, using a microcapillary method on day 1. On day 2, the same procedure was repeated. The concentration of the four neuropeptides in the tears was determined using an enzyme-linked immunosorbent assay (ELISA) method. The ELISA kits were tested for specificity and sensitivity as per manufacturer’s guidelines and the experiments were repeated three times to determine reproducibility. The limit of detection was based on the variance of the blank samples and the variance of the lowest level of each individual tear samples added.

Results: RM-ANOVA showed no statistical difference in the concentration of CGRP, NPY and VIP between basal and flush tears for days 1 and 2 (p > 0.05). However, statistically significant differences were found for SP between basal and flush tears for day 1 (p = 0.037) and flush tears for days 1 and 2 (p = 0.018) respectively.

Conclusion: ELISA is a sensitive method that can be adopted to quantify neuropeptides in the human tear film. The optimized technique can be used to identify differences in the level of various neuropeptides in patients with contact lens discomfort and varying degrees of dry eye.

Luensmann D, van Doorn K, May C, Srinivasan S, Jones L. Physical Dimension and Optical Assessment of Currently Marketed Silicone Hydrogel Contact Lenses After Exposure to Cosmetics American Academy of Optometry, San Antonio, USA, 2018 [ Show Abstract ][ PDF ]

Purpose: Contact lens wearers may inadvertently expose their lenses during the lens insertion and removal process or while wearing their lenses to cosmetic products being used. This study investigated the impact of various cosmetics on the physical dimension and optical properties of three recently marketed silicone hydrogel contact lenses.

Methods: In this in-vitro study, senofilcon C, samfilcon A, and lotrafilcon B+EOBO (polyoxyethylene-polyoxybutylene) were individually coated with cosmetic products followed by a 1-hour soak in phosphate-buffered saline. Cosmetic products included; 3 hand creams (HC1: Glysomed; HC2: Vaseline Healthy Hand & Nail Conditioning; HC3: Intense Relieve), 3 make-up removers (MR1: Lid-Care Towelettes; MR2: Gentle waterproof eye and Lip Makeup Remover; MR3: Oil-Free Makeup Remover), and 3 mascaras (MA1: Great Lash – waterproof; MA2: Wonder’Lash – waterproof, MA3: Voluminous Original). Lens diameter, sagittal depth, and base curve were measured using the Chiltern (Optimec Limited), while lens power and optical quality were assessed using the Contest Plus II (Rotlex) (n=6 for each lens/ cosmetic combination). The impact of cosmetics was tested between lenses and compared to baseline (uncoated control lenses).

Results: For lens diameter, makeup removers (MR2 & MR3) had the largest impact, with an increase of up to 0.27mm (MR2) and 0.36mm (MR3) for senofilcon C and samfilcon A respectively (p<0.01 compared to baseline), while lotrafilcon B+EOBO showed a decrease of only 0.01mm (p<0.01 between lens types). For sagittal depth, mascara MA1 had the greatest impact, followed by makeup removers MR2 & MR3. All lenses had increases in sagittal depth after MA1 exposure (0.16±0.06mm in lotrafilcon B+EOBO, 0.24±0.22 mm and 0.26±0.09mm in samfilcon A and senofilcon C respectively; p<0.01 for all lenses compared to baseline). For base curve, the makeup removers (MR2 & MR3) caused increases for both senofilcon C (up to 0.36mm) and samfilcon A (up to 0.45mm), but lotrafilcon B+EOBO was unaffected. Lens power changes were generally minor (less than 0.25D). However, senofilcon C had a significant increase 1.19±0.65D more minus after MA1 exposure (p0.05). Hand creams had no effect on any variable investigated for any lens material.

Conclusion: Overall, mascara MA1 and make-up removers MR2 & MR3 had the largest affect on lens dimensions, and mascara MA1 had the largest affect on optical lens properties. Some dimensional changes were outside of the ISO tolerance, which could affect lens fit. Lotrafilcon B+EOBO lenses were generally least affected by these cosmetic products.

Marx S, Kwan J, Jones-Jordan L, Powell D, Srinivasan S, Sickenberger W, Jones J, Pucker A. Degree of Meibomian Gland Tortuosity in Successful Soft Contact Lens Wearers and Dropouts American Academy of Optometry, San Antonio, USA, 2018 [ Show Abstract ]

Purpose: The etiology of meibomian gland (MG) tortuosity (deviated glands) is unknown, but it may be caused by chronic terminal duct obstruction or by genetic predisposition. The study purpose was to determine if MG tortuosity impacts successful contact lens (CL) wear and if degree of tortuosity was associated with other signs or symptoms of ocular dryness.

Methods: This five-site case-control study recruited subjects between 18 and 45 years of age. Cases had ceased CL use within the past 6-12 months due to discomfort, while age- and sex-matched controls were able to comfortably wear CLs for ≥8 hours/day for ≥5 days/week. Each subject was administered a study-specific CL questionnaire and a SPEED questionnaire. Clinical testing included non-invasive tear break-up time (NITBUT), tear meniscus height (TMH), MG expressibility, meibum quality, and meibography (OCULUS Keratograph 5M). MG tortuosity for each eyelid was graded using the 5-point Halleran scale (Grade 0: no tortuosity; Grade 4: ≥75% of visible MG being tortuous). Worse eyes (determined by worse eye for tortuosity) comparisons were made with paired t-tests (means) or McNemar’s test (frequencies).

Results: Fifty-six matched-pairs were recruited across sites. The mean ± SD age of the cases (28.5 ± 7.1 years) and controls (28.6 ± 7.0 years) were not significantly different (p = 0.66). The cases had significantly higher SPEED scores than the controls (6.42 ± 4.96 vs. 2.62 ± 2.66; p < 0.001). Cases did not have significantly higher upper (2.13 ± 1.09 vs. 1.80 ± 0.96; p = 0.07), lower (0.82 ± 0.64 vs. 1.00 ± 0.74; p = 0.12) or total (2.97 ± 1.30 vs. 2.80 ± 1.29; p = 0.39) eyelid tortuosity scores than controls. Tortuosity was significantly associated with TMH (p = 0.02), MG expressibility of upper (p = 0.03) and lower eyelids (p = 0.01) but not SPEED, NITBUT, meibum quality, or MG atrophy (all p ≥ 0.14).

Conclusion: At least some degree of MG tortuosity was commonly noted in both groups of subjects in the upper and lower eyelids. While tortuosity may not be a risk factor for CL dropout, tortuosity is likely a sign of decreased MG health. Tortuosity may result in altered tear lipid production, which could result in decreased meibum expressibility and reduced tear volume noted in this study.

Mohammadi S, Jones L, Gorbet M. Investigation of Latanoprost Release from Contact Lens Materials in the presence of cells and under in vitro Tear Replenishment Invest Ophthalmol Vis Sci 2018;E-Abstract 1770 [ Show Abstract ]

Purpose: To effectively mimic the ocular environment for biocompatibility and drug delivery studies, the limited volume and replenishment of the tear film and the presence of cells should be considered. By using an in vitro corneal epithelial cell model combined with a tear replenishment (TR) method, this study aimed to investigate the delivery of Latanoprost by commercially available contact lenses (CL) and compare the dynamic release results to non-replenished (immersion) conditions.

Methods: To enable in vitro “lens wear”, cell culture inserts were formed to recreate the geometry of the cornea prior to seeding of human corneal epithelial cells. The curved cornea models (CCMs) were ready after 7 and 14 days for mono-layer and stratified models respectively. The in vitro TR was achieved via intermittent flow of a tear solution analogue over the CCMs at a rate of 1mL/hour. Three CLs (balafilcon A; senofilcon A; etafilcon A), were soaked for 24hrs in the glaucoma drug, Latanoprost, at concentrations of 123 µg/mL (high doping; HD) and 9.5 µg/mL (low doping; LD). Lenses were then onlayed on the CCMs (n=3) and drug concentration was determined on the basal (diffusion/transport) and apical (supernatant) sides after 1, 4, 8 and 12hrs.

Results: A zero-order kinetic was observed for basal drug concentration over the 12hr period. The drug release and diffusion through the CCMs was significantly higher in etafilcon A (p<0.001). Also for HD lenses, the overall release was comparable to the prescribed daily dose. The apical release of the drug was significantly lower for replenished vs. immersed CCMs (p<0.001) in HD lenses. In contrast to stratified CCMs, cell viability was significantly lower under replenished conditions compared to immersed mono-layer CCMs (p=0.002). The release ratio of HD to LD lenses were in agreement to the doping ratio.

Conclusions: The Latanoprost release studies under dynamic conditions further confirmed the significant role that cells play in the release of that drug from a CL material. These results also demonstrated yet another important role that a dynamic release model will have in predicting the amount of drug that can be absorbed through the cornea or lost from a CL into the tear film/lacrimal system. Recreating the microfluidics of the TR in vitro can contribute to a better understanding of interactions between the ocular surface and drug-delivery CL.

Nakhla N, Killeen RM, de Waal D, Haines L, Srinivasan S, Sivak A, Walsh K, Pantazi F. Enhancing Eye Care Through Interprofessional Collaboration – A joint pharmacist-optometrist initiative Lifelong Learning in Pharmacy conference. Brisbane, Australia, 2018

Nakhla N, Killeen RM, de Waal D, Haines L, Srinivasan S, Sivak A, Walsh K, Pantazi F. Enhancing Eye Care Through Interprofessional Collaboration – A joint pharmacist-optometrist initiative Association of Faculties of Pharmacy of Canada conference. Ottawa, ON, Canada, 2018

Powell D, Jones-Jordan L, Srinivasan S, Kwan J, Marx S, Sickenberger W, Jones L, Pucker A. Impact of Soft Contact Lens Factors and Compliance on Contact Lens Dropout American Academy of Optometry, San Antonio, USA, 2018 [ Show Abstract ]

Purpose: To determine if certain contact lens (CL) factors or compliance issues may contribute to CL dropout (CLD).

Methods: Subjects 18-45 years of age who had dropped out of soft CL wear (cases) within the past 6-12 months due to discomfort were enrolled across five study sites. Cases were compared to age- and sex-matched successful soft CL-wearing controls (CLDEQ-8 score ≤ 10). Each subject was administered a study-specific questionnaire containing items that queried CL history and compliance: Age at first CL wear; number of years, days/week and hours/day of wear; primary CL solution used (multipurpose vs. hydrogen peroxide); lens material (conventional vs. silicone hydrogel) and modality (daily disposable/biweekly/monthly replacement); napping/overnight sleeping in CLs, and routine exposure of the lens case or CLs to tap water. Comparisons were made using paired t-tests and McNemar’s tests for means and frequencies, respectively.

Results: Fifty-six matched-pairs completed the one-visit study. Mean age (± SD) of cases and controls were 28.5 ± 7.1 and 28.6 ± 7.0 years, respectively (p = 0.66). There was no difference in the age at first CL wear (p = 0.19), although controls had worn CLs nearly 3 years longer overall than cases (p = 0.01). Over two-thirds of cases reported wearing their CLs ≤ 4 days/week before dropping out of CLs while nearly the same proportion of controls wore their CLs 6-7 days/week (p < 0.001). Cases also had a shorter average wear time by at least 2 hours/day when compared to controls (p < 0.001). Lens modality, primary CL solution used, CL or case exposure to tap water, on-time CL replacement, case replacement at least every 3 months, sleeping in CLs, or wearing a pair CLs beyond the clinician-recommended timeframe were not associated with CLD (all p ≥ 0.41). Although borderline significant, the odds of controls having worn a conventional hydrogel CL was higher than that for cases (OR = 2.5, p = 0.05). Controls napped more often in their CLs than cases (p = 0.01).

Conclusion: Successful soft CL wearers are more likely to wear their lenses on or nearly every day of the week and for more hours each day than those who eventually dropped out of soft CL wear due to discomfort. The material that comprises a soft CL may factor into CLD. CL compliance within this cohort does not appear to be associated with CLD.

Pucker A, Jones-Jordan L, Srinivasan S, Powell D, Kwan J, Marx S, Sickenberger W, Jones L. Association Between Meibomian Gland Health and Soft Contact Lens Dropout American Academy of Optometry, San Antonio, USA, 2018 [ Show Abstract ]

Purpose: There is virtually no growth in the global contact lens (CL) market because there are as many CL dropouts as new CL wearers. The purpose of this study was to determine if meibomian gland (MG) atrophy has an impact on successful CL wear.
Methods: This five-site study recruited subjects between the ages of 18 and 45 years who had discontinued CL use within the past 6-12 months due to discomfort. CL dropout subjects (cases) were compared to age- and sex-matched successful CL wearing controls (≥8 hours/day for ≥5 days/week). Each subject was administered a study-specific CL questionnaire and a standard SPEED questionnaire. Clinical testing included non-invasive tear break-up time (NITBUT), tear meniscus height (TMH), meibomian gland function (expression and plugging), and meibography (OCULUS Keratograph 5M). MG atrophy was graded subjectively on a 0 to 3 scale by eyelid for each eye; atrophy was categorized as significant if the upper or lower eyelid grade was ≥ 2 or the total grade for both upper and lower eyelids was ≥ 4. Subjects were considered to have diagnosed dry eye if they had a SPEED score > 5.0 and a positive NITBUT (< 10 s) or TMH (< 0.2 mm) test. Worse eye comparisons were made with paired t-tests (means) or McNemar’s test (frequencies).
Results: 56 matched-pairs were recruited across sites. The mean ± SD age of the cases (28.5 ± 7.1 years) and controls (28.6 ± 7.0 years) were similar (p = 0.66). Cases had significantly higher SPEED scores than controls (6.4 ± 5.0 vs. 2.6 ± 2.7; p < 0.0001). Diagnosed dry eye was significantly associated with CL dropout (p < 0.001). NITBUT, TMH, and significant upper, lower and total MG atrophy was not different between groups (all p ≥ 0.16). Upper (p < 0.001) and lower (p = 0.002) MG plugging and upper (p < 0.001) but not lower (p = 0.11) meibum quality were associated with CL dropout. Neither upper nor lower MG atrophy were associated with upper or lower MG plugging or upper or lower meibum quality (all p ≥ 0.35).
Conclusion: CL dropout may be precipitated by underlying dry eye, though most dry eye signs, with the exception of MG function, have minimal predictive value for CL dropout. Nevertheless, evidence from this study suggests that practitioners should screen for and educate CL patients about the importance of eyelid hygiene in order to maintain comfortable CL use.

Pucker A, Jordan L, Srinivasan S, Powell D, Kwan J, Marx S, Sickenberger W, Jones L. Is Compliance and Ocular Surface Factors Associated with Contact Lens Dropout? Invest Ophthalmol Vis Sci 2018;E-Abstract 3933 [ Show Abstract ]

Purpose: Discontinuation from contact lens (CL) wear is estimated to be approximately equal to the numbers of new wearers per year, resulting in virtually no growth in the global CL market. The purpose of this study was to determine factors associated with successful wear that may impact CL dropout.

Methods: This five-site study recruited subjects 18-45 years of age who had ceased CL wear within the past 6-12 months due to discomfort. Dropout subjects were compared to age- and sex-matched successful CL wearers (≥8 hours/day for ≥5 days/week). Each subject was administered a study-specific questionnaire that queried general CL history and compliance. Clinical testing included non-invasive tear break-up time and tear meniscus height (OCULUS Keratograph 5M), blepharitis assessment, and meibum quality and expression. Comparisons were made with paired t-tests for means or McNemar’s test for agreement for frequencies.

Results; 25 matched-pairs (50 total subjects) were recruited across sites. The mean ± SD age of the subjects were 28.6 ± 7.1 years (range = 18 to 44); the sample was 73.7% female. Successful CL wearers had worn CLs for 10.6 ± 5.5 years while CL dropouts had worn CLs for 6.8 ± 5.9 years (p = 0.03). CL dropout was not associated with exposing CLs to tap water (p = 1.00), replacing CLs on time (p = 0.99), replacing their CL case at least every 3 months (p = 0.73), sleeping in CLs (p = 0.32), or wearing CLs longer than their clinician recommended (p = 1.00); current CL wearers, however, napped more frequently in their CLs (p = 0.03). Non-invasive tear break-up time (p = 0.19), tear meniscus height (p = 0.33), upper (p = 0.27) and lower (p = 0.26) eyelid blepharitis, lower eyelid meibum quality (p = 0.92) and lower eyelid meibum expressibility (p = 0.33) were also not associated with CL dropout; nevertheless, upper eyelid meibum quality (p = 0.03) and expressibility (p = 0.002) were associated with CL dropout.

Conclusions: CL compliance does not appear to be associated with CL dropout, but this study did collect some evidence indicating that decreased meibomian gland function may reduce one’s ability to successfully wear CLs. These data support the need for early meibomian gland dysfunction prevention and treatment because interventions may promote better long-term ocular health and the ability to comfortably wear CLs.

Redfern RL, Nichols J, Sickenberger W, Fogt JS, Schulze M, Lievens C, Szczotka-Flynn L, Schwarz S, Shows A, Lemp-Hull J.. Ex Vivo Analysis of Lipid Deposition with Silicone Hydrogel Contact Lenses and EOBO-Based Lens Care Solutions Investigative Ophthalmology & Vision Science 2018;E-abstract 1768 [ Show Abstract ]

Purpose : To compare the cholesterol deposition profile of a regimen of lotrafilcon B lenses packaged in blister solution containing the EOBO (polyoxyethylene-polyoxybutylene) wetting agent (AIR OPTIX plus HydraGlyde, AOHG) and lens care solutions formulated with EOBO (OPTI-FREE PureMoist, OFPM or CLEAR CARE PLUS, CCP) with a regimen of marketed silicone hydrogel (SiHy) lenses and marketed multipurpose solutions (MPS) that do not contain EOBO.

Methods : Adult, habitual SiHy lens wearers and habitual MPS users participated in a multi-center, prospective, stratified, controlled, parallel-group, masked study. Subjects (n=252) were randomized to wear either AOHG or habitual SiHy lenses (Acuvue Oasys, Acuvue Vita, Biofinity, or Ultra) daily for 30 (+3) days. Subjects in the AOHG lens group were further randomized to use either OFPM or CCP to care for their lenses. Lenses were replaced according to the manufacturer recommendation for each lens material. Subjects assigned to habitual SiHy lenses continued to use their habitual multipurpose solution (HMPS). Lenses (n=20 to 28 per regimen) were collected for assessment of total cholesterol uptake. Cholesterol sorption was measured using a fluorometric enzymatic assay as previously described (Nash et al, E&CL 2014).

Results : AOHG/CCP regimen demonstrated significantly less cholesterol uptake (median = 0.30 µg) than the following regimens: Biofinity/HMPS (median = 1.55 µg), Vita/HMPS (median = 4.20 µg), Ultra/HMPS (median = 1.90 mg) and Oasys/HMPS (median = 1.55 mg), (p < 0.0001 for all). Likewise, the AOHG/OFPM regimen had significantly less cholesterol uptake (median = 0.10 µg) than all habitual lens and solution regimens (p < 0.0001 for all).

Conclusions : The AOHG/CCP and AOHG/OFPM regimens resulted in less cholesterol sorption than each of the habitual SiHy/MPS regimens (p < 0.0001). Further research is necessary to understand the impact of cholesterol deposition on patient clinical outcomes.

Schmidt T, Srinivasan S, Heynen M, Jay G, Sullivan B, Subbaraman L, Caffery B, Jones L, Regmi S. Quantification of proteoglycan 4 (PRG4) / lubricin in normal and Sjögren Syndrome human tears Invest Ophthalmol Vis Sci 2018;E-Abstract 3827 [ Show Abstract ]

Purpose: Sjögren’s syndrome (SS) is an autoimmune disease with hallmark clinical symptoms of dry eye and dry mouth. Proteoglycan 4 (PRG4), or lubricin, is a boundary lubricant that is naturally present on the ocular surface and in tears. Recently PRG4 in human tears was shown to be susceptible to proteolytic digestion by cathepsin S, an enzyme with increased activity in SS tears, which destroyed the in vitro ocular surface boundary lubricating ability. However, whether levels of PRG4 are diminished in SS tears remains to be determined. The objective of this study was to quantify PRG4 levels in normal and SS human tears.

Methods; Tears were collected from 17 SS (15 F, 2 M, 56.2±16.7 years old) and 20 asymptomatic (n=20, 7 M, 13 F, 31.2±11.4 years old) participants, with approval from the Office of Research Ethics (UWaterloo). SS participants were diagnosed using the American European Consensus Criterion. Tears were collected without anaesthetic, from the inferior temporal tear meniscus of each eye, using a disposable microcapillary tube and frozen at -80C until use. The concentration of PRG4 was determined via a sensitive, competitive amplified luminescent proximity homogeneous assay using recombinant human PRG4 as the control. Total mass of PRG4 was calculated by normalizing concentration by tear volume, using 5.0 ul for normal tears and measured SS tear volume (0.1 to 2.3 ul). Data is reported as mean±SD, nonparametric statistics were employed (Mann-Whitney U & Levine tests).

Results; The concentration of PRG4 in SS (28.6±44.3 ug/ml) was not significantly different than that of normal tears (2.6±2.0 ug/ml, p=0.15), but did demonstrate significantly greater variation (p<0.001). The mass of PRG4 in SS tears (10.6±4.8 ng) was significantly diminished compared to normal tears (12.8±1.4 ng, p<0.05).

Conclusions; PRG4 concentration is significantly more variable in SS tears, and when normalized by volume, the PRG4 mass in SS tears is diminished compared to normal tears. These data suggest either a reduction in PRG4 production or an increase in PRG4 catabolism in SS tears relative to normal tears, which could be the cause of the variability of PRG4 concentration in SS tears. Given the role PRG4 plays in ocular surface health and its susceptibility to degradation by cathepsin S in SS tears, diminished PRG4 could contribute to signs and symptoms of dry eye in SS.

Sivak A, Srinivasan S, Walsh K, Haines L, MacIver S, Killeen R, Nakhla N, Jones L. Professional Collaboration for Patient-Centred Eye Care – A Continuing Education Program for Optometrists and Pharmacists American Academy of Optometry, San Antonio, USA, 2018 [ Show Abstract ][ PDF ]

SIGNIFICANCE: Collaboration between North American pharmacists and optometrists is inconsistent, despite overlapping goals and concerns relating to eye care.
PURPOSE: The Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science and School of Pharmacy at the University of Waterloo (UW) collaborated to address this gap in information sharing by developing a series of web-based multimedia continuing education modules directed at pharmacists, optometrists and optometric assistants. These modules were designed to highlight unique and overlapping spheres of knowledge in addition to providing guidance with respect to developing a plan for interprofessional collaboration.
METHODS: Content was developed through interprofessional discussion and by consulting emerging research, evidence-based guidelines and needs assessments, and was informed by the Canadian Interprofessional Health Collaborative competency framework. The UW Centre for Extended Learning provided guidance with respect to instructional design and usability. Content was reviewed by community-based optometrists and pharmacists as well as external content matter experts representing both professions. The modules were reviewed and accredited by the Council on Optometric Practitioner Education (COPE) and the Canadian Council on Continuing Education in Pharmacy (CCCEP).
RESULTS: The completed program includes four hours of content comprising four modules: (1) an overview of interprofessional collaboration, (2) contact lens care systems, (3) management of dry eye disease, and (4) contact lens red eye. Each module includes profession-specific perspectives, guidelines related to ocular needs and treatment options, and profession-specific roles in addressing patient needs. Modules also outline topic-specific opportunities for communication, collaboration and referral.
CONCLUSIONS: Opportunities for collaboration between optometrists and pharmacists are rich but largely unexplored within the confines of profession-specific “tunnel vision.” These CE modules aim to start a conversation about the ways in which optometrists and pharmacists can work together to enhance patient-focused care.

Sivak A, Woods J, Srinivasan S, Subbaraman L, Jones L. The Centre for Ocular Research & Education American Academy of Optometry, San Antonio, USA, 2018 [ Show Abstract ]

The Centre for Ocular Research & Education (CORE) at the University of Waterloo, Canada has been conducting ocular research for over 30 years (formerly as the Centre for Contact Lens Research), and has been involved in some of the most meaningful advances in eye and contact lens research. CORE seamlessly integrates clinical observations and educational materials with insights grounded in basic bioscience. The CORE team has the experience, technology and regulatory framework to support fundamental and clinical research focusing on pharmaceuticals, biomaterials (including contact lenses), ocular physiology and imaging.

CORE’s biosciences team has the expertise to analyze biological samples; engineer novel biomaterials; test product biocompatibility; analyze contact lens materials; develop in vitro models; test lens care systems for antimicrobial efficacy and cytotoxicity; analyze proteins, lipids and inflammatory markers; evaluate, analyze and identify bacteria and biofilms; and test the viability of ocular surface cells.

CORE’s clinical team has the capacity to execute all stages of study development, from protocol design through report generation for clinical research and Phase II, III and IV clinical trials. Features include specialized imaging and image analysis; resources for coordinating multi-site clinical trials; staff trained to collect patient and practitioner perspectives via focus groups, interview and web-based surveys; dedicated in-house teams dedicated to regulatory oversight, data analysis and subject recruitment.

Over the years, CORE’s team has published hundreds of peer-reviewed publications, presented results at scientific conferences and meetings around the world, and lent its expertise to a variety of scientific panels and associations. In addition to providing training for post-graduates and industry teams, CORE is committed to sharing its observations and knowledge with eye care professionals worldwide via web-based resources, information sheets and posters, conventional print articles, continuing education seminars, conference reports, user manuals and fitting guides and instructional videos.

Srinivasan S, Caffery B, Harthan J, Acs M, Barnett M, Johnson-Tong L, Papinski D, Pemberton B. Prevalence of Meibomian Gland Dysfunction in Sjogren’s Syndrome Patients Invest Ophthalmol Vis Sci 2018;E-Abstract 921

Subbaraman L, Dare E, Fung CK, McCanna D, Jones L. Establishment of optimal culture media in human corneal epithelial wound healing models Invest Ophthalmol Vis Sci 2018;E-Abstract 4337 [ Show Abstract ]

Purpose: Damage to the human corneal epithelium can potentially result in severe vision loss. Corneal epithelial cell damage should be quickly repaired to prevent infection and adequate wound healing is required for corneal transplants and recovery from LASIK surgery. To study corneal epithelial wound healing, an in vitro scratch model and an in vitro exclusion zone model are often used. The purpose of this study was to establish the optimum media to use as a control solution in wound healing models.

Methods: Immortalized human corneal epithelial cells were cultured in different growth media. A scratch wound was made on the epithelial cell monolayers and cell recovery was followed for up to 48 hours by measuring the area of the wound. The effect of normoxic and hypoxic conditions on tight junctional integrity and metabolic activity of cells grown in different growth media were also investigated. Using an exclusion zone model, the degree of cell proliferation into the exclusion zone was determined after seven and nine days of growth in cell culture media.

Results: Wound healing with Dulbecco’s Modified Eagle Medium: Nutrient mixture F-12 (DMEM/F-12) was significantly faster than both the keratinocyte serum-free medium (KSFM) (p<0.05) and EpiLife (p<0.05) 10 hours after wounding using the scratch model and nine days after wounding using the exclusion zone technique (p<0.05). In addition, hypoxic culture significantly delayed wound healing by an average of 32.4%. In the culture media DMEM/F-12, human corneal epithelial cells stained for abundant zona occludens-1 (ZO-1), connexion 43 (Cx43) and had a high metabolic activity indicating significant epithelial barrier formation, gap junction formation and high cell viability.

Conclusions: DMEM/F-12 led to superior wound healing under hypoxic and normoxic conditions and in two different wound healing models. DMEM/F-12 appears to be the optimum wound healing control for corneal wound healing models due to superior metabolic activity, wound healing and formation of a greater number of tight junctional proteins in cells grown in this medium over the other media tested.

Varikooty J, Woods J, Lumb E. Validation of Multifocal Soft Lens Power Calculator in OptiExpert Application for Clariti 1-Day Multifocal Lens Fitting American Academy of Optometry, San Antonio, USA, 2018 [ Show Abstract ][ PDF ]

Purpose: The multifocal soft lens calculator component of the OptiExpert-multifunctional app was developed by CooperVision Inc to make multifocal CL fitting easy, by predicting the required powers for clariti-1 day multifocal (C1DM) from the spectacle prescription, in a presbyopic population. This retrospective data analysis was conducted to validate the software.

Methods: The data used for validation came from a sample of 26 subjects, whose subjective refraction data (sph, cyl, add, ocular dominance) was already determined and C1DM had already been fit and dispensed according to clinical assessments using the C1DM fitting guide. After 3-10 days all subjects attended a power optimization visit where the contact lens (CL) power was re-assessed and, if required, a new prescription was dispensed. The subjective refraction data was subsequently entered in the OptiExpert app, and the recommended CL power for each eye (OptiExpert-Rx) was compared to the power dispensed after the optimization visit (Optimized-Rx). Correlation analysis was conducted between OptiExpert-Rx and Optimized-Rx. A Bland-Altman analysis comparison was also conducted to measure agreement between methods.

Results: The 26 presbyopes (21 female, 5 male) had a mean (±SD) age of 56.7 (±7.4) years. Subjective refraction range across all 52 eyes was +5.00 to -6.00 D sph with ≤ -1.00 D cyl. The reading add ranged between +1.50 to +2.50 D. 96% (25) of the subjects were successfully fit in the initial trial with the first pair of C1DM CLs, and the remaining 1 subject required 2 pairs of CLs. At the optimization visit a few days later, only 10% of eyes (5 eyes across 4 subjects) required a change in lens power, meaning 100% of eyes were successfully fit with just 1 additional lens. In subjective responses, 92% reported that C1DM CLs met or exceeded their visual needs. The suggested OptiExpert-Rx was significantly correlated with Optimized-Rx (r ≥ 0.996 and p <0.0001). Bland Altman analysis showed a mean difference (and 95% limits of agreement) between OptiExpert-Rx and Optimized-Rx of 0.09 D (-0.64 to +0.46). Compared to the final optimized lens powers, over 80% of eyes were within 0.25DS of the predicted power using OptiExpert.

Conclusion: The clariti-1 day multifocal powers recommended by the OptiExpert app were in close agreement with investigator determined CL powers. Given this high level of agreement, OptiExpert multifocal soft lens calculator can be confidently used as a clinical tool to aid clariti-1 day multifocal fitting success, potentially saving valuable chair time.

Woods J, Moezzi A, Varikooty J, Jones L. Comparison of lens orientation stability of two daily disposable silicone hydrogel toric lenses Contact Lens & Anterior Eye 2018;41, Supp 1:S93

Woods J, Ng AY, Luensmann D, Guthrie S, Jones L. Short-term comfort comparison of two daily disposable contact lenses of different material and modulus Invest Ophthalmol Vis Sci 2018;E-Abstract 1753 [ Show Abstract ][ PDF ]

Purpose: Daily disposable contact lenses (DDs) are now widely available in both silicone hydrogel (SH) and hydrogel (H) materials. The higher oxygen transmissibility of SH materials provides many benefits, but their higher modulus has been linked with reduced lens comfort compared to H lenses. This randomized, double-masked clinical trial assessed the short-term comfort of two DDs of differing modulus, yet similar water content (WC): a SH-DD (somofilcon A; clariti® 1 day; CooperVision; 0.50MPa modulus, 56% WC) and a H-DD (etafilcon A; 1-Day Acuvue® Moist®; Johnson & Johnson; 0.29MPa modulus, 57% WC).

Methods: 120 subjects wore the lenses contralaterally, over one day. Targeted recruitment meant that 60 subjects were habitual H-DD wearers (all adapted wearers of 1-Day Acuvue Moist), 60 were non-DD habitual wearers (adapted to various SH and H re-usable lenses). Subjects rated lens comfort on a 0-100 integer scale (100= cannot be felt) at insertion and then hourly until 8hrs. Of particular interest was the comfort at the beginning and end of the 8hr wear period and these data points were tested for equivalence. At the final visit subjects were asked for their lens preference, based on comfort.

Results: Mean subjective comfort was not different between SH-DD and H-DD across the wear period (p>0.05), on insertion (87±14 SH-DD vs 89±14 H-DD; p>0.05) or after 8hrs (82±18 SH-DD vs 83±17 H-DD; p>0.05). Based on equivalency margins of ±5-points, the study lenses showed equivalent comfort at insertion (p=0.03) and at 8hrs (p=0.001). Both lenses exhibited a significant reduction in comfort over the 8hr period (both p0.05). Lens preference was not different between lenses at dispensing or at the final visit (both p>0.05).

Conclusions: Initial and 8hr comfort were not compromised with the SH-DD compared to the H-DD, despite its higher modulus, and there was no difference in the lens preference distribution. The results suggest that lower comfort should not be anticipated when fitting SH-DDs of an appropriate design, thus allowing other material properties such as high oxygen permeability to be considered.

Woods J, Ng AY, Luensmann D, Jones L. Short-term comfort comparison of a low modulus hydrogel vs a higher modulus silicone hydrogel daily disposable lens Contact Lens & Anterior Eye 2018;41, Supp 1:S42

Woods J, Panjwani F, Papinski D, Varikooty J, Jones L. In-vivo dehydration comparison of omafilcon A and stenfilcon A with delefilcon A Contact Lens & Anterior Eye 2018;41, Supp 1:S41

Yee A, Jabeen A, Subbaraman L, McCanna D, Phan C-M, Jones L. Novel In-Vitro Method to Study Bacterial Interaction with Contact Lenses American Academy of Optometry, San Antonio, USA, 2018 [ Show Abstract ][ PDF ]

Purpose: Previous in-vitro studies have used a “soak” or closed vial method to assess bacterial binding to contact lenses (CL). The purpose of this study was to develop a novel in-vitro drip model to determine if bacterial adhesion to a CL material was possible. The novel in-vitro drip model would more closely resemble an accurate eye model in comparison to current methods undertaken.

Methods: The novel in-vitro drip method consists of a 5.5 mL syringe with saline solution and a flow rate controller dispensing 5 µl of saline solution containing the bacteria. The consistent drip volume is adjustable and mimics the normal human tear volume and flow. The solution flows through a silicone tube and onto a CL. The CL was placed on a sterile glass eyeball in an enclosed container to maintain the environment’s humidity. In the soak method, the CL was placed on top of a sterile glass eyeball and placed in the enclosed container with a 5 mL saline solution of 1.0 x 107 colony forming units (CFU)/mL. For both methods, lenses were incubated in the solution for 16 hours. After removal, the viable cells were diluted in serial dilutions. Aliquots of each dilution were plated on a trypticase soy agar plate and incubated for 24 hours at 37°C. After 24 hours, the CFU per lens were calculated manually under magnification.

Results: Using the in-vitro drip method, adhesion of Staphyloccocus aureus onto senofilcon A was successfully demonstrated. Preliminary analysis showed no significant difference (p = 0.34) between the drip and soak method when compared at high CFU/mL.

Conclusion: The novel drip method is a promising alternative to the conventional soak method, as this model is closer to the contamination that would occur in a human eye. The drip method may be an acceptable method of testing once the method can be further developed and tested in future studies, using a variety of lenses and bacteria.

2017

Caffery B, Harthan J, Acs M, Barnett M, Johnson-Tong L, Kelly S, Papinski D, Pemberton B, Srinivasan S. Comparison of the Severity of Dry Eye in Sjogren’s syndrome Versus Aqueous Deficient Dry Eye Optom Vis Sci 2017;94: E-Abstract 170014

Chamberlain P, Back A, Lazon de la Jara P, Jones D. Adaptation of children to daily disposable soft contact lenses British Contact Lens Association Conference, 2017

Chamberlain P, Back A, Lazon de la Jara P, Logan N, Jones D. 3 year effectiveness of a dual-focus 1 day soft contact lens for myopia control British Contact Lens Association Conference, 2017

Dantam J, McCanna D, Subbaraman L, Jones L. Pro-inflammatory cytokine expression in human corneal epithelial cells after exposure to LPS derived from Pseudomonas aeruginosa Optom Vis Sci 2017;94: E-Abstract 174082

Dantam J, Subbaraman L, Jones L. Adhesion of emerging pathogens to contact lenses under the influence of an artificial tear solution Invest Ophthalmol Vis Sci 2017;E-Abstract 3079

Drolle E, Leonenko Z, Subbaraman L, Jones L. Nanoscale Differences in Meibum Thin Films from Dry Eye and Non-Dry Eye Individuals ISCLR, Portland, Oregon, USA, 2017

Drolle E, Leonenko Z, Subbaraman L, Jones L. Nanoscale comparison of meibum and an in vitro lipid model Invest Ophthalmol Vis Sci 2017;E-Abstract 2250

Gorbet M, Toameh D, Zhang J, Phan C-M, Walther H, Jones L. Development of a dynamic co-culture ocular cell in vitro model for ocular biocompatibility testing Invest Ophthalmol Vis Sci 2017;E-Abstract 4727

Heynen M, Qiao H, Subbaraman L, Scales C, Riederer D, Fadli Z, Jones L. Location of non-polar lipids in monthly replacement silicone hydrogel contact lens materials Canadian Optometry Schools Research Conference, 2017

Jabeen A, Subbaraman L, Babaei Omali N, Srinivasan S, Jones L. Method optimization to quantify calcitonin gene-related peptide (CGRP) in human tear film Optom Vis Sci 2017;94: E-Abstract 175270

Khalid S, McCanna D, Jones L. Efficacy of a peroxide-based contact lens care solution against Pseudomonas aeruginosa and Staphylococcus aureus biofilms formed under four different nutrient conditions Optom Vis Sci 2017;94: E-Abstract 174072

Kroeker D, van Doorn K, Walther H, Subbaraman L, Jones L. Development of a novel, objective metric to determine tear film stability Invest Ophthalmol Vis Sci 2017;E-Abstract 3089

Liu S, Tsugimatsu A, Chang C, Liang H, Reyad MM, Boyd S, Jones L, Gu F. Tracking ocular retention of precorneal formulations using near-infrared dyes Invest Ophthalmol Vis Sci 2017;E-Abstract 4444

McCanna D, Bidar M, Subbaraman L, Jones L. The effect of artificial tear solution and organic load on the efficacy of contact lens disinfectant solutions Invest Ophthalmol Vis Sci 2017;E-Abstract 3075

Moezzi A, Varikooty J, Luensmann D, Schulze M, Ng AY, Karkkainen T, Xu J, Jones L. Evaluation of Clinical Success with etafilcon A multifocal daily disposable lenses Optom Vis Sci 2017;94: E-Abstract 175341

Schulze M, Wong A, Haider S, Ebare K, Fadli Z, Coles-Brennan C, Jones L. Blink Rate in Silicone Hydrogel Contact Lens Wearers during Digital Device Use The 9th Canadian Optometry School’s Research (COSRC), 2017

Sivak A, Spafford M, Irving E. Purchasing eyewear on the Internet: patient views Canadian Optometry Schools Research Conference, 2017

Spafford M, Sivak A, Irving E. Motivators and deterrents for seeking eye care Optom Vis Sci 2017;94: E-Abstract 170073

Subbaraman L, Hwang Y, Liu L, McCanna D, Jones L. Metabolic activity of human corneal epithelial cells after exposure to artificial tear-like formulations with varying pH and osmolalities Invest Ophthalmol Vis Sci 2017

Wong S, Lum E, Planaguma Cornella A, Murphy P, Jones L. Surface temperature change in soft contact lenses: an in vitro study Invest Ophthalmol Vis Sci 2017;E-Abstract 3097

Wong S, Srinivasan S, Jones L. Comparison of meibomian gland dropout using two infrared imaging devices Optom Vis Sci 2017;94: E-Abstract 174064

Woods J, Hutchings N, Srinivasan S, Jones L. Geographic distribution of corneal staining in symptomatic dry eye Optom Vis Sci 2017;94: E-Abstract 174056

2016

Back A, Chamberlain P, Logan N, Jones D, Gonzalez-Meijome J, Mei Saw S, Young G. Clinical evaluation of a dual-focus myopia control 1 day soft contact lens - 2-year results Optom Vis Sci 2016;93: E-abstract 160035

Chamberlain P, Back A, Jones L, Logan N, Peixoto-de-Matos S, Mei Saw S, Young G. Parental perspectives on their child wearing daily disposable soft contact lenses in a multicenter clinical study Optom Vis Sci 2016;93: E-abstract 165325

Chamberlain P, Back A, Woods J, Logan N, Peixoto-de-Matos S, Mei Sae S, Young G. Wearer experience and subjective responses with a dual focus myopia control 1 day soft contact lens Optom Vis Sci 2016;93: E-abstract 165326

Heynen M, Qiao H, Subbaraman L, Scales C, Riederer D, Fadli Z, Jones L. Location of non-polar lipids in monthly replacement silicone hydrogel contact lens materials Optom Vis Sci 2016;93: E-abstract 166116 [ PDF ]

Jones L. Management and therapy of dry eye TFOS conference, Montpelier, France, 2016

Jones L. Tear film components and their impact on contact lens wear Japanese Contact Lens Society conference, Tokyo, 2016

Jones L, Guthrie S, Dumbleton K. Is there a relationship between care system and compliance? Asian Cornea and Contact lens Conference, Hong Kong, 2016 [ PDF ]

Jones L, Varikooty J, Schulze M, Keir N. Assessment of contact lens comfort: Single report scores vs cumulative comfort Asian Cornea and Contact Lens Conference, Hong Kong, 2016

Liu S, Dozois M, Chang C, Hileeto D, Liang H, Reyad M, Boyd S, Jones L, Gu F. Mucoadhesive nanoparticle eye drop platform: tracking of ocular retention and treatment of experimental dry eye Invest Ophthalmol Vis Sci 2016;57: E-abstract 3990

Moezzi A, Fonn D, Hutchings N, Simpson T. Mixed model analysis of corneal deswelling following overnight wear of silicone hydrogel lenses Invest Ophthalmol Vis Sci 2016;57: E-abstract 1491 [ PDF ]

Moezzi A, Varikooty J, Luensmann D, Ng A, Schulze M, Karkkainen T, Xu J, Jones L. Open-eye clinical performance of etafilcon a multifocal daily disposable hydrogel contact lenses compared to habitual silicone hydrogel lens wear Optom Vis Sci 2016;93: E-abstract 165259 [ PDF ]

Mohammadi S, Jones L, Gorbet M. Ocular drug release models: comparisons between in vitro cell, dynamic release, and fixed volume models 10th World Biomaterials Congress, Montreal, 2016

Muntz A, Subbaraman L, Jones L. Is there an association between lid wiper epitheliopathy, lens type and contact lens discomfort? Optom Vis Sci 2016;93: E-abstract 160047

Ngo W, Jones L, Srinivasan S, Bitton E. Discomfort over Time Associated with various Ocular Demodex Treatment Products Invest Ophthalmol Vis Sci 2016;57: E-abstract 2838 [ PDF ]

Ngo W, Srinivasan S, Jones L. Comparison of dry eye tests between symptomatic and asymptomatic age-matched females Optom Vis Sci 2016;93: E-abstract 165089 [ PDF ]

Phan C-M, Walther H, Riederer D, Smith R, Subbaraman L, Jones L. Determination of the release of wetting agents from nelfilcon a using a novel in vitro eye model Optom Vis Sci 2016;93: E-abstract 165114 [ PDF ]

Phan C, Bajgrowicz M, Subbaraman L, Jones L. Release of moxifloxacin from daily disposable contact lenses using an in vitro eye model: Impact of artificial tear fluid composition and mechanical rubbing Invest Ophthalmol Vis Sci 2016;57: E-abstract 1474 [ PDF ]

Qiao H, Phan C-M, Walther H, Subbaraman L, Jones L. Localizing lysozyme deposition on contact lenses using a novel in vitro eye model Optom Vis Sci 2016;93: E-abstract 160100

Schulze M, Wong A, Haider S, Ebare K, Fadli Z, Coles-Brennan C, Jones L. Blink rate in silicone hydrogel contact lens wearers during digital device use Optom Vis Sci 2016;93: E-abstract 165122 [ PDF ]

Stahl U, Keir N, Guthrie S, Jones L. Effect of monocular lens wear on ocular comfort TFOS conference, Montpelier, France, 2016

Subbaraman L, Omali N, Lada M, Canavan K, Fadli Z, Jones L. An in-vitro lipid uptake model to predict ex-vivo lipid depostion on worn silicone hydrogel contact lenses Optom Vis Sci 2016;93: E-abstract 160099

Subbaraman L, Omali N, Lada M, Canavan K, Fadli Z, Jones L. An in-vitro lipid uptake model to predict ex-vivo lipid deposition on worn silicone hydrogel contact lenses TFOS conference, Montpelier, France, 2016

Subbaraman L, Suko A, Omali N, Riederer D, Scales C, Fadli Z, Jones L. Polar and non-polar lipid deposition on monthly replacement contact lens materials Optom Vis Sci 2016;93: E-abstract 165119

Walther H, Phan C-M, Qiao H, Liu Y, Subbaraman L, Jones L. In vitro eye model to simulate the impact of blinking on contact lens deposition and drug delivery Optom Vis Sci 2016;93: E-abstract 160101

Walther H, Phan C, Subbaraman L, Jones L. Cholesterol Penetration into Daily Disposable Contact Lenses Using a Novel In Vitro Eye-Blink Model Invest Ophthalmol Vis Sci 2016;57: E-abstract 1476 [ PDF ]

Yang M, Luensmann D, Fonn D, Woods J, Gordon K, Jones L, Jones D. Myopia prevalence in canadian school children Optom Vis Sci 2016;93: E-abstract 165328 [ PDF ]

2015

Babaei Omali N, Subbaraman L, Coles-Brennan, Fadli Z, Jones L. Selective uptake of lysozyme by various hydrogel contact lens materials Invest Ophthalmol Vis Sci 2015;56: E-abstract 6109 [ PDF ]

Bajgrowicz M, Phan C, McCanna D, Subbaraman L, Jones L. Effects of antifungal soaked silicone hydrogel contact lenses on Candida albicans in an agar eye model ISCLR Budapest, Hungary, 2015

Bajgrowicz M, Phan C, Subbaraman L, Jones L. Release of ciprofloxacin and moxifloxacin from daily disposable contact lenses using an in vitro eye model Invest Ophthalmol Vis Sci 2015;56: E-abstract 6085 [ PDF ]

Bitton E, Kronish S, Bouchard J-F, Jones L. The impact of hand rinsing time on soap residue left on the surface of silicone hydrogel CL Optom Vis Sci 2015;92: E-Abstract 155255

Dantam J, Heynen M, Coles-Brennan C, Fadli Z, Subbaraman L.  Kinetics of lysozyme sorption by various contact lens materials over short time periods BCLA Clinical Conference and Exhibition, 2015 [ PDF ]

Dantam J, Heynen M, Dominici C, Subbaraman L, Coles-Brennan C, Fadli Z, Jones L. Qualitative asymmetric mapping of lysozyme deposited on various contact lens materials using confocal laser scanning microscopy Invest Ophthalmol Vis Sci 2015;56: E-abstract 6091 [ PDF ]

Guthrie S, Dumbleton K, Jones L. Is there a relationship between care system and compliance? BCLA Clinical Conference and Exhibition, 2015 [ PDF ]

Guthrie S, Woods J, Dumbleton K, Fonn D, Jones L. Contact lens discomfort management strategies of ECPs Optom Vis Sci 2015;92: E-abstract 155050 [ PDF ]

Jones L, Babaei Omali N, Heynen M, Coles-Brennan C, Fadli Z, Subbaraman L. Determining qualitative and quantitative uptake of lysozyme by various contact lens materials BCLA Clinical Conference and Exhibition, 2015 [ PDF ]

Keir N, Srinivasan S, Ngo W, Chamberlain P, Feng W, Jones L, McNally J. Impact of time of day and length of wear on contact lens discomfort Invest Ophthalmol Vis Sci 2015;56: E-abstract 6107

LeBlanc S, Verma M, Jones L, Gu F. Detecting bacteria colorimetrically on contact lens cases using immobilized gold nanoparticles Invest Ophthalmol Vis Sci 2015;56: E-abstract 2268

Liu S, Dozois M, Ng D, Chang C, Hileeto D, Jones L, Gu F. Weekly dosing regimen of eye drop formulations delivered through mucoadhesive nanoparticles enhances treatment of experimental dry eye Invest Ophthalmol Vis Sci 2015;56: E-abstract 5036

McCabe K, Piper S, Jones L, Papinski D, Fadli Z. In-vitro bacterial adhesion to silicone hydrogel contact lenses: Does a surface coating inhibit bacterial adhesion? Optom Vis Sci 2015;92: E-abstract 155249

McCabe K, Piper S, Jones L, Papinski D, Fadli Z. Bacterial Adhesion to Silicone Hydrogel and Conventional Hydrogel Lenses Optom Vis Sci 2015;92: E-abstract 150026

McCanna D, Oh S, Seo J, Coles_brennan C, Fadli Z, Subbaraman L. In vitro evaluation of the effect of lysozyme coated contact lenses on cell viability and inflammatory response BCLA Clinical Conference and Exhibition, 2015 [ PDF ]

McCanna D, Oh S, Seo J, Subbaraman L, Coles-Brennan C, Fadli Z, Jones L. Effect of Denatured Lysozyme on Human Corneal Epithelial Cells Invest Ophthalmol Vis Sci 2015;56: E-abstract 3511 [ PDF ]

Muntz A, vanDoorn K, Subbaraman L, Jones L. Impression cytology of the lid wiper area Invest Ophthalmol Vis Sci 2015;56: E-abstract 4432 [ PDF ]

Ng AY, Keech A, Jones L. Detection of Tear Film Osmolarity Changes After Use of a Hydroxypropyl Guar-Based Lubricating Eye Drop Invest Ophthalmol Vis Sci 2015;56: E-abstract 4429 [ PDF ]

Ngo W, Caffery B, Srinivasan S, Jones L. Effect of Lid Debridement-Scaling on Dry Eye Signs and Symptoms in Sjogren’s Syndrome Invest Ophthalmol Vis Sci 2015;56: E-abstract 2487 [ PDF ]

Ngo W, Srinivasan S, Jones L. The impact of an Eyelid Warming Device in the Management of Meibomian Gland Dysfunction Optom Vis Sci 2015;92: E-abstract 150013

Ngo W, Srinivasan S, Jones L, Bitton E. Enhancement of Clinical Observation of Demodex Folliculorum Optom Vis Sci 2015;92: E-abstract 155233 [ PDF ]

Panjwani F, Papinski D, Varikooty J, Woods J, Jones L. In-vivo dehydration of stenfilcon A and delefilcon A silicone hydrogel materials Optom Vis Sci 2015;92: E-abstract 155262 [ PDF ]

Panjwani F, Papinski D, Woods J, Jones L. In-vivo dehydration of omafilcon A and delefilcon A Optom Vis Sci 2015;92: E-abstract 155048 [ PDF ]

Phan C, Jones L, Subbaraman L, Bajgrowicz M. Release of fluconazole from daily disposable contact lenses using a novel in vitro eye model Invest Ophthalmol Vis Sci 2015;56: E-abstract 3085

Phan C, Walther H, Gao H, Bajgrowicz M, Subbaraman L, Jones L. Developing a novel in vitro eye-blink platform for drug delivery and deposition research ISCLR Budapest, Hungary, 2015

Schulze M, Luensmann D, Ng AY, Panjwani F, Srinivasan S, Jones L. The relationship between the positioning of multifocal contact lens optics and satisfaction with vision Optom Vis Sci 2015;92: E-abstract 155256 [ PDF ]

Schulze M, Srinivasan S, Hickson-Curran S, Toubouti Y, Cox S, Mirza A, Nichols J, Morgan P, Jones L. Comparisons between Age, Gender, Lens Type and Lid Wiper Epitheliopathy with Soft Contact Lens Comfort Invest Ophthalmol Vis Sci 2015;56: E-abstract 6069 [ PDF ]

Srinivasan S, Ngo W, Jones L. The Relief of Dry Eye Signs and Symptoms Using a Combination of Lubricants, Lid Hygiene and Ocular Nutraceuticals Invest Ophthalmol Vis Sci 2015;56: E-abstract 4465 [ PDF ]

Subbaraman L, Heynen M, McCanna D, Omali N, Jansen M, Fadli Z, Toubouti Y, Coles-Brennan C, Jones L . Impact of pigment presence in etafilcon A on in vitro interaction of lysozyme and impact on inflammatory biomarker release Optom Vis Sci 2015;92: E-abstract 150097

Subbaraman L, McCanna D, Oh S, Ng A, Coles-Brennan C, Fadli Z, Jones L. Lysozyme activity on contact lenses and the impact of denatured lysozyme on human corneal epithelial cells BCLA Clinical Conference and Exhibition, 2015 [ PDF ]

Subbaraman L, Ng A, Coles-Brennan C, Fadli Z, Jones L. Surface versus bulk activity of lysozyme deposited on soft contact lens materials Invest Ophthalmol Vis Sci 2015;56: E-abstract 3168

vanDoorn K, Subbaraman L, Lemp J, Maissa C, Jones L. A device to model pollen deposition on contact lenses Invest Ophthalmol Vis Sci 2015;56: E-abstract 6112 [ PDF ]

vanDoorn K, Subbaraman L, Lemp J, Maissa C, Jones L. Design and validation of a device for modeling pollen adhesion to contact lenses BCLA Clinical Conference and Exhibition, 2015 [ PDF ]

vanDoorn K, Subbaraman L, Lemp J, Maissa C, Jones L. Reversibility of pollen adhesion to contact lenses Optom Vis Sci 2015;92: E-abstract 150025

Walther H, Phan C, Subbaraman L, Jones L. Cholesterol Penetration into Daily Disposable Contact Lenses Using a Novel In Vitro Eye-Blink Model ISCLR Budapest, Hungary, 2015

Walther H, Subbaraman L, Jones L. Novel in vitro method to determine pre-lens tear break up time of hydrogel and silicone hydrogel contact lenses Invest Ophthalmol Vis Sci 2015;56: E-abstract 6105 [ PDF ]

2014

Babaei Omali N, Subbaraman L, Heynen M, Thangavelu M, Dare E, Canavan K, Fadli Z, Jones L. Protein Deposition on Senofilcon A Contact Lenses in Symptomatic and Asymptomatic Lens Wearers Optom Vis Sci 2014;91: E-abstract 145186 [ PDF ]

Babaei Omali N, Subbaraman L, Schulze M, Heynen M, Canavan K, Fadli Z, Jones L. Clinical Signs, Symptoms, Tear Film and Meibum Composition in Asymptomatic Senofilcon A Contact Lens and Spectacle Wearers Optom Vis Sci 2014;91: E-abstract 145185 [ PDF ]

Berntsen D, Hickson-Curran S, Jones L, Mathew J, Mirza A, Morgan P, Schulze M, Nichols J. Comparison of soft contact lens comfort using three contact lens materials and four contact lens solutions Invest Ophthalmol Vis Sci 2014;55: E-abstract 863

Berntsen D, Varikooty J, Nichols J, Mathew J, Jones L, Morgan P, Smith S, Hickson-Curran S, Toubouti Y. Soft contact lens wear time and subjective dryness using different contact lens materials and solutions Optom Vis Sci 2014;91: E-abstract 140085

Cheung S, Subbaraman L, Schmidt T, Jones L. Localization of full-length recombinant human proteoglycan 4 in commercial contact lenses using confocal microscopy Invest Ophthalmol Vis Sci 2014;55: E-abstract 6059 [ PDF ]

Cox S, Berntsen D, Chatterjee N, Hickson-Curran S, Jones L, Moezzi A, Morgan P, Nichols J. Eyelid margin characteristics associated with a large cohort of soft contact lens wearers Optom Vis Sci 2014;91: E-abstract 140080

Dantam, McCanna D, Subbaraman L, Lakkis C, Morgan P, Nichols J, Jones L. Microbial contamination of contact lens storage cases with the use of different contact lens care solutions and lens materials Invest Ophthalmol Vis Sci 2014;55: E-abstract 4675 [ PDF ]

Dillehay S, Woods J, Situ P, Guthrie S, Paynor R, Griffin R, Tyson M, Jones L. Comparison of Three Power Levels of A Novel Soft Contact Lens Optical Design to Reduce Suspected Risk Factors for the Progression of Juvenile Onset Myopia Invest Ophthalmol Vis Sci 2014;55: E-abstract 3637

Feng W, Woods J, Keir N, Chamberlain P. Subjective questionnaire data collection using two different scales Optom Vis Sci 2014;91: E-abstract 145054

Hall B, Jones L, Forrest J. The effect of lactoferrin on lysozyme deposition and activity on silicone hydrogel contact lenses Invest Ophthalmol Vis Sci 2014;55: E-abstract 6061 [ PDF ]

Heynen M, Trieu D, Lorentz H, Jones L. Comparing and optimizing cholesterol extraction from hydrogel and silicone hydrogel contact lens materials Invest Ophthalmol Vis Sci 2014;55: E-abstract 6058 [ PDF ]

Hui A, Jones L. Uptake and release of atropine and pirenzepine from commercial hydrogel and silicone hydrogel contact lens materials Optom Vis Sci 2014;91: E-abstract 140059

Hui A, Jones L. Material Properties of Antibiotic Releasing Contact Lenses Invest Ophthalmol Vis Sci 2014;55: E-abstract 4642 [ PDF ]

Hui A, Willcox M, Jones L. Material properties and antimicrobial efficacy of novel antibacterial silicone hydrogel contact lenses BCLA Clinical Conference and Exhibition, 2014 [ PDF ]

Jones L. Tune in or drop out BCLA Clinical Conference and Exhibition, 2014

Jones L, Dantam J, McCanna D, Subbaraman L, Morgan P, Nichols J, Lakkis C. Impact of different contact lens care solutions and lens materials on contact lens storage case contamination BCLA Clinical Conference and Exhibition, 2014 [ PDF ]

Liu S, Chang C, Verma M, Hileeto D, Muntz A, Stahl U, Woods J, Jones L, Gu F. Phenylboronic acid modified mucoadhesive nanoparticles facilitate weekly treatment of dry eye syndrome Invest Ophthalmol Vis Sci 2014;55: E-abstract 2160

Lorentz H, McCanna D, Subbaraman L, Jones L, Salapatek A, Soong F. Changes in cytokine expression for dry eye and non dry eye subjects exposed to a low humidity environmental exposure chamber Optom Vis Sci 2014;91: E-abstract 140106

Luensmann D, Situ P, Fonn D, Jones L. Evaluation of the Performance of a New Silicone Hydrogel Color Contact Lens Optom Vis Sci 2014;91: E-abstract 145179 [ PDF ]

McCanna D,Liu L, Seo J, Subbaraman L, Jones L. Assessment of the growth of Stenotrophomonas maltophilia, Elizabethkingia meningoseptica and Delftia acidovorans in contact lens cases and on recovery media Invest Ophthalmol Vis Sci 2014;55: E-abstract 6051

Moezzi A, Varikooty J, Schulze M, Ngo W, Lorenz K, Boree M. Open-eye corneal swelling with etafilcon A daily disposable hydrogel contact lenses compared to no lens wear BCLA Clinical Conference and Exhibition, 2014 [ PDF ]

Moezzi A, Varikooty J, Schulze M, Ngo W, Lorenz K, Jones L. Open Eye Corneal Swelling with 1-DAY ACUVUE® DEFINE™ and 1-DAY ACUVUE® DEFINE™ with Lacreon® compared to 1-DAY ACUVUE® MOIST® Invest Ophthalmol Vis Sci 2014;55: E-abstract 4672 [ PDF ]

Ngo W, Feng Y, Keir N, Simpson T. Selecting a Sensory Panel to Judge Contact Lens Discomfort Invest Ophthalmol Vis Sci 2014;55: E-abstract 4666 [ PDF ]

Ngo W, Srinivasan S, Feng Y, Keir N, Simpson T. Comparison of Two Sensory Panel Selection Strategies for Beginning and End of Day Lens Discomfort Optom Vis Sci 2014;91: E-abstract 140089

Payor R, Woods J, Fonn D, Situ P, Dillehay S, Griffin R, Tyson M, Jones L. Feasibility Testing of a Novel Soft Contact Lens Optical Design to Reduce Suspected Risk Factors for the Progression of Juvenile Onset Myopia Invest Ophthalmol Vis Sci 2014;55: E-abstract 3638

Phan C, Subbaraman L, Jones L. Delivery of natamycin using cyclodextrin functionalized contact lenses Invest Ophthalmol Vis Sci 2014;55: E-abstract 4643 [ PDF ]

Pucker A, Kwan J, Jones-Jordan L, Jones L, Lin Meng, Marx S, Srinivasan S, Li W, Sickenberger W. Factors Associated with Meibomian Gland Atrophy in Daily Contact Lens Wearers Optom Vis Sci 2014;91: E-abstract 140082

Schulze M, Luensmann D, Hickson-Curran S, Toubouti Y, Cox S, Plowright A, Nichols J, Morgan P, Jones L. Analysis of lid wiper epitheliopathy in habitual soft lens wearers Optom Vis Sci 2014;91: E-abstract 140104

Schulze M, Srinivasan S, Hickson-Curran S, Bemsten D, Howarth G, Nichols J, Morgan P, Jones L. Upper lid margin staining with different soft contact lenses and lens care solution combinations BCLA Clinical Conference and Exhibition, 2014 [ PDF ]

Schulze M, Subbaraman L, Babaei Omali N, Stahl U, Canavan K, Jones L. Is there a difference between clinical signs and symptoms in asymptomatic adapted contact lens and spectacle wearers? BCLA Clinical Conference and Exhibition, 2014 [ PDF ]

Soong F, Lorentz H, Subbaraman L, Jones L, Salapatek A. The Controlled Low Humidity Environmental Exposure Chamber (LH-EEC) is a sensitive and specific tool for study of the Signs and Symptoms of Dry Eye (DE) versus Non-Dry Eye (NDE) Participant Invest Ophthalmol Vis Sci 2014;55: E-abstract 2016

Srinivasan S, Pucker A, Jones-Jordan L, Li W, Kwan J, Sickenberger W, Marx S, Lin M, Jones L. Meibomian Gland Atrophy Rate in Pre-presbyopic Contact Lens and Non-Contact Lens Wearers Optom Vis Sci 2014;91: E-abstract 140081

Srinivasan S, Schulze M, Hickson-Curran S, Berntsen D, Howarth G, Nichols J, Morgan P, Jones L. Comparison of upper lid margin staining with different soft contact lens materials and care product combinations Invest Ophthalmol Vis Sci 2014;55: E-abstract 4673 [ PDF ]

Stahl U, Luensmann D, Lemp J, Moezzi A, Schulze M, Varikooty, Dumbleton K, Jones L. Determination of higher order aberrations with two silicone hydrogel toric lenses Optom Vis Sci 2014;91: E-abstract 145188 [ PDF ]

Subbaraman L, Babaei Omali N, Heynen M, Lada M, Canavan K, Jones L. Could lipid deposition on contact lenses be beneficial? BCLA Clinical Conference and Exhibition, 2014

Subbaraman L, Babaei Omali N, Heynen M, Lakkis C, Morgan P, Bertsen D, Nichols J, Jones L. Impact of different lens care solutions on protein deposition on various soft contact lenses: A multicenter study Optom Vis Sci 2014;91: E-abstract 140057

Subbaraman L, McCanna D, Lorentz H, Soong F, Salapatek A, Jones L. Tear Cytokines in Non-Dry Eye and Dry Eye Participants After Exposure to a Low Humidity Environmental Exposure Chamber Invest Ophthalmol Vis Sci 2014;55: E-abstract 3682

Subbaraman L, Stahl U, Heynen M, Babaei Omali N, Canavan K, Jones L. Is there a difference in tear film and meibum composition in asymptomatic adapted contact lens and spectacle wearers? BCLA Clinical Conference and Exhibition, 2014 [ PDF ]

Varikooty J, Woods J, Jones L. Assessment of pre-lens tear film particle velocity measurements in participants wearing daily disposable silicone hydrogel lenses BCLA Clinical Conference and Exhibition, 2014 [ PDF ]

Verma M, Chen P, Jones L, Gu F. Gold nanostars for the colorimetric detection of emerging bacterial contaminants that affect contact lens wearers Invest Ophthalmol Vis Sci 2014;55: E-abstract 2158

Walther H, Subbaraman L, Wettig S, Jones L. In vitro surface pressure measurements of various tear film lipids Invest Ophthalmol Vis Sci 2014;55: E-abstract 43 [ PDF ]

2013

Cheung S, Lorentz H, Drolle E, Leonenko Z, Jones L. Contact lens solution efficacy at removing in vitro tear film constituents from silicone hydrogel contact lenses: An atomic force microscopy study Optom Vis Sci 2013;90: E-Abstract 135010

Cheung S, Lorentz H, Drolle E, Leonenko Z, Jones L. Contact lens solution efficacy at removing in vitro tear film constituents from silicone hydrogel contact lenses: An atomic force microscopy study Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Dare E, Subbaraman L, Jones L. Effects of environmental changes on in vitro corneal epithelial wound healing Contact Lens & Anterior Eye 2013;36, S2:e20

Dare E, Subbaraman L, Jones L. Impact of environmental changes on in vitro corneal epithelial wound healing Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Dare E, Subbaraman L, Jones L. Impact of environmental changes on in vitro corneal epithelial wound healing Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

Dumbleton K, Richter D, Jones L, Fonn D. Eye examination frequency and contact lens purchase patterns Optom Vis Sci 2013;90: E-Abstract 135126

Dumbleton K, Richter D, Woods C, Aakre B, Plowright A, Jones L. A multi-country assessment of compliance with daily disposable contact lens wear Contact Lens & Anterior Eye 2013;36, S2:e12

Dumbleton K, Richter D, Woods C, Morgan P, Aakre BM, Jones L. Wearing and replacement patterns of patients using daily disposable contact lenses Optom Vis Sci 2013;90: E-Abstract 135767

Flanagan J, Stavropoulos A, Luensmann D, Postnikoff C, Gorbet M. Comparison of the Cellular Response to Overnight Contact Lens Wear on the Sclera and Cornea Invest Ophthalmol Vis Sci 2013;54:E-abstract 5654

Gorbet M, Luensmann D, Jones L. The response of tear film neutrophils to occasional overnight lens wear Invest Ophthalmol Vis Sci 2013;54: E-Abstract 2069

Gu F, Liu S, Jones L. Long-lasting eye drop delivery platform for targeted ocular delivery applications Invest Ophthalmol Vis Sci 2013;54: E-Abstract 1074

Hall B, Phan C, Subbaraman L, Jones L, Forrest J. Extraction versus in situ techniques for measuring surface adsorbed lysozyme Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Hall B, Phan C, Subbaraman L, Jones L. Forrest J. Direct comparison between in situ versus extraction techniques for measuring absorbed proteins: Application to lysozome deposited onto hydrogel contact lenses Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5467

Hui A, Jones L. Uptake and release of ciprofloxacin and dexamethasone from commercial contact lens materials Invest Ophthalmol Vis Sci 2013;54: E-Abstract 1086

Hui A, Jones L. Release of ciprofloxacin and dexamethasone from commercial contact lens materials Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Hui A, Willcox M, Jones L. In vitro evaluation of antimicrobial activity of novel ciprofloxacin releasing silicone hydrogels Optom Vis Sci 2013;90: E-Abstract130748

Hui A, Willcox M, Jones L. In vitro evaluation of the antimicrobial properties of a novel silicone hydrogel material designed for the sustained release of the antibiotic ciprofloxacin NSERC 20/20 Meeting, 2013

Hui A, Willcox M, Jones L. In vitro evaluation of the antimicrobial properties of a novel silicone hydrogel material designed for the sustained release of the antibiotic ciprofloxacin ISCLR conference, Kyoto, Japan, 2013

Jayakumar V, Hutchings N, Lakshminarayanan V, Jones L. Analysis of interocular surface aberrations using surface aberrometry Invest Ophthalmol Vis Sci 2013;54: E-Abstract 2608

Jones L. A report card on hydrogel contact lens materials: Where are we and what's new and novel? Contact Lens & Anterior Eye 2013;36, S2:e9

Jones L. Contact lens materials, design, and care Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

Jones L. A report card for silicone hydrogel contact lens materials: Pass or fail? Canadian Biomaterials Society Meeting, Ottawa, Canada, 2013

Jones L, Brennan N, Gonzalez-Meijome, Lally J, Maldonado-Codina C, Schmidt T, Subbaraman L, Young G. Contact lens materials, design and solutions: Relationship to contact lens discomfort Tear Film & Ocular Surface Society meeting, Seattle, US, 2013

Jones L, Hui A. Release of ciprofloxacin and dexamethasone from commercial contact lens materials Contact Lens & Anterior Eye 2013;36, S2:e38

Jones L, Hui A. Antibiotic drug delivery via contact lenses 20/20 NSERC ophthalmic materials conference, Niagara Falls, Canada, 2013

Jones L, Varikooty J, Keir N, Soong F, Patel P. The evaluation of lid wiper epitheliopathy in contact lens wearers in a controlled low humidity enivironmental exposure chamber Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

Jones L, Varikooty J, Keir N, Soong F, Patel P. The evaluation of lid wiper epitheliopathy in contact lens wearers in a controlled low humidity environmental exposure chamber Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5475

Korogiannaki M, Jones L, Sheardown H. Simultaneous release of a wetting agent and a therapeutic agent from model silicone hydrogel materials used for extended ocular drug delivery Canadian Biomaterials Society Meeting, Ottawa, Canada, 2013

Liu S, Jones L, Gu F. Long lasting front-of-the-eye drug delivery system: treatment of experimental dry eye NSERC 20/20 Meeting, 2013

Liu S, Jones L, Gu F. Mucoadhesive nanoparticles for topical ocular drug delivery Canadian Biomaterials Society Meeting, Ottawa, Canada, 2013

Liu S, Verma M, Jones L, Gu F. Long-lasting eye drop delivery platform for targeted ocular delivery applications International Conference on Bioencapsulation, Berlin, Germany, 2013

Lorentz H, Guidi G, Jones L, Sheardown H. Lipid adherence to model contact lens materials Invest Ophthalmol Vis Sci 2013;54: E-Abstract 512

Lorentz H, Sheardown H, Jones L. Lipid adherence to model contact lens materials 20/20 NSERC ophthalmic materials conference, Niagara Falls, Canada, 2013

McCanna D, Chang J, Subbaraman L, Jones L. Efficacy of contact lens solutions against Achromobacter xylosoxidans biofilms using confocal microscopy Invest Ophthalmol Vis Sci 2013;54: EAbstract 523

McCanna D, Chang J, Subbaraman L, Jones L. Efficacy of contact lens solutions against Achromobacter xylosoxidans biofilms using confocal microscopy Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

McCanna D, Chang J, Subbaraman L, Jones L. Efficacy of contact lens solutions against Achromobacter xylosoxidans biofilms using confocal microscopy Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

McCanna D, Jones L. The effect of contact lens solutions on membrane permeability of Staphylococcus aureus aggregates Contact Lens & Anterior Eye 2013;36, S2:e40-e41

McCanna D, Jones L. Membrane permeability of staphylococcus aureus aggregates exposed to contact lens care solutions Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

McCanna D, Jones L. Membrane permeability of staphylococcus aureus aggregates exposed to contact lens care solutions Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

Moezzi A, Richter D, Varikooty J, Simpson T. A Novel Method for removing inter-observer Bias in Optical Pachometry 8th Canadian Optometry Schools Research Conference (COSRC), 2013

Mohammadi S, Jones L, Gorbet M. Investigation of Latanoprost release from contact lens materials using in vitro cell models Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5472

Mohammadi S, Jones L, Gorbet M. In vitro cell models for drug release studies from contact lenses Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Ngo W, Srinivasan S, Schulze M, Jones L. Inter- and intra-observer agreement and repeatability of imaging the meibomian glands with the oculus Keratograph 4 and Keratograph 5M Invest Ophthalmol Vis Sci 2013;54: E-Abstract 3569 [ PDF ]

Ngo W, Srinivasan S, Schulze M, Jones L. Inter- and intra-observer agreement using infrared meibography systems Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Ngo W, Srinivasan S, Schulze M, Jones L. Inter- and intra-observer agreement and repeatability of imaging the meibomian glands with the Oculus Keratograph 4 and Keratograph 5M Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

Otchere H, Sorbara L, Jones L. Repeatability and accuracy of the Oculus Pentacam HR corneal topographer in measuring radius of curvature and shape factor Global Specialty Lens Symposium, Las Vegas, USA, 2013

Otchere H, Sorbara L, Jones L . Fitting semi-scleral contact lenses using corneal sagittal depth measurements and evaluation of visual acuity and comfort ratings Optom Vis Sci 2013;90: E-Abstract 130968.

Patel P, Soong F, Salapatek AM, Varikooty J, Keir N, Jones L. Ocular signs and symptoms in contact lens wearers in a controlled low humidity environmental exposure chamber (LH-EEC) a natural provocation research model Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

Patel P, Soong F, Varikooty J, Keir N, Jones L. Ocular signs and symptoms in contact lens wearers in a controlled low humidity environmental exposure chamber (LH-EEC), a natural provocation research model Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5473

Phan C, Lui S, Gu F, Jones L. In vitro uptake and release of Natamycin dex-b-PLA nanoparticles from silicone hydrogel contact lens materials 20/20 NSERC ophthalmic materials conference, Niagara Falls, Canada, 2013

Phan C, Subbaraman L, Jones L. Delivery of natamycin using cyclodextrin functionalized contact lenses NSERC 20/20 Meeting, 2013

Phan C, Subbaraman L, Jones L, Liu S, Gu F. In vitro uptake and release of natamycin dex-b-pla nanoparticles from silicone hydrogel contact lens materials Invest Ophthalmol Vis Sci 2013;54: E-Abstract 501

Phan C, Subbaraman L, Liu S, Gu F, Jones L. Drug delivery of natamycin from contact lens materials using Dex-b-PLA nanoparticles ISCLR conference, Kyoto, Japan, 2013

Phan C, Subbaraman L, Liu S, Gu F, Jones L. In vitro uptake and release of natamycin Dex-b-PLA nanoparticles from silicone hydrogel contact lens materials Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Salapatek AM, Soong F, Varikooty J, Keir N, Jones L, Patel P. In-vivo wettability of contact lenses worn in a low humidity environmental exposure chamber (LH-EEC) show comparable changes to traditional field trials Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

Samsom M, Chan A, Jones L, Schmidt T. PRG4 as a natural boundary lubricant for commerical silicone hydrogel contact lenses Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5468

Schulze M, Simpson T, Situ P, Menzies K, Walther H, Jones L. Effects of magnification on tear meniscus parameters using optical coherence tomography (OCT) images Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Soong F, Varikooty J, Keir N, Jones L, Patel P. In-vivo wettability of contact lenses worn in a low humidity environmental exposure chamber (LH-EEC) show comparible changes to traditional field trials Invest Ophthalmol Vis Sci 2013;54: E-Abstract 499

Srinivasan S, Keech A, Keir N, Jones L. Self vs. examiner-guided administration of ocular surface disease index (OSDI) Optom Vis Sci 2013;90: E-Abstract 130001

Srinivasan S, Keech A, Keir N, Jones L. Self vs. examiner-guided administration of ocular surface disease index (OSDI) Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Srinivasan S, Menzies K, Jones L. Infra-red imaging of meibomian glands & evaluation of the lipid layer in Sjogren’s syndrome patients Invest Ophthalmol Vis Sci 2013;54: E-Abstract 6012

Srinivasan S, Menzies K, Jones L. Meibography and lipid layer evaluation in sjogern's syndrome patients Contact Lens & Anterior Eye 2013;36, S2:e45

Srinivasan S, Menzies K, Jones L. Meibography and lipid layer evaluation in Sjogren’s syndrome Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Srinivasan S, Menzies K, Jones L. Infra-red imaging of meibomian glands & evaluation of the lipid layer in Sjogren’s syndrome patients Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

Stahl U, Keir N, Varikooty J, Nandakumar K, Keech A, Landers A, Jones L. The effect of recovery periods on end of day comfort Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5462

Subbaraman L, Martell E, Heynen M, Ng A, Jones L. Kinetic activity of lysozyme when exposed to two differing contact lens care systems Optom Vis Sci 2013;90: E-Abstract 130015

Subbaraman L, Mistry R, Thangavelu M, Jones L. Quantification of lipocalin-1 in tears and contact lens deposits using a sandwich ELISA technique Contact Lens & Anterior Eye 2013;36, S2:e45-e46

Subbaraman L, Mistry R, Thangavelu M, Jones L. Quantification of lipocalin-1 in tears and contact lens deposits using a sandwich elisa technique Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

Subbaraman L, Thangavelu M, McCanna D, Jones L. Tear film cytokine analyses using a novel electrochemiluminescent array technique Invest Ophthalmol Vis Sci 2013;54: E-Abstract 4325

Subbaraman L, Thangavelu M, McCanna D, Jones L. Tear film cytokine analyses using a novel electrochemiluminescent array technique Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Subbaraman L, Thangavelu M, McCanna D, Jones L. Quantification of lipocalin-1 in tears and contact lens deposits using a sandwich elisa technique Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Subbaraman L, Thangavelu M, McCanna D, Jones L. Quantifying tear film inflammatory markers using a novel, multiplex electrochemiluminescent technique Tear Film & Ocular Surface International Conference, Sicily, Italy, 2013

Subbaraman L, Thangavelu M, McCanna, Jones L. A novel, multiplex electrochemiluminescent technique to quantify tear film inflammatory markers Contact Lens & Anterior Eye 2013;36, S2:e45

Subbaraman L, Walther H, Kay L, Jones L. In vitro efficiency of contact lens care solutions in removing cholesterol deposits from silicone hydrogel contact lenses Contact Lens & Anterior Eye 2013;36, S2:e41

Varikooty J , Lay B, Keir N, Burdin H, Jones L, Simpson T, Lemp J. The relationship between clinical grading and objective image analysis of lid wiper epitheliopathy Invest Ophthalmol Vis Sci 2013;54: E-Abstract 5460

Verma M, Lehtovaara B, Jones L, Gu F. Beta-glucans for developing multifunctional drug delivery platforms International Conference on Bioencapsulation, Berlin, Germany, 2013

Walther H, Subbaraman L, Jones L. Efficacy of multi-purpose solutions in removing cholesterol desposits from silicone hydrogel contact lenses Invest Ophthalmol Vis Sci 2013;54: E-Abstract 517

Walther H, Subbaraman L, Jones L. Method optimization to quantify oxidative stress in tear film lipids Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

Woods J, Subbaraman L, Jones L. In-vitro wettability of four silicone hydrogel lenses with differing surface properties Contact Lens & Anterior Eye 2013;36, S2:e29

Woods J, Woods C, Foon D, Jones L. Acceptance of a silicone hydrogel multifocal lens in emmetropic presbyopes Canadian Optometry Schools Research Conference, Waterloo, Canada, 2013

2012

Caffery B, Joyce E, Heynen M, Ritter R, Jones L, Senchyna M. TNF-Alpha MRNA expression in aqueous deficient dry eye Optom Vis Sci 2012;89:E-abstract 120007

Dumbleton K, Richter D, Jones L. Compliance with lens replacement and the interval between eye examinations Optom Vis Sci 2012;89:E-abstract 120059

Dumbleton K, Woods C, Moezzi A, Fonn D, Jones L. The influence of masked lens replacement on subjective comfort and vision with aging soft contact lenses Contact Lens & Anterior Eye 2012;35, S1:e38

Dumbleton K, Woods CA, Woods J, Moezzi A, Fonn D, Jones L. An Investigation Into The Role Of Masked Lens Replacement On Subjective Comfort And Vision With Aging Soft Contact Lenses Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 4722

Fonn D, Holden B, Moezzi A, Lazon de la Jara P, La Hood D, Richter D. Overnight Corneal Swelling (ONCS) of the Contralateral Non-Lens Wearing Eye is affected by the amount of ONCS in the Lens Wearing Eye American Academy of Optometry, 2012

Fonn D, Situ P, Paquette L, Keir N, Dillehay S. Extra-curricular Activities Of Myopic Children Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 4722

Gorbet M, Cira D, Peterson R, Woods C, Luensmann D. The acute effect of benzalkonium chloride and sodium fluorescein on epithelial cells collected from the human ocular surface Contact Lens & Anterior Eye 2012;35, S1:e22-e23

Gorbet M, Luensmann D, Luck S, Jones L. Response Of Tear Film Neutrophils To Different Stimuli Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 5271

Gorbet M, Mohammadi S, Jones L. Investigation of drug-release materials using in vitro cell models 2020 NSERC ophthalmic materials conference, Burlington, Canada, 2012

Hall B, Jones L, Forrest J. Measuring The Kinetics and Activity of Adsorbed Proteins: In Vitro Lysozyme Deposited Onto Contact Lenses Over Short Time Periods Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 6125

Holden B, Fonn D, La Hood D, Moezzi A, Richter D, Lazon de la Jara P. Revised Estimate of the Oxygen Transmissibility Needed to produce Same Level of Overnight Corneal Swelling as that which occurs when No Lens is worn American Academy of Optometry, 2012

Hutchings N, Jayakumar V, Srinivasan S, Trusit D, Keir N, Jones L. Comparison of anterior surface aberrations between subjects with clinically stable and unstable tear films Optom Vis Sci 2012;89:E-abstract 125122

Jerchel N, Sickenberger W, Schulze M. Objective classification and documentation of bulbar redness using a corneal topographer Contact Lens & Anterior Eye 2012;35, S1:e18

Jones D, Paquette L, Despres M, Nandakumar K, Woods C. Ease of contact lens fitting and training in a child and youth population Contact Lens & Anterior Eye 2012;35, S1:e2

Jones D, Woods C, Paquette L, Nandakumar K. The acceptability of contact lens wear to children and teenagers Contact Lens & Anterior Eye 2012;35, S1:e45-e46

Jones L, Keir N. Comfort from a different view Materials Science and Chemistry of Contact Lenses, New Orleans, 2012

Keir N, Richter D, Varikooty J, Jones L, Woods C, Fonn D. End Of Day Comfort Interpreted Using A Novel Cumulative Comfort Score Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 4728

Keir N, Richter D, Varikooty J, Jones L, Woods C, Fonn D. End of day comfort interpreted using a novel cumulative comfort score for symptomatic contact lens wearers Contact Lens & Anterior Eye 2012;35, S1:e37

Keir N, Varikooty J, Richter D, Jones L, Woods C, Fonn D. Evaluation of lens surface appearance and ocular physiology with three silicone hydrogel daily disposables Contact Lens & Anterior Eye 2012;35, S1:e6

Lorentz H, Heynen M, Khan W, Trieu D, Jones L. The Impact of Intermittent Air Exposure on the Deposition of Lipids on Silicone Hydrogel and Conventional Hydrogel Contact Lens Materials Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 3412

Luensmann D, Srinivasan S, Ochtere H, Yu M, Yang G, Jones L. The impact of cosmetics on the physical dimension and optical performance of silicone hydrogel contact lenses Contact Lens & Anterior Eye 2012;35, S1:e6

Maram J, Sorbara L, Simpson T. Conjunctival effects and blood flow changes related to silicone hydrogel lens wear and their relationship with end of day comfort Contact Lens & Anterior Eye 2012;35, S1:e19

McCanna D, Jones L. Membrane Permeability Of Staphylococcus Aureus Aggregates Exposed To Contact Lens Care Solutions Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 6089

Menzies K, Jones L. Sessile drop contact angle analysis of hydrogel and silicone hydrogel daily disposable and frequent replacement contact lenses Contact Lens & Anterior Eye 2012;35, S1:e12-e13

Menzies K, Subbaraman L, Jones L. In vitro wettability comparison of hydrogel and silicone hydrogel daily disposable and frequent replacement contact lenses Optom Vis Sci 2012;89:E-abstract 125032

Mohammadi S, Gorbet M. Design and Development of an In Vitro Tear Replenishment System Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 6109

Ng A, Heynen M, Subbaraman L, Jones L. Optimization of a novel fluorescent based lysozyme activity assay for contact lens studies Optom Vis Sci 2012;89:E-abstract 120052

Phan C, Jacob J, Subbaraman L, Jones L. Visualizing the uptake and release of natamycin from commercial contact lenses using confocal microscopy 2020 NSERC ophthalmic materials conference, Burlington, Canada, 2012

Schulze M, Varikooty J, Keir N, Jones L. The clinical performance of three contact lens solutions in symptomatic and asymptomatic contact lens wearers Contact Lens & Anterior Eye 2012;35, S1:e8

Situ P, McCanna D, Gorbet M, Jones L. Confocal Imaging Of Hyper-reflective Corneal Epithelial Cells During And After Contact Lens Wear Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 4698

Soluri A, Hui A, Jones L. Ocular Delivery Of Ketotifen Fumarate By Silicone Hydrogel And Conventional Hydrogel Contact Lens Materials Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 6101

Sorbara L, Dalton K. Use of MSD mini-scleral lens for patient with INTACS: Case Report GSLS, 2012

Srinivasan S, Luensmann D, Otchere H, Yu M, Yang J, Jones L. The impact of cosmetics on the surface appearance and wettability of silicone hydrogel contact lenses Optom Vis Sci 2012;89:E-abstract 120317

Srinivasan S, Menzies K, Sorbara L, Jones L. Infra-red Imaging Of Meibomian Gland Structure Using A Novel Keratograph Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 591

Srinivasan S, Menzies K, Sorbara L, Jones L. Non-contact meibography using a novel keratograph Contact Lens & Anterior Eye 2012;35, S1:e31-e32

Srinivasan S, Menzies K, Sorbara L, Jones LW. Appearance of meibomian gland structures imaged using a Keratograph Global Specialty Lens Symposium, 2012

Subbaraman L, Sheardown H, Jones L. Incorporating novel agents to improve the wettability of contact lens materials Materials Science and Chemistry of Contact Lenses, New Orleans, 2012

Subbaraman LN. What influences contact lens-related dry eye? Netherlands Contact Lens Congress (Amsterdam, Netherlands), 2012

Subbaraman LN. Bacterial adhesion to contact lens materials Netherlands Contact Lens Congress (Amsterdam, Netherlands), 2012

Subbaraman LN. Contact lens multipurpose solutions composition Netherlands Contact Lens Congress (Amsterdam, Netherlands), 2012

Varikooty J, Keir N, Jones L. Optimization of assessment and grading for lid wiper epitheliopathy Optom Vis Sci 2012;89:E-abstract 120241

Varikooty J, Keir N, Richter D, Jones L, Woods C, Fonn D. Subjective comfort with three silicone hydrogel daily disposables in symptomatic contact lens wearers Contact Lens & Anterior Eye 2012;35, S1:e7-e8

Varikooty J, Keir N, Simpson T. Estimating in vivo contact lens wettability through tear film hydrodynamics Contact Lens & Anterior Eye 2012;35, S1:e31

Varikooty J, Keir N, Simpson T. Estimating in-vivo Contact Lens Wettability Through Tear Film Hydrodynamics Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 6098

Walther H, Subbaraman L, Jones L. In Vitro Dehydration of Daily Disposable and Silicone Hydrogel Contact Lens Materials Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 6121

Woods C, Keir N, Woods M, Jones L. A new video-based tool for grading clinical observations of soft lens surface deposits Contact Lens & Anterior Eye 2012;35, S1:e37-e38

Woods C, Keir N, Woods M, Jones L. The Development Of A New Grading Scale For In Vivo Front Surface Contact Lens Deposits Invest Ophthalmol Vis Sci 2012;53:ARVO E-Abstract 4700

Woods J, Keir N, Jones L. Solution-induced-corneal-staining (SICS): symptoms and staining patterns Optom Vis Sci 2012;89:E-abstract 125625

Woods J, Keir N, Jones L. The impact of saline rinsing on solution-induced corneal staining (SICS) Contact Lens & Anterior Eye 2012;35, S1:e36-e37

2011

Anderson T, Moezzi A, Varikooty J, Jones L, Woods C, Fonn D. A novel method for measuring contact lens movement and centration using a high speed camera and computer vision Optom Vis Sci 2011;88:E-abstract 115439

Basuthkar S, Simpson T, Fonn D. Correlates of Subjective and Objective Measures of Ocular Discomfort Invest Ophthalmol Vis Sci 2011;52:ARVO E-Abstract 1970

Dumbleton K. The patient; the weakest link? Contact Lens & Anterior Eye 2011;34, S1:S5

Dumbleton K. The BCLA and me: a contact lens autobiography Contact Lens & Anterior Eye 2011;34, S1:S8

Dumbleton K, Woods C, Fonn D, Jones L. An internet based survey to investigate lapsed contact lens wearers in Canada International Society for Contact Lens Research (Napa Valley, California), 2011

Dumbleton K, Woods C, Jones L, Fonn D. Comparing contact lens compliance and complications in a university clinic with private optometry offices Optom Vis Sci 2011;88:E-abstract 110257

Dumbleton K, Woods C, Jones L, Fonn D. A survey to investigate lapsed contact lens wearers in Canada Optom Vis Sci 2011;88:E-abstract 110416

Fisher G, Leung T, Luensmann D, Heynen M, Jones L. 3D TOF-SIMS characterisation of drug-loaded silicone hydrogel contact lenses in the frozen hydrated state 18th SIMS Conference (Trentino, Italy), 2011

Gorbet M, Tanti N, Jones L. Impact of contact lens solution/material combinations on corneal epithelial cells in vitro International Society for Contact Lens Research (Napa Valley, California), 2011

Guthrie S, Woods J, Keir N, Dillehay S, Tyson M, Griffin R, Fonn D, Jones L, Irving E. Controlling lens induced myopia in chickens with peripheral lens design Optom Vis Sci 2011;88:E-Abstract 110421

Hui A, Boone A, Jones L. Uptake and Release of Ciprofloxacin and Dexamethasone from Commercially Available Conventional and Silicone Hydrogel Materials 15th Symposium on the Material Science and Chemistry of Contact Lenses (New Orleans, USA), 2011

Hui A, Sheardown H, Jones L. Molecular imprinted silicone hydrogel materials for ciprofloxacin drug delivery Optom Vis Sci 2011;88: E-abstract 110429

Hui A, Sheardown H, Jones LW. Molecular Imprinted Silicone Hydrogels for Ciprofloxacin Drug Delivery International Society for Contact Lens Research (ISCLR) Meeting (Napa Valley, California), 2011

Hui A, Weeks A, Sheardown H, Jones L. Novel silicone hydrogel contact lens materials for ciprofloxacin drug delivery Invest Ophthalmol Vis Sci 2011;52:E-Abstract 6531

Jadi S, Heynen M, Luensmann D, Jones L. Incubation solution composition impacts in vitro protein uptake to silicone hydrogel contact lenses Optom Vis Sci 2011;88:E-abstract 110546

Jones L. Contact lens solutions: What do we really know? International Society for Contact Lens Research (Napa Valley, California), 2011

Jones L. Compliance: Just how bad is it? Contact Lens & Anterior Eye 2011;34, Supplement 1:S4

Jones L. The contact lens market today: An overview of trends 15th symposium on the Materials Science and Chemistry of Contact Lenses (New Orleans, USA), 2011

Jones L. Uptake and release of preservatives into soft lenses: Clinical implications Global Contact Lens Care Summit, Seatle, WA, 2011

Jones L, Lorrentz H, Walther H, Heynen M, Kay L. Impact of lipid concentration, exposure time and tear film components on in vitro model lipid deposition to silicone hydrogel and hydrogel contact lens materials International Society for Contact Lens Research (Napa Valley, California), 2011

Kao E, McCanna D, Jones L. In vitro model for determining the viability and strength of adhesion of human lens epithelial cells to silicone NSERC 2020 Network Meeting (Orllia, Ontario), 2011

Keir N, Woods C, Fonn D. The Impact Of Lens Wear On In Vivo Wettability Of Silicone Hydrogel Contact Lenses Invest Ophthalmol Vis Sci 2011;52:ARVO E-Abstract 6505

Lorentz H, Walther H, Heynen M, Kay L, Jones L. Radiochemical kinetic uptake of three lipids on silicone hydrogel and conventional hydrogel contact lens materials Invest Ophthalmol Vis Sci 2011;52:E-Abstract 6479

Lorrentz H, Khan W, Trieu D, Heynen M, Jones L. The effect of intermittent air exposure on the deposition of lipids on silicone hydrogel and conventional hydrogel contact lens materials NSERC 2020 Network Meeting (Orllia, Ontario), 2011

Lorrentz H, Khan W, Trieu D, Heynen M, Jones L. The effect of intermittent air exposure on the deposition of lipids on silicone hydrogel and conventional hydrogel contact lens materials International Society for Contact Lens Research (Napa Valley, California), 2011

Luensmann D, Keir N, Richter D, Woods C, Fonn D. In vivo wettability changes over 3 days using daily disposable contact lenses Optom Vis Sci 2011;88:E-abstract 115384

Maram J, Simpson T, Sorbara L, Bizheva K, Song ES. An apparent imaging artifact occurring at the edge of a contact lens when imaged with OCT; The underlying tissue appears erroneously discontinuous Invest Ophthalmol Vis Sci 2011;52: E-abstract 6540

Maram J, Simpson T, Sorbara L, Song ES, Hutchings N, Bizheva K. Lens edge artifact occurring when imaged with an ultra-high resolution optical coherence tomographer ISCLR Meeting , 2011

McCanna D, Mikkelsen S, Rahimi M, So F, Zhou Y, Sivak J, Jones L. Determining toxicity thresholds in ocular in vitro test batteries using benzalkonium chloride International Society for Contact Lens Research (Napa Valley, California), 2011

Moezzi A, Situ P, Luensmann D, Fonn D, Woods C, McNally J, Jones L. Does comfort with aging silicone hydrogel lenses relate to changes in lens fit and conjunctival staining? Optom Vis Sci 2011;88:E-abstract 115708

Muntz A, Lorentz H, Walther H, Heynen M, Joyce E, Sickenberger W, Jones L. Utility of a pulsating contact lens case to aid cholesterol removal from contact lens materials soaked in a no-rub MPS regimen Contact Lens & Anterior Eye 2011;34, S1:S9

Ng A, Heynen M, Jones L. The impact of lactoferrin and lipids on kinetic lysozyme deposition on contact lenses Optom Vis Sci 2011;88:E-abstract 110771

Paquette L, Jones D, Mespres M, Nandakumar K, Woods C. Ease of contact lens fitting and training in a child and youth population Optom Vis Sci 2011;88:E-abstract 115833

Robinson B, Feng Y, Fonn D, Woods C, Gordon K, Gold D. Risk Factors For Visual Impairment- Report From A Population-based Study (C.U.R.E.S.) Invest Ophthalmol Vis Sci 2011;52:ARVO E-Abstract 4217

Schulze M, Simpson T, Situ P, Menzies K, Walther H, Jones L. Effects of magnification on tear meniscus parameters using optical coherence tomography (OCT) images Optom Vis Sci 2011;88:E-abstract 115482

Schulze M, Simpson T, Stolee P. Rasch Analysis Of Bulbar Redness Scaling And The Relationship Between Physical Redness (u’) and “Rasch Redness” Invest Ophthalmol Vis Sci 2011;52:E-abstract 1966

Sheardown H, Wells L, Josephson J, Myers R, Jones L. Self destructive cases for improved patient compliance International Society for Contact Lens Research (Napa Valley, California), 2011

Simpson T, Schulze M, Stolee P. Rasch Analysis of Clinical Grading of Corneal Staining Invest Ophthalmol Vis Sci 2011;52:E-abstract 1967

Situ P, Simpson T, Jones L, Fonn D, Woods C. The relationship between solution induced corneal staining and ocular surface sensitivity Invest Ophthalmol Vis Sci 2011;51:E-Abstract 6514

Situ P, Simpson T, Schultze M, Menzies K, Walther H, Jones L. Intra- and inter-operator variability of meridional corneal and epithelial thickness measurements obtained using optical coherence tomography (OCT) Optom Vis Sci 2011;87: E-abstract 115021

Sorbara L, Maram J, Mueller K. Use of the Visante™ OCT anterior segment image to measure the saggital depth of keratoconus corneae compared to normal's at a 15mm chord length Contact Lens & Anterior Eye 2011;34, S1:S26

Sorbara L, Maram J, Mueller K. Use of the Visante™ OCT anterior segment image to measure the saggital depth of keratoconus corneae compared to normal's at their HVID GSLS (Las Vegas, USA), 2011

Srinivasan S, Menzies K, Sorbara L, Jones L. Imaging meibomian gland structures using the oculus keratograph Optom Vis Sci 2011;87:E-abstract 110775

Subbaraman LN. Silicone: the best and worst material for a soft contact lens Ontario Opticians Association (Toronto, Canada), 2011

Subbaraman LN, Schmidt TA, Sheardown H. Incorporation of a glycoprotein to enhance wettability of conventional and silicone hydrogel contact lenses NSERC 2020 Network Meeting (Orillia, Ontario), 2011

Walther H, Lorentz H, Heynen M, Kay L, Jones L. The effect of in vitro lipid concentration on lipid deposition on silicone hydrogeland conventional hydrogel contact lens materials Contact Lens & Anterior Eye 2011;34, s21:

Woods J, Guthrie S, Keir N, Choh V, Fonn D, Jones L, Irving E. Myopia development – what can the chicken tell us? Contact Lens & Anterior Eye 2011;34, Supplement 1:s13

Woods J, Guthrie S, Keir N, Dillehay S, Tyson M, Griffin R, Jones L, Irving E. The effect of a unique lens designed for myopia progression control (MPC) on the level of induced myopia in chicks Invest Ophthalmol Vis Sci 2011;51:E-Abstract 6651

Woods M, Dumbleton K, Woods C, Jones L, Fonn D. Do contact lens wearers remember what products they are using? Optom Vis Sci 2011;87:E-abstract 115811

2010

Dumbleton K. The secrets of success in presbyopic contact lens fitting 13th International Cornea & Contact Lens Congress (Sydney, Australia), 2010

Dumbleton K. Searching for comfort, cleanliness and compatibility 13th International Cornea & Contact Lens Congress (Sydney, Australia), 2010

Dumbleton K. When it all goes horribly wrong! - Compliance in contact lens wear 13th International Cornea & Contact Lens Congress (Sydney, Australia), 2010

Dumbleton K. Pursuing the perfect contact lens - are we there yet? 13th International Cornea & Contact Lens Congress (Sydney, Australia), 2010

Dumbleton K. Compliance with replacement of contact lenses: The figures and the fallout British Contact Lens Association (Birmingham, England), 2010

Dumbleton K, Richter D, Woods C, Jones L, Fonn D. Patient and practitioner compliance with silicone hydrogel and daily disposable lens replacement in Canada Ontario Association of Optometrists, 2010

Dumbleton K, Richter D, Woods C, Jones L, Fonn D. Relationship between compliance with lens replacement and contact lens related problems in silicone hydrogel wearers Optom Vis Sci 2010;87:E-abstract 100183

Dumbleton K, Woods C, Jones L, Richter D, Fonn D. The effect of compliance with replacement frequency on comfort and vision with silicone hydrogel lenses Contact Lens & Anterior Eye 2010;33, 6:263

Fonn D, Moezzi A, Richter D, Woods CA. Can Overnight Lens Induced Corneal Swelling Be Minimised to Equal No Lens Wear Regardless of Oxygen Transmissibillity? Optom Vis Sci 2010;87:E-Abstract 100318

Fonn D, Woods C, Richter D, Moezzi A. Critical Oxygen Transmissiblity to Avoid Overnight Lens Induces Corneal Swelling Contact Lens & Anterior Eye 2010;33, 6:267

Forrest J, Kaur K, Ilic K, Hall B, Jones L. In situ measurements of protein structural changes during adsorption American Physical Society 2010:Abstract #J10.012

Gorbet M, Tanti N, Crockett B, Jones L. Impact of lens material on in vitro cytotoxicity potential of multipurpose solutions on human corneal epithelial cells Invest Ophthalmol Vis Sci 2010;51:E-Abstract 3415

Heynen M, Lorentz H, Dumbleton K, Varikooty J, Woods C, Jones L. Lipid deposition on senofilcon A silicone hydrogel contact lenses disinfected with 1-step hydrogen peroxide and polyquad/aldox-preserved care regimens 7th Canadian University Conference in Optometry (Montreal, Canada), 2010

Hui A, Weeks AK, Sheardown H, Jones L. Novel contact lens materials for ciprofloxacin drug delivery 7th Canadian University Conference in Optometry (Montreal, Canada), 2010

Hui A, Weeks AK, Sheardown H, Jones L. Novel contact lens materials for ciprofloxacin drug delivery 20:20 National Science and Engineering Council Network Meeting (Horseshoe Valley, Ontario, Canada), 2010

Jones L. Contact lens solutions: Where next? Keynote address Tear Film and Ocular Surface Society (Florence, Italy), 2010

Jones L. The role of disinfecting solutions on contact lens performance and success international Society for Eye Research (Montreal, Canada), 2010

Jones L. Against the motion: With modern silicone hydrogel lenses continuous wear is not a crazy idea Contact Lens & Anterior Eye 2010;33, 6:271

Jones L. What your patients don’t tell you! Contact Lens & Anterior Eye 2010;33, 6:265

Jones L. New specialist lens solutions and care techniques Contact Lens & Anterior Eye 2010;33, 6:260

Jones L, Jones R. In vitro bulk dehydration rates of hydrogel and silicone hydrogel daily disposable and frequent replacement contact lens materials Optom Vis Sci 2010;87:E-abstract 105217

Jones L, Joyce E, Heynen M. Utility of a contact lens case pulsator to aid lysozyme removal from etafilcon A hydrogel lenses soaked in a no rub MPS regimen Contact Lens & Anterior Eye 2010;33, 6:290

Jones L, Menzies K. In vitro analysis of the physical properties of blister pack solutions of silicone hydrogel contact lenses Contact Lens & Anterior Eye 2010;33, 6:262

Jones L, Nguyen D, Weeks A, Heynen M, Joyce E, Sheardown H. Uptake and release of ciprofoloxacin by soft contact lens materials loaded with hyaluronic acid Contact Lens & Anterior Eye 2010;33, 6:286

Jones L, Nguyen D, Weeks AK, Heynen M, Joyce E, Sheardown H. Uptake and release of ciprofloxacin by soft contact lens materials loaded with hyaluronic acid Invest Ophthalmol Vis Sci 2010;51:ARVO E-Abstract 3412

Jones L, Rodriguez Celis E, Tourigny M, Blain A. Elemental analysis of hydrogel contact lenses using laser-induced breakdown spectroscopy (LIBS) Contact Lens & Anterior Eye 2010;33, 6:295

Jones R, Jones L. In vitro bulk dehydration rates of hydrogel and silicone hydrogel daily disposable and frequent replacement contact lens materials 7th Canadian University Conference in Optometry (Montreal, Canada), 2010

Keech A, Senchyna M, Sullivan BD, Lemp MA, Jones L, Brubaker MJ. Impact of time between collection on human tear film fluid osmolarity Invest Ophthalmol Vis Sci 2010;51:E-Abstract 4174

Keir N, Fonn D. Performance of visual acuity and contrast sentsitivity tests with multifocal contact lenses Optom Vis Sci 2010;87:E-abstract 105912

Lorentz H, Heynen M, Jones L. Impact of tear film components on in vitro lipid uptake to silicone hydrogel and hydrogel contact lens materials 7th Canadian University Conference in Optometry (Montreal, Canada), 2010

Lorentz H, Heynen M, Jones L. The impact of tear film components on in vitro lipid uptake to silicone hydrogel and hydrogel contact lens materials Contact Lens & Anterior Eye 2010;33, 6:268

Lorrentz H, Heynen M, Jones L. Impact of tear film components on in vitro lipid uptake to silicone hydrogel and hydrogel contact lens materials 20:20 National Science and Engineering Council Network Meeting (Horseshoe Valley, Ontario, Canada), 2010

Maram J, Simpson T, Sorbara L, Bizheva K. Anterior segment optical coherence tomography: Non-contact ultra high resolution imaging of contact lens edge profiles Optom Vis Sci 2010;87:E-abstract 105330

Menzies K, Jones L. In vitro analysis of the physical properties of blister pack solutions of silicone hydrogel contact lenses Invest Ophthalmol Vis Sci 2010;51:E-Abstract 1526

Peterson R, Fonn D, Woods C, Jones L. How to stop SICS! Contact Lens & Anterior Eye 2010;33, 6:272

Robinson B, Feng Y, Woods C, Gold D, Gordon K, Fonn D. Canadian Uncorrected Refractive Error Study - A Pilot Study Invest Ophthalmol Vis Sci 2010;51:ARVO E-Abstract 1718

Rodriguez Celis E, Tourigny M, Blain A, Jones L. Elemental analysis of hydrogel contact lenses using laser-induced breakdown spectroscopy (LIBS) Invest Ophthalmol Vis Sci 2010;51:E-Abstract 3411

Schulze M, Simpson T, Feng Y, Lucchetti E, Chou R, Hutchings N. Statistical Approach for Differentiating Happy and Unhappy Progressive Addition Lens Wearers Optom Vis Sci 2010;87:E-Abstract 105398

Sorbara L, Richter D, Peterson R, Schneider S, Woods C, Jones L, Fonn D. Comparison between live and digital slit lamp images of corneal staining Optom Vis Sci 2010;87:E-abstract 100083

Srinivasan S, Martell E, Heynen M, Jones L. Clinical signs, tear lipocalin and lysozyme concentrations in postmenopausal women symptomatic of dry eye 7th Canadian University Conference in Optometry (Montreal, Canada), 2010

Srinivasan S, Martell E, Heynen M, Luensmann D, Cira D, Gorbet M, Jones L. Ocular surface sampling techniques 7th Canadian University Conference in Optometry (Montreal, Canada), 2010

Srinivasan S, Martell E, Heynen M, Luensmann D, Cira D, Gorbet M, Jones L. Ocular surface sampling techniques 20:20 National Science and Engineering Council Network meeting (Horseshoe Valley, Ontario, Canada), 2010

Szczotka-Flynn LB, Albright M, Gillespie B, Kuo J, Fonn D, Lass JH. The Association Between Mucin Balls and a Decreased Incidence of Corneal Infiltrative Events During Extended Contact Lens Wear Canadian Uncorrected Refractive Error Study- A Pilot Study Invest Ophthalmol Vis Sci 2010;51:ARVO E-Abstract 1517

Weeks AK, Jones L, Sheardown H. Imprinted HA as a releasable wetting agent in model contact lenses 20:20 National Science and Engineering Council Network Meeting (Horseshoe Valley, Ontario, Canada), 2010

Weeks AK, Jones L, Sheardown H. Imprinted HA as a releasable wetting agent in model contact lenses Invest Ophthalmol Vis Sci 2010;51:E-Abstract 3420

Woods C, Dumbleton K, Richter D, Jones L, Fonn D. Compliance with lens care and contact lens case care and replacement Optom Vis Sci 2010;87:E-abstract 100194

2009

Brodland G, Jones L, Horst C, McDonald M, Guthrie S. A novel method for measuring contact lens tensile properties Optom Vis Sci 2009;86:E-abstract 095818

Dalton K, Hui A, Jones L, Simpson T. Diurnal variation in tear film osmolality, stability, ocular surface redness and ocular comfort Contact Lens & Anterior Eye 2009;32, 5:220

Dalton K, Schneider S, Jones L, Sorbara L. OCT and confocal imaging techniques used in the evaluation of two cases of hereditary granular dystrophy Contact Lens & Anterior Eye 2009;32, 5:235

Dumbleton K. Silicone Hydrogel Update: What we have learnt in the past ten years and what is new Rendez-Vous Contacto (Paris, France), 2009

Dumbleton K. Patient and Practitioner Compliance with Silicone Hydrogel and Daily Disposable Lens Replacement Rendez-Vous Contacto (Paris, France), 2009

Dumbleton K, Richter D, Guthrie S, Woods C, Jones L, Fonn D. Patient and practitioner compliance with silicone hydrogel and daily disposable lens replacement CAO (Charlottetown, PEI), 2009

Dumbleton K, Richter D, Woods CA, Jones L, Fonn D. Patient and practitioner compliance with silicone hydrogel and daily disposable lens replacement in USA and Canada Optom Vis Sci 2009;86:E-abstract 90615

Dumbleton K, Woods C, Jones L, Fonn D. Does compliance with replacement frequency of silicone hydrogel lenses play a role in subjective comfort and vision rating? ISCLR meeting (Crete, Greece), 2009

Dumbleton K, Woods C, Jones L, Guthrie S, Fonn D. Patient and practitioner compliance with silicone hydrogel and daily disposable lens replacement Contact Lens & Anterior Eye 2009;32, 5:213

Dumbleton K, Woods CA, Jones L, Fonn D. The role of compliance with replacement frequency of silicone hydrogel lenses on subjective comfort and vision Optom Vis Sci 2009;86:E-abstract 090626

Fonn D, Moezzi A, Varikooty J. Distribution of overnight corneal swelling across subjects with 4 different silicone hydrogel lenses Invest Ophthalmol Vis Sci 2009;50:E-abstract 5658

Fonn D, Moezzi A, Varikooty J. Average and individual overnight central corneal swelling with four different silicone hydrogel lenses Contact Lens & Anterior Eye 2009;32, 5:229

Heynen M, Lorentz H, Dumbleton K, Varikooty J, Woods C, Jones L. Lipid deposition on senofilcon A silicone hydrogel contact lenses disinfected with 1-step hydrogen peroxide and polyquad/aldox-preserved care regimens Invest Ophthalmol Vis Sci 2009;49:E-abstract 5660

Ho Y-H, Artes P, Chaglasian M, Comer G, Fingeret M, Twa MD, Prokopich C, Dumbleton KA, Flanagan JG. Normal aging characteristics of the Heidelberg Edge Perimeter Invest Ophthalmol Vis Sci 2009;50:ARVO E-Abstract 5295

Horst CR, McDonald M, Brodland G, Jones L. Extracting properties from variable thickness tensile specimens: A contact lens study International Conference on Mechanics of Biomateials & Tissues (Clearwater Beach, Florida), 2009

Jones L. Contact lens materials update - the rise of siloxane-based materials 20:20 National Science and Engineering Council (NSERC) Opthalmic Materials Network meeting (Waterloo, Canada), 2009

Jones L. But we forgot solutions! Contact Lens & Anterior Eye 2009;32, 5:215

Jones L. Microbial keratitis - I saw it coming! Contact Lens & Anterior Eye 2009;32, 5:212

Jones L, Brodland G, Horst C, McDonald M, Guthrie S. A novel method for measuring contact lens tensile properties Contact Lens & Anterior Eye 2009;32, 5:254

Jones L, Heynen M, Joyce E, Lorentz H, Dumbleton K, Varikooty J, Woods C. Tear film deposition on silicone hydrogel contact lenses disinfected with hydrogen peroxide and rub or enhanced no-rub care regimens Optom Vis Sci 2009;86:E-abstract 095929

Jones L, Heynen M, Joyce E, Lorentz H, Dumbleton K, Varikooty J, Woods C. Tear film deposition on silicone hydrogel contact lenses disinfected with hydrogen peroxide and rub or enhanced no-rub care regimens Contact Lens & Anterior Eye 2009;32, 5:249

Jones L, Joyce E, Heynen M. Utility of a contact lens case pulsator to aid lysozyme removal from etafilcon A hydrogel lenses soaked in a no rub MPS regimen Optom Vis Sci 2009;86:E-abstract 090650

Keech A, Simpson T, Flanagan J, Jones L. Repeatability of pachymetry measures by the RTVue-100 spectral domain optical coherence tomographer Optom Vis Sci 2009;86:E-abstract 095916

Keir N, Srinivasan S, Jones L, Woods C, Fonn D. The performance of a silicone hydrogel daily disposable contact lens in a group of asymptomatic silicone hydrogel lens wearers Asia Pacific Contact Lens Meeting (Hong Kong), 2009

Keir N, Varikooty J, Woods C, Fonn D. A novel in vivo method for measuring the refractive index of soft contact lenses using refractometry Contact Lens & Anterior Eye 2009;32, 5:229

Luensmann D, Heynen M, Jones L. Determination of albumin sorption to intraocular lenses by radiolabeling and confocal scanning laser microscopy Ivey Research Institute Day (London, Canada), 2009

Luensmann D, Heynen M, Jones L. Penetration profile of lysozyme and albumin in silicone hydrogel and pHEMA-based contact lens materials assessed using confocal microscopy Contact Lens & Anterior Eye 2009;32, 5:224

Luensmann D, Heynen M, Liu L, Sheardown H, Jones L. The impact of rub & no-rub care products on protein removal and localization Optom Vis Sci 2009;86:E-abstract 090517

Maram J, Sorbara L, Simpson T and Bizheva K. Anterior segment OCT: non-contact high and ultra high resolution imaging of contact lens edge profiles Optom Vis Sci 2009;86:E-abstract 95641

Maram J, Sorbara L, Simpson T and Bizheva K. Metrics of the average cornea: anterior segment imaging with Visante™ OCT Optom Vis Sci 2009;86:E-abstract 95645

Maram J, Sorbara L, Simpson T, Bizheva K. UHR-OCT imaging of profiles of silicone hydrogel lenses Optom Vis Sci 2009;86:E-Abstract 95641

Menzies K, Jones L. In vitro analysis of wettability and physical properties of blister pack solutions of daily disposable lenses Contact Lens & Anterior Eye 2009;32, 5:248

Moezzi A, Fonn D, Varikooty J, Richter D. Distribution of overnight central corneal swelling with high powered silicone hydrogel lenses Optom Vis Sci 2009;86:E-abstract 90898

Ngo W, Heynen M, Joyce E, Jones L. Impact of protein, lipid and lens polymer on neutralization times of hydrogen peroxide care regimens Optom Vis Sci 2009;86:E-abstract 095631

Nguyen D, Weeks A, Heynen M, Joyce E, Sheardown H, Jones L. Uptake and release of ciprofloxacin by soft contact lens materials loaded with hyaluronic acid 20:20 National Science and Engineering Council (NSERC) Network Meeting (Toronto, Canada), 2009

Papas E, Decenz-Verbeten T, Fonn D, Kollbaum P, Situ P, Tan J, Woods CA. Predicting satisfaction with multifocal contact lenses Contact Lens & Anterior Eye 2009;32, 5:213

Peterson R, Gorbet M, Woods CA, Fonn D. The transient nature of solution induced corneal staining Optom Vis Sci 2009;86:E-abstract 90816

Peterson R, Schneider S, Woods CA, Jones L, Fonn D. Optimising fluorescein observations of solution induced corneal staining Optom Vis Sci 2009;86:E-abstract 95820

Peterson R, Woods C, Jones L, Fonn D. The impact of rub and rinse on solution-induced corneal staining ISCLR Meeting (Crete), 2009

Robinson B, Feng Y, Woods CA, Fonn D, Gold D, Gordon K. Canadian uncorrected refractive error study - preliminary findings from the pilot study Optom Vis Sci 2009;86:E-abstract 95956

Schneider S, Woods CA, Fonn D. Hyper-reflective cells observed by confocal microscopy with staining caused by different lens-solution combinations Optom Vis Sci 2009;86:E-abstract 95912

Schulze M, Hutchings N, Simpson T. Grading Bulbar Redness using Cross-calibrated Grading Scales Optom Vis Sci 2009;86:E-Abstract 95543

Schulze M, Hutchings N, Simpson T. Clinical Scale Constancy – The Relationship between Bulbar Redness Grading Scales Contact Lens & Anterior Eye 2009;32210-254

Situ P, Simpson T, Jones L, Fonn D. Changes in corneal and conjunctival sensitivity with silicone hydrogel lens wear Invest Ophthalmol Vis Sci 2009;50:E-abstract 6347

Spurr-Michaud SJ, Senchyna M, Srinivasan S, Ritter III R, Heikkila E, Heynen M, Jones L, Gipson I. Assay of membrane-associated mucins in conjunctiva and tears of postmenopausal women with and without dry eye Invest Ophthalmol Vis Sci 2009;50: E-Abstract 539

Stahl U, Jones L, Willcox M, Stapleton F. Tear osmolality measurements - effect of instrumentation and of freezing Invest Ophthalmol Vis Sci 2009;50: E-abstract 2611

Subbaraman L, Jones L. In vitro wettability of surface modified and non-surface modified silicone hydrogel contact lens materials Contact Lens & Anterior Eye 2009;32, 5:240

Subbaraman L, Jones L, Borazjani R, Zhao Z, Zhu H, Willcox M. Bacterial adhesion to lactoferrin-coated conventional and silicone hydrogel contact lens materials International Society of Contact Lens Research (ISCLR) Meeting (Crete), 2009

Subbaraman L, Jones L, Borazjani R, Zhao Z, Zhu H, Willcox M. Bacterial adhesion to lactoferrin-coated conventional and silicone hydrogel contact lens materials Optom Vis Sci 2009;86:E-abstract 090758

Subbaraman L, Jones L, Zhao Z, Zhu H, Willcox M. Bacterial adhesion to lysozyme-coated conventional and silicone hydrogel contact lens materials Contact Lens & Anterior Eye 2009;32, 5:229

Subbaraman L, Jones L, Zhao Z, Zhu H, Willcox MDP. Bacterial adhesion to protein-coated conventional and silicone hydrogel contact lens materials Ivey Institute Research Day (London, Ontario), 2009

Subbaraman LN, Jones L. In vitro wettability of surface modified and non-surface modified silicone hydrogel contact lens materials Optom Vis Sci 2009;86:E-abstract 095754

Subbaraman LN, Jones L, Borazjani R, Zhao Z, Zhu H, Willcox MDP. Bacterial adhesion to proteincoated conventional and silicone hydrogel contact lens materials 15th Scientific Meeting of the International Society for Contact Lens Research (Crete, Greece), 2009

Tanti N, Jones L, Gorbet M. Effect of MPS released from silicone hydrogel lenses on corneal epithelial cell adhesion phenotype and apoptotic pathways in vitro Invest Ophthalmol Vis Sci 2009;50:E-abstract 4614

Weeks A, Jones L, Sheardown H. Incorporating HA as an internal wetting agent Canadian Biomaterials Society annual meeting (Quebec City, Canada), 2009

Weeks A, Jones L, Sheardown H. Incorporating HA as an internal wetting agent Invest Ophthalmol Vis Sci 2009;50:E-abstract 5651

Weeks A, Luensmann D, Jones L, Sheardown H. Crosslinked HA decrease lysozyme sorption and denaturation in model contact lens materials 20:20 National Science and Engineering Council (NSERC) Network meeting (Toronto, Canada), 2009

Woods CA, Varikooty J, Keir N, Fonn D. Investigation of a novel in vivo method for measuring the refractive index of soft contact lenses using refractometry Invest Ophthalmol Vis Sci 2009;50:E-abstract 5655

Woods J, Woods CA, Fonn D. Using objective tests and novel subjective rating assessments to compare the performance of a new silicone hydrogel multifocal lens design to monovision Contact Lens & Anterior Eye 2009;32, 5:232

2008

Basuthkr S, Rao S, Simpson TL. Interaction of vision on ocular comfort Optom Vis Sci 2008;85:E-abstract 85078

Bitton E, Jones L, Simpson T. Temporal sequencing of the tear meniscus height Optom Vis Sci 2008;85: E-abstract 80015

Dalton K, Jones L, Guthrie S. pH, Osmolality and viscosity of artificial tears Optom Vis Sci 2008;85: E-abstract 85310

Dalton K, Jones L, Guthrie S. Physical properties of artificial tears Contact Lens & Anterior Eye 2008;31, 5:272

Dalton K, Schneider S, Jones L, Sorbara L. Use of digital imaging in sisters with hereditary granular dystrophy Optom Vis Sci 2008;85:E-abstract 85292

Dalton K, Senchyna M, Srinivasan S, Jones L. Tear film osmolality in a symtomatic dry eyes population Optom Vis Sci 2008;85: E-abstract 85314

Duench S, Simpson T, Tiso A, Grisan E, Ruggeri A, Fonn D. Measurement of average real-time red blood cell velocity in conjunctival vessels Invest Ophthalmol Vis Sci 2008;49:E-Abstract 6051

Dumbleton K. Contact lens materials: Is the news all good? Nordic Contact Lens Congress (Copenhagen, Denmark), 2008

Dumbleton K. Contact lens solutions: Problems and problem solving Nordic Contact Lens Congress (Copenhagen, Denmark), 2008

Dumbleton K. Drop-out: Reasons why, and what to do about it Nordic Contact Lens Congress (Copenhagen, Denmark), 2008

Dumbleton K. Improving dryness symptoms with new technology contact lens materials 6th Assottica Congress (Rome, Italy), 2008

Dumbleton K. What are our patients doing with their lenses? 6th Assottica Congress (Rome, Italy), 2008

Dumbleton K. Patients say (and do) the darndest things! Optom Vis Sci 2008;85:E-abstract CL-05

Dumbleton K. Patients say (and do) the darndest things! Dutch Contact Lens Congress (Veldhoven, Netherlands), 2008

Dumbleton K, Woods C, Schneider S, Fonn D. Comparison of signs and symptoms of dry eye when using ocular lubricants of differering viscosity Optom Vis Sci 2008;85: E-abstract 80019

Fonn D, Moezzi A, Varikooty J, Simpson TL. The effect of oxygen transmissibility on central and peripheral overnight corneal swelling with four different silicone hydrogel lenses Optom Vis Sci 2008;85: E-abstract 85077

Gorbet M, Jones L, Sheardown H. The adverse effect of borate buffered versus phosphate buffered packaging solutions on corneal cellular viability and integrin expression Contact Lens & Anterior Eye 2008;31, 6:290-291

Hui A, Boone A, Jones L. Uptake and release of Ciprofloxacin-HCl from conventional and silicone hydrogel contact lens materials Rising Stars of Research Conference (Alberta, Canada), 2008

Jones D, Jones L. The use of O2Optix Custom in a case of pediatric aphakia Contact Lens & Anterior Eye 2008;31, 5:246

Jones L. Allergy vs toxicity – what’s the difference clinically? Contact Lens & Anterior Eye 2008;31, 6:297

Jones L, Boone A, Heynen M, Joyce E, Varikooty J. Ex vivo protein deposition on two-weekly daily wear silicone hydrogel contact lens materials Contact Lens & Anterior Eye 2008;31, 5:262-263

Jones L, Glasier M, Boone A, Keir N, Dumbleton K. Protein deposition on continuous wear surface modified (balafilcon a) and non-surface modified (comfilcon a) silicone hydrogel contact lens materials Contact Lens & Anterior Eye 2008;31, 5:263

Jones L, Subbaraman L. In vitro wettability of a non surface modified silicone hydrogel contact lens material Contact Lens & Anterior Eye 2008;31, 5:262

Jones L, Subbaraman L, Glasier MA, Dumbleton K. Quantification of protein deposition on five commercially available silicone hydrogel contact lens materials Contact Lens & Anterior Eye 2008;31, 5:263

Jones L, Subbaraman L, Woods J. Protein deposition on a novel lathe-cut silicone hydrogel contact lens material (sifilcon A) Contact Lens & Anterior Eye 2008;31, 5:262

Keir N, Boone A, Dumbleton K, Jones L, Woods C, Fonn D. In vivo and ex vivo wettability and the association with contact lens comfort Contact Lens & Anterior Eye 2008;31, 6:292

Keir N, Schneider S, Dumbleton K, Woods CA, Feng Y. Clinical performance of peroxide-based care system and a multi-purpose care system formulated for use with silicone hydrogels Optom Vis Sci 2008;85: E-abstract 85058

Luensmann D, Heynen M, Jones L. Albumin penetration into intraocular lenses imaged by confocal microscopy Optom Vis Sci 2008;85; E-abstract 80029

Maram J, Sorbara L, Simpson TL. Calibration of the new Visante Optical Coherence Tomographer Optom Vis Sci 2008;85:E-abstract 80013

Menzies K, Jones L. In vitro wettability of a novel surface-modified silicone hydrogel material (Asmofilcon A) Contact Lens & Anterior Eye 2008;31, 5:261

Moezzi A, Fonn D, Varikooty J, Simpson TL. The effect of lens power on central and peripheral overnight corneal swelling with four different silicone hydrogel lenses Optom Vis Sci 2008;85: E-abstract 85076

Papas E, Decenzo-Verbeten T, Fonn D, Holden B, Kollbaum PS, Situ P, Woods CA. Utility of immediate evaluation of multifocal contact lens performance Optom Vis Sci 2008;85: E-abstract 80113

Peterson R, Woods CA, Fonn D. Comparing the CCLR grading system for corneal staining to a traditional 0-4 scale Optom Vis Sci 2008;85: E-abstract 85324

Schneider S, Simpson T, Woods C, Richter D, Fonn D. Hyper-reflective cells observed by confocal microscopy as an indicator of lens and lens care interactions Optom Vis Sci 2008;85: E-abstract 80028

Schulze M, Hutchings N, Simpson TL. Perceptual differences between reference images of bulbar redness grading scales Optom Vis Sci 2008;85: E-abstract 80036

Situ P, Simpson T, Fonn D. Ocular surface sensitivity and lens-solution induced corneal staining and symptoms Optom Vis Sci 2008;85: E-abstract 85073

Situ P, Simpson TL, Fonn D. Corneal and Conjunctival Mechanical and Chemical Sensitivity in Contact Lens Wearers Invest Ophthalmol Vis Sci 2008;49: E-Abstract 4835

Srinivasan S, Joyce E, Boone A, Simpson T, Jones L, Senchyna M. Clinical characteristics and tear lysozyme concentration in dry eyed postmenopausal women Optom Vis Sci 2008;85: E-Abstract 070069

Srinivasan S, Simpson T, Senchyn M, Jones L. Use of dry eye questionnaires to assess ocular surface dryness in postmenopausal females with and without dry eye Invest Ophthalmol Vis Sci 2008;49: E-abstract 5850

Srinivasan S, Simpson T, Senchyna M, Jones L. Assessment of ocular surface dryness in postmenopausal females using dry eye questionnaires Optom Vis Sci 2008;85: E-abstract 80023

Subbaraman L, Chow L, Sheardown H, Jones L. Kinetics of in vitro lactoferrin deposition on FDA group II, FDA group IV and silicone hydrogel contact lens materials Invest Ophthalmol Vis Sci 2008;49: E-abstract 2022

Subbaraman L, Chow L, Sheardown H, Jones L. Lactoferrin uptake kinetics on silicone hydrogel and conventional hydrogel contact lens materials Optom Vis Sci 2008;85: E-Abstract 085047

Subbaraman L, Jones L, Zhao Z, Zhu H, Willcox M. Bacterial adhesion to lysozyme-coated conventional and silicone hydrogel contact lens materials Optom Vis Sci 2008;85:E-abstract 80108

Tanti N, Gorbet M, Jones L. In vitro analysis of the potential cytotoxicity of contact lenses soaked in multi-purpose solutions Contact Lens & Anterior Eye 2008;31, 5:250-251

Weeks AK, Sheardown H, Jones L. The effects of crosslinked hyaluronic acid on pHEMA and pHEMA/TRIS hydrogel contact lens materials Invest Ophthalmol Vis Sci 2008;49: E-abstract 4866

Woods C, Dumbleton K, Fonn D, Schneider S. Signs and symptoms of dryness in habitual users of over-the-counter ocular lubricants Optom Vis Sci 2008;85: E-Abstract 80014

Woods C, Richter D, Fonn D. Rate of change of comfort in symptomatic and asymptomtic lens wearers Optom Vis Sci 2008;85: E-Abstract 90014

Woods J, Schneider S, Woods CA, Fonn D. Application of a novel method for evaluating corneal vascularization Optom Vis Sci 2008;85: E-Abstract 80083

Woods J, Woods CA, Fonn D. Comparison of the simplicity of completing an initial fit of symptomatic early presbyopes with monovision and an aspheric multifocal silicone hydrogel Optom Vis Sci 2008;85: E-Abstract 80089

2007

Bitton E, Keech A, Jones L. Overnight variation in tear ferning 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Bitton E, Keech A, Simpson T, Jones L. Inter- and intra-observer variability in TMH using the OCT 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Boone A, Heynen M, Joyce E, Varikooty J, Jones L. Ex vivo protein deposition on two-weekly daily wear silicone hydrogel contact lens materials Optom Vis Sci 2007;84: E-abstract 075140

Caffery B, Joyce E, Boone A, Jones L, Simpson T, Slomovic A, Senchyna M. Tear flow and lysozyme concentration in Sjogren’s Syndrome, KCS and normals Optom Vis Sci 2007;84: E-abstract 075333

Caffery B, Joyce E, Heynen M, Ritter R, Jones L, Simpson T, Slomovic A, Gamache D, Senchyna M. Tear flow and MUC16 expression in Sjögren’s Syndrome, KCS and normals 5th International Conference on the Tear Film and Ocular Surface (Sicily, Italy), 2007

Caffery B, Joyce E, Slomovic A, Jones L, Simpson T. Tear volume and tear lipocalin ratios in Sjogrens, severe KCS and non-dry eye subjects ISCLR meeting (Whistler, Canada), 2007

Dalton K, Subbaraman L, Rogers R, Jones L. Physical properties of soft contact lens solutions 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Duench S, Simpson T, Fonn D. Measurement of relative haemoglobin oxygen saturation in conjunctival vessels Optom Vis Sci 2007;84: E-Abstract 075287

Dumbleton K. Contact Lenses and Solutions: Understanding how they work together and when they don’t Association des Optométristes de France (AOF) 26th Conference on Optometry and Contact Lenses (Lyon, France), 2007

Dumbleton K, Jones L, Woods CA, Feng Y, Moezzi A and Fonn D. Clinical performance of a hydrogen peroxide care regimen with silicone hydrogel lenses Contact Lens & Anterior Eye 2007;30, 5:301

Dumbleton K, Woods C, Jones L, Fonn D. Comfort and adaptation to silicone hydrogel lenses for daily wear BCLA, 2007

Dumbleton K, Woods J, Woods C, and Fonn D. Compliance with current contact lens care regiments Optom Vis Sci 2007;84: E-abstract 070087

Fonn D. Epithelial thickness changes with Hyperopic CRT RGP lenses ISCLR meeting, Whistler, BC, Canada, 2007

Fonn D. Assessment of ocular discomfort: oxygen and discomfort ISCLR meeting, Whistler, BC, Canada, 2007

Fonn D. Refractive error and corneal shape ISCLR meeting, Whistler, BC, Canada, 2007

Gorbet M, Duan X, Jones L, Sheardown H. Activation of human corneal epithelial cells on collagen gels Invest Ophthalmol Vis Sci 2007;48: E-abstract 1891

Gorbet M, Jones L, Sheardown H. Corneal epithelial cell viability and integrin expression is affected by contact lens packaging solutions ISCLR meeting, (Whistler, Canada), 2007

Jones D, Jones L. The use of 02Optix Custom in a case of pediatric aphakia Optom Vis Sci 2007;84: E-abstract 075149

Jones L. Ocular biomaterials and their interaction with the human tear film 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Jones L, Glasier MA, Boone A, Keir N, Dumbleton K. Protein deposition on continuous wear surface modified (balafilcon A) and non-surface-modified (comfilcon A) silicone hydrogel contact lens materials Optom Vis Sci 2007;84: E-abstract 075139

Jones L, Srinivasan S, Joyce E, Senchyna M. Increased tear osmolality and altered tear ferning patterns in postmenopausal women with mild and moderate symptoms of dry eye Contact Lens & Anterior Eye 2007;30, 5:293

Jones L, Subbaraman L. Kinetics of lysozyme activity recovered from conventional and silicone hydrogel lenses Contact Lens & Anterior Eye 2007;30, 5:284-285

Jones L, Subbaraman L, Srinivasan S, Varikooty J, Glasier M. Subjective comfort is correlated with the activity of lysozyme recovered from one-day etafilcon lenses British Contact Lens Association Annual Meeting, Manchester, England, 2007

Jones L, Subbaraman LN, Varikooty J, Srinivasan S, Glasier M. Activity of lysozyme deposited on oneday etafilcon contact lenses is correlated with subjective comfort 14th Scientific Meeting of the International Society for Contact Lens Research (Whistler, Canada), 2007

Keir N, Simpson T, Jones L, Fonn D. The relationship between manifest refraction and higher order aberrations for wavefront-guided LASIK Optom Vis Sci 2007;84: E-abstract 075084

Keir N, Subbaraman L, Woods C, Jones L, Fonn D. Clinical impact of pre-soaking a silicone hydrogel lens in a MPS care solution on a group of symptomatic wearers ISCLR meeting (Whistler, BC, Canada), 2007

Lorentz H, Campbell F, Subbaraman L, Jones L. The impact of drop solution on the out of pack wettability of conventional and silicone hydrogel contact lens materials 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Lorentz H, Rogers R, Jones L. The impact of in vitro lipid deposition on contact angle wettability of various contact lens materials 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Lorentz H, Rogers R, Jones L. In vitro deposition of lipid onto contact lens materials can lower contact angle wettability of surface-modified silicone hydrogel contact lens materials ISCLR meeting, Whistler, BC, Canada, 2007

Luensmann D, Heynen M, Jones L. The use of confocal microscopy to investigate albumin penetration into pHEMA-based and silicone hydrogel contact lens materials Biomedical Imaging and Computer Vision (BICV) Workshop (University of Waterloo, Canada), 2007

Luensmann D, Heynen M, Jones L. The use of confocal microscopy to investigate albumin penetration into pHEMA-based and silicone hydrogel contact lens materials Invest Ophthalmol Vis Sci 2007;48: E-abstract 5377

Luensmann D, Heynen M, Jones L. The use of confocal microscopy to investigate albumin penetration into pHEMA-based and silicone hydrogel contact lenses 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Luensmann D, Heynen M, Jones L. Confocal microscopy and albumin penetration into contact lenses Optom Vis Sci 2007;84, 9:839-847

Peterson R. Objective measures of changes in corneal staining ISCLR meeting, Whistler, BC, Canada, 2007

Schneider S, Simpson T, Fonn D. Observations of inferior and central corneal subbasal nerve orientation obtained using confocal microscopy Invest Ophthalmol Vis Sci 2007;48: E-abstract 3859

Schneider S, Simpson T, Fonn D. Does fluorescein induce corneal epithelial hyper-reflectivity when using confocal microscopy Optom Vis Sci 2007;84: E-Abstract 070075

Schulze M, Hutchings N, Simpson T. Cross-calibrating between grading scales of redness: is it possible? Biomedical Imaging & Computer Vision (BICV) Conference, Waterloo, ON, CA., 2007

Schulze M, Hutchings N, Simpson T. The use of fractal analysis to estimate the accuracy of bulbar redness grading scales 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Schulze M, Simpson TL, Hutchings N. Cross-calibrating between grading scales of redness — is it possible? Invest Ophthalmol Vis Sci 2007;48: E-abstract 5369

Situ P, Simpson T, Jones L, Fonn D. Conjunctival and corneal sensitivity associated with dry eye symptomatology 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Situ P, Simpson TL. Evoked sensation by mechanical and chemical stimulation in central and peripheral cornea Invest Ophthalmol Vis Sci 2007;48: E-abstract 5387

Sorbara L. The use of videokeratoscopy in determining the back optic zone diameter and overall lens diameter for contact lenses for keratoconus Global Keratoconus Meeting, 2007

Sorbara L, Haque S, Fonn D, Simpson T. Refractive and topographic keratometric effects of Corneal Refractive Therapy for Hyperopia after one night of lens wear: comparison of two fitting parameters Contact Lens & Anterior Eye 2007;30, 5:286

Spurr-Michaud S, Senchyna M, Srinivasan S, Ritter R, Argueso P, Joyce E, Heynen M, Jones L, Gamache D, Gipson I. Assay of MUC16 in conjunctiva and tears of postmenopausal women with and without dry eye 5th International Conference on the Tear Film and Ocular Surface (Sicily, Italy), 2007

Srinivasan S, Jones L, Joyce E, Simpson T, Senchyna M. Clinical signs and symptoms in post-menopausal females with dry eye 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Srinivasan S, Jones L, Joyce E, Simpson T, Senchyna M. Comparsion of tear lipocalin ratios in dry eyed and non-dry eyed post-menopausal woman 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Srinivasan S, Joyce E, Heynen M, Jones L, Simpson T, Gamache D, Senchyna M. Expression of soluble and membrane bound MUC16 in dry eyed postmenopausal women 5th International Conference on the Tear Film and Ocular Surface (Sicily, Italy), 2007

Srinivasan S, Joyce E, Jones L, Senchyna M. Comparison of tear lipocalin ratios in asymptomatic and symptomatic dry eyed postmenopausal women Invest Ophthalmol Vis Sci 2007;48: E-abstract 6024

Srinivasan S, Joyce E, Jones L, Simpson T, Gamache D, Senchyna M. Clinical characteristics and tear lipocalin concentration in dry eyed postmenopausal women Optom Vis Sci 2007;84: E-abstract 075330

Srinivasan S, Joyce E, Jones L, Simpson T, Senchyna M. Comparison of tear lipocalin ratios in dry eyed and non dry eyed postmenopausal women 6th Canadian Optometry Conference on Vision Science (Waterloo, Ontario), 2007

Subbaraman L, Glasier MA, Dumbleton K, Jones L. Quantification of protein deposition on five commercially available silicone hydrogel contact lens materials Optom Vis Sci 2007;84:E-abstract 070031

Subbaraman L, Jones L. In vitro wettability of a non surface modified silicone hydrogel contact lens material 6th Canadian Optometry Conference on Vision Science (Waterloo, Ontario), 2007

Subbaraman L, Jones L. An in vitro comparison of the activity of lysozyme recovered from contact lens materials as a function of time Optom Vis Sci 2007;84:E-abstract 075141

Subbaraman L, Jones L. In vitro wettability of a non-surface-modified silicone hydrogel contact lens material Optom Vis Sci 2007;84:E-abstract 075172

Subbaraman L, Jones L. An in vitro comparison of the activity of lysozyme recovered from contact lens materials as a function of time 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Subbaraman L, Jones L. In vitro wettability of a non-surface-modified silicone hydrogel contact lens material 6th Canadian Optometry Conference on Vision Science, Waterloo, Ontario, 2007

Subbaraman L, Jones L. Activity of lysozyme deposited on conventional and silicone hydrogel contact lenses as a function of time ISCLR meeting (Whistler, BC, Canada), 2007

Subbaraman L, Jones L. Determination of lysozyme activity recovered from conventional and silicone hydrogel contact lenses as a function of time University of Waterloo Graduate Student Research Conference, 2007

Subbaraman L, Jones L. Activity of lysozyme deposited on conventional and silicone hydrogel contact lenses as a function of time Invest Ophthalmol Vis Sci 2007;47:E-Abstract 5393

Subbaraman L, Woods J, Jones L. Protein deposition on a novel lathe-cut silicone hydrogel contact lens material (sifilcon A) Optom Vis Sci 2007;84:E-abstract 070038

Varikooty J, Srinivasan S, Chan A, Subbaraman L, Woods C, Simpson T, Jones L, Fonn D. Clinical manifestations of upper lid staining in adapted silicone hydrogel lens wearers British Contact Lens Association Annual meeting (Manchester, UK), 2007

Woods J, Schneider S, Woods CA, Jones LW, Fonn D. Short term satisfaction and physiological response in wearers of high power hydrogel lenses refit with a custom silicone hydrogel lens Optom Vis Sci 2007;84: E-abstract 070034

Woods J, Woods CA. Vision test that discriminates multifocal contact lenses BCLA Clinical Conference and Exhibition, 2007

2006

Bitton E, Keech A, Jones L. Overnight variation in tear ferning Optom Vis Sci 2006;83: E-Abstract 065200

Bitton E, Keech A, Simpson T, Jones L. Inter and intra observer variability in tear meniscus determined using OCT Optom Vis Sci 2006;83: E-Abstract 065191

Dalton K, Jones L. The performance of a novel nanolitre osmometer to investigate diurnal tear-film osmolality Contact Lens & Anterior Eye 2006;29, 4:204

Dalton K, Rogers R, Jones L. Osmolality, pH, viscosity and surface tension of multi-purpose contact lens solutions Optom Vis Sci 2006;83: E-Abstract 065236

Dalton KN, Rogers R, Jones L. Physical properties of multi-purpose contact lens solutions Invest Ophthalmol Vis Sci 2006;47: E-Abstract 89

Dalton KN, Rogers R, Jones L. Physical properties of multi-purpose contact lens solutions 13th Symposium on the Materials Science and Chemistry of Contact Lenses (New Orleans, USA), 2006

Duench S, Sorbara L, Simpson TL, Jones L, Fonn D. The use of fluorophotometry to measure corneal epithelial permeability to contact lenses and contact lens care regimens Optom Vis Sci 2006;83:E-Abstract 65238

Duench S, Simpson T, Jones L, Fonn D. Corneal staining is not correlated with limbal or bulbar redness in subjects using daily wear silicone hydrogel contact lenses Invest Ophthalmol Vis Sci 2006;47: E-Abstract 87

Dumbleton K. Silicone Hydrogel Lenses: What makes them different and how to look after them Silicone Hydrogel Symposium to celebrate Centenary of Optometry in Quebec (Montreal, Canada), 2006

Dumbleton K. Silicone hydrogels: fitting the future today! Looking at oxygen BCLA Platinum Sponsor Showcase. Birmingham, England, 2006

Dumbleton K, Jones L, Woods C, Feng Y, Moezzi A, Fonn D. Clinical performance of a hydrogen peroxide care regimen with silicone hydrogel lenses Optom Vis Sci 2006;83: E-Abstract 060069

Dumbleton K, Keir N, Varikooty J, Fonn D, Janakiraman P. Toric silicone hydrogel lenses for extended wear Contact Lens & Anterior Eye 2006;29, 4:184

Dumbleton K, Moezzi A, Fonn D, Simpson T. Comparision of overnight corneal swelling induced by lotrafilcon b toric versus alphafilcon a toric lenses Contact Lens & Anterior Eye 2006;29, 4:193

Dumbleton K, Woods C, Jones L, Feng Y, Moezzi A, Fonn D. Comfort and adaptation to silicone hydrogel lenses for daily wear Optom Vis Sci 2006;83: E-Abstract 060066

Feng Y, Dumbleton K, Keir N, Woods CA, Jones L, Simpson T, Fonn D. The influence of a guar-based lubricant eye drop on ocular discomfort in symptomatic hydrogel contact lens wearers Invest Ophthalmol Vis Sci 2006;47:ARVO E-Abstract 2381

Glasier M, Keech A, Sheardown H, Corstorphine L, Jones L. Galyfilcon (Acuvue Advance) silicone hydrogel contact lenses deposit low levels of relatively active lysozyme Contact Lens & Anterior Eye 2006;29, 4:193

Glasier M, Suwala M, Jones L. Activity of lysozyme deposited on conventional and silicone hydrogel contact lens materials using an in vitro model Contact Lens & Anterior Eye 2006;29, 4:193-194

Guthrie S, Simpson T, Varikooty J, Fonn D. Background subtraction and contrast enhancement for interferometric images of the human corneal tear film Invest Ophthalmol Vis Sci 2006;47:E-abstract 2399

Haque S, Jones L, Simpson T. Mapping corneal & epithelial thickness using OCT: comparing neophytes, RGP lens wearers & keratoconics Invest Ophthalmol Vis Sci 2006;47: E-Abstract 1311

Haque S, Jones L, Simpson T. Mapping corneal and epithelial thickness using OCT: Comparing neophytes, RGP lens wearers and keratoconics Canadian Student Health Research Forum (Winnipeg, Canada), 2006

Harvey KM, Simpson T, Jones L, Fonn D. The effects of silicone hydrogel contact lens wear on the corneal epithelium’s sub-basal nerve fibre layer Invest Ophthalmol Vis Sci 2006;47: E-Abstract 2393

Jones D, Woods C, Jones L, Morgan P. The use of silicone hydrogel contact lenses by Canadian optometrists: 2000-2006 Optom Vis Sci 2006;83: E-Abstract 065281

Jones L. Contact lens solutions: Composition and function 13th symposium on the Material Science and Chemistry of Contact Lenses (New Orleans, USA), 2006

Jones L. Prescribing the best care system for the patient British Contact Lens Association Annual Meeting, Birmingham, England,, 2006

Jones L. The interface between lens and tears British Contact Lens Association Annual Meeting, Birmingham, England, 2006

Jones L, Keir N, Situ P, Fonn D. The impact of post–insertion time on corneal staining and comfort with Group II hydrogel materials 13th Symposium on the Materials Science and Chemistry of Contact Lenses (New Orleans, USA), 2006

Jones L, Sheardown H, Liu L, Croll A, Dalnoki-Varess K. A novel daily disposable contact lens with improved in-eye and end of day comfort British Contact Lens Association Annual Meeting, Birmingham, England, 2006

Keech A, Joyce E, Senchyna M, Jones L. A rapid method for the extraction of mucin from hydrogel contact lenses Invest Ophthalmol Vis Sci 2006;47: E-Abstract 119

Keir N, Dumbleton K, Jones L, Fonn D. A 12 month clinical comparison of continuous wear surface modified and non-surface modified silicone hydrogel contact lens materials Optom Vis Sci 2006;83: E-Abstract 060070

Keir N, Feng Y, Dumbleton K, Woods C, Jones L, Simpson T, Fonn D, Cohen S, Potter W. The influence of a lubricant eye drop on ocular discomfort in symptomatic hydrogel contact lens wearers Optom Vis Sci 2006;83: E-Abstract 065249

Keir N, Moezzi A, Fonn D, Varikooty J, Simpson T. Overnight corneal swelling of silicone hydrogel contact lenses with high oxygen transmissibility Contact Lens & Anterior Eye 2006;29, 4:196

Keir N, Rogers R, Dumbleton K, Jones L, Fonn D. Comparison of ex vivo wettability measurements of continuous wear surface treated and non-surface treated silicone hydrogel contact lens materials British Contact Lens Association Annual Meeting (Birmingham, England), 2006

Keir N, Rogers R, Dumbleton K, Jones L, Fonn D. Comparision of ex-vivo wettability measurements of continuous wear surface treated and non-surface treated silicone hydrogel contact lens materials Contact Lens & Anterior Eye 2006;29, 4:195

Keir N, Situ P, Richter D, Jones L, Fonn D. Clinical performance of alexidine-based and polyquad-based multipurpose solutions when used with daily wear etafilcon lenses Optom Vis Sci 2006;83: E-Abstract 065232

Keir NJ, Simpson T, Jones L, Fonn D. Higher order aberration profiles differ for myopes and hyperopes before and 6 months after a CustomCornea LASIK procedure Invest Ophthalmol Vis Sci 2006;47:E-Abstract 60

Lakshmi S, Cronje S, Jayanna K, Sweeney D, Fonn D. IACLE’s role in improving contact lens education in india: a case study Optom Vis Sci 2006;83: E-Abstract 065114

Lorentz H, Rogers R, Jones L. In vitro deposition of lipid onto contact lens materials can lower contact angle wettability of surface-modified silicone hydrogel contact lens materials British Contact Lens Association Annual Meeting, Birmingham, England, 2006

Lorentz HI, Rogers R, Jones LW. In vitro deposition of lipid onto contact lens materials can lower contact angle wettability of surface-modified silicone hydrogel contact lens materials Invest Ophthalmol Vis Sci 2006;47: E-Abstract 2389

Lu F, Simpson T, Sorbara L, Fonn D. Moldability of the ocular surface in response to local mechanical stress Invest Ophthalmol Vis Sci 2006;47, 5:2390

Luensmann D, Glasier MA, Zhang F, Jones L. A novel in vitro method to determine the penetration profile of albumin into silicone hydrogel and conventional hydrogel contact lens materials Optom Vis Sci 2006;83:E-Abstract 060092

Moezzi A, Fonn D, Simpson T. Comparison of overnight corneal swelling induced by prototype lotrafilcon a toric versus balafilcon a toric Optom Vis Sci 2006;83: E-Abstract 060095

Rogers R, Jones L, Dalton K. Physical properties of multi-purpose contact lens solutions Contact Lens & Anterior Eye 2006;29, 4:189-190

Rogers R, Jones L, Srinivasan S, Varikooty J, Fonn D. The influence of care regimen composition and wear time on ex vivo wettability of etafilcon contact lenses Contact Lens & Anterior Eye 2006;29, 4:189

Schneider S, Fonn D, Simpson T. Central corneal clouding induced by PMMA lens wear during eye closure Invest Ophthalmol Vis Sci 2006;47, 5:2397

Sheardown H, Liu L, Jones L. Chemical characterization of 1-DAY ACUVUE® MOIST and 1-DAY ACUVUE Contact Lenses Invest Ophthalmol Vis Sci 2006;47: E-Abstract 2388

Situ P, Simpson T, Jones L, Fonn D. Conjunctival and corneal sensitivity is associated with dry eye symptomatology Invest Ophthalmol Vis Sci 2006;47: E-Abstract 262

Srinivasan S, Chan C, Jones L, Simpson T, Fonn D. Diurnal variation in interior tear meniscus height that occurs in dry-eyed and non-dry-eyed participants British Contact Lens Association Annual Meeting, Birmingham, England, 2006

Srinivasan S, Jones L, Joyce E, Simpson T, Senchyna M. Characterization of clinical signs and symptoms in asymptomatic and symptomatic dry eyed postmenopausal women Optom Vis Sci 2006;83: E-Abstract 065201

Srinivasan S, Jones L, Joyce E, Simpson T, Senchyna M. Clinical signs and symptoms in postmenopausal females with and without symptoms of dry eye Invest Ophthalmol Vis Sci 2006;47: E-Abstract 249

Srinivasan S, Joyce E, Jones L, Senchyna M. Tear osmolality and ferning patterns in postmenopausal women with and without symptoms of dry eye Optom Vis Sci 2006;83: E-Abstract 060011

Srinivasan S, Varikooty J, Subbaraman L, Chan A, Woods C, Simpson T, Jones L, Fonn D. Atypical manifestation of upper lid margin staining in silicone hydrogel lens wearers with symptoms of dry eye Optom Vis Sci 2006;83:E-Abstract 065255

Subbaraman L, Glasier M, Senchyna M, Sheardown H, Jones L. Comparison of the in vitro lysozyme uptake kinetics on PMMA, conventional hydrogel and first and second generation silicone hydrogel contact lens materials 13th Symposium on the Materials Science and Chemistry of Contact Lenses (New Orlean, USA), 2006

Subbaraman L, Glasier MA, Senchyna M, Sheardown H, Jones L. Lysozyme uptake kinetics on PMMA, FDA groups I, II, IV and first & second generation silicone hydrogel contact lens materials Optom Vis Sci 2006;83:E-Abstract 065258

Subbaraman L, Jones L, Srinivasan S, Varikooty J. Clinical signs & symptoms and protein deposition in one day wear of etafilcon lenses in symptomatic & asymptomatic subjects British Contact Lens Association Annual Meeting, Birmingham, England, 2006

Subbaraman L, Jones L, Srinivasan S, Varikooty J, Glasier MA. The relationship between protein deposition and clinical signs and symptoms in one day wear of etafilcon lenses in symptomatic and asymptomatic subjects Canadian Student Health Research Forum (Winnipeg, Canada), 2006

Subbaraman L, Jones L, Srinivasan S, Varikooty J, Glasier MA. Activity of lysozyme deposited on one-day etafilcon contact lenses is correlated with subjective comfort Optom Vis Sci 2006;83:E-Abstract 060091

Subbaraman LN, Glasier M, Senchyna M, Sheardown H, Jones L. Comparison of in vitro lysozyme uptake kinetics on PMMA, Conventional Hydrogel and First & Second generation Silicone Hydrogel contact lens materials Contact Lens & Anterior Eye 2006;29, 4:195

Subbaraman LN, Glasier MA, Senchyna M, Sheardown H, Jones L. Comparison of in vitro lysozyme uptake kinetics on PMMA, Conventional Hydrogel and First & Second generation Silicone Hydrogel contact lens materials Biomaterials meeting (New Orleans, USA), 2006

Subbaraman LN, Glasier MA, Srinivasan S, Varikooty J, Jones L. Correlation between clinical signs & symptoms and protein deposition in one day wear of etafilcon lenses in symptomatic and asymptomatic subjects University of Waterloo Graduate Student Research Conference, 2006

Subbaraman LN, Jones L, Srinivasan S, Varikooty J, Glasier M. The role of protein deposition and surface wettability in symptoms of contact lens-induced dryness during one day wear of etafilcon lenses in symptomatic and asymptomatic subjects Contact Lens & Anterior Eye 2006;29, 4:194-195

Subbaraman LN, Jones L, Srinivasan S, Varikooty J, Glasier MA. Clinical signs & symptoms and protein deposition in one day wear of etafilcon lenses in symptomatic and asymptomatic subjects Invest Ophthalmol Vis Sci 2006;47: E-Abstract 2400

Suwala M, Glasier M, Subbaraman LN, Jones L. Quantity and conformation of lysozyme deposited on conventional and silicone hydrogel contact lens materials using an in vitro model Biomaterials meeting (New Orleans, USA), 2006

Suwala M, Glasier MA, Jones L. Activity of lysozyme deposited on conventional and silicone hydrogel contact lens materials using an in vitro model Invest Ophthalmol Vis Sci 2006;47:E-Abstract 108

Suwala M, Glasier MA, Subbaraman L, Jones L. Quantity and conformation of lysozyme deposited on conventional and silicone hydrogel contact lens materials using an in vitro model Optom Vis Sci 2006;83:E-Abstract 065259

van Beek M, Sheardown H, Jones L. The effect of wetting agents on competitive protein adsorption to HEMA and HEMA/MA/PVP hydrogels Invest Ophthalmol Vis Sci 2006;47: E-Abstract 112

Varikooty J, Srinivasan S, Subbaraman L, Chan A, Woods C, Jones L, Simpson T, Fonn D. Clinical manifestations of upper lid staining in adapted silicone hydrogel lens wearers Optom Vis Sci 2006;83:E-abstract 065256

Varikooty J, Srinivasan S, Subbaraman L, Feng Y, Jones L, Simpson T, Fonn D. The influence of pre-soaking single-use etafilcon contact lenses on ocular comfort in symptomatic and asymptomatic contact lens wearers Optom Vis Sci 2006;83:E-Abstract 065245

Woods C, Dumbleton K, German T, Dong G, Fonn D. The assessment of contact lens symptomology using wireless handheld communication devices Optom Vis Sci 2006;83: E-Abstract 060073

Woods C, Scott M, Woods J, Simpson T, Fonn D. Clinical grading scales: how many images is ideal? Contact Lens & Anterior Eye 2006;29, 4:207

Woods C, Tsang K, Fonn D. Comparing gravimetric and refractive methods of measuring water content for various soft lenses Optom Vis Sci 2006;83: E-abstract 065276

Woods CA, Roy A, Fonn D. Radial power profiles of single vision slicone hydrogel lenses Optom Vis Sci 2006;83: E-abstract 065286

Woods J, Woods C, Varikooty J, Jones L, Simpson T, Fonn D. A novel method of recording corneal staining that facilitates parametric analysis Optom Vis Sci 2006;83: E-Abstract 065236

Zhang F, Glasier M, Sheardown H, Corstorphine, Jones L. Efficacy of multi-purpose contact lens solutions on passive lysozyme removal from silicone hydrogel and conventional hydrogel contact lenses British Contact Lens Association Annual Meeting, Birmingham, England, 2006

Zhang F, Glasier MA, Sheardown H, Corstorphine L, Jones L. Efficacy of multi-purpose contact lens solutions on passive lysozyme removal from silicone hydrogel and conventional hydrogel contact lenses 13th Symposium on the Materials Science and Chemistry of Contact Lenses (New Orleans, USA), 2006

Zhang F, Glasier MA, Sheardown H, Jones L. The use of confocal microscopy to determine the location of lysozyme deposition in conventional hydrogel and silicone hydrogel contact lens materials 13th Symposium on the Materials Science and Chemistry of Contact Lenses (New Orleans, USA), 2006

Zhang F, Glasier MA, Sheardown H, Jones L. The use of confocal microscopy to determine the location of lysozyme deposition in conventional hydrogel and silicone hydrogel contact lens materials Invest Ophthalmol Vis Sci 2006;47: E-Abstract 2405

Zhang F, Gu Y, Pawliszyn J, McMahon T, Jones L. Bioanalytical analysis of non-polar lipids in human tears using LC/MS American Society for Mass Spectrometry Conference (Seattle, USA), 2006

2005

Dalton K, Jones L. The performance of a novel nanolitre osmometer to investigate diurnal tear film osmolality Optom Vis Sci 2005;82: E-abstract 055071

Duench S. The assessment of diurnal variation of bulbar conjunctival blood flow before and after sleep Graduate Student Research Conference (University of Waterloo, Ontario), 2005

Duench S, Simpson T, Jones L, Flanagan J, Fonn D. Assessment of the diurnal relationship between bulbar conjunctival redness, temperature and blood flow Optom Vis Sci 2005;82: E-Abstract 055003

Dumbleton K. Silicone Hydrogel Lenses: What’s new and different? Envision Meeting. (SUNY, New York), 2005

Dumbleton K. Silicone Hydrogel Contact Lenses: What’s All the Fuss About? Ontario Association of Optometrists congress (Hamilton, Canada), 2005

Dumbleton K. Demanding Eyes / Demanding Lives – Still Room for Improvement? Synoptik Spring Symposium (Gothenburg, Sweden), 2005

Dumbleton K. Detection to Management – What do I do next? Synoptik Spring Symposium (Gothenburg, Sweden), 2005

Dumbleton K, Keir N, Varikooty J, Fonn D. Corneal thickness changes over six months of contralateral extended wear with low and high DK hydrogel lenses Optom Vis Sci 2005;82: E-Abstract 055109

Feng Y, Simpson TL, Fonn D, Hickson–Curran S. The Effect of Soft Toric Contact Lens Wear on Corneal and Conjunctival Sensitivity Measured With a Belmonte Esthesiometer Invest Ophthalmol Vis Sci 2005;46: E-Abstract 2071

Glasier MA, Keech A, Sheardown H, Corstorphine L, Jones L. Galyfilcon (Acuvue Advance) silicone hydrogel contact lenses deposit low levels of relatively active lysozyme Optom Vis Sci 2005;82:E-abstract 055109

Haque S. Corneal Refractive Therapy for hyperopia, mesured with optical coherence tomography Graduate Student Research Conference, University of Waterloo, Ontario, 2005

Haque S, Fonn D, Simpson T, Jones L. Corneal, stromal and epithelial thickness changes following overnight CRT, comparing two high-Dk lens materials Optom Vis Sci 2005;82: E-abstract 050041

Harvey K, Jones L, Simpson T. Using confocal microscopy to investigate the corneal epithelium Graduate Student Research Conference (University of Waterloo, Ontario), 2005

Jones L. Risks and benefits of refractive surgery vs. silicone hydrogels 2nd Asia Cornea & Contact Lens Conference, Hong Kong Polytechnic University (Hong Kong, China), 2005

Jones L. It's all in the surface British Contact Lens Association Annual Meeting (Brighton, England), 2005

Jones L. Differential diagnosis of a red eye British Contact Lens Association Annual Meeting, Brighton, England, 2005

Jones L. A contact lens fairy tale British Contact Lens Association Annual Meeting, Brighton, England, 2005

Jones L. Surface properties of silicone hydrogels International Society for Contact Lens Researchers (ISCLR) Conference (Coolum, Australia), 2005

Jones L, Keir N, Situ P, Fonn D. The impact of post-insertion time on corneal staining and comfort with Group II hydrogel mateials disinfected with various lens care regimens Invest Ophthalmol Vis Sci 2005;46: E-abstract 917

Jones L, Keir N, Situ P, Fonn D. The impact of post-insertion time on corneal staining and comfort with group II hydrogel materials disinfected with various lens care regimens British Contact Lens Association Annual Meeting, Brighton, England, 2005

Jones L, Ngai V, Medley J. Measurement of friction associated with lotrafilcon and polyHEMA hydrogel contact lenses British Contact Lens Association Annual Meeting, Brighton, England, 2005

Jones L, Sheardown H. In vitro absorption of radiolabelled albumin and lysozyme from mixed protein solutions to contact lens materials British Contact Lens Association Annual Meeting, Brighton, England, 2005

Jones L, Srinivasan S, Varikooty J, Simpson T. Novel methodologies to investigate patients with symptoms of dry eye British Contact Lens Association Annual Meeting, Brighton, England, 2005

Jones L, Teichroeb J, Forrest J, Ngai V, Martin J, Medley J. Imaging protein deposits on silicone hydrogel contact lens materials British Contact Lens Association Annual Meeting, Brighton, England, 2005

Keir N, Simpson T, Jones L, Fonn D. Factor analysis of postoperative outcome variables for a CustomCornea(R) LASIK clinical trial Invest Ophthalmol Vis Sci 2005;46: E-abstract 4352

Keir N, Simpson T, Jones L, Fonn D. Factor analysis of postoperative outcome variables for a CustmCornea LASIK clinical trial Graduate Student Research Conference( University of Waterloo, Ontario), 2005

Keir N, Situ P, Richter D, Jones L, Sijpson T, Fonn D. Impact of post-insertion time on corneal staining, sensitivity and comfort with an FDA group II lens disinfected with various care regimens Optom Vis Sci 2005;82: E-abstract 055103

Liu L, Jones L, Sheardown H. Wetting agent release from contact lenses Invest Ophthalmol Vis Sci 2005;46: E-abstract 908

Lu F, Simpson T, Fonn D, Sorbara L. Corneal shape and optical performance after one night of lens wear with two different oxygen transmissible corneal refractive therapy lense Optom Vis Sci 2005;82: E-abstract 050042

Lu F, Simpson T, Sorbara L, Fonn D. The relationship between treatment zone diameter with visual and optical performance in hyperopic corneal refractive therapy lens wearers Invest Ophthalmol Vis Sci 2005;46: E-abstract 2057

Lu F, Simpson TL, Sorbara L, Fonn D. The Relationship Between the Treatment Zone Diameter With Visual and Optical Performance in Hyperopic Corneal Refractive Therapy Lens Wearers Invest Ophthalmol Vis Sci 2005;46: E-Abstract 2057

Moezzi A, Fonn D, Varikooty J, Simpson T. Overnight corneal swelling of silicone hydrogel contact lenses with high oxygen transmissibility Optom Vis Sci 2005;82: E-abstract 050083

Ngai V, Medley JB, Jones L, Forrest J, Teichroeb J. Friction simulation of the anterior surface of hydrogel contact lenses Canadian Biomaterials Society (Waterloo, Ontario), 2005

Ngai V, Medley JB, Jones L, Forrest J, Teichroeb J. Friction of contact lenses: silicone hydrogel versus conventional hydrogel Tribology and Interface Engineering Series 2005;48371-379

Princz MA, Jones L, Sheardown H. Release of wetting agents from Nelfilcon contact lenses Invest Ophthalmol Vis Sci 2005;46: E-abstract 907

Rogers R, Jones L. In vitro and ex vivo wettability of pHEMA and siloxane-based contact lens polymers Invest Ophthalmol Vis Sci 2005;46: E-abstract 918

Rogers R, Jones L. In vitro and ex vivo wettability of pHEMA and siloxane-based contact lens polymers Canadian Biomaterials Society (Waterloo, Ontario), 2005

Rogers R, Jones L. In vitro and ex vivo wettability of pHEMA and siloxane-based contact lens polymers Graduate Student Research Conference (University of Waterloo, Ontario), 2005

Schneider S, Simpson T, Fonn D. Repeatability of Normalized Light Scatter of the Cornea Determined Using Optical Coherence Tomography (OCT) Invest Ophthalmol Vis Sci 2005;46: E-Abstract 2751

Simpson T. Ocular surface sensory channels ISCLR, 2005

Simpson T, Sin S. Bulbar redness and temperature during short-term hydrogel lens-wear Optom Vis Sci 2005;82: E-abstract 050082

Situ P. The relationship between corneal and conjunctival sensitivity, dry eye symptoms, tear film stability and ocular surface characteristics ISCLR, 2005

Situ P, Simpson T, Jones L. Association between corneal and conjunctival sensitivity, tear film stability and ocular surface appearance in subjects with and without dryness symptoms Graduate Student Research Conference (University of Waterloo, Ontario), 2005

Situ P, Simpson T, Jones L, Fonn D, Vehige J, Simmons P. The association between corneal & conjunctival sensitivity, tear film stability & ocular surface appearance in subjects with & without dry eye symptoms Optom Vis Sci 2005;82: E-Abstract 050066

Situ P, Simpson TL, Jones L, Fonn D. Effect of symptoms of dryness, age, and gender on corneal and conjunctival sensitivity to cooling stimuli Optom Vis Sci 2005;46: E-abstract 4448

Sorbara L, Lu F, Fonn D, Simpson T. Topographic keratometric effects of corneal efractive therapy for hyperopia after one night of lens wear Invest Ophthalmol Vis Sci 2005;46: E-abstract 2061

Sorbara L, Lu F, Fonn D, Simpson T. Topographic Keratometric Effects of Corneal Refractive Therapy for Hyperopia After One Night of Lens Wear GOS, 2005

Srinivasan S, Chan C, Jones L, Simpson T, Fonn D. Diurnal variation in inferior tear meniscus height that occurs in dry eyed and non-dry eyed participants Optom Vis Sci 2005;82: E-abstract 050064

Srinivasan S, Heikkila E, Kyveris A, Senchyna M, Jones L. Method optimization for the isolation of total protein from human conjunctival epithelial cells collected via impression cytology Invest Ophthalmol Vis Sci 2005;46: E-abstract 2667

Srinivasan S, Jones L, Senchyna M. Comparison of bulbar conjunctival hyperemia in postmenopausal dry eyed and non-dry eyed subjects Graduate Student Research Conference (University of Waterloo, Ontario), 2005

Subbaraman L, Glasier M, Senchyna M, Jones L. Determination of lysozyme deposition on silicone hydrogel, group II and group IV contact lenses as a function of time Graduate Student Research Conference (University of Waterloo, Ontario), 2005

Subbaraman L, Glasier M, Senchyna M, Jones L. An in vitro comparison of the kinetics of lysozyme deposition on silicone hydrogel, group II and group IV contact lens materials Graduate Student Research Conference, University of Waterloo, Ontario, 2005

Subbaraman L, Glasier M, Senchyna M, Jones L. An in vitro comparison of the kinetics of lysozyme deposition on silicone hydrogel, group II and group IV contact lens materials British Contact Lens Association Annual Meeting (Brighton, England), 2005

Subbaraman L, Glasier MA, Senchyna M, Jones L. Kinetics of 1251-labelled lysozyme deposition on silicone hydrogel, FDA group II and group IV contact lenses Optom Vis Sci 2005;82:E-abstract 050046

Subbaraman L, Senchyna M, Jones L. Determination of in vitro lysozyme uptake kinetics on silicone hydrogel, FDA group II and FDA group IV hydrogel contact lens materials 24th Canadian Biomaterials Society Conference (Waterloo, Ontario), 2005

Subbaraman L, Senchyna M, Jones L. Kinetics of 1251-labelled lysozyme deposition on silicone hydrogel FDA Group II and Group IV contact lenses 13th Scientific Meeting of the International Society for Contact Lens Research, Coolum, Australia, 2005

Subbaraman LN. Subjective and objective measures of corneal staining related to multipurpose care systems

Subbaraman LN, Glasier MA, Senchyna M, Jones L. Kinetics of in vitro lysozyme deposition on silicone hydrogel, group II and group IV contact lens materials Invest Ophthalmol Vis Sci 2005;46:E-abstract 910

Subbaraman LN, Glasier MA, Senchyna M, Jones L. An in vitro comparison of the lysozyme uptake kinetics on first & second generation silicone hydrogel and conventional hydrogel contact lens materials Institute for Ocular Biomaterials Research Meeting (Hamilton, Ontario), 2005

Subbaraman LN, Jones L, Srinivasan S, Varikooty J, Glasier M. The relationship between protein deposition and clinical signs & symptoms in one day wear of etafilcon lenses in symptomatic and asymptomatic subjects Canadian Student Health Research Forum, 2005

Teichroeb J, Forrest J, Jones L. Protein deposition onto implantable biomaterials measured with Quartz Crystal Microblanace (QCM) Graduate Student Research Conference (University of Waterloo, Ontario), 2005

Teichroeb J, Ngai V, Forrest J, Jones L. Thermal stability of lysozyme adsorbed onto gold nanoparticles Canadian Biomaterials Society (Waterloo, Ontario), 2005

Vaccari S, Simpson T, Jones L, Flanagan J, Fonn D. The assessment of diurnal variation of bulbar conjunctival hyperemia, temperature and conjunctival blood flow before and after sleep Invest Ophthalmol Vis Sci 2005;46; E-abstract 2681

Varikooty J. Ocular surface sensations during forced eye opening International Vision Science and Optometry Conference (EIVOC), Elite School of Optometry, Chennai, India, 2005

Varikooty J, Situ P, Jones L, Fonn D. Clinical performance of alexidine-based and polyquad-based multipurpose solutions when used with daily wear balafilcon lenses Optom Vis Sci 2005;82: E-abstract 055100

Vehige J, Simmons P, Feng Y, Situ P, Simpson T, Jones L, Fonn D. Does the subjective evaluation of symptoms of dryness (SESoD) as a single variable predict the severity of signs and symtpoms of dry eye disease? Optom Vis Sci 2005;82: E-abstract 050067

Woods C, Jones D, Jones L, Morgan P. Canadian optometrists prescribing habits, a six-year period (2000-05) Optom Vis Sci 2005;82: E-abstract 055128

Woods C, Scott M, Woods J, Simpson T, Fonn . A novel method to create clinical grading scales Optom Vis Sci 2005;82: E-abstract 050040

Zhang F, Glasier MA, Sheardown H, Corstorphine L, Jones L. Efficacy of multi-purpose contact lens solutions on passive lysozyme removal from silicone hydrogel and conventional hydrogel contact lenses Optom Vis Sci 2005;82 [ Show Abstract ]

E-abstract 055098

2004

Bayer S, Jones L, Senchyna M, Subbaraman L, Glasier M, Dumbleton K, Fonn D. Effect of rewetting drops on comfort and protein deposition of silicone hydrogel (Focus Night & Day) contact lenses Invest Ophthalmol Vis Sci 2004;45ARVO E-Abstract 1575

Bayer S, Jones LW, Senchyna M, Subbaraman L, Glasier M, Dumbleton K, Fonn D. Effect of rewetting drops on comfort and protein deposition of silicone hydrogel (Focus Night&Day) contact lenses Invest Ophthalmol Vis Sci 2004;45, 4:s65

Dalton K, Teichroeb J, Chan J, Forrest J, Jones L. Study of protein deposition on hydrogels with QCM technology Waterloo-Guelph Physics Conference (Guelph, Ontario), 2004

Dumbleton K. Contact Lens Troubleshooting International Symposium on the Eye and Vision (Montreal, Quebec), 2004

Dumbleton K. Clinical Aspects of Silicone Hydrogel Contact Lenses: Mucin Balls, Myopia and Microcysts Silicone Hydrogel Contact Lenses: Challenges, Controversies & New Opportunities. AOA Special Symposium (Orlando, Florida), 2004

Dumbleton K. Success with Silicone Hydrogel Lenses SBAO Meeting (Lugano, Switzerland), 2004

Dumbleton K. Differential Diagnosis of Contact Lens Complications SBAO Meeting (Lugano, Switzerland), 2004

Dumbleton K, Jones L, Bayer S, Fonn D. Clinical performance and corneal staining associated with silicone hydrogel materials used on a daily wear basis Contact Lens & Anterior Eye 2004;27, 2:97-98

Dumbleton K, Keir N, Moezzi A, Jones L, Fonn D. Redness, dryness and comfort following refitting long-term low Dk lens wearers with silicone hydrogel lenses Optom Vis Sci 2004;81, 12s:31

Dumbleton K, MacDougall N, Jones L, Moezzi A, Fonn D, McNally J. Changes in hyperemia subsequent to refitting long-term low Dk wearers with silicone hydrogel lenses on a daily wear basis Contact Lens & Anterior Eye 2004;27, 2:102

Feng Y, Situ P, Jones L, Simpson T. Tear meniscus height is a poor predictor of ocular dryness symptoms Tear Film and Ocular Surface Society (Puerto Rico), 2004

Fonn D, Jones L, Chan A. Corneal staining does not affect the comfort of soft contact lens wear Tear Film and Ocular Surface Society (Puerto Rico), 2004

Fonn D, Moezzi A, Simpson TL, Situ P. Confirmation of a yoked corneal swelling response between the test and contralateral control eye Optom Vis Sci 2004;81, 12s:30

Glasier MA, Senchyna M, Jones L, Mahabir N. Method optimization for the quantification of total protein deposited on silicone hydrogel contact lens materials Invest Ophthalmol Vis Sci 2004;45; E-Abstract 1583

Haque S, Fonn D, Sorbara L, Simpson TL. Corneal and epithelial thickness changes following one night of CRT gas permeable lens wear for hyperopia, measured with optical coherence tomography Optom Vis Sci 2004;81, 12s:27

Haque S, Jones L, Simpson T. Corneal and epithelial thickness in keratoconus: a comparison of ultrasonic pachymetry, orbscan and optical coherence tomography measurements Invest Ophthalmol Vis Sci 2004;45: E-Abstract 2891

Jones L, Bayer S, Dumbleton K, Fonn D. Corneal staining associated with silicone hydrogel materials used on a daily wear basis with ReNu and AOSept care regimens International American Academy Meeting (Hawaii), 2004

Jones L, Bayer S, Senchyna M, Subbaraman L, Glasier M, Dumbleton K, Fonn D. Rewetting drops influence comfort and protein deposition on silicone hydrogel contact lenses Optom Vis Sci 2004;81, 12s:57

Jones L, Rahman S, Leech R, Simpson T, Fonn D. Determination of inferior tear meniscus height and inferior tear meniscus volume using optical coherence tomography Invest Ophthalmol Vis Sci 2004;45: E-Abstract 144

Jones L, Rahman S, Leech R, Simpson T, Fonn D. Determination of inferior tear meniscus height and volume using optical coherence tomography Tear Film and Ocular Surface Society (Puerto Rico), 2004

Jones L, Schickler J, Sorbara L, Dumbleton K, Keir N, Bayer S. Corneal staining with FDA group II and silicone hydrogel contact lens materials used with PHMB-based disinfection systems 7th World Biomaterials Conference (Sydney, Australia), 2004

Jones L, Senchyna M, Glasier MA. Quantification and conformational state of lysozyme deposition on daily wear etafilcon, balafilcon and lotrafilcon contact lens materials Tear Film and Ocular Surface Society (Puerto Rico), 2004

Jones L, Senchyna M, Glasier MA. Quantification and conformational state of lysozyme deposition on daily wear etafilcon, balafilcon and lotrafilcon contact lens materials 7th World Biomaterials Conference (Sydney, Australia), 2004

Lazon de la Jara P, Capaldi P, Williams L, Fonn D, Cronje S, Sweeney D, Holden BA. IACLE influence broad and beneficial to contact lens education in Latin America Optom Vis Sci 2004;81, 12s:268

Lorentz H, Senchyna M, Jones L. Optimized procedure for the extraction of lipid deposits from silicone hydrogel contact lenses Invest Ophthalmol Vis Sci 2004;45: E-Abstract 1537

Lu F, Simpson TL, Sorbara L, Fonn D. Optical performance after one night of hyperopic corneal refractive therapy lens wear Optom Vis Sci 2004;81, 12s:72

Lu FU, Simpson TL, Sorbara L, Fonn D, Jones LW. The relationship between treatment zone diameter and visual, optical and subjective performance in CRT(TM) wearers Invest Ophthalmol Vis Sci 2004;45: E-Abstract 1576

Ngai V, Medley J, Jones L. Measurement of friction associated with lotrafilcon and HEMA hydrogel contact lenses Tear Film and Ocular Surface Society (Puerto Rico), 2004

Ngai V, Medley JB, Jones L. Friction of contact lenses: Silicone and conventional hydrogels 7th World Biomaterials Conference (Sydney, Australia), 2004

Senchyna M, Heikkila E, Vehige J, Simmons P, Jones L, Bornstein M. Relative quantitation of major basic protein species found in the human tear film Invest Ophthalmol Vis Sci 2004;45: E-Abstract 4831

Sheardown H, Jones L. In vitro adsorption of albumin and lysozyme from mixed protein solutions to commercial contact lenses Tear Film and Ocular Surface Society (Puerto Rico), 2004

Sheardown H, Jones L. In vitro adsorption of albumin and lysozyme from mixed protein solutions to commercial contact lenses 7th World Biomaterials Conference (Sydney, Australia), 2004

Simpson T, Situ P, Jones L. Association between corneal and conjunctival sensitivity, tear film stability and ocular surface appearance in subjects with and without dryness symptoms Tear Film and Ocular Surface Society (Puerto Rico), 2004

Situ P, Moezzi A, Fonn D, Simpson TL. Comparing perilimbal hyperemia after overnight wear of O2 Optix and Acuvue 2 contact lenses Optom Vis Sci 2004;81, 12s:59

Sorbara L, Lu F, Fonn D, Simpson TL. Refractive and keratometric effects of corneal refractive therapy for hyperopia after one night of lens wear Optom Vis Sci 2004;81, 12s:72

Sorbara L, Lu FU, Kort R, Fonn D, Simpson TL. Topographic keratometric effects of corneal refractive therapy after one month of lens wear Invest Ophthalmol Vis Sci 2004;45, 4:65

Srinivasan S, Jones L, Senchyna M. Comparison of bulbar conjunctival hyperemia in postmenopausal dry eyed and non dry eyed subjects Optom Vis Sci 2004;81, 12s:213

Srinivasan S, Jones L, Senchyna M. Comparison of non-invasive tear break up time and bulbar conjunctival hyperemia in postmenopausal dry-eyed and non dry-eyed subjects Tear Film and Ocular Surface Society (Puerto Rico), 2004

Srinivasan S, Senchyna M, Heikkila L, Jones L. Method optimization for the isolation of total RNA from human conjunctival epithelial cells collected via impression cytology Invest Ophthalmol Vis Sci 2004;45: E-Abstract 1500

Subbaraman LN, Senchyna M, Jones L. Stabilization of lysozyme mass extracted from silicone hydrogel contact lens materials Invest Ophthalmol Vis Sci 2004;45:ARVO E-Abstract 1556

Subbaraman LN, Senchyna M, Jones L. Stabilization of lysozyme mass extracted from silicone hydrogel contact lens materials Graduate Student Research Conference (University of Waterloo, Ontario), 2004

Teichroeb J, Forrest J, Ngai V, Martin J, Jones L, Medley J. In situ imaging of in vitro deposited lysozyme and albumin on silicone hydrogel and Hema contact lens materials Tear Film and Ocular Surface Society (Puerto Rico), 2004

Teichroeb J, Forrest J, Ngai V, Martin J, Jones L, Medley J. Imaging protein deposits on silicone hydrogel contact lens materials Optom Vis Sci 2004;81, 12s:83

Vaccari S, Simpson T, Jones L, Fonn D. Assessment of diurnal variation of bulbar conjunctival hyperemia using a novel objective method Invest Ophthalmol Vis Sci 2004;45: E-Abstract 4828

Varikooty JP, Simpson TL, Jones LW, Fonn D. Subjective sensations reported during the interblink interval reflect different components of ocular surface sensitivity Invest Ophthalmol Vis Sci 2004;45: E-abstract 99

2003

Bayer S, Simpson T, Sorbara L, Fonn D. Variation of objective ocular redness related to age and gender Invest Ophthalmol Vis Sci 2003;44: E-Abstract 3703

Cronje S, Williams L, Sweeney D, Fonn D, Sorbara L, Holden B, IACLE team. Providing educational support to contact lens educators Optom Vis Sci 2003;80, 12s:68

Dumbleton K. Silicone-Hydrogel Continuous Wear Contact Lenses: The Biggest Breakthrough in Contact Lens History? Clinical Research Update Canadian Association of Optometrists congress (Halifax, Canada), 2003

Dumbleton K. Diagnosis and Management of Clinical Complications Canadian Association of Optometrists congress (Halifax, Canada), 2003

Dumbleton K. Differential Diagnosis and Management of Contact Lens Complications Night and Day Clinical Council Symposium (Ottawa, Canada), 2003

Dumbleton K. Mucin Balls, Myopia and Microcysts Night and Day Clinical Council Symposium (Ottawa, Canada), 2003

Dumbleton K. Mechanical Complications with Silicone Hydrogels Canadian Continuous Wear Symposium (Waterloo, Canada), 2003

Feng Y, Simpson T. Interaction of corneal thermal, mechanical and chemical stimuli at threshold measured using a Belmonte Esthesiometer Invest Ophthalmol Vis Sci 2003;44:E-abstract 3710

Feng Y, Simpson TL. Interpretation of Optical Coherence Tomography in the anterior segment of the eye University of Waterloo Graduate Research Conference Handbook, 2003

Fonn D. Corneal and epithelial thickness changes from overnight wear of CRT lenses Contact Lens & Anterior Eye 2003;26, 4:204

Fonn D. New discoveries on how the cornea changes with contact lens wear British Contact Lens Association Conference, Brighton, England, 2003

Fonn D. Contact lenses for life, what can be done for presbyopes International Soceity for Contact Lens Research, Biennial Scientific Conference, Mallorca, Spain, 2003

Fonn D. Has silicone hydrogels had an effect on dryness and discomfort symptoms? Contact Lens & Anterior Eye 2003;26, 4:203

Haque S, Jones L, Fonn D, Simpson T, Sorbara L. Changes in topographical thickness of the total cornea following 4 weeks of overnight CRT RGP lens wear measured with OCT Optom Vis Sci 2003;80, 12s:243

Jones L. Ocular compatibility of silicone hydrogel contact lens materials MMO/EMK Research Day in Biointerfaces (McMaster University, Canada), 2003

Jones L, Dumbleton K, Fonn D, Dillehay S. Comfort and compliance with frequent replacement soft contact lenses in North America: a survey Contact Lens & Anterior Eye 2003;26, 4:205-206

Jones L, Dumbleton K, Woods C, Joseph J. Practitioner perspectives towards recommendation of daily disposable and continuous wear lenses: a global view Contact Lens & Anterior Eye 2003;26, 2:105

Jones L, Leech R, Rahman S, Simpson T, Fonn D. A novel method to determine tear prism height Contact Lens & Anterior Eye 2003;26, 4:206-207

Jones L, Rahman S, Leech R, Simpson T, Fonn D. The use of optical coherence tomography to determine tear volume International Society for Contact Lens Research (Mallorca, Spain), 2003

Jones L, Rahman S, Leech R, Simpson T, Fonn D, Vehige J, Simmons P. Determination of tear meniscus height using a novel method based upon optical coherence tomography BCLA Conference (Brighton, England), 2003

Jones L, Rahman S, Leech R, Simpson T, Fonn D, Vehige JG, Simons PA. Determination of tear meniscus height using a novel method based upon Optical Coherence Tomography Invest Ophthalmol Vis Sci 2003;44: E-Abstract 2461

Karlgard C, Jones L, Sarkar D, Leung T, Moresoli C. XPS characterization of soft contact lens materials Contact Lens & Anterior Eye 2003;26, 4:206

Lazon P, Capaldi P, Fonn D, Cronje S, Sweeney D, Holden B. Setting an educational standard in contact lens education in Latin America development of the IACLE accreditation examination Optom Vis Sci 2003;80, 12s:64

Lu F, Simpson T, Jones L. Repeatability of Orbscan II pachymetry measures Optom Vis Sci 2003;80, 12s:100

Lu F, Sorbara L, Kort RA, Fonn D, Simpson T, Jones L. Topographic keratometric effects of corneal refractive therapy after one night of lens wear Invest Ophthalmol Vis Sci 2003;44: E-Abstract 3699

Lu F, Sorbara L, Kort RA, Fonn D, Simpson T, Jones L. Effects of corneal shape after one night of CRT lens wear University of Waterloo Graduate Research Conference Handbook, 2003

MacDougall N, Situ P, Chan A, Fonn D, Simpson TL, Jones L, Hakim O. Quality of vision outcomes following custom LASIK University of Waterloo Graduate Research Conference Handbook, 2003

MacDougall N, Situ P, Chan A, Simpson T, Jones L, Fonn D, Hakim O. Low contrast acuity, contrast sensitivity and higher order aberration outcomes following Custom LASIK Invest Ophthalmol Vis Sci 2003;44: E-Abstract 2629

Quaid P, Simpson T, Flanagan J. Monocular and dichoptic masking effects on the frequency doubling illusion Invest Ophthalmol Vis Sci 2003;44, 4:

Senchyna M, Glasier M, Jones L, Dumbleton K. Assessing the degree of denatured lysozyme deposited on conventional and silicone hydrogel contact lenses Contact Lens & Anterior Eye 2003;26, 4:206

Senchyna M, Jones L, Glasier M, Dumbleton K, Bayer S. The influence of peroxide-based versus a polyhexanide-based MPS in controlling the quantity and conformation of deposited lysozyme on silicone-hydrogel contact lenses Invest Ophthalmol Vis Sci 2003;44: E-Abstract 3688

Simpson TL, Fonn D, Wang J, Hickson-Curran S. Suprathreshold scaling of limbal mechanical stimuli Invest Ophthalmol Vis Sci 2003;44: E-Abstract 3709

Simpson TL, Henderson L, Bond D. The association between eye colour and corneal sensitivity Optom Vis Sci 2003;80, 12s:256

Situ P, Simpson TL, Fonn D. Objective measure of halo size with multifocal contact lenses Invest Ophthalmol Vis Sci 2003;44: E-Abstract 2615

Sorbara L, Lu F, Kort RA, Fonn D, Simpson TL. Refractive, keratometric and visual effects of corneal refractive therapy after one month of lens wear Optom Vis Sci 2003;80, 12s:189

Sorbara L, MacDougall N, Situ P, Chan A, Hakim O, Fonn D, Jones L, Simpson T. Relationship between corneal shape and refractive power pre- and post-Custom LASIK Invest Ophthalmol Vis Sci 2003;44: E-Abstract 2615

Varikooty J, Simpson TL, Fonn D. Changes in ocular surface temperature and redness Invest Ophthalmol Vis Sci 2003;44: E-Abstract 3752

Vasudevan B, Simpson T. Comparison of corneal thickness using 4 pachymetry devices Optom Vis Sci 2003;80, 12s:100

Wang J, Simpson TL, Fonn D. Objective measurements of corneal light backscatter during corneal swelling using Optical Coherence Tomography Invest Ophthalmol Vis Sci 2003;44: E-Abstract 3666

2002

Bayer S, Simpson T, Sorbara L, Fonn D. Hawthorne effect related to ocular redness with artificial tears Optom Vis Sci 2002;79, 12s:306

Chalmers R, Begley C, Venkataraman K, Mertzanis P, Abetz L, Snyder C, Simpson T, Edrington T, Caffery B, Nelson JD. Clinical diagnostic criterion for dry eyes: a comparison of signs between Sjogren’s Syndrome, dry eye subjects and normal controls Optom Vis Sci 2002;79, 12s:255

Dumbleton K. Inflammation and Infection: Differential Diagnosis and Management in Contact Lens Wearers New Zealand tour for New Zealand Association of Optometrists (Auckland Centre, Taupo, Wellington, Auckland North Shore), 2002

Dumbleton K. Silicone Hydrogel Lenses Victorian College of Optometry 2002 Continuing Education Program (Melbourne, Australia), 2002

Dumbleton K. Mucin Balls, Myopia and Microcysts Night and Day Clinical Council Symposium (Quebec City, Canada), 2002

Dumbleton K. Extended Wear Contact Lenses – They’re Back! University of Waterloo School of Optometry Annual Continuing Education Program: Contemporary Assessment and Treatment of Refractive Error (Waterloo, Ontario), 2002

Dumbleton K. Mucin Balls, Myopia and Microcysts Night and Day Clinical Council Symposium (Atlanta, Georgia), 2002

Dumbleton K. Do adverse events occur with silicone hydrogel continuous wear? Contact Lens & Anterior Eye 2002;25, 4:186

Dumbleton K. Severity and management of contact lens related complications with continuous wear of high Dk hydrogel lenses Contact Lens & Anterior Eye 2002;25, 1:31-32

Dumbleton K. Silicone hydrogel lenses – for everyone or just a select few? Contact Lens & Anterior Eye 2002;25, 4:179-180

Dumbleton K, Jones L. Managing Continuous Wear Adverse Events Night and Day Clinical Council Symposium (Atlanta, Georgia), 2002

Dumbleton K, Jones L, MacDougall N, Simpson T, Fonn D. Patient satisfaction with silicone hydrogel continuous wear contact lenses Optom Vis Sci 2002;79, 12s:8

Dumbleton K, MacDougall N, Jones L, Simpson T, Fonn D. Patient satisfaction with continuous wear contact lenses versus LASIK CIBA-Vision Educators Meeting abstract book (Atlanta, Georgia), 2002

Edwards K, Jones L. Torics without tears Contact Lens & Anterior Eye 2002;25, 1:25

Flanagan J, Forrest A, Simpson T. Retinal adaptation of the contralateral eye influences frequency doubling sensitivity Invest Ophthalmol Vis Sci 2002;43:E-abstract 2163

Fonn D. Contact lens correction of presbyopia – how to make it work The Irving Fatt Memorial Lecture, The Annual Sarver Series Continuing Education, University of California, Berkeley, California, 2002

Hrynchak P, Hutchings N, Jones D, Simpson T. A comparison of cup-to-disc ratio measurement in normal subjects using OCT image analysis of the optic nerve head and stereo biomicroscopy Optom Vis Sci 2002;79, 12s:90

Jones L. Visual acuity and visual performance: an update on its measurement Contact Lens & Anterior Eye 2002;25, 4:182

Jones L. Novel contact lens materials: What problems remain? Contact Lens & Anterior Eye 2002;25, 4:179

Jones L. In vitro evaluation of the dehydration characteristics of silicone-hydrogel and conventional hydrogel contact lens materials Contact Lens & Anterior Eye 2002;25, 1:27

Jones L, Cheng A, Woods C, Levitt L. Frequency of follow-up in asymptomatic contact lens wearers: reaching a consensus view Contact Lens & Anterior Eye 2002;25, 1:39

Jones L, Dumbleton K, Fonn D. A survey to determine the patient comfort and compliance with different contact lens replacement schedules CIBA-Vision Educators Meeting abstract book (Atlanta, Georgia), 2002

Jones L, Dumbleton K, Fonn D, Dillehay S. Comfort and compliance with frequent replacement soft contact lenses Optom Vis Sci 2002;79, 12s:259

Jones L, Dumbleton K, MacDougall N, Fonn D. Subjective comfort with daily wear of silicone hydrogel contact lenses CIBA-Vision Educators Meeting abstract book (Atlanta, Georgia), 2002

Jones L, Dumbleton K, Woods C, Joseph J. Practitioner perspectives towards recommendation of daily disposable and continuous wear lenses: a global view Optom Vis Sci 2002;79, 12s:6

Jones L, Leech R, Rahman S, Simpson T, Fonn D. A novel method to determine tear prism height Optom Vis Sci 2002;79, 12s:252

Jones L, Long J, Chen P. The impact of contact lens care regimens on the in vitro wettability of conventional and silicone-hydrogel contact lens materials Invest Ophthalmol Vis Sci 2002;43; E-abstract 3097

Jones L, MacDougall N, Sorbara L, Fonn D. The clinical performance of a polyquad-based care regimen with a silicone-hydrogel material used on a daily wear basis Contact Lens & Anterior Eye 2002;25, 4:211

Jones L, May C, Nazar L, Simpson T. In vitro evaluation of the dehydration characteristics of silicone-hydrogel and conventional hydrogel contact lens materials Society of Biomaterials, 28th Annual Conference (Tampa, Florida), 2002

Jones L, Sarkar D, Leung T, Moresoli C. XPS characterization of soft contact lens materials Optom Vis Sci 2002;79, 12s:134

Jones L, Senchyna M, Dumbleton K. Ocular biocompatibility of silicone-hydrogel contact lens materials 1st World Summit on Silicone-Hydrogel Contact Lenses (San Diego, California), 2002

Jones L, Senchyna M, Forbes I, May C. The influence of multipurpose care regimens in controlling lysozyme deposition on Etafilcon contact lenses Contact Lens & Anterior Eye 2002;25, 4:211

Jones L, Senchyna M, Louie D, May C, Schickler J. A comparative evaluation of lysozyme and lipid deposition on Etafilcon, Balafilcon and Lotrafilcon contact lens materials Society for Biomaterials, Trans 28th Ann Clin Conf (Tampa, Florida), 2002

Jones L, Senchyna M, Louie D, May C, Schickler J. A comparative evaluation of lysozyme and lipid deposition on Etafilcon, Balafilcon and Lotrafilcon contact lens materials Contact Lens & Anterior Eye 2002;25, 1:38

Karlgard C, Jones L, Moresoli C. Ciprofloxacin interaction with silicone hydrogel contact lenses Society for Biomaterials, Trans 28th Ann Clin Conf, Tampa, Florida, 2002

Karlgard C, Jones L, Moresoli C. Deposition of ocular pharmaceutical agents onto silicone hydrogel contact lens materials Society for Biomaterials, Trans 28th Ann Clin Conf, Tampa, Florida, 2002

Karlgard C, Jones L, Moresoli C. Uptake and release of Acular from silicone-hydrogel and conventional hydrogel contact lens materials Contact Lens & Anterior Eye 2002;25, 1:38

Karlgard C, Sarkar DK, Leung KT, Jones L, Moresoli C. Surface characterization of silicone hydrogel contact lens materials Canadian Biomaterials Society Annual Conference, Toronto, Canada, 2002

Karlgard C, Sarkar DK, Leung KT, Jones L, Moresoli C. Sample preparation of soft contact lenses for surface analysis by XPS Surface Science Canada 2002, University of Ottawa, Canada, 2002

Karlgard C, Wong N, Jones L, Moresoli C. Uptake and release of topical ocular pharmaceuticals from silicone-hydrogel and conventional hydrogel contact lenses in vitro Contact Lens & Anterior Eye 2002;25, 4:208

Karlgard C, Wong NS, Jones L, Moresoli C. Drug interactions with soft contact lenses University of Waterloo Graduate Research Conference, Waterloo, Ontario, 2002

MacDougall N, Situ P, Chan A, Fonn D, Jones L, Simpson T. Comparison between orbscan and ultrasound central corneal thickness measurements Optom Vis Sci 2002;79, 12s:264

MacDougall N, Situ P, Chan A, Fonn D, Jones L, Simpson T. Single site 6-month clinical outcomes for custom LASIK Optom Vis Sci 2002;79, 12s:173

Senchyna M, Glasier M, Thorogood N, Jones L, Dumbleton K. Assessing the degree of denatured lysozyme deposited on conventional and silicone-hydrogel contact lenses Optom Vis Sci 2002;79, 12s:135

Senchyna M, Jones L, Louie D, Forbes I, May C. Optimization of methodologies to characterise lysozyme deposition found on balafilcon and etafilcon contact lens materials Invest Ophthalmol Vis Sci 2002;43: E-abstract 3082

Senchyna M, Louie D, Meadows E, Jones L. Quantification of sIgA concentration in tears of dry eye and non-dry eye individuals Contact Lens & Anterior Eye 2002;25, 1:38

Simpson T, Sin T. The effect of topical vasoconstriction on bulbar redness measured objectively Invest Ophthalmol Vis Sci 2002;43:E-abstract 3108

Simpson T, Sin T, Joseph J. Repeatibility of corneal and epithelial thickness using OCT Optom Vis Sci 2002;79, 12s:7

Situ P, du Toit R, Fonn D, Simpson T. Refractive error in presbyopes after 6 months of monovision contact lens wear Invest Ophthalmol Vis Sci 2002;43, 4:125

Sorbara L, Bayer S, Simpson T, Fonn D. Comparison of objective, clinical and self-reported bulbar conjunctival redness Invest Ophthalmol Vis Sci 2002;43: E-Abstract 119

Sorbara L, Kort R, Lu H, Simpson T, Fonn D. Overnight refractive and keratometry effects of refractive therapy Optom Vis Sci 2002;79, 12s:127

Sorbara L, Kort RA, Lu FH, Simpson T, Fonn D. Refractive and keratometric effects of corneal refractive therapy after one night of lens wear Optom Vis Sci 2002;79, 12s:

Subbaraman LN. Stereopsis and Luminance Disparity 6th All India Optometry Conference (Kolkata, India), 2002

Varikooty J, Simpson T, Jones L, Fonn D. Ocular discomfort during tear film drying Invest Ophthalmol Vis Sci 2002;43: E-abstract 3106

Wang J, Fonn D, Simpson T. Topographical thickness changes of the epithelium and total corneal after overnight lens wear of CRT™ rigid gas permeable lenses measured with OCT Optom Vis Sci 2002;79, 12s:2

Wang J, Fonn D, Simpson T, Jones L. The measurement of corneal epithelial thickness using the OCT in response to hypoxia induced by soft contact lens and eye closure Contact Lens & Anterior Eye 2002;25, 1:36

Wang JH, Fonn D, Simpson TL, Jones L. Pre-corneal and pre- and post-lens tear film thickness measured with optical coherence tomography Invest Ophthalmol Vis Sci 2002;43: E-abstract 3078

2001

du Toit R, Situ P, Simpson T, Fonn D. Predicting preference for monovision and bifocal contact lens wear: results from a one year clinical trial Invest Ophthalmol Vis Sci 2001;42: E-abstract 3170

Dumbleton K. Continuous Wear Silicone-Hydrogel Contact Lenses: Practical Considerations 20th Optometry Congress, Association of Optometrists of France (Paris, France), 2001

Dumbleton K, Chalmers R, Bayer S, Fonn D, NcNally J. Lens base curve and subjective comfort with silicone hydrogel continuous wear lenses Optom Vis Sci 2001;78, 12s:227

Dumbleton K, Fonn D, Jones L, Williams-Lyn D, Richter D. Severity and management of contact lens related complications with continuous wear of high Dk silicone hydrogel lenses BCLA Conference, Brighton, England, 2001

Feng Y, Simpson T. Comparison of corneal and conjunctival chemical sensitivity evoked by CO2 delivered by the Belmonte esthesiometer Invest Ophthalmol Vis Sci 2001;42, 4:s590

Hartwick A, Oriowo O, Jones L, Sivak J. In vitro ocular Irritancy of multipurpose contact lens solutions Invest Ophthalmol Vis Sci 2001;42:ARVO Abstract 3184

Hrynchak P, Simpson T, Jones D, Hutchings N. A comparison of cup-to-disc ratio evaluation in normal subjects using stereo biomicroscopy and a digital image of the optic nerve Optom Vis Sci 2001;78, 12s:65

Jones D, Schulze M, Simpson T. The Application of Clinical Grading Scales by Trained and Non-trained Observers Contact Lens & Anterior Eye 2001;2523-51

Jones L. Contact lens materials: A practitioner’s viewpoint New Zealand Contact Lens Society (Blenheim, New Zealand), 2001

Jones L, May C, Nazar L. In vitro evaluation of the dehydration characteristics of silicone-hydrogel and conventional hydrogel contact lens materials 12th Symposium on the Material Science and Chemistry of Contact Lens Materials (New Orleans), 2001

Jones L, Senchyna M, Louie D, Schickler J. A comparative evaluation of lysozyme and lipid deposition on Etafilcon, Balafilcon & Lotrafilcon contact lens materials 12th Symposium on the Material Science and Chemistry of Contact Lens Materials (New Orleans), 2001

Jones L, Senchyna M, Louie D, Schickler J. A comparative evaluation of lysozyme and lipid deposition on Etafilcon, Balafilcon & Lotrafilcon contact lens materials Invest Ophthalmol Vis Sci 2001;42: E-abstract 3186

Karlgard C, Jones L, Moresoli C. Uptake and release of topical ophthalmic pharmaceuticals from silicone-hydrogel and conventional hydrogel contact lens materials International Society for Contact Lens Research (Sun Valley, Idaho), 2001

Karlgard C, Jones L, Moresoli C. Uptake and release of Ciprofloxacin from silicone-hydrogel and conventional hydrogel contact lens materials 12th Symposium on the Material Science and Chemistry of Contact Lens Materials, New Orleans, 2001

Karlgard C, Jones L, Moresoli C. Uptake and release of Ciloxan from silicone-hydrogel and conventional hydrogel contact lens materials Optom Vis Sci 2001;78, 12s:202

Karlgard C, Jones L, Moresoli C. Uptake and release of Ciloxan from silicone-hydrogel and conventional hydrogel contact lens materials Invest Ophthalmol Vis Sci 2001;42: E-abstract 3179

MacDougall N, Sorbara L, Jones L, Fonn D. The clinical performance of a polyquad-based care regimen with a silicone-hydrogel material used on a daily wear basis Optom Vis Sci 2001;78, 12s:309

Moezzi A, Fonn D, Sorbara L, Simpson T. Effects of contact lens induced swelling on anterior and posterior corneal surfaces Optom Vis Sci 2001;78, 12s:303

Renner D, Begley C, Wilson G, Wright A, Westen S, Simpson T. Ocular sensations associated with tear break-up Invest Ophthalmol Vis Sci 2001;42, 4:s36

Schulze M, Jones D, Simpson T. The Production of an Enhanced Grading Scale for Determination of Ocular Hyperaemia (BCLA 2001 Da Vinci Award) Contact Lens & Anterior Eye 2001;2523-51

Senchyna M, Jones L, Forbes I, May C, MacDougall N, Sorbara L. The influence of multipurpose care regimens in controlling lysozyme deposition on Etafilcon contact lenses Optom Vis Sci 2001;78, 12s:308

Senchyna M, Louie D, Meadows E, Jones L. Quantification of sIgA concentration in tears of dry eye and non-dry eye individuals Invest Ophthalmol Vis Sci 2001;42, 4:s37 #211

Simpson T, Feng Y. Properties of psychometric functions obtained from the cornea using the Belmonte esthesiometer Invest Ophthalmol Vis Sci 2001;42, 4:s596

Simpson T, Feng Y, Fonn D, Hickson-Curran S. Scaling ocular discomfort induced using different concentrations of CO2 Optom Vis Sci 2001;78, 12s:119

Situ P, Simpson TL, Fonn D. Objective measure of ocular redness: the repeatability and the association with subjective scale Invest Ophthalmol Vis Sci 2001;42, 4:s597 #3212

Sorbara L, Machalitza A, Simpson T, Jones L, Fonn D. Is tear turnover rate measured by fluorophotometry a valuable tool in identifying dry eye patients? Invest Ophthalmol Vis Sci 2001;42, 4:s39 #218

Varikooty JP, Simpson TL, Jones L, Fonn D. Ocular discomfort during tear drying: A method to simultaneously acquire discomfort ratings, ocular surface video and sensation attributes on a pseudocontinuous scale Invest Ophthalmol Vis Sci 2001;42, 4:s941 #5038

Varikooty JP, Simpson TL, Jones L, Fonn D. Ocular discomfort during tear drying International Society for Contact Lens Research, Sun Valley, Idaho, 2001

Wang J, Fonn D, Simpson T. Topographical thickness of the epithelium and total cornea after hydogel and PMMA contact lens wear and eye closure Optom Vis Sci 2001;78, 12s:303

Wang J, Fonn D, Simpson T, Jones L. Tear film thickness measured with optical coherence tomography International Society for Contact Lens Research, Sun Valley, Idaho, 2001

2000

Averbeck K, Jones D, Westall C. A comparison of two logmar-based crowded visual acuity tests for the assessment of vision in children American Academy of Optometry, Orlando, 2000

Bayer S, MacDougall N, Simpson T. The correlation between grades of limbal and bulbar redness, tarsal redness and roughness and corneal staining type and depth Optom Vis Sci 2000;77, 12s:214

Begley C, Renner D, Wilson G, Al-Olikay S, Simpson T. Ocular sensation and symptoms associated with tear break-up over the corneal surface Optom Vis Sci 2000;77, 12s:121

Chan M, Louie D, Senchyna M, Jones L. Inter- and intra-subject variability in IgA levels within the tear film of non-contact lens wearers Optom Vis Sci 2000;77, 12s:265

du Toit R, Pritchard N, Simpson T, Heffernan S, Fonn D. Comparison of three different types of rating scales Optom Vis Sci 2000;77, 12s:261

du Toit R, Situ P, Simpson T, Fonn D. Results of a one year clinical trial comparing monovision and bifocal contact lenses Optom Vis Sci 2000;77, 12s:18

du Toit R, Situ P, Simpson T, Fonn D. Factors that discriminate between monovision and bifocal contact lens preference Optom Vis Sci 2000;77, 12s:160

du Toit R, Situ P, Simpson T, Fonn D, Begley C. The ocular surface and symptoms of presbyopes before and after six months of contact lens wear Invest Ophthalmol Vis Sci 2000;41, 4:s73

Dumbleton K. Refractive Error Change in Extended Wear Cornea and Contact Lens Section Symposium, American Academy of Optometry (Orlando, Florida), 2000

Dumbleton K, Fonn D, Jones L, Williams-Lyn D, Richter D. Severity and management of contact lens related complications with continuous wear of high Dk silicone hydrogel lenses Optom Vis Sci 2000;77, 12s:216

Feng Y, Varikooty J, Simpson TL. Diurnal variation of corneal and corneal epithelial thickness measured using optical coherence tomography Invest Ophthalmol Vis Sci 2000;41, 4:s675

Feng Y, Varikooty J, Simpson TL. Optical coherence tomography measurement of overnight swelling of human cornea and corneal epithelium Invest Ophthalmol Vis Sci 2000;41, 4:s675

Fonn D, du Toit R, Situ P, Simpson T, Bayer S. Determination of lens prescription for monovision and Acuvue Bifocal contact lenses Optom Vis Sci 2000;77, 12s:160

Fonn D, Wang J, Simpson T. Topographical thickness of the epithelium and total cornea using optical coherence tomography Invest Ophthalmol Vis Sci 2000;41, 4:s675

Jones D, Jones L, Dumbleton K, Pritchard N. Recording of contact lens complications using digital image technology Contact Lens & Anterior Eye 2000;23, 4:160

Jones L . Continuous wear contact lenses: Practical considerations International Symposium on Eye & Vision (Montreal, Canada), 2000

Jones L. High Dk hydrogel contact lenses: The facts Danish Opthalmology Meeting (Copenhagen, Denmark), 2000

Jones L. Extended wear contact lenses: A historical perspective Danish Opthalmology Meeting (Copenhagen, Denmark), 2000

Jones L. Mucin ball development in high Dk hydrogel contact lenses BCLA Conference (Birmingham, UK), 2000

Jones L. Mucin ball post lens debris in high Dk silicone hydrogel wearers Contact Lens & Anterior Eye 2000;23, 4:150-151

Jones L, Cheng A, Woods C, Levitt L. Frequency of follow-up in asymptomatic contact lens wearers: Reaching a consensus view B&L ERS (Berlin, Germany), 2000

Jones L, Cheng A, Woods C, Levitt L. Frequency of follow-up in asymptomatic contact lens wearers: reaching a consensus view Optom Vis Sci 2000;77, 12s:119

Jones L, Dumbleton K, Simpson T, Fonn D. Direct vs off-line grading of bulbar and limbal hyperemia: a comparison of high Dk vs low Dk extended wear lenses Contact Lens & Anterior Eye 2000;23, 4:175

Jones L, Evans K, Mann A, Tighe B. The impact of contact lens polymer water content and charge on the deposition of tear-derived proteins and lipids Institute for Polymer Research Symposium, University of Waterloo, 2000

Jones L, Lau J. Physical properties of multi-purpose contact lens solutions B&L ERS (Berlin, Germany), 2000

Jones L, Lau J. Physical properties of multi-purpose contact lens solutions Contact Lens & Anterior Eye 2000;23, 4:172

Jones L, Louie D, Senchyna M, Dumbleton K, Sorbara L. A comparative evaluation of lysozyme deposition on Etafilcon & silicone-hydrogel contact lens materials Optom Vis Sci 2000;77, 12s:176

Jones L, Louie D, Senchyna M, Dumbleton K, Sorbara L. A comparative evaluation of lysozyme deposition on Etafilcon & silicone-hydrogel contact lens materials B&L ERS (Berlin, Germany), 2000

Jones L, Senchyna M, Louie D, May C, Dumbleton K. A comparative evaluation of IgA and lysozyme deposition on Etafilcon and Lotrafilcon contact lens materials Contact Lens & Anterior Eye 2000;23, 4:175

Jones L, Senchyna M, Louie D, May C, Schubert N, Dumbleton K. A comparative evaluation of IgA and lysozyme deposition on Etafilcon and Lotrafilcon contact lens materials Invest Ophthalmol Vis Sci 2000;41: E-abstract 368

Karlgard C, Jones L, Moresoli C. Uptake and release of Acular from silicone-hydrogel and conventional hydrogel contact lens materials Optom Vis Sci 2000;77, 12s:179

Louie D, Senchyna M, Jones L, May C, Schubert N, Dumbleton K. Lysozyme deposition and removal from a high Dk silicone-hydrogel contact lens material: A comparison of 7-day vs 30-day wear B&L ERS (Berlin, Germany), 2000

Louie D, Senchyna M, Jones L, May C, Schubert N, Dumbleton K. Lysozyme deposition and removal from a high Dk silicone-hydrogel contact lens material: a comparison of 7 day vs 30 day wear Contact Lens & Anterior Eye 2000;23, 4:176

Louie D, Senchyna M, Jones LW, May C, Dumbleton K. Lysozyme deposition and removal from a high Dk silicone hydrogel contact lens material: a comparison of 7 day vs 30 day wear Optom Vis Sci 2000;77, 12s:177

Louie D, Senchyna M, Jones LW, May C, Schubert N, Dumbleton K. Lysozyme deposition and removal from a high Dk silicone hydrogel contact lens material: a comparison of 7-day vs. 30-day wear Invest Ophthalmol Vis Sci 2000;41, 4:s71 #369

May C, Jones L, Nazar L, Simpson T. In vitro evaluation of the dehydration characteristics of silicone-hydrogel and conventional hydrogel contact lens materials Optom Vis Sci 2000;77, 12s:215

Morgan P, Efron N, Helland M, Jones L, van der Worp E, Woods C. Trends in international contact lens prescribing 2000 Optom Vis Sci 2000;77, 12s:258

Robinson B, Sorbara L. Introducing evidence-based principals in clinical education Optom Vis Sci 2000;77, 12s:30

Schulze M, Jones D, Simpson T. The production of an enhanced grading scale for determination of ocular hyperemia Optom Vis Sci 2000;77, 12s:184

Simpson T, Bugescu D. Spectral characteristics of reflections off the conjunctiva/sclera Optom Vis Sci 2000;77, 12s:260

Simpson T, Lau J, Jones L, Fonn D. Chemical properties predict the dimensions of ocular discomfort of ophthalmic drops BCLA Conference (Birmingham, UK), 2000

Simpson T, Lau J, Jones L, Fonn D. Chemical properties predict the dimensions of ocular discomfort of ophthalmic drops Invest Ophthalmol Vis Sci 2000;41: E-abstract 1440

Simpson T, Lau J, Jones L, Richter D, Dumbleton K, Fonn D. Physical chemistry predicts the dimensions of ocular discomfort of ophthalmic drops Contact Lens & Anterior Eye 2000;23, 4:172

Situ P, du Toit R, Simpson T, Fonn D. The detection of change in tests of tear film break-up time (BUT) and phenol red thread test Optom Vis Sci 2000;77, 12s:267

Situ P, du Toit R, Simpson T, Fonn D. Visual function assessments and subjective vision ratings of bifocal and monovision contact lens wearers Optom Vis Sci 2000;77, 12s:161

Situ P, Simpson T, du Toit R, Fonn D. Comparison of Acuvue bifocal and habitual monovision lenses on binocular function and subjective vision rating in adapted monovision wearers Invest Ophthalmol Vis Sci 2000;41, 4:s72

Sorbara L, Robinson B, Luong J. The frequency of presentation of common contact lens complications in a teaching contact lens clinic Optom Vis Sci 2000;77, 12s:164

Sorbara L, Simpson T, Fonn D. Comparison of an objective method of measuring bulbar redness to the use of traditional grading scales Optom Vis Sci 2000;77, 12s:262

Wang J, Fonn D, Simpson T, Jones L. The measurement of corneal epithelial thickness using the OCT in response to hypoxia induced by soft contact lens and eye closure Optom Vis Sci 2000;77, 12s:170

1999

Begley C, Nichols KK, Chalmers R, Caffery B, Simpson T, du Toit R, Kapoor N, Davis L, Meetz RE. An analysis of patient responses to the contact lens dry eye questionnaire (CLDEQ) Optom Vis Sci 1999;76, 12s:228

Bhoola DJ, Simpson TL. Monocular sensitivity during foveal fusion is dependent on stimulus size Invest Ophthalmol Vis Sci 1999;40, 4:s421

Caffery B, Begley C, Simpson T, du Toit R, Situ P, Chalmers R, Dry Eye Investigation Group. Contact lens dry eye questionnaire (CLDEQ) Invest Ophthalmol Vis Sci 1999;40, 4:s909

Chan A, Taylor S, du Toit R, Chong T, Fonn D. Determination of the accuracy of the glare scatter test: comparison of GST data to bagolini lens-induced glare Optom Vis Sci 1999;76, 12s:229

Crosson C, Simpson T. Monocular defocus does not shift the cyclopean eye Optom Vis Sci 1999;76, 12s:157

du Toit R, Situ P, Fonn D. Ocular surface physiology and ocular irritation symptoms in a presbyopic population Optom Vis Sci 1999;76, 12s:109

du Toit R, Vega JA, Simpson TL, Fonn D. Corneal temperature variation over 24 hours Invest Ophthalmol Vis Sci 1999;40, 4:s979

Dumbleton K. Contact Lens Problem Solving: The Top Ten Complications International Symposium on the Eye and Vision (Quebec City, Canada), 1999

Dumbleton K. Refractive error and corneal curvature changes associated with hypoxia Future in Sight meeting (Barcelona, Spain), 1999

Dumbleton K. Hypoxic effects on hyperemia and neovascularization in extended wear Future in Sight meeting (Barcelona, Spain), 1999

Dumbleton K, Jones L, Williams-Lyn D, Fonn D, Chalmers R. Mucin ball post lens debris in high Dk silicone hydrogel wearers Optom Vis Sci 1999;76, 12s:226

Dumbleton K, Jones L, Williams-Lyn D, Fonn D, Chalmers R. Mucin ball post-lens debris in high-Dk silicone hydrogel wearers Optom Vis Sci 1999;76, 12s:226

Dumbleton KA, Richter DB, Fonn D, Chalmers R. Hypoxic effects on ocular hyperemia and neovascularization in extended wear Contact Lens & Anterior Eye 1999;22, 4:158

Dumbleton KA, Richter DB, Fonn D, Chalmers R. Refractive error and corneal curvature changes associated with hypoxia Contact Lens & Anterior Eye 1999;22, 4:147

Fonn D. Does overnight unilateral contact lens wear induce a sympathetic effect on the contralateral eye? Debate – “Practitioner reluctance to prescribe extended wear will not limit its use” British Contact Lens Association, Birmingham, United Kingdom, 1999

Fonn D. Refractive changes with high and low Dk hydrogel lenses International Society for Contact Lens Research, Phuket, Thailand, 1999

Fonn D. Refractive development of the eye International Agency for Prevention of Blindness – The Right to Sight Conference, Beijing, China, 1999

Hutchings N, Jones L. Evaluation of the measurement of ocular rotation by a computerised Hess screen Optom Vis Sci 1999;76, 12s:131

Jones D, Jones L, Simpson T. The subjective satisfaction of presbyopes wearing disposable/frequent replacement lenses: a comparison of monovision versus reading over-spectacles Optom Vis Sci 1999;76, 12s:174

Jones D, Jones L, Simpson T. The subjective satisfaction of presbyopes wearing disposable/frequent replacement lenses: a comparison of monovision versus reading over-spectacles Contact Lens & Anterior Eye 1999;22, 4:162

Jones L. The impact of material composition and replacement frequency on contact lens deposition Peter-Abel Contact Lens Award Presentation, VDC Congress (Fulda, Germany), 1999

Jones L, Dumbleton K, Simpson T, Fonn D. Direct vs off-line grading of bulbar and limbal hyperemia: a comparison of high Dk vs low Dk extended wear lenses Optom Vis Sci 1999;76, 12s:14

Jones L, Evans K, Mann A, Tighe B. Inter and intra-subject variability in the subjective performance and deposition of single-use daily disposable contact lenses BCLA Conference (Birmingham, UK), 1999

Jones L, Evans K, Mann A, Tighe B. Inter- and intra-subject variability in the subjective performance and deposition of single-use daily disposable contact lenses Invest Ophthalmol Vis Sci 1999;40, 4:s907

Jones L, Evans K, Mann A, Tighe B. Inter- and intra-subject variability in the deposition of group II and group IV single-use daily disposable lenses Contact Lens & Anterior Eye 1999;22, 4:162

Jones L, Jones D, Franklin V, Tonge S, Tighe B. Multi-purpose solution effects on the clinical performance and spoilation of daily wear monthly planned-replacement contact lenses Contact Lens & Anterior Eye 1999;22, 4:155

Jones L, Jones D, Simpson T. The impact of replacement frequency and care regimen on subjective satisfaction with disposable/frequent replacement lenses Optom Vis Sci 1999;76, 12s:172

Jones L, Jones D, Simpson T. The influence of replacement frequency and care regimens on subjective satisfaction with disposable/frequent replacement lenses Contact Lens & Anterior Eye 1999;22, 4:147

Kinney Nichols K, Begley CG, Caffery BE, Chalmers R, Simpson TL, Davis LJ, Portello JK. Results of a dry eye questionnaire (DEQ) from optometric practices Optom Vis Sci 1999;76, 12s:110

Lau J, Jones L. Physical properties of multi-purpose contact lens solutions Optom Vis Sci 1999;76, 12s:161

Nobile R, Bobier W, Simpson T. Opening the accommodative loop in infants Invest Ophthalmol Vis Sci 1999;40, 4:s361

Pritchard N, Fonn D. Myopia associated with extended wear of low-oxygen-transmissible hydrogel lenses Optom Vis Sci 1999;76, 12s:169

Sehizadeh M, Simpson T, Jones L. The accuracy and repeatability of two autorefractor-keratometers (Nikon NRK-8000 and Canon RK-1) using a dioptric power matrix method Optom Vis Sci 1999;76, 12s:185

Simpson T. Interocular suppression of uniocular gaussian blur: is blur uniocular required? Invest Ophthalmol Vis Sci 1999;40, 4:s420

Simpson T, Dumbleton K, Fonn D, Chong T. Multidimensional scaling of ocular discomfort by soft contact lenses Optom Vis Sci 1999;76, 12s:109

Simpson T, Lau J, Jones L, Richter D, Dumbleton K, Fonn D. Physical properties predict the dimensions of ocular discomfort of ophthalmic drops Optom Vis Sci 1999;76, 12s:237

Situ P, Simpson T, Fonn D. Clinical measures do not discriminate symptomatic and asymptomatic contact lens wearers Invest Ophthalmol Vis Sci 1999;40, 4:s909

Sorbara L, Luong J. Nomogram for fitting keratoconic eyes utilising computerised video-keratoscopy Optom Vis Sci 1999;76, 12s:54

1998

Bahoshy LP, Simpson TL, Situ P, Fonn D. In vivo contact lens drying reduces contrast sensitivity and increases measurement variability Optom Vis Sci 1998;75, 12s:169

Begley CG, Caffery B, Kinney KA, Portello J, Davis L, Simpson T, Chalmers R, Dry Eye Investigation Group . Results of a dry eye questionnaire (DEQ) from optometric practices in the United States and Canada Optom Vis Sci 1998;75, 12s:65

Caffery B, Begley CG, Kinney KA, Portello J, Davis L, Simpson T, Chalmers R, Dry Eye Investigation Group. Dry eye symptoms in contact lens wear based on clinical diagnosis Optom Vis Sci 1998;75, 12s:63

Chan AA, Simpson TL, du Toit R, Fonn D. Glare shadow test: evaluation of a novel glare-halo test Optom Vis Sci 1998;75, 12s:171

du Toit R, Fonn D, Simpson TL. Recovery from hyperemia after overnight wear of hydrogel lenses Invest Ophthalmol Vis Sci 1998;39, 4:s336

du Toit R, Vega JA, Simpson TL, Fonn D. Diurnal variation of corneal thickness, sensitivity and temperature Optom Vis Sci 1998;75, 12s:82

Dumbleton K. New Approaches to the Assessment of Subjective Responses in Contact Lens Wearers European Symposium on Contact Lenses (Prague, Czech Republic), 1998

Dumbleton K. Multidimensional Ocular Comfort Scaling of Ophthalmic Drops in a Dry Eye Population CCLR 10th Anniversary Symposium, University of Waterloo (Waterloo, Ontario, Canada), 1998

Dumbleton K, Richter D, Fonn D, Chalmers R. Refractive and keratometric changes following extended wear Optom Vis Sci 1998;75, 12s:170

Dumbleton K, Richter D, Simpson T, Fonn D, Chalmers R. A comparison of the vascular response to extended wear of conventional lower Dk and experimental high Dk hydrogel contact lenses Optom Vis Sci 1998;75, 12s:170

Fonn D, du Toit R, Vega JA, Simpson T. Apparent sympathetic response of the contralateral non-lens wearing eyes after overnight contact lens wear in the fellow eye Fourth Biomedical Optics and Implant Colloquim, Bascom Palmer Eye Institute, University of Miami, Florida, 1998

Fonn D, du Toit R, Vega JA, Simpson TL, Chalmers R. Apparent sympathetic response of contralateral nonlens wearing eyes after overnight lens wear in the fellow eye Invest Ophthalmol Vis Sci 1998;39, 4:s336

Jones D, Jones L, Franklin V, Tonge S, Tighe B. Multi-purpose solution effects on the clinical performance and spoilation of daily-wear monthly planned replacement contact lenses Optom Vis Sci 1998;75, 12s:276

Jones D, Jones L, Franklin V, Tonge S, Tighe B. Multi-purpose solution effects on the clinical performance and spoilation of daily-wear monthly planned replacement contact lenses B&L ERS Symposium (Prague), 1998

Jones D, Jones L, Franklin V, Tonge S, Tighe B. Multi-purpose solution effects on the clinical performance and spoilation of daily-wear monthly planned replacement contact lenses Tenth Symposium on the Material Science and Chemistry of Contact Lenses (New Orleans), 1998

Jones L . The influence of tear and non-tear derived surface active components on the wettability of group IV hydrogel lenses B&L European Conference (Prague), 1998

Jones L. Contact lens materials - same or different? Contact Lens & Anterior Eye 1998;21, 4:125

Jones L. Continuous wear vs single-use daily disposables: Practitioner & patient perspectives Contact Lens & Anterior Eye 1998;21, 4:128

Jones L, Evans K, Mann A, Tighe B. Inter- and intra-subject variability in the deposition of group II and group IV single-use daily disposable contact lenses Optom Vis Sci 1998;75, 12s:164

Jones L, Franklin V, Evans K, Mann A, Tighe BJ. The influence of NVP on the deposition performance of Group IV hydrogel materials Optom Vis Sci 1998;75, 12s:163

Jones L, Franklin V, Evans K, Mann A, Tighe BJ. The influence of NVP on the deposition performance of Group IV hydrogel materials B&L ERS (Prague), 1998

Jones L, Franklin V, Evans K, Mann A, Tighe BJ. The influence of NVP on the deposition performance of Group IV hydrogel materials Tenth Symposium on the Material Science and Chemistry of Contact Lenses (New Orleans), 1998

Jones L, Norris A. Continuous wear vs single-use daily disposables: Practitioner and patient perspectives in the UK Optom Vis Sci 1998;75, 12s:186

Jones L, Norris A. Continuous wear vs single-use daily disposables: Practitioner and patient perspectives in the UK B&L ERS (Prague), 1998

Jones L, Norris A. Continuous wear vs single-use daily disposables: Practitioner and patient perspectives in the UK Tenth Symposium on the Material Science and Chemistry of Contact Lenses (New Orleans), 1998

Jones L, Tonge S, Goodall S, Tighe B. The influence of tear and non-tear derived surface active components on the wettability of group IV hydrogel lenses Optom Vis Sci 1998;75, 12s:274

Jones L, Tonge S, Goodall S, Tighe B. The influence of tear and non-tear derived surface active components on the wettability of group IV hydrogel lenses Tenth Symposium on the Material Science and Chemistry of Contact Lenses (New Orleans), 1998

Mann A, Jones L, Tighe B. The impact of daily disposability on the deposition of immuno-regulatory proteins Tenth Symposium on the Material Science and Chemistry of Contact Lenses, New Orleans, 1998

Pritchard N, Fonn D. Prevalence of “clear” corneas in potential clinical trial participants Optom Vis Sci 1998;75, 12s:161

Simpson T, Bhoola D. Interocular suppression of Gaussian blur is local Invest Ophthalmol Vis Sci 1998;39, 4:s397

Simpson T, Chan A, Fonn D. Measuring ocular redness: first order (luminance and chromaticity) measurements provide more information than second order (spatial structure) measurements Optom Vis Sci 1998;75, 12s:279

Simpson T, Fonn D, Orsborn G. Measuring ocular discomfort: metric scaling of typical analogue scores reveals at least 2 dismensions of discomfort of ophthalmic drops Optom Vis Sci 1998;75, 12s:67

Situ P, Simpson TL. Multidimensional scaling of Snellen optotype confusion and Fourier spectra Invest Ophthalmol Vis Sci 1998;39, 4:s411

Sorbara L, Chong T, Higazy MT, Fonn D. Visual acuity of keratoconic eyes as a function of RGP contact lens base curves Optom Vis Sci 1998;75, 12s:173

Tonge S, Goodall S, Rai H, Jones L, Tighe B. Validation of an in vitro model for studying the persistence of surfactants on the surface of group II and IV hydrogel contact lenses Contact Lens & Anterior Eye 1998;21, 4:138

1997

Dengis C, Simpson T, Steinbach M, Ono H. The cyclops effect in adults: sighting without visual cues Invest Ophthalmol Vis Sci 1997;38, 4:s909

du Toit R, Simpson TL, Fonn D. Factor analysis of symptoms of soft contact lens wearers Optom Vis Sci 1997;74, 12s:201

Dumbleton KA, Fonn D, Richter DB. The influence of a UV blocking filter on the comfort and performance of an extended wear lens Optom Vis Sci 1997;74, 12s:196

Dumbleton KA, Simpson TL, Richter DB, Fonn D, Orsborn G, Bolanowski SJ. Multidimensional scaling of ocular comfort in symptomatic “dry eye” post menopausal women Optom Vis Sci 1997;74, 12s:188

Elliott M, Fandrich H, Simpson TL, Fonn D. Analysis of tear break-up time measurement techniques Optom Vis Sci 1997;74, 12s:191

Fonn D, Situ P, Pritchard N. The incidence of corneal infiltrates and ulcers in daily and extended wear clinical trials Invest Ophthalmol Vis Sci 1997;38, 4:s136

Fonn D, Vega JA, du Toit R, Simpson TL. High DK versus approved 7-day extended wear hydrogel lenses: The overnight corneal swelling response Optom Vis Sci 1997;74, 12s:76

Jones L. Contact lens deposition: Myths vs reality New Zealand Contact Lens Society Conference (Auckland), 1997

Jones L. Contact lens materials - clinical implications of choice New Zealand Contact Lens Society Conference (Auckland), 1997

Jones L, Franklin V, Tighe BJ. The relationship between physical and mechanical properties and handling performance of commercially available contact lens materials Contact Lens & Anterior Eye 1997;20, 4:166

Jones L, Jones D, Langley C, Houlford M. The influence of solution regimes on the in vivo wettability of Group II and Group IV frequent replacement lenses Contact Lens & Anterior Eye 1997;20171

Jones L, Mann A, Evans K, Franklin V, Tighe BJ. The influence of replacement period on the deposition of FDA group II and group IV hydrogel contact lenses Invest Ophthalmol Vis Sci 1997;38, 4:50

Jones L, Tonge S, Goodall S, Tighe BJ. The influence of tear and non-tear derived surface active components on the wettability of hydrogel lenses Contact Lens & Anterior Eye 1997;20, 4:163

Simpson T. Interocular suppression of uniocular Gaussian blur Invest Ophthalmol Vis Sci 1997;38, 4:s989

Simpson TL, Higazy M, Fonn D. Corneal and conjunctival sensitivity: A comparison of the non-contact air puff and the Cochet-Bonnet esthesiometers Optom Vis Sci 1997;74, 12s:20

Simpson TL, Richter DB, Dumbleton KA, Fonn D, Orsborn G, Bolanowski SJ. Multidimensional scaling of ocular discomfort induced by ophthalmic drops Optom Vis Sci 1997;74, 12s:187

Situ P, Fonn D, Pritchard N. Subjective responses of symptomatic and asymptomatic hydrogel contact lens wearers Optom Vis Sci 1997;74, 12s:202

Situ P, Fonn D, Pritchard N, Simpson TL. Dryness, comfort levels and lens dehydration in symptomatic and asymptomatic hydrogel lens wearers Invest Ophthalmol Vis Sci 1997;38, 4:s135

Situ P, Simpson T. Legibility of low-contrast optotypes Optom Vis Sci 1997;74, 12s:110

Tonge S, Goodall S, Jones L, Tighe B. The influence of non-tear derived surface-active components on the wettability of hydrogel lenses Contact Lens & Anterior Eye 1997;20173

Tonge S, Goodall S, Jones L, Tighe B. The persistence of surfactants used on multipurpose solutions on the surface of hydrogel contact lens materials. An in vitro vs in vivo comparison Ninth Symposium on the Material Science and Chemistry of Contact Lenses (New Orleans), 1997

Vega JA, Simpson TL, Fonn D. The measurement of ocular surface sensitivity using a noncontact esthesiometer Optom Vis Sci 1997;74, 12s:103

1996

Caffery B, Richter D, Simpson T, Fonn D, Doughty M, Gordon K. The prevalence of dry eye in contact lens wearers: Part 2 of the Canadian dry eye epidemiology study (CANDEES) Invest Ophthalmol Vis Sci 1996;37, 3s:72

Chong T, Simpson T, Pritchard N, Dumbleton K, Richter D, Fonn D. Clinical grading scales: Continuous vs. discrete Optom Vis Sci 1996;73, 12s:

Chong T, Simpson TL, Pritchard N, Dumbleton KA, Richter DB, Fonn D. Repeatability of discrete and continuous clinical grading scales Optom Vis Sci 1996;73, 12s:232

Dumbleton KA, Simpson TL, Sorbara L, Fonn D, Lennox B. Ocular comfort measurements of neophyte contact lens wearers Invest Ophthalmol Vis Sci 1996;37, 3:s72

Fonn D, Richter DB, Pritchard N, Simpson TL. Effects of hypoxic stress on post-PRK corneas Invest Ophthalmol Vis Sci 1996;37, 3s:61

Franklin V, Evans K, Jones L, Tighe BJ. White spots and lipid profile variations J BCLA 1996;19, 4:152

Gschwind KP, Simpson TL, Richter DB, Fonn D. The effect of increasing monocular defocus on interocular suppression scotoma diameter Optom Vis Sci 1996;73, 12s:139

Jones L. The influence of care regimens on the deposition of FDA group II & group IV disposable contact lenses B&L Research Symposium (Seville, Spain), 1996

Jones L, Evans K, Franklin V, Mann A, Tighe BJ. The effect of wearing time on the deposition of group II & group IV contact lenses J BCLA 1996;19, 4:145

Jones L, Evans K, Franklin V, Mann A, Tighe BJ. The influence of replacement frequency on the deposition of group II & group IV disposable contact lenses B&L ERS Symposium (Seville), 1996

Jones L, Franklin V, Evans K, Mann A, Tighe BJ. The influence of NVP on the deposition performance of Group IV hydrogel materials BCLA Conference (Bournemouth), 1996

Jones L, Franklin V, Evans K, Sariri R, Tighe BJ. An in vivo comparison of the spoilation performance of NVP and PVA containing high water content hydrogel contact lenses Optom Vis Sci 1996;73, 12s:95

Jones L, Franklin V, Evans K, Sariri R, Tighe BJ. An in vivo comparison of the spoilation performance of NVP and PVA containing high water content hydrogel contact lenses BCLA Conference (Birmingham, UK), 1996

Jones L, Franklin V, Evans K, Sariri R, Tighe BJ. An in vivo comparison of the spoilation performance of NVP and PVA containing high water content hydrogel contact lenses B&L ERS Symposium (Seville), 1996

Jones L, Franklin V, Evans K, Sariri R, Tighe BJ. The spoilation and clinical performance of monthly versus three monthly group II disposable contact lenses B&L Symposium (Seville), 1996

Jones L, Jones D, Houlford M. A clinical comparison of three polyhexanide-preserved multi-purpose contact lens solutions Optom Vis Sci 1996;73, 12s:95

Jones L, Jones D, Houlford M. A clinical comparison of three polyhexanide-preserved multi-purpose contact lens solutions BCLA Conference (Birmingham, UK), 1996

Jones L, Jones D, Houlford M. A clinical comparison of three polyhexanide-preserved multi-purpose contact lens solutions B&L ERS Symposium (Seville), 1996

Jones L, Jones D, Langley C, Houlford M. Reactive or proactive contact lens fitting - does it make a difference? B&L Symposium (Seville), 1996

Jones L, Mann A, Evans K, Franklin V, Tighe BJ. The effect of wearing time on the deposition of group II and group IV disposable contact lenses Optom Vis Sci 1996;73, 12s:162

Jones R, Sariri R, Evans K, Franklin V, Tighe BJ. A comparison of the effects of solution regimes on the deposition profiles of group II & group IV disposable contact lenses Optom Vis Sci 1996;73, 12s:164

Simpson T, Chong T, Pritchard N. Continuous clinical grading scales using morphing software Contact Lens Anterior Eye 1996;19, 4:151

Simpson TL, Richter DB, Fonn D. Adaptation to uniocular blur in monovision Invest Ophthalmol Vis Sci 1996;37, 3s:75

Simpson TL, Vega JA, Fonn D, Patil S. Corneal temperature and sensitivity measured using noncontact devices Optom Vis Sci 1996;73, 12s:67

Sorbara L, Fonn D, Chong T. Evaluation and comparison of videokeratoscopic simulated fluorescein programs Optom Vis Sci 1996;73, 12s:223

Vega JA, Simpson TL, Fonn D, Patil S. Noninvasive assessment of corneal sensitivity: A preliminary report Optom Vis Sci 1996;73, 12s:104

1995

Doughty MJ, Fonn D, Caffery B, Gordon K, Richter D, Simpson TL. The Canadian dry eye epidemiology study (CANDEES): A first report Optom Vis Sci 1995;72, 12s:154

Fonn D. Continuous wear of hydrogel contact lens - the potential for increasing the success rate of contact lens wear American Academy of Optometry - Symposium of the Cornea and CL Section, 1995

Fonn D. Continuous wear - session 5 Transactions of ht ISCLR symposium (Jackson Hole, Wyoming), 1995

Fonn D, Pritchard N, Brazeau D, Michaud L, GEQCLC. Discontinuation of contact lens wear : The numbers, reasons and patient profiles Invest Ophthalmol Vis Sci 1995;36, 4:s312

Franklin V, Evans K, Jones L, Sariri R, Singh-Gill U, Tighe BJ. Further studies on the interaction of the biochemical species of the ocular environment and soft contact lenses BCLA Conference (London), 1995

Franklin V, Evans K, Jones L, Sariri, Singh-Gill U, Tighe BJ. Further studies on the interaction of the biochemical species of the ocular environment and soft contact lenses Optom Vis Sci 1995;72, 12s:145

Franklin V, Evans K, Jones L, Singh-Gill U, Tighe BJ. Interaction of tear lipids with soft contact lenses Optom Vis Sci 1995;72, 12s:145

Franklin V, Evans K, Jones L, Singh-Gill U, Tighe BJ. 299.Interaction of tear lipids with soft contact lenses BCLA Conference (London), 1995

Franklin V, Sariri R, Evans K, Jones L, Ma J, Mann A, Singh-Gill U, Tighe BJ. The interaction of care solutions with tear components deposited on soft contact lenses Optom Vis Sci 1995;72, 12s:152

Franklin V, Sariri R, Evans K, Jones L, Ma J, Mann A, Singh-Gill U, Tighe BJ. The interaction of care solutions with tear components deposited on soft contact lenses BCLA Conference (London), 1995

Gschwind KP, Pritchard N, Simpson TL, Cox I, Fonn D. Repeatability of a computer assisted VA test Optom Vis Sci 1995;72, 12s:121

Jones D, Jones L. Problems, problems, problems J BCLA 1995;18, 4:139

Jones L. A multi-solution comparison of group II vs group IV disposable contact lenses 7th Symposium on Material Science & Chemistry of Contact Lenses (New Orleans), 1995

Jones L, Franklin V, Evans K, Sariri R, Tighe BJ. The spoilation and clinical performance of monthly versus three monthly group II disposable contact lenses Optom Vis Sci 1995;72, 12s:147

Jones L, Franklin V, Evans K, Sariri R, Tighe BJ. A multi-solution comparison of group II v group IV disposable contact lenses J BCLA 1995;18, 4:136

Jones L, Franklin V, Evans K, Sariri R, Tighe BJ. The spoilation and clinical performance of monthly versus three monthly group II disposable contact lenses 7th Symposium on Material Science & Chemistry of Contact Lenses (New Orleans), 1995

Jones L, Franklin V, Evans K, Sariri R, Tighe BJ. The spoilation and clinical performance of monthly versus three monthly group II disposable contact lenses BCLA Conference (London), 1995

Jones L, Jones D, Langley C, Houlford M. Reactive or proactive contact lens fitting - does it make a difference? Optom Vis Sci 1995;72, 12s:146

Jones L, Jones D, Langley C, Houlford M. Reactive or proactive contact lens fitting - does it make a difference? BCLA Conference (London), 1995

McDonald KE, Fonn D, Richter D, Robboy M. Comparsion of the physiological response to extended wear of an experimental high DK soft lens versus a 38% hema lens Invest Ophthalmol Vis Sci 1995;36, 4:s310

Pritchard N, Fonn D. Postlens tear debris during extended wear of hydrogels Optom Vis Sci 1995;72, 12s:149

Simpson T. Suppression of blur affects monocular motion processing Invest Ophthalmol Vis Sci 1995;36, 4:s668

Simpson T, Pritchard N. Continuous grading scales of ocular redness, papillae and corneal staining Optom Vis Sci 1995;72, 12s:77

Simpson TL, Richter D, Dumbleton K, Fonn D. The repeatability of a new clinical test of interocular suppression of uniocular blur Optom Vis Sci 1995;72, 12s:86

Sivak JG, Herbert KL, Fonn D. In vitro ocular irritancy measures of four contact lens solutions - damage and recovery Invest Ophthalmol Vis Sci 1995;36, 4:s311

Tighe BJ, Fitton JH, Jones L, Guillon M. Vitronectin as an inflammatory marker in contact lens wear monitored by a novel on-lens assay 7th Symposium on Material Science & Chemistry of Contact Lenses (New Orleans), 1995

Tonge SR, Ma J, Jones L, Tighe BJ. Studies of in vivo versus in vitro wettability of soft contact lenses J BCLA 1995;18, 4:139

Zheng P, Campbell MCW, Fonn D. Measurement of retinal image quality variation with asphericity and decentrarion of contact lenses Invest Ophthalmol Vis Sci 1995;36, 4:s939

1994

Butuner Z, Fonn D, Ellis E, Leahy C. Rigid contact lens wettability: The relationship of in vivo and in vitro testing Optom Vis Sci 1994;71, 12s:133

Butuner Z, Leahy C, Ellis E, Fonn D. Repeatability of non invasive tear film structure and stability assessment in three groups of subjects Invest Ophthalmol Vis Sci 1994;35, 4:1690

Carroll EA, Guillon M, Fonn D, Guillon J-P, Leahy CD. Effect of polymeric composition on the in vivo wettability of RGP contact lenses Invest Ophthalmol Vis Sci 1994;35, 4:1178

Doughty MJ, Potvin R, Pritchard N, Fonn D. Quantitative morphometric analyses of the size and shape of fluorescein-highlighted patterns of the human tarsal conjunctiva Invest Ophthalmol Vis Sci 1994;35, 4:1796

Dumbleton K. High Water Content Lenses and Frequent Replacement European Symposium on Contact Lenses (Lisbon, Portugal), 1994

Franklin V, Goodwin C, Jones L, Ma J, Sariri R, Singh-Gill U, Evans K, Goodwin C, Tighe BJ. The effect of currently available disinfection regimes on ocular spoilation processes J BCLA 1994;17, 4:153

Franklin V, Jones L, Ma J, Sariri R, Singh-Gill U, Evans K, Tighe BJ. Studies on the interaction of ocular deposition on spoilation resistant materials J BCLA 1994;17, 4:153

Franklin V, Jones L, Tighe BJ. It's a dirty business... BCLA Conference (Torquay), 1994

Grant R, Jones L, Grant T. A new high water content hydrogel lens vs a low water content benchmark: a comparative study Optom Vis Sci 1994;71, 12s:54

Jones D, Jones L. Every picture tells a story J BCLA 1994;17, 4:154

Jones L, Davies I, Jones D. The time dependent effect of hydrogen peroxide neutralisation on the fitting characteristics of group IV disposable lenses B&L ERS (Lisbon), 1994

Jones L, Franklin V, Tighe BJ. The spoilation and clinical performance of a new biomimetic contact lens material J BCLA 1994;17, 4:145

Jones L, Jones D, Langley C. A comparative evaluation of two high Dk aspheric RGP contact lenses J BCLA 1994;17, 4:154

Jones L, Jones D, Langley C. A comparative evaluation of two high Dk aspheric RGP contact lenses B&L ERS (Lisbon), 1994

Jones L, Ma J, Franklin V, Tighe BJ. In vivo versus in vitro wettability of hydrogel materials J BCLA 1994;17, 4:154

Potvin RJ, Fonn D, Sorbara L. Measurement of polycarbonate aspheres with corneal topography systems Invest Ophthalmol Vis Sci 1994;35, 4:2194

Richter D, Simpson T. The effect of monocular defocus on low contrast binocular acuity Optom Vis Sci 1994;71, 12s:59

Tighe BJ, Fitton JH, Jones L, Guillon M. Vitronectin as an inflammatory marker in contact lens wear monitored by a novel on-lens assay Optom Vis Sci 1994;70, 12s:67

Tighe BJ, Fitton JH, Jones L, Guillon M. Vitronectin as an inflammatory marker in contact lens wear monitored by a novel on-lens assay BCLA Conference (Torquay), 1994

1993

Butuner Z, Arnal R, Fonn D. Comparison of two measurement methods of in vivo contact lens movement Optom Vis Sci 1993;70, 12s:77

Dumbleton K, Efron N, Veys J, Terry P. Characteristics of microfenestrated contact lenses Optom Vis Sci 1993;70, 12s:139

Efron N, Dumbleton KA, Veys J, Terry P. Clinical evaluation of microfenestrated contact lenses Optom Vis Sci 1993;70, 12s:48

Fonn D, Pritchard N, Weed K, Potvin R, Arnal R, Lennox B. Frequent replacement of soft contact lenses reduces complications: 2 year results Optom Vis Sci 1993;70, 12s:121

Holden BA, Fonn D, Sulaiman S, Sweeney D. International optometric education: The need for an integrated international program Optom Vis Sci 1993;70, 12s:59

Jones L. Effect of hydrogen peroxide neutralisation times on the fitting characteristics of group iv disposable Page 47 lenses Society for Experimental Optometry Meeting (Birmingham, England), 1993

Jones L. The comparative surface spoilation and clinical performance of two daily-wear disposable lens systems BCLA Annual Clinical Conference (London), 1993

Jones L. Daily disposable lenses 25th Anniversary Conference Barraquer Clinic (Bogota, Columbia), 1993

Jones L. The effect of neutralisation times on parameter stability of group IV disposable lenses 25th Anniversary Conference Barraquer Clinic (Bogota, Columbia), 1993

Jones L, Davies I, Jones D. Effect of hydrogen peroxide neutralisation times on the fitting characteristics of group IV disposable contact lenses Opthal Physiol Opt 1993;14, 1:108

Potvin R, Fonn D, Sorbara L. Topographic keratography modelling systems: Numbers behind the graphics Invest Ophthalmol Vis Sci 1993;34, 4:1252

Pritchard N, Fonn D. In vivo soft lens dehydration, movement and diameter characteristics and dryness symptoms Invest Ophthalmol Vis Sci 1993;34, 4:1008

Skaff A, Cullen AP, Doughty M, Fonn D. Contact lens induced corneal swelling in young adult insulin dependent diabetics Optom Vis Sci 1993;70, 12s:49

Sorbara L, Fonn D, Holden BA, Wong R. A comparison of the performance of “centred” vs “upper-lid” attached rigid gas permeable lenses Optom Vis Sci 1993;70, 12s:18

Weed K, Fonn D, Potvin R. Discontinuation of contact lens wear Optom Vis Sci 1993;70, 12s:140

1992

Dumbleton KA, Flanagan JG, Trope GE, Coyle E. A fast strategy for threshold estimation in glaucoma Invest Ophthalmol Vis Sci 1992;331387

Elliott DB, Fonn D, Flanagan J. The relative sensitivity of various clinical tests to contact lens induced corneal oedema Optom Vis Sci 1992;69, 12s:43

Fonn D, Pritchard N, Weed K, Potvin R. Ocular responses associated with frequently replaced and non-replaced hydrogel lenses Optom Vis Sci 1992;69, 12s:26

Jones L, Horne A, Franklin V, Tighe BJ. The comparative surface spoilation and clinical performance of two daily-wear disposable lens systems Optom Vis Sci 1992;69, 12s:23

Sorbara L, Fonn D, Holden BA, Wong R. Factors affecting rigid gas permeable vertical lens decentration Optom Vis Sci 1992;69, 12s:153

Williams-Lyn D, MacNeill K, Fonn D. Parameter alterations can affect comfort of rigid gas permeable lenses Optom Vis Sci 1992;69, 12s:152

1991

Fonn D, Davids L, Garnett B, Gauthier C, Pritchard N. Palpebral aperture size of contact lens wearers and non-contact lens wearers Optom Vis Sci 1991;68, 12s:146

Fonn D, Dumbleton K, Sorbara L, Hrynchak P. Comparative clinical performance of three RGP materials CLAO J 1991Supp.

Fonn D, Sorbara L, Dumbleton K, Gauthier C, MacNeill K. Adverse responses to a chlorhexidine tablet disinfection system Invest Ophthalmol Vis Sci 1991;32, 4:738

Franklin V, Horne A, Jones L, Tighe BJ. Early deposition trends of group 1 (polymacon & tetrafilcon A) and group 3 (bufilcon A) materials and the efficacy of surfactant cleaning CLAO Meeting (Las Vegas, Nevada), 1991

Gauthier C, Fonn D, Pritchard N. Patient preferences and comparative ocular responses to rigid and soft contact lenses Optom Vis Sci 1991;68, 12s:145

Jones L. Deposition and ionic Lenses B&L ERS (Geneva, Switzerland), 1991

Jones L. Ionic lenses - What are they? Scottish Contact Lens Society Conference (Turnberry), 1991

Jones L. Whose profile is it? Scottish Contact Lens Society Conference (Turnberry), 1991

Jones L. Deposition trends of daily-wear Acuvue disposable lenses CLAO Meeting (Las Vegas, Nevada), 1991

Jones L, Franklin V, Horne A, Tighe BJ. Deposition trends of daily-wear Acuvue disposable lenses - preliminary findings Optom Vis Sci 1991;68, 12s:72

Sorbara L, MacNeill K, Fonn D. Effect of RGP lens flexure on vision Invest Ophthalmol Vis Sci 1991;32, 4:731

1990

Callender M, Gauthier C, Charles A, Fonn D, Davids L. Evaluation of Aquasteril: A contact lens cleaning and disinfecting unit Optom Vis Sci 1990;67, 10:71

Dumbleton K. RGP Fitting Made Easy University of Waterloo (Waterloo, Ontario, Canada), 1990

Dumbleton K, Fonn D, Hrynchak P, Davids L. Deposit resistance of RGP materials Optom Vis Sci 1990;67, 10:138

Fonn D. Ptosis in contact lens wearers International Society for Contact Lens Research The 6th Biannual Conference, 1990

Fonn D, Gauthier C. Dynamic and static fluorescein pattern evaluation of a biaspheric back surface rigid lens design Optom Vis Sci 1990;67, 10:139

Fonn D, Gauthier C. Lens diameter and its effect on rigid lens comfort Optom Vis Sci 1990;67, 10:45

1989

Cullen AP, Dumbleton KA and Doughty MJ. Protection by a UV-absorbing RGP contact lens Optom Vis Sci 1989;66, 10:167

Davids L, Dobson A, Fonn D, Callender M. Measurement of soft contact lens base curves by an ultrasonic test unit Optom Vis Sci 1989;66, 10:96

Fonn D, Gauthier C, Hrynchak P. Superficial fibrillary lines of the cornea Optom Vis Sci 1989;66, 10:239

Fonn D, Gauthier C, Sorbara L. In eye wettability of rigid contact lenses Optom Vis Sci 1989;66, 10:164

Fonn D, Sorbara L, Gautheir C. Permeability of rigid lenses: the higher the better? European Research Symposium Edinburgh, 1989 [ Show Abstract ]

(Poster)

Hrynchak P, Dumbleton K, Davids L, Fonn D. Base curve stability and durability of rigid gas permeable lenses Optom Vis Sci 1989;66, 10:169

MacNeill K, Gauthier C, Fonn D. Comparison of two automated refractors and keratometers with traditional subjective techniques Optom Vis Sci 1989;66, 10:141

Sorbara L, Dumbleton K, Fonn D, Hrynchak P. Daily wear of an extended wear fluorosilicone acrylate material Optom Vis Sci 1989;66, 10:165

1988

Dumbleton K. UV Absorbing Soft Lenses International Society for Contact Lens Research (Kauai), 1988

Dumbleton K. The Effects of UV-A Induced Lenticular Fluorescence on Visual Function Departmental Seminar, University of Waterloo (Waterloo, Ontario, Canada), 1988

Dumbleton KA and Cullen AP. Ultraviolet Absorbing Soft Lenses: Visual function and subjective comfort International Society for Contact Lens Research Kauai, 1988

Dumbleton KA and Cullen AP. Lenticular fluorescence and visual function Am J Optom Physiol Opt 1988;65, 10:62

Fonn D. In-eye wettability of rigid lenses International Society for Contact Lens Research The 5th Biannual Conference, 1988

Fonn D, Sorbara L, Dumbleton K. Comparative fitting characteristics of aspheric and spherical design rigid gas permeable lenses Am J Optom Physiol Opt 1988;65, 10:131

Fonn D, Sorbara L, Dumbleton KA. Comparative fitting characteristics of aspheric and spherical design rigid gas permeable lenses Research Symposium on Contact Lenses (Berlin) 1988

Fonn D, Sorbara L, Gauthier C, Dumbleton K. In-vivo wetting of RGP lenses International Society for Contact Lens Research (Kauai), 1988

1987

Callendar MGE, Fonn D. Comparing the overnight corneal swelling response of collagen contact lenses with other extended wear hydrophilic lenses Am J Optom Physiol Opt 1987;64, 10:22

Cullen AP, Chou BR, Dumbleton KA. Protection factors of ultra-violet-blocking contact lenses Am J Optom Physiol Opt 1987;64, 10:80P

Dumbleton K. Ocular Fluorescence Departmental Seminar, University of Waterloo (Waterloo, Ontario, Canada), 1987

Fonn D. The clinical performance of high DK rigid gas permeable lenses used for extended wear Am J Optom Physiol Opt 1987;64, 10:6

1986

Dumbleton K. Contact Lenses and Contact Lens Solutions Update University of Waterloo (Waterloo, Ontario, Canada), 1986

Fonn D. Soft contact lens induced edema at high altitude Am J Optom Physiol Opt 1986;63, 10:131

Fonn D. Comparing overnight contact lens induced corneal swelling and deswelling with 6 hours patched eye response Am J Optom Physiol Opt 1986;63, 10:131p

Jabeen A, Luensmann D, Woods J, Hill J, Jones L. Evaluation of the Lag of accommodation with DOT spectacle lenses The Association for Research in Vision and Ophthalmology, New Orleans, LA, USA, April, [ Show Abstract ][ PDF ]

Purpose: Alteration in contrast have shown to impact the accommodative accuracy in myopes. This study investigated whether the Diffusion Optics Technology™ (DOT) spectacles that are
designed to reduce the contrast on peripheral retina, have an impact on the lag of accommodation (LOA) in emmetropic children after short-term wear.

Methods: This was a single visit, prospective, randomized, subject-masked study. Participants were eligible if they had ±1.00 diopters prescription or less and they had no history of previous myopia control treatment. The logMAR visual acuity was measured and ocular dominance was tested using the sighting method. Participants then wore a pair of plano DOT spectacles (not featuring a central clear zone) and standard plano spectacles (control) in a randomized order and, after 5 minutes adaptation to the lenses, ten open-field autorefraction measurements (Grand Seiko 5500) were taken for each eye, with the target at 6m and 40cm. Analysis was conducted on the mean auto-refraction to determine differences in LOA between lens types for the right eye and also for the dominant eye.

Results: A total of 30 participants (20 female:10 male) with a mean (± SD) age of 10.4 ± 2.8 years (range 7 to 17) completed the study. The mean ± SD LOA was 0.57 ± 0.39D for the right eye and 0.60 ± 0.40D for the dominant eye whilst wearing DOT spectacles and similarly, 0.62 ± 0.34D for the right eye and 0.68 ± 0.33D for the dominant eye while wearing control spectacles. Mann Whitney U test results indicated no statistically significant difference between DOT and control spectacles for the right eye data (p=0.64) or for the dominant eye data (p=0.25). Similarly, no difference was observed in the mean LOA when compared between males and females, and between the younger (6-11) and older (12-17) age groups for both right eye and dominant eye with DOT and control spectacles (all p>0.05).

Conclusion: DOT lenses have no significant effect on the lag of accommodation compared to single vision spectacles after short-term wear. The study counters the supposition that reduced contrast may influence accommodative accuracy.

Continuing Education Presentations

2024

Barnett M, Compton J, Pal S, Jones L. The Greatest Contact Lens Course Ever Vision Expo East, New York, USA, Mar 15, 2024

Carrasquillo K, Fadel D, Cardenas N, Flores P . Workshop: Conquering Scleral Lens Complications (Spanish & English session) Global Specialty Lens Symposium, Las Vegas, Jan 19, 2024

Chalmers R, Ng AY, Pucker A. You Can Help Avoid Contact Lens Dropouts NCC, Veldhoven, Netherlands, Mar 11, 2024

Davison J, Morrison S, Jones L, Compton J. Global Contact Lens Forum: Myopia Control: The Good, The Bad, and The Ugly Vision Expo East, New York, USA, Mar 14, 2024

Fadel D. Mastering Scleral, Corneal, and Myopia Management With Contact Lenses! Ontario Association of Optometrists, Symposium, April 12, 2024

Fadel D. Scleral Lenses Know No Bounds Ontario Association of Optometrists, Symposium, April 12, 2024

Fadel D, Barnett M. Masterclass: Scleral Lens Special Applications Global Specialty Lens Symposium, Las Vegas, Jan 18, 2024

Fadel D, Frogozo M. Aspheric Optics in Scleral Lenses for Normal and Diseased Eyes Global Specialty Lens Symposium, Las Vegas, Jan 20, 2024

Jones D. Instruments and diagnostics - IMI review International Myopia Conference, Sanya, Hainan, China, Sep 27 , 2024

Jones D. Confidence in Practice – Your Myopic Patients Deserve the Best Care Webinar: https://cybersight.org/library/lecture-confidence-in-practice-your-myopic-patients-deserve-the-best-care/ Oct 17, 2024 [ Show Abstract ]

During this live webinar, we will discuss the main myopia control modalities, emphasizing factors influencing the choice of modality, and detail the necessary instrumentation for successful myopia management. The webinar will cover identifying at-risk patients, determining the right time to start and stop myopia control, and managing patient and parent expectations. The webinar is designed for both novice and experienced practitioners in myopia control. (Level: All)

Jones D, Thakrar V. Myopia Management - So Many Options, How Do You Choose American Academy of Optometry Meeting, Indianapolis, Nov 7, 2024

Jones D, Woods J. Myopia Control: Do the Benefits Outweigh the Risks? American Academy of Optometry Meeting, Indianapolis, Nov 9, 2024

Jones L. The future of frequent replacement silicone hydrogels Alcon Innovation Meeting, Ft Worth, Texas, April 22, 2024

Jones L. Contact lens comfort: Inevitable or manageable? ECLSO, Istanbul, Turkey, April 26, 2024

Jones L. The battle against contact lens discomfort and dropout Alcon Lecture Series, Ft Worth, Texas, USA, May 14, 2024

Jones L. Everything you wanted to know about contact lens care but were afraid to ask! Ophtecs Event, Coventry, UK, Jun 4, 2024

Jones L. Dry eye and contact lenses: Harmony or havoc? GrandVision on-line webinar (Europe), Jun 10, 2024

Jones L. Opportunity, opportunity, opportunity. Alcon Sales Force presentation, Waterloo, Canada, Jun 12, 2024

Jones L. Contact Lens Research around the World - Update on Contact Lens Care The 66th Annual Meeting of the Japan Contact Lens Society, Tokyo, Japan, Jul 14, 2024 [ Show Abstract ]

Despite the growing use of daily disposable lenses, analysis of the contact lens market suggests that some 50% of the lenses fitted globally are reusable, necessitating the use of contact lens solutions. Over the past 30 years the development of contact lens solutions has shown tremendous changes, with products becoming increasingly complex and diverse in their composition and performance. To many practitioners and patients, contact lens solutions appear relatively similar in their composition, resulting in many choosing to change between products on a whim, often driven by cost considerations rather than sound clinical or scientific acumen.
This presentation will briefly review the major components of care regimens and investigate the importance of cleaning, wetting and compatibility when choosing a modern care regimen. Of particular note are updates on biocides to produce a broader spectrum of disinfection and reduce biofilm formation, along with novel wetting agents, particularly those which can enhance wettability of silicone hydrogel materials. It will emphasise up-to date results to help clinicians understand the importance of choosing a solution – rather than letting the patient choose the solution themselves.

Jones L. The Battle Against Contact Lens Discomfort and Dropout Synoptik, Oslo, Norway, April 18, 2024

Jones L. The Great Debate: Silicone Hydrogels or Hydrogels? Synoptik, Oslo, Norway, April 18, 2024

Jones L. Compliance and its impact on solutions ECLSO, Istanbul, Turkey, April 26, 2024

Jones L. Impact of contact lenses on the ocular surface ECLSO, Istanbul, Turkey, April 27, 2024

Jones L, Morgan P. Corneal Infiltrative Events (CIEs) and Contact Lenses: Avoidable or Not? NCC, Veldhoven, Netherlands, Mar 10, 2024

Jones L, Morgan P, Closson C. Contact Lens Comfort Drivers: Fact Vs. Myth - Option 1 Global Vision Summit 2024, Virtual Session, Mar 20, 2024

Jones L, Morgan P, Closson C. Correcting Low Astigmatism with Toric Soft Contact Lenses – Is It Worth It? - Option 1 Global Vision Summit 2024, Virtual Session, Mar 20, 2024

Jones L, Morgan P, Closson C. Multifocal Contact Lens Fitting: Maximizing Success - Option 1 Global Vision Summit 2024, Virtual Session, Mar 20, 2024

Jones L, Morgan P, Closson C. Contact Lens Comfort Drivers: Fact Vs. Myth - Option 2 Global Vision Summit 2024, Virtual Session, Mar 20, 2024

Jones L, Morgan P, Closson C. Correcting Low Astigmatism with Toric Soft Contact Lenses – Is It Worth It? - Option 2 Global Vision Summit 2024, Virtual Session, Mar 20, 2024

Jones L, Morgan P, Closson C. Multifocal Contact Lens Fitting: Maximizing Success - Option 2 Global Vision Summit 2024, Virtual Session, Mar 20, 2024

Jones L, van Tilborg M. Contact lens wear and artificial tears, a good or a bad marriage? Synoptik, Oslo, Norway, April 18, 2024

Jones L, Willcox M. Contact lens care is the key to improve contact lens discomfort - From recent research The 66th Annual Meeting of the Japan Contact Lens Society, Tokyo, Japan, Jul 15, 2024

Morrison S, Compton J, Jones L. Global Contact Lens forum: What's New and Sexy in Contacts? Vision Expo East, New York, USA, Mar 14, 2024

Morrison S, Compton J, Jones L, Davison J. Global Contact Lens forum: Level Up Your Contact Lens Practice - The Business of Contact Lenses Vision Expo East, New York, USA, Mar 14, 2024

Morrison S, Sorkin S, Fadel D, Severinsky B, Seira P. Rapid Fire CE Breakout: Contemporary Topics in Specialty Contact Lenses Global Specialty Lens Symposium, Las Vegas, Jan 19, 2024

Ng AY, Jones L, Chalmers R. The Importance of Contact Lens Care on Safety  NCC, Veldhoven, Netherlands, Mar 10, 2024

Pucker A, Jones L, Redfern R. Latest Development and the Future of Dry Eye Management NCC, Veldhoven, Netherlands, Mar 10, 2024

Pucker A, Jones L, Redfern R. Latest Development and the Future of Dry Eye Management - Day 2 NCC, Veldhoven, Netherlands, Mar 11, 2024

Qiu S, Fadel D. The Future of Scleral Lenses: Empirical Fitting and Customization American Academy of Optometry Meeting, Indianapolis, Nov 8, 2024

Sindt C, Jedlicka J, Fadel D, Garcia C . Oculus: Specialty Contact Lens fitting solutions for every patient and every doctor Global Specialty Lens Symposium, Las Vegas, Jan 18, 2024

Wolf A, Fadel D. Presentation Provided by WAVE: Become a more Successful Scleral Fitter by Utilizing WAVE and Advanced Technologies! Global Specialty Lens Symposium, Las Vegas, Jan 18, 2024

2023

Bitton E, Craig J, Jones L. Rapid Fire: Dry Eye in 2023 American Academy of Optometry, New Orleans, October 13, 2023 [ Show Abstract ]

Symptoms related to ocular surface disease, which includes dry eye disease (DED), are the main drivers of patient consultations. This rapid-fire lecture will focus on three main themes concerning DED, namely a brief overview of the definition, classification and diagnosis of DED from the TFOS DEWS II; innovations in management technologies; and the projected pharmaceutical pipeline for DED.

Carrasquillo K, Fadel D. Fitting, evaluating, and troubleshooting the fit FitAcademy, Boston, USA, Sep 15, 2023

Craig J, Jones L, Wolffsohn J. The Dry Eye Wheel – A better way to tackle dry eye 4th World Congress of Optometry O=MEGA23, Melbourne, Sep 8, 2023

Fadel D. Expert Panel Discussion FitAcademy, Boston, USA, Sep 16, 2023

Fadel D. Therapeutic Contact lenses. How to manage each individual case? IPEC Conference Contactologia Especializada. Buenos Aires, Argentina, Aug 3, 2023

Fadel D. Meet the experts: Which lens to apply in irregular corneas? IPEC Conference Contactologia Especializada. Buenos Aires, Argentina, Aug 3, 2023

Fadel D. Scleral lens design and calculation of parameters based on corneal topography. Workshop. IPEC Conference Contactologia Especializada. Buenos Aires, Argentina, Aug 3, 2023

Fadel D. Scleral lens complications and management. IPEC Conference Contactologia Especializada. Buenos Aires, Argentina, Aug 3, 2023

Fadel D. Take Control of Your Scleral Fitting International Congress of Scleral Contact (ICSC), Florida USA, Jul 28, 2023

Fadel D. Scleral Lenses Using WAVE Design Software: Once You Start, There’s no Going Back Global Specialty Lens Symposium, Las Vegas, Jan 20, 2023

Fadel D, Dutta D. Specialist Lens Cases British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 10, 2023

Fadel D, Frogozo M. Optical Challenges When Fitting Scleral Lenses Global Specialty Lens Symposium, Las Vegas, Jan 21, 2023

Fadel D, jedlicka J, Gelles J, Sindt C. The Future of Contact Lens Fitting Global Specialty Lens Symposium, Las Vegas, Jan 20, 2023

Fadel D, Weshefsky T. Advanced Specialty Lens Designs Global Specialty Lens Symposium, Las Vegas, Jan 20, 2023

Hiscox R, Morgan P, Jones L.. Surely that can’t be true, or can it? British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 9, 2023

Hui A. Sustained Drug Delivery Devices for the Eye American Academy of Optometry, New Orleans, October 14, 2023 [ Show Abstract ]

This presentation will detail the barriers to effective pharmacokinetics for drug delivery to the eye with currently available therapies such as eye drops, and provide supportive evidence for the need for sustained drug delivery in appropriate instances. Commercially available, drug releasing devices will be presented, and their indications and experience when used clinically will be discussed. How ocular sustained drug delivery devices may be incorporated into the practice of today as well as the practice of the future will also be presented and discussed within the context of currently available and developing devices.

Jones D. Myopia Control is the Standard of Care! 47th Congress of the International Society of Contact Lens Specialists, Tucson, AZ, USA, Apr 30, 2023

Jones D. Axial Length - The Final Piece of the Puzzle 47th Congress of the International Society of Contact Lens Specialists, Tucson, AZ, USA, Apr 30, 2023

Jones D. State-of-the-art instrumentation for myopia management THE Myopia Meeting, Toronto, Canada, Dec 2, 2023

Jones D. Optical Biometry - The long and the short of it Global Specialty Lens Symposium, Las Vegas, Jan 19, 2023

Jones D. Optical Biometry - The Long And The Short Of It 4th World Congress of Optometry O=MEGA23, Melbourne, Sep 10, 2023

Jones D, Woods J.. Workshop: Multi-function Instruments for Myopia management: A Review of Current Instruments and their Capabilities. British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 10, 2023

Jones L. The CL Practice of the Future 47th Congress of the International Society of Contact Lens Specialists, Tucson, AZ, USA, Apr 29, 2023

Jones L. Dry Eye & Contacts: Harmony or Havoc? 47th Congress of the International Society of Contact Lens Specialists, Tucson, AZ, USA, May 1, 2023

Jones L. How well do you know your ocular lubricants? British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 10, 2023

Jones L. Fabrication of a Microfluidic Chip for Evaluating Drug Delivery and Ocular Cytotoxicity with Contact Lenses British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 11, 2023

Jones L. Opening Keynote - Opportunity, Opportunity, Opportunity: What you’re not seeing! 38th Congress of the Canadian Association of Optometrists, Québec City, Canada, Jul 6, 2023

Jones L. Fast Forward to the Future: Novel CL Innovations Global Specialty Lens Symposium, Las Vegas, Jan 21, 2023

Jones L, Craig J, Wolffsohn J. Contact Lens Comfort in Practice 4th World Congress of Optometry O=MEGA23, Melbourne, Sep 8, 2023

Jones L, Jedlicka J. The Future of Contact Lenses: What does the future for contact lenses look like? Contact Lens Spectrum Livestream Series, Episode 1, Jul 21, 2023

Jones L, Maldonado-Codina C. The Future of Contact Lenses: Smart Materials and Optics Contact Lens Spectrum Livestream Series, Episode 4, Oct 5, 2023

Jones L, Szczotka-Flynn L, Dutta D. . The Future of Contact Lenses: How does the Contact Lens Practice evolve? Contact Lens Spectrum Livestream Series, Episode 3, Sep 21, 2023

Jones L, Walsh K. TFOS lifestyle report summary & Clinical Applications Canada Dry Eye Summit, Toronto, ON, Canada, Nov 18, 2023

Jones L, Wolffsohn J. The Future of Contact Lenses: The Quest for Greater Comfort Contact Lens Spectrum Livestream Series, Episode 2, Aug 3, 2023

Phan C-M. Enhanced ocular drug delivery with spherical nucleic acids and screening methods thereof Centre for Eye and Vision Research Conference, Hong Kong, May 18, 2023

Phan C-M. Development of photoresponsive drug delivery systems and in vitro models for testing thereof Centre for Eye and Vision Research Conference, Hong Kong, May 18, 2023

Sawyer G, Morgan P, Jones L.. Comfort is the beginning, middle and end of contact lens wearer success British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 9, 2023

Shukla M. Contact Lenses as a platform for ocular drug delivery Controlled Release Society – Ocular Delivery Focus Group, Webinar, Feb 10, 2023

Wolffsohn J, Craig J, Jones L. Dry Eye Wheel British Contact Lens Association Clinical Conference & Exhibition, Manchester, Jun 10, 2023

Woods J. Maximizing Success with Soft Contact Lenses for Myopia Control THE Myopia Meeting, Toronto, Canada, Dec 2, 2023

2022

Barnett M, Fadel D, Gelles J, Sclafani L. Panel Discussion: International Keratoconus Academy (IKA) Session: New thoughts on keratoconus prevalence and its impact on clinical management The Summit of Specialty Contacts, Sorrento, Italy, Oct 14, 2022

Carnt N, Jones D. Children and Contact Lenses BCLA Focus Hybrid Conference, Brimingham, UK, Jun 12, 2022

Eiden B, Gelles J, Fadel D, Morgenstern A, Sclafani L, Sindt C. Workshop: Adapting to the new normal with scleral lens empirical design using advanced technology American Academy of Optometry, San Diego, 2022

Fadel D. “I did it my way”… How to fit without advanced technology The Summit of Specialty Contacts, Sorrento, Italy, Oct 16, 2022

Fadel D. Scleral lens fitting with Boston® materials CLASS Symposium 2022, Cartagena, Colombia, Nov 4, 2022

Fadel D. Scleral lenses: Procedure for correct fitting CLASS Symposium 2022, Cartagena, Colombia, Nov 3, 2022

Fadel D, Howard N. Panelist: British Contact Lens Association (BCLA): Pandemic Positives The Summit of Specialty Contacts, Sorrento, Italy, Oct 14, 2022

Fadel D, van der Worp E, Norvik Jervel A, Morgan P. Panel Discussion: Keratconus detection and its management with specialty contact lenses Specsavers Clinical Conference (Virtual), Copenhagen, Denmark, Oct 6, 2022

Hui A. Evaluation of novel contact lens materials 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 4, 2022

Hui A. Help Satisfy the Ocular Allergy Contact Lens Wearer Canadian Association of Optometrists Congress, St John's, Newfoundland, Jul 8, 2022

Jones D. Myopia Control: Where we are and where we are going THE Myopia Meeting, Toronto, Canada, Nov 6, 2022

Jones D. Myopia Management – Non-pharmacological options Eye Recommend National Training Event, Victoria, BC, April 23, 2022

Jones D. CORE involvement in the MiSight clinical story 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 4, 2022

Jones D. Myopia Control - Putting on the brakes Waterloo Eye Institute annual CE and trade show. Markham, ON, Canada, November, 2022

Jones D. Optical Biometry - The long and the short of it Global Myopia Symposium, Virtual, September, 2022

Jones D. Myopia Control - Where Are We now and Where We Are Going Canadian Association of Optometrists Congress, St John's, Newfoundland, Jul 7, 2022

Jones D. Instrumentation for myopia control - what you need to be successful Canadian Association of Optometrists Congress, St John's, Newfoundland, Jul 7, 2022

Jones D. Clinical Pearls New Brunswick Association of Optometrists Annual Meeting (Virtual), Sep 29, 2022

Jones D. Introduction to myopia management New Brunswick Association of Optometrists Annual Meeting (Virtual), Sep 29, 2022

Jones D. Myopia management – non-pharmacological options Eye Recommend National Training Event, Ottawa, Oct 1, 2022

Jones D, Jones L.. Myopia control: The good, the bad and the ugly Canadian Association of Optometrists Congress, St John's, Newfoundland, Jul 7, 2022

Jones L. Biomimicry & CL materials: Are we there yet? Canadian national launch of Alcon Total30, online webinar, Canada, February, 2022

Jones L. Innovation vs invention: Same or different? Alcon R&D seminar, Ft Worth, Texas, USA, February, 2022

Jones L. Future applications of contact lenses Aston University Alumnus lecture, online webinar, Birmingham, UK, March, 2022

Jones L. Innovative Use of Contact Lenses Beyond Vision Correction American Academy of Optometry's Innovation Council Symposium, Webinar, May 11, 2022

Jones L. Contact Lens Mythbusters Eyes On Eyecare® Maximizing Clinical & Business Insights, Webinar #1, May 13, 2022

Jones L. Contact Lens Mythbusters Eyes On Eyecare® Maximizing Clinical & Business Insights, Webinar #2, May 14, 2022

Jones L. Wildest dreams about contact lenses World Ophthalmology Congress, Webinar, September , 2022

Jones L. Dry Eye: We Have the Evidence – Why Don’t We Use It? 10th Canadian Optometry School Research Conference, Montréal, Canada, Dec 3, 2022

Jones L. The past, present, and future of contact lens technology Optometry Times EyeCON, Virtual Meeting, Marco Island, Florida, USA, Dec 16 , 2022

Jones L. Dry Eye and Contact Lenses: COVID Did Not Help! Canadian Association of Optometrists Congress, St John's, Newfoundland, Jul 8, 2022

Jones L. Truth or myth: Astigmatic patients do just fine with spherical lenses? J&J webinar, Singapore, Jun, 2022

Jones L. Innovative use of contact lenses beyond vision correction. American Academy of Optometry Innovation Council webinar, May, 2022

Jones L. Therapeutic contact lenses for anterior segment drug delivery: Dream or reality? Orbital Drug Delivery Network, Keynote Address, Santiago de Compostela, Spain, Mar, 2022

Jones L. Innovative use of contact lenses beyond vision correction Danish Optometric & Contact Lens Conference, Aarhus, Denmark, Oct 1, 2022

Jones L. The contact lens practice of the future Danish Optometric & Contact Lens Conference, Aarhus, Denmark, Oct 2, 2022

Jones L. Panel Discussion: Future of Optometry? Danish Optometric & Contact Lens Conference, Aarhus, Denmark, Oct 2, 2022

Jones L. Grand Opening: The Future of Optometry Specsavers Clinical Conference (Virtual), Copenhagen, Denmark, Oct 5, 2022

Jones L, Dickhoof H, van Beusekom M, Walsh K, Molkenbaer V. Daily disposables: Room to grow? Nederlands Contactlens Congres, Veldhoven, Netherlands, Jun, 2022

Jones L, Muttuvelu DV. The Role of Optometry in the Management of Pre- & Post-Surgical Dry Eye Disease Specsavers Clinical Conference (Virtual), Copenhagen, Denmark, Oct 6, 2022

Logan N, Jones D. MiSight® 1 day contact lenses what we now know: 6 Years of Evidence and Beyond BCLA Focus Hybrid Conference, Brimingham, UK, Jun 12, 2022

Walline J, Pal S, Jones D. Knowledge is the key to control of myopia Optometry Times EyeCON, Virtual Meeting, Panel Discussion, Marco Island, Florida, USA, Dec 16 , 2022

Wolffsohn J, Jones L. What we have learned over the last 10 years that has changed clinical practice? BCLA Focus Hybrid Conference, Brimingham, UK, Jun 11, 2022

Wolffsohn J, Jones L, Nagra M . Slip Into Something More Comfortable – The cost of comfort Nederlands Contactlens Congres, Veldhoven, Netherlands, Jun 26, 2022

2021

Craig J, Jones L, Papas E, Sawyer WG. Comfort in Practice - Powered by Alcon BCLA Virtual Clinical Conference & Exhibition, June 13, 2021

Jones D. Myopia management – the non-pharmaceutical options The 19th Hong Kong International Optometric Symposium, Virtual Keynote Address, November, 2021

Jones D. Myopia Management in Clinical Practice: Module 1: Why is myopia management essential in clinical practice Canadian Association of Optometrists – Online CE modules for Canadian ODs, March, 2021

Jones D. Myopia Management in Clinical Practice: Module 2: Myopia Management options Canadian Association of Optometrists – Online CE modules for Canadian ODs, March, 2021

Jones D. Myopia Management. Online module for Canadian Certified Optometric Assistants Canadian Association of Optometrists, Virtual presentation, April , 2021

Jones D. Myopia – How to control the Epidemic British Columbia Doctors of Optometry, Virtual Presentation, September 17, 2021

Jones D. Instrument Fundamentals - Workshop Global Myopia Symposium, Virtual Conference, September 19, 2021

Jones D. Multifunction Instruments Global Myopia Symposium, Virtual Conference, September 19, 2021

Jones D. Biometry in Myopia Management IACLE Global Webinar, September 22, 2021

Jones D, Thakrar V. Myopia Management in Clinical Practice: Module 3: How to implement myopia management in to clinical practice Canadian Association of Optometrists – Online CE modules for Canadian ODs, March, 2021

Jones L. Contact lens comfort: Materials and methodologies to reduce drop outs Optician Contact Lens Week webinar, February 10, 2021

Jones L. Material and solution impacts on contact lens discomfort and dropout OVN (Netherlands Association of Optometrists) webinar, March 15, 2021

Jones L. Dry eye & contact lenses: COVID-19 did not help! Online Optom Learning Series, Webinar (India), March 6, 2021

Jones L. CLEAR: Future applications of contact lenses BCLA Virtual Clinical Conference & Exhibition, June 13, 2021

Jones L. What does the future for contacts look like? Nova Scotia Association of Optometrists meeting, webinar, Halifax Canada, November, 2021

Jones L. The contact lens practice of the future Nova Scotia Association of Optometrists meeting, webinar, Halifax Canada, November, 2021

Jones L. Myopia management update Nova Scotia Association of Optometrists meeting, webinar, Halifax Canada, November, 2021

Jones L. Potential future pharmaceutical options to manage dry eye disease Canadian Dry Eye Summit, Toronto, Canada, November, 2021

Jones L. Biomimicry & CL materials: Are we there yet? USA limited launch of Alcon Total30, online webinar, USA, December, 2021

Muntz A, Walther H.. Das trockene Auge im digitalen Alter: Updates aus der Forschung Sichtkontakte, Virtual Conference, October 9, 2021

Phan C. Can we simulate the anterior eye to further improve contact lenses of the future? BCLA Virtual Clinical Conference & Exhibition, June 13, 2021

Walsh K. Managing lid margin disease in dry eye and contact lens wearers Online Optometry Learning Series, April, 2021

Walsh K. Sharing the unique perspective of a practitioner, a patient, and a parent. Reshaping the future of community eye health virtual conference, Singapore, March 2021, 2021

Walsh K, Jones L. Improving contact lens comfort without changing the lens or modality American Academy of Optometry, Boston, November, 2021

Williams R, Srinivasan S, Jones L. Career Transitions ARVO Advance Research Career Development Conference, Virtual Conference, February 26, 2021

2020

Alexander C, Jones L, Moody K. Evidence-based contact lens prescribing decisions Covalent Careers webinar, USA, November, 2020

Alexander C, Jones L, Moody K. Evidence-based contact lens prescribing decisions Johnson & Johnson Vision webinar, USA, September, 2020

Craig J, Jones L, Wolffsohn J. TFOS DEWSII Diagnosis and management of dry eye disease – LIVE! 11th Congreso Anual de Oftalmología, Bogota, Colombia, 2020

DeLoss K, van der Worp E, Jones L, Pal S, Steele K, Szczotka-Flynn L. A vision on specialty lens care Global Specialty Lens Symposium, Las Vegas, USA, 2020

Jones L. COVID-19 and contact lens wear Alcon webinar, North America, June, 2020

Jones L. COVID-19 and contact lens wear Bausch & Lomb webinar, Canada, May, 2020

Jones L. Lids and their impact on successful contact lens wear Alcon webinar, Canada, April, 2020

Jones L. Lids and their impact on successful contact lens wear Alcon webinar, Canada, April, 2020

Jones L. TFOS DEWSII Management of dry eye disease report 11th Congreso Anual de Oftalmología, Bogota, Colombia, 2020

Jones L. TFOS DEWS II Epidemiology of dry eye disease report 11th Congreso Anual de Oftalmología, Bogota, Colombia, 2020

Jones L. Contact lens comfort update Menicon, Nagoya, Japan, 2020

Jones L. Myopia control update R&D Meeting, Menicon, Nagoya, Japan, 2020

Jones L. Lids and Contact Lenses Interactive Webinar. April 9th, 2020

Jones L. Lids and Contact Lenses Interactive Webinar. April 15th, 2020

Jones L. How do I diagnose dry eye again; I’m confused? Canadian Dry Eye Symposium, Webinar, November, 2020

Jones L. Dry eye & contact lenses: COVID-19 did not help! Canadian Dry Eye Symposium, Webinar, November, 2020

Jones L. Microbial keratitis & corneal infiltrative events (CIE) in CL wearers: Avoidable or not? Vision Institute webinar, November, 2020

Jones L. COVID-19 and the eye – considerations for optometry UW CE webinar, Canada, November, 2020

Jones L. COVID-19 and the eye C2020 Grant Keynote Address. Webinar, Canada, October, 2020

Jones L. Precision-1 launch Alcon webinar, Canada, August, 2020

Jones L. Precision-1 launch Alcon webinar, Canada, July, 2020

Jones L. COVID-19 and contact lens practice opening considerations Alcon webinar, Asia and Australia, July, 2020

Jones L. COVID-19 and contact lens practice opening considerations Alcon webinar, Europe, July, 2020

Jones L. Contact lens compliance CooperVision webinar, Australia and Asia, July, 2020

Jones L. COVID-19 and contact lens practice opening considerations Alcon webinar, North America, June, 2020

Jones L, Cerenzie A, Goodhew T, Morrison S, O'Grady T. Successfully integrating myopia management into your practice Global Specialty Lens Symposium, Las Vegas, USA, 2020

Jones L, Walsh K, Wolffsohn J. Contemporary dry eye disease practice Global Specialty Lens Symposium, Las Vegas, USA, 2020

van der Worp E, Jones L, Wolffsohn J. A clear vision on dropouts Global Specialty Lens Symposium, Las Vegas, USA, 2020

Walsh K. Lids and Dry Eye Interactive Webinar. April 8th, 2020

Walsh K. Lids and Dry Eye Interactive Webinar. April 14th, 2020

Walsh K. Sharing the unique perspective of a practitioner, a patient, and a parent Global Myopia Symposium, Virtual Conference, September, 2020

Walsh K. Lids and Dry Eye BCDO conference, Vancouver, April, 2020

Walsh K, Jones L. Dry eye and contacts: Harmony or havoc? Global Specialty Lens Symposium, Las Vegas, USA, 2020

Walsh K, Jones L, Kojima R. Working smart: How to streamline your dry eye practice with new technology Global Specialty Lens Symposium, Las Vegas, USA, 2020

Walsh K, Jones L, Wolffsohn J. Dry Eye Workshop Global Specialty Lens Symposium, Las Vegas, USA, Jan, 2020

Walsh K, Schulze M. New Findings to Help Contact Lens Wearers in our New Normal Alberta Association of Optometrists, Webinar. November 3rd, 2020

2019

Craig J, Srinivasan S, Wolffsohn J, Jones L. Dry eye tech LIVE! BCLA Conference, Manchester, UK. Jun 2019, 2019

Craig J, Wolffsohn J, Bitton E, Purslow C, Jones L. Controversies in optimising the ocular surface BCLA Conference, Manchester, UK., 2019

Jones D. Are you being short-sighted about myopia OSI annual summit, Whistler, BC, Canada, 2019

Jones D. Are you being short-sighted about myopia CAO Congress, Victoria, BC, Canada, 2019

Jones L. The future for contacts 30 years from now… CREATE Biomedical Training program meeting, University of Waterloo, Waterloo, Ontario, Canada, 2019

Jones L. Confessions of a contact lens researcher Cameron Heights School, Kitchener, Ontario, Canada, 2019

Jones L. Complex dry eye cases: Expert panel University of Waterloo School of Optometry Continuing Education seminar, 2019

Jones L. Top 10 tips from TFOS DEWS II University of Waterloo School of Optometry Continuing Education seminar, 2019

Jones L. SiHy daily disposable lenses . CooperVision seminar series, Paris, France., 2019

Jones L. SiHy daily disposable lenses CooperVision seminar series, Milan, Italy., 2019

Jones L. SiHy daily disposable lenses CooperVision seminar series, Budapest, Hungary., 2019

Jones L. Compliance in contact lens wear CooperVision seminar series, Budapest, Hungary., 2019

Jones L. Soft contact lenses: Just another piece of plastic or more than meets the eye? BCLA Medal Address BCLA Conference, Manchester, UK, 2019

Jones L. Does modality matter? BCLA Conference, Manchester, UK, 2019

Jones L. SiHy daily disposable lenses CooperVision seminar series, Prague, Czech Republic, 2019

Jones L. SiHy daily disposable lenses Nordic Contact Lens Conference, Stockholm, Sweden, 2019

Jones L. CIE’s and contacts: Avoidable or not? EFCLIN manufacturers meeting, Brussels, Belgium, 2019

Jones L. The future for contacts EFCLIN manufacturers meeting, Brussels, Belgium, 2019

Jones L. Case-based dry eye: Lessons from DEWS II Alcon seminar series, Toronto, Canada, 2019

Jones L. Silicone hydrogel daily disposables. The best of both worlds? CooperVision seminar series, Warsaw, Poland, 2019

Jones L. Compliance and the contact lens wearer CooperVision seminar series, Warsaw, Poland, 2019

Jones L. Silicone hydrogels: the clinical perspective CooperVision seminar series, London, UK, 2019

Jones L. Myopia management – delivering results CooperVision seminar series, London, UK, 2019

Jones L. Silicone hydrogels: the clinical perspective CooperVision seminar series, Birmingham, UK, 2019

Jones L. Myopia management – delivering results CooperVision seminar series, Birmingham, UK, 2019

Jones L. Silicone hydrogel daily disposables. The best of both worlds? Procornea Contact Lens Seminar, Amsterdam, Netherlands, 2019

Jones L. What does the future for contacts look like? Swedish Optometric Association, Stockholm, Sweden, 2019

Jones L. The contact lens practice of the future Swedish Optometric Association, Stockholm, Sweden, 2019

Jones L. Comfort and contacts – an update on what we know and don’t know Menicon research forum, Nagoya, Japan, 2019

Jones L. Myopia management update Menicon research forum, Nagoya, Japan, 2019

Jones L. Scleral contact lens solutions Ophtecs meeting, Kobe, Japan, 2019

Jones L. Contact lens comfort: What we know and don’t know Japanese Contact Lens Society conference, Kyoto, Japan, 2019

Jones L. TFOS DEWS II report: Applying the clinical recommendations through case-based learning Canadian Association of Optometrists meeting, Victoria, Canada, 2019

Jones L. Myopia control update CooperVision Educators meeting, Global Specialty Lens Symposium, Las Vegas, 2019

Jones L. Opportunities for developing IP in the contact lens space ORF Grant Day, McMaster University, Hamilton, Ontario, 2019

Jones L. Management and therapy of dry eye: Implementing TFOS DEWS II recommendations. CORE Educational evening, 2019

Jones L. Myopia control update Texas Optometric Association, Austin, Texas, 2019

Jones L. The great debate: Silicone hydrogels vs hydrogels Texas Optometric Association, Austin, Texas, 2019

Jones L. The future for contacts: What does it look like? Texas Optometric Association, Austin, Texas, 2019

Jones L. Myopia control update Southern College of Optometry CE weekend, Memphis, USA, 2019

Jones L. Compliance: How far do patients bend the rules? Southern College of Optometry CE weekend, Memphis, USA, 2019

Jones L. Top 10 tips from TFOS DEWS II Southern College of Optometry CE weekend, Memphis, USA, 2019

Jones L. The future of contact lenses Southern College of Optometry CE weekend, Memphis, USA, 2019

Jones L. Silicone hydrogel daily disposable lens update Hong Kong Association of Private Practice Optometrists, Hong Kong, 2019

Jones L. Dry eye and contact lenses: Harmony or havoc? Canadian Dry Eye Symposium, Toronto, Canada, 2019

Jones L. From fitting to follow-up: Keeping your contact lens patients satisfied Johnson & Johnson educational evening, Rome, Italy, 2019

Jones L. Contact lens solutions: Friends or foes? Johnson & Johnson educational evening, Rome, Italy, 2019

Jones L, Fadli Z. The tear film and contacts: Friend or foe? BCLA Conference, Manchester, UK. Jun 2019, 2019

Jones L, Lievens C. Hydrogen peroxide Care systems: Should it be the 1st choice? Global Specialty Lens Symposium, Las Vegas, Nevada, 2019

Jones L, Ng AY. TFOS DEWS II report: Applying the clinical recommendations through case-based learning Alcon CE meeting, Calgary, Canada, 2019

Jones L, Walsh K. Sensitive to silicone? Understanding and managing the patient who presents with an adverse reaction to their silicone hydrogel contact lenses Global Specialty Lens Symposium, Las Vegas, Nevada, 2019

Jones L, Walsh K. TFOS DEWS II report: Applying the clinical recommendations through case-based learning Alcon CE meeting, Edmonton, Canada, 2019

Jones L, Walsh K, Ng AY, Ngo W. TFOS DEWS II report: Applying the clinical recommendations through case-based learning Alcon CE meeting, Cambridge, Canada, 2019

Morgan P, Jones L. Tear film interactions with contact lens materials Assotticca Conference, Rome, Italy, 2019

Morgan P, Jones L. Contact lens issues for tomorrow: How can technology address them Assotticca Conference, Rome, Italy, 2019

Walsh K, Jones L. Does research guide contact lens clinical practice? Assotticca Conference, Rome, Italy, 2019

Walsh K, Jones L. Developing an enhanced contact lens clinical routine Assotticca Conference, Rome, Italy, 2019

2018

Bitton E, Jones L. TFOS DEWS II – case based discussion Alcon meeting, Toronto, 2018

Craig J, Jones L. Iatrogenic dry eye: Findings from TFOS DEWS II American Optometric Association, Denver, USA, 2018

Craig J, Wolffsohn J, Jones L. Incorporating TFOS DEWS II into clinical practice American Optometric Association, Denver, USA, 2018

Craig J, Woods C, Jones L. Dry eye detection and management – LIVE! Scottish Contact Lens & Ocular Surface Society, Glasgow, Scotland, 2018

Jones D. Myopia management – from research to clinical practice Clinical and Experimental Optometry. Webinar, 2018

Jones D. Myopia, can we control the epidemic Eye Trust Network. Toronto, 2018

Jones D. Examination of the pediatric patient Manitoba Association of Optometrists annual meeting. Brandon, Manitoba, 2018

Jones D. Prescribing for the pediatric patient Manitoba Association of Optometrists annual meeting. Brandon, Manitoba, 2018

Jones D. Controlling the myopia epidemic Manitoba Association of Optometrists annual meeting. Brandon, Manitoba, 2018

Jones D. What went wrong? Manitoba Association of Optometrists annual meeting. Brandon, Manitoba, 2018

Jones D. Myopia Control Ontario Association of Optometrists annual meeting. Toronto, ON, 2018

Jones D. Examination of the pediatric patient Ontario Association of Optometrists annual meeting. Toronto, ON, 2018

Jones D. Myopia- The Epidemic IRIS meeting. Puerta Vallarta, 2018

Jones D. Myopia control, results of MiSight study Training webinar, 2018

Jones D, Woods J. Controlling the myopia epidemic Fall CE Manitoba Association of Optometrists, 2018

Jones L. Nutrition and dry eye: An update CIOCV Congress, Braga, Portugal, 2018

Jones L. Disease monitoring, biosensing and drug delivery NCC, Veldhoven, Netherlands, 2018

Jones L. SiHy vs hydrogels – same or different? East-West eye conference, Cleveland, Ohio, 2018

Jones L. The great debate: Silicone hydrogels vs hydrogels East-West eye conference, Cleveland, Ohio, 2018

Jones L. Myopia control: An update East-West eye conference, Cleveland, Ohio, 2018

Jones L. Management & therapy of dry eye disease: Incorporating TFOS DEWS II into practice East-West eye conference, Cleveland, Ohio, 2018

Jones L. Contact lenses in 2020 and beyond: What does the future for contacts look like? East-West eye conference, Cleveland, Ohio, 2018

Jones L. Highlights of TFOS DEWS II report and its clinical implications Novartis Symposium, Victoria Island, British Columbia, 2018

Jones L. Highlights of TFOS DEWS II report and its clinical implications Novartis Symposium, Regina, Saskatchewan, 2018

Jones L. Highlights of TFOS DEWS II report and its clinical implications Novartis Symposium, Thunder Bay, Ontario, 2018

Jones L. Implications of TFOS DEWS II to successful contact lens fitting Acuvue Eye-Health Advisor Symposium, Mexico City, Mexico, 2018

Jones L. How CL wear is affected by dryness: Diagnosis & solutions Acuvue Eye-Health Advisor Symposium, Mexico City, Mexico, 2018

Jones L. From fitting to follow-up: How to maximise success Acuvue Eye-Health Advisor Symposium, Buenos Aires, Argentina, 2018

Jones L. Corneal infiltrative events (CIE) and contact lenses: Avoidable or not? Acuvue Eye-Health Advisor Symposium, Buenos Aires, Argentina, 2018

Jones L. Implications of TFOS DEWSII to successful contact lens fitting Acuvue Eye-Health Advisor Symposium, Buenos Aires, Argentina, 2018

Jones L. Uptake and release of preservatives to soft lens materials – a clinical perspective Acuvue Eye-Health Advisor Symposium, Moscow, Russia, 2018

Jones L. Retaining patients and sales in today’s optometric practice Saskatchewan Optometric Association, Regina, Saskatchewan, 2018

Jones L. The future for contacts? Saskatchewan Optometric Association, Regina, Saskatchewan, 2018

Jones L. Contact lens solutions: Friends or foes? Saskatchewan Optometric Association, Regina, Saskatchewan, 2018

Jones L. Management and therapy of dry eye disease: A TFOS DEWS II update Saskatchewan Optometric Association, Regina, Saskatchewan, 2018

Jones L. Myopia control update Saskatchewan Optometric Association, Regina, Saskatchewan, 2018

Jones L. The impact of MGD and demodex on contact lens success Saskatchewan Optometric Association, Regina, Saskatchewan, 2018

Jones L. Proteins and their role in the tear film Acuvue Eye-Health Advisor Symposium, Warsaw, Poland, 2018

Jones L. Is this the end of hydrogels? Acuvue Eye-Health Advisor Symposium, Warsaw, Poland, 2018

Jones L. Protein deposits and contact lenses: Good or bad? Hong Kong Cornea and Contact Lens Society, Hong Kong Polytechnic University, Hong Kong, 2018

Jones L. Contact lenses in 2020 and beyond Hong Kong Cornea and Contact Lens Society, Hong Kong Polytechnic University, Hong Kong, 2018

Jones L. TFOS DEWS reports – change over time NCC, Veldhoven, Netherlands, 2018

Jones L. Digital eye fatigue Alcon meeting, Toronto, 2018

Jones L. Daily disposable update IRIS meeting, Puerto Vallarta, Mexico, 2018

Jones L. The future for contact lenses IRIS meeting, Puerto Vallarta, Mexico, 2018

Jones L. Future of contact lenses AOCLE Educators meeting, Global Specialty Lens Symposium, Las Vegas, 2018

Jones L. Contact lenses for drug and cell delivery – dream or reality? Menicon research forum, Nagoya, Japan, 2018

Jones L. Update on TFOS DEWSII Alcon Sales Reps meeting, Toronto, Canada, 2018

Jones L. Aftercare routine on trial Scottish Contact Lens & Ocular Surface Society, Glasgow, Scotland, 2018

Jones L, Craig J. Highlights of TFOS DEWS II report and its clinical implications Novartis Symposium, Brampton, Ontario, 2018

Jones L, Morgan P. Interactions between lens materials and the tear film Acuvue Eye-Health Advisor Symposium, Moscow, Russia, 2018

Jones L, Morgan P, Nichols J. Breakthroughs in lens materials Global Specialty Lens Symposium, Las Vegas, 2018

Jones L, Walsh K. Silicone hydrogel daily disposables Philadelphia, 2018

Jones L, Walsh K. Silicone hydrogel daily disposables Budapest, 2018

Jones L, Walsh K. 1 day silicone hydrogels: the best of both worlds? CooperVision Symposium, Budapest, Hungary, 2018

Jones L, Woods J, Walsh K. Contact lens selection on trial Part 1: neophytes NCC, Veldhoven, Netherlands, 2018

Jones L, Woods J, Walsh K. Contact lens selection on trial Part 2: existing wearers NCC, Veldhoven, Netherlands, 2018

McArthur C, Tempany K, Jones L. Myopia control: A call to action! Scottish Contact Lens & Ocular Surface Society, Glasgow, Scotland, 2018

Morgan P, Nichols J, Jones L. Where have all the wearers gone? Global Specialty Lens Symposium, Las Vegas, 2018

Papas E, Jones L, Morgan P. How Close is the Future? NCC, Veldhoven, Netherlands, 2018

Stahl U. Highlights of TFOS DEWS II report and its clinical implications Novartis Symposium, Moncton, New Brunswick, 2018

Stahl U. Highlights of TFOS DEWS II report and its clinical implications Novartis Symposium, Halifax, Nova Scotia, 2018

Stahl U. Highlights of TFOS DEWS II report and its clinical implications Novartis Symposium, Cambridge, Ontario, 2018

Walsh K, Jones L, Luensmann D, Woods J. Rapid Fire: Celebrating 20 Years of Silicone Hydrogels: The Past, Present and Future American Academy of Optometry, San Antonio, USA, 2018 [ Show Abstract ]

Using the analogy of a child growing up, four presenters cover the twenty-year timeline of silicone hydrogels (SiHys). How does the historical performance of this material inform both currently available lenses and future applications? Each part of the talk covers a specific period in the timeline since 1998: from infancy, through to elementary and high school years, balancing properties for comfortable daily wear and gaining increased understanding of interactions with the ocular surface and tear film. At age 20, SiHys have yet to graduate from college, leaving the last talk to share what the future may hold.

Woods J. Technology & contact lenses: looking into the future Fall CE Manitoba Association of Optometrists, 2018

Woods J. Challenging the contact lens recommendation Fall CE Manitoba Association of Optometrists, 2018

Woods J. Toric lenses CooperVision educational event, Toronto, Ontario, 2018

Woods J, Jones D. What went wrong? Fall CE Manitoba Association of Optometrists, 2018

2017

Craig J, Wolffsohn, Jones L. Incorporating TFOS DEWS II into clinical practice American Academy of Optometry, Chicago, USA, 2017

Jones D. Myopia – can we control the epidemic? CooperVision annual sales meeting, Orlando, Florida, 2017

Jones D. Myopia. It’s an epidemic, can anything be done? Salon Vision, Montreal, 2017

Jones D. Myopia – The epidemic Nova Scotia Association of Optometrists Annual Meeting, Halifax, NS, 2017

Jones D. Myopia, can we control the epidemic Nova Scotia Association of Optometrists Annual Meeting, Optometric Personnel. Halifax, NS , 2017

Jones D. Pediatrics in Practice Nova Scotia Association of Optometrists Annual Meeting, Optometric Personnel. Halifax, NS , 2017

Jones D. Myopia control – Dream or reality Journées Optométriques. Quebec City , 2017

Jones D. Myopia prevalence and what it means to optometry British Columbia Association of Optometrists, Vancouver, 2017

Jones D, Jones L. Overcoming challenges to growth in a competitive environment Eyerecommend seminar, Costa Rica, 2017

Jones D, Leat S. Children’s Vision School of Optometry & Vision Science 50th anniversary celebration event, 2017

Jones L. Challenges for drug delivery with contact lenses ISCLR, Portland, Oregon, USA, 2017

Jones L. Therapeutic contact lenses for drug and cell delivery: Dream or reality? British Contact Lens Association, Liverpool, England, 2017

Jones L. DEWSII update on management and therapy of dry eye ECLSO, London, England, 2017

Jones L. Uptake and release of preservatives – clinical pearls ECLSO, London, England, 2017

Jones L. The case for daily disposable lenses OSI conference, Lake Louise, Alberta, Canada, 2017

Jones L. To drop or not to drop, that is the question Alcon AdBoard meeting, Toronto, Ontario, Canada, 2017

Jones L. Current research topics in cornea and contact lenses CCLRT Diplomate Preparation course, American Academy of Optometry, Chicago, USA, 2017

Jones L. Myopia control update Newfoundland & Labrador Association of Optometrists, Corner Brook, Newfoundland & Labrador, Canada, 2017

Jones L. Demodex diagnosis and management Newfoundland & Labrador Association of Optometrists, Corner Brook, Newfoundland & Labrador, Canada, 2017

Jones L. Contact lens complications: You decide Newfoundland & Labrador Association of Optometrists, Corner Brook, Newfoundland & Labrador, Canada, 2017

Jones L. Contact lenses in 20/20 and beyond Newfoundland & Labrador Association of Optometrists, Corner Brook, Newfoundland & Labrador, Canada, 2017

Jones L. Dry eye update: The impact of DEWS II Vision Source meeting, Toronto, Canada, 2017

Jones L. What’s new and sexy in contacts? University of Waterloo CE meeting (Assistants program), Waterloo, Ontario, Canada, 2017

Jones L. Dry eye and contact lenses: How they can work in harmony University of Waterloo CE meeting, Waterloo, Ontario, Canada, 2017

Jones L. Myopia control update Canadian Association of Optometrists (OD program), Ottawa, Ontario, Canada, 2017

Jones L. Contact lenses of the future Canadian Association of Optometrists (OD program), Ottawa, Ontario, Canada, 2017

Jones L. Contact lenses in 20/20 and beyond Canadian Association of Optometrists (OD program), Ottawa, Ontario, Canada, 2017

Jones L. Dry eye update Canadian Association of Optometrists (Assistants program), Ottawa, Ontario, Canada, 2017

Jones L. Management and therapy of dry eye: TFOS DEWS II report British Contact Lens Association, Liverpool, England, 2017

Jones L. Contact lens types and how to fit them Alcon educator’s day, Waterloo, Ontario, Canada, 2017

Jones L. Contact lens progress checks and compliance Alcon educator’s day, Waterloo, Ontario, Canada, 2017

Jones L. Contact lenses: The good, the bad and the downright ugly! CPRO meeting, Quebec City, Quebec, Canada, 2017

Jones L. The tear film: What’s the latest news? Johnson & Johnson Eye-Health Symposium, Hamburg, Germany, 2017

Jones L. The hidden secrets of the tear film Johnson & Johnson Eye-Health Symposium, Warsaw, Poland, 2017

Jones L. Contact lens case management: You decide! Johnson & Johnson Eye-Health Symposium, Warsaw, Poland, 2017

Jones L. Contact lens discomfort: What can we do? Johnson & Johnson Acuvue Eye Health Advisor meeting, Kuwait City, Kuwait, 2017

Jones L. Ten steps to a happy, successful contact lens wearer Johnson & Johnson Acuvue Eye Health Advisor meeting, Kuwait City, Kuwait, 2017

Jones L. Contact lens discomfort: What can we do? Johnson & Johnson Acuvue Eye Health Advisor meeting, Dubai, UAE, 2017

Jones L. Daily disposables: The revolution continues Johnson & Johnson Acuvue Eye Health Advisor meeting, Dubai, UAE, 2017

Jones L. Ten steps to a happy, successful contact lens wearer Johnson & Johnson Acuvue Eye Health Advisor meeting, Dubai, UAE, 2017

Jones L. Contact lenses of the future Tear Film & Ocular Surface Society, Rome, Italy, 2017

Jones L. Using contact lenses to grow your practice Canadian Association of Optometric Students, University of Waterloo, Waterloo, Canada, 2017

Jones L. The impact of MGD and demodex infestation on contact lens discomfort University of Waterloo CE cruise, 2017

Jones L. Contact lenses in 2020 and beyond University of Waterloo CE cruise, 2017

Jones L. What your patients don’t tell you! University of Waterloo CE cruise, 2017

Jones L, Jones D. Retaining patients and sales in today’s optometric practice Eyerecommend seminar, Costa Rica, 2017

Jones L, Morgan P. What the contact lens does to the tear film and how it impacts succesful wear British Contact Lens Association, Liverpool, England, 2017

Karpecki P, Nichols K, O’Dell L, Jones L. TFOS DEWS II Ocular Surface Symposium American Academy of Optometry, Chicago, USA, 2017

Woods J. One day disposables: Simplifying the choices OSI conference, Lake Louise, Alberta, Canada, 2017

2016

Jones L. Revolutionary future uses of contact lenses CCLRT Diplomate Preparation course, American Academy of Optometry, Anaheim, California, 2016

Jones L. Current research topics in cornea and contact lenses CCLRT Diplomate Preparation course, American Academy of Optometry, Anaheim, California, 2016

Jones L. SiHy – the only material for the future? Danish Optometry & Contact Lens Conference, Aarhus, Denmark, 2016

Jones L. Impact of meibomian glands and mites on contact lens success Danish Optometry & Contact Lens Conference, Aarhus, Denmark, 2016

Jones L. Getting comfortable with deposits Danish Optometry & Contact Lens Conference, Aarhus, Denmark, 2016

Jones L. One day disposable silicone hydrogel lenses CooperVision educational event, Cambridge, Ontario, Canada, 2016

Jones L. Contact lenses in 2020 and beyond Alberta Association of Optometrists, Edmonton, Alberta, Canada, 2016

Jones L. Comfortable contacts – realistic or just a dream? Alberta Association of Optometrists, Edmonton, Alberta, Canada, 2016

Jones L. Contact lens and cleaning solutions: Friends or foes? Alberta Association of Optometrists, Edmonton, Alberta, Canada, 2016

Jones L. Real time comfort assessment across a 14 hour day via SMS assessments of a new daily disposable silicone hydrogel Johnson and Johnson seminar, Tokyo, Japan, 2016

Jones L. Lysozyme deposition and contact lenses: Good or bad? Johnson and Johnson seminar, Tokyo, Japan, 2016

Jones L. One day disposable silicone hydrogel lenses CooperVision educational event, Mississauga, Ontario, Canada, 2016

Jones L. Compliance and the contact lens wearer BCLA Conference, Birmingham, UK, 2016

Jones L. Room 101: Banishing the misconceptions! BCLA Conference, Birmingham, UK, 2016

Jones L. One day disposable silicone hydrogel lenses CooperVision educational event, Toronto, Ontario, Canada, 2016

Jones L. On the sofa with Dr Jones Optometric Association of the Philippines National Convention, Manila, Philippines, 2016

Jones L. How to start a research program IACLE meeting, Optometric Association of the Philippines National Convention, Manila, Philippines, 2016

Jones L. Demodex – what is it and how do you treat it? Optometric Association of the Philippines National Convention, Manila, Philippines, 2016

Jones L. Allergic reactions to contact lenses and solutions: Possible or not? Optometric Association of the Philippines National Convention, Manila, Philippines, 2016

Jones L. Clinical performance of three silicone hydrogel daily disposable contact lenses Asian Cornea and Contact lens Conference, Hong Kong, 2016

Jones L. Impact of the tear film on successful contact lens wear Johnson & Johnson Eye-Health Symposium, Moscow, Russia, 2016

Jones L. Contact lens discomfort and dropout Johnson & Johnson Eye-Health Symposium, Moscow, Russia, 2016

Jones L. Protein deposits and contact lenses: Good or bad? Johnson & Johnson Eye-Health Symposium, Kuwait City, Kuwait, 2016

Jones L. Contact lens complications: You decide! Johnson & Johnson Eye-Health Symposium, Kuwait City, Kuwait, 2016

Jones L. Protein deposits and contact lenses: Good or bad? Johnson & Johnson Eye-Health Symposium, Dubai, UAE, 2016

Jones L. Contact lens complications: You decide! Johnson & Johnson Eye-Health Symposium, Dubai, UAE, 2016

Jones L. Impact of the tear film on successful contact lens wear Johnson & Johnson Eye-Health Symposium, Warsaw, Poland, 2016

Jones L. Protein deposits and contact lenses: Good or bad? Johnson & Johnson Eye-Health Symposium, Warsaw, Poland, 2016

Jones L. Disease monitoring, biosensing and drug delivery via contacts NCC Meeting, Eindhoven, Netherlands, 2016

Jones L. Contact lens solutions: Friends or foes? NCC Meeting, Eindhoven, Netherlands, 2016

Jones L. Contact lenses for the dry eye patient Association of Optometrists of France, Paris, France, 2016

Jones L, Bitton E. The demise of hydrogels has been overemphasised Association of Optometrists of France, Paris, France, 2016

Woods J. One day disposables: Simplifying the choices CooperVision educational event, Markham, Ontario, 2016

Woods J. Why daily disposable lenses and which to choose? Ontario Association of Optometrists Northwestern District meeting, Thunder Bay, Ontario, 2016

Woods J. One day disposables: Simplifying the choices CooperVision educational event, Cambridge, Ontario, 2016

2015

Jones D. Pediatrics - when an what to prescribe University of Waterloo CE cruise, 2015

Jones D. Myopia control - dream or reality University of Waterloo CE cruise, 2015

Jones L. Contact lenses in 2020 and beyond Springer Annual Lecture Award, Birmingham, Alabama, 2015

Jones L. Contact lenses in 2020 and beyond Interlens meeting, Lucerne, Switzerland, 2015

Jones L. Contact lens deposits – relevant or not? Interlens meeting, Lucerne, Switzerland, 2015

Jones L. Extended wear contact lens update for 2015 Interlens meeting, Lucerne, Switzerland, 2015

Jones L. Contact lenses: Future focus CAO congress, Fredericton, New Brunswick, Canada, 2015

Jones L. Contact lenses in 2020 and beyond Johnson & Johnson ADVISE symposium presentation, Jacksonville, Florida, 2015

Jones L. Doc, any chance you can make these contacts more comfortable? APSOLC Symposium, San Juan, Puerto Rico, 2015

Jones L. Contact lens solutions update: same or different? APSOLC Symposium, San Juan, Puerto Rico, 2015

Jones L. Impact of demodex on contact lens comfort APSOLC Symposium, San Juan, Puerto Rico, 2015

Jones L. TFOS comfort overview British Contact Lens Association, Liverpool, UK, 2015

Jones L. What’s new and sexy in contacts? Global Specialty Lens Symposium, Las Vegas, 2015

Jones L. Epidemiology of microbial keratitis Global Specialty Lens Symposium, Las Vegas, 2015

Jones L. Myopia control: An update University of Waterloo CE Cruise, Eastern Caribbean, 2015

Jones L. Contact lens solutions. Same or different? University of Waterloo CE Cruise, Eastern Caribbean, 2015

Jones L. Comfortable contacts: A realistic dream? University of Waterloo CE Cruise, Eastern Caribbean, 2015

Morgan P, Jones L, Papas E, Brennan N. The great debate: Silicone hydrogel vs hydrogels? British Contact Lens Association, Liverpool, UK, 2015

Morgan P, Subbaraman L, Jones L. Getting comfortable with deposits British Contact Lens Association, Liverpool, UK, 2015

2014

Jones D. Chidren's Vision Pre-School and Beyond Ontario Association of Optometrists annual meeting. Niagara Falls, ON, 2014

Jones L. Kids and contact lenses Heart of America meeting, Kansas City, Missouri, 2014

Jones L. The future for contact lenses: What will contacts look like in 2020? New England College of Optometry, Boston, MA, 2014

Jones L. Contact lens solutions update: same or different? New England College of Optometry, Boston, MA, 2014

Jones L. Doc, any chance you can make these contacts more comfortable? Eye-Sight 2020, Boston, MA, 2014

Jones L. What will contacts look like in 2020? Eye-Sight 2020, Boston, MA, 2014

Jones L. Kids and contacts Eye-Sight 2020, Boston, MA, 2014

Jones L. Doc, any chance you can make these contacts more comfortable? Donald Korb Award Lecture, American Optometric Association, Philadelphia, PA, 2014

Jones L. Innovations in lens designs and materials CLAO Meeting, Toronto, Ontario, Canada, 2014

Jones L. Undertaking clinical research in practice British Contact Lens Association, Birmingham, UK, 2014

Jones L. Tune in – or dropout! British Contact Lens Association, Birmingham, UK, 2014

Jones L. How can I use contact lenses to grow my practice? DCC, German Contact Lens Meeting, Munich, Germany, 2014

Jones L. Why say that? DCC, German Contact Lens Meeting, Munich, Germany, 2014

Jones L. Twenty years with daily disposables Johnson & Johnson Eye-Health Symposium, Zurich, Switzerland, 2014

Jones L. Solutions and contact lens compliance Johnson & Johnson Eye-Health Symposium, Zurich, Switzerland, 2014

Jones L. The future of the contact lens Global Contact Lens Forum, New York, USA, 2014

Jones L. Comfortable contacts: Dream or reality? Global Contact Lens Forum, New York, USA, 2014

Jones L. Twenty years with daily disposables Johnson & Johnson Eye-Health Symposium, Warsaw, Poland, 2014

Jones L. Solutions and contact lens compliance Johnson & Johnson Eye-Health Symposium, Warsaw, Poland, 2014

Jones L. Impact of deposits and frequency of replacement on contact lens discomfort NCC Meeting, Eindhoven, Netherlands, 2014

Jones L. What does that do? Understanding solutions composition NCC Meeting, Eindhoven, Netherlands, 2014

Jones L. Twenty years with daily disposables Johnson & Johnson Eye-Health Symposium, Ankara, Turkey, 2014

Jones L. Solutions and contact lens compliance Johnson & Johnson Eye-Health Symposium, Ankara, Turkey, 2014

Jones L. Contact lens compliance Johnson & Johnson Eye-Health Symposium, Kuwait City, Kuwait, 2014

Jones L. Contact lens compliance Johnson & Johnson Eye-Health Symposium, Dubai, UAE, 2014

Jones L. Conducting in-practice clinical research Hereford local meeting, Hereford, England, 2014

Jones L. What could the future for the contact lens look like? Heart of America meeting, Kansas City, Missouri, 2014

Jones L. Ocular drug delivery update Heart of America meeting, Kansas City, Missouri, 2014

Jones L. Comfortable contact lenses: Dream or reality? Heart of America meeting, Kansas City, Missouri, 2014

Jones L. What your patients don’t tell you! Heart of America meeting, Kansas City, Missouri, 2014

Jones L, Morgan P. On the sofa with Jones & Morgan British Contact Lens Association, Birmingham, UK, 2014

2013

Jones L. Contact lens developments to grow your practice Alcon meeting, Taipei, Taiwan, 2013

Jones L. Contact lens developments to grow your practice Alcon meeting, Kaohsiung, Taiwan, 2013

Jones L. Priming faculty to do publishable research Philippine College of Optometrists, Tagaytay, Philippines, 2013

Jones L. Could the solution be the solution? Philippine College of Optometrists, Tagaytay, Philippines, 2013

Jones L. Myopia control: Dream or reality? Philippine College of Optometrists, Tagaytay, Philippines, 2013

Jones L. Current status and the future for contact lenses Philippine College of Optometrists, Tagaytay, Philippines, 2013

Jones L. Contact lens solutions – same or different? CPRO Meeting, Montreal, Quebec, Canada, 2013

Jones L. Current status and the future for contact lenses CPRO Meeting, Montreal, Quebec, Canada, 2013

Jones L. But I always hated chemistry... American Academy of Optometry, Seattle, Washington, 2013

Jones L. Update on contact lens drug delivery American Academy of Optometry, Seattle, WA, USA, 2013

Jones L. Non compliance and frequent replacement of lenses Indiana Optometric Association meeting, Bloomington, Indiana, 2013

Jones L. What your patients don’t tell you! Indiana Optometric Association meeting, Bloomington, Indiana, 2013

Jones L. Kids and contact lenses Indiana Optometric Association meeting, Bloomington, Indiana, 2013

Jones L. What’s new and sexy in contact lenses? Canadian Association of Optometrists, Edmonton, Alberta, Canada, 2013

Jones L. Contact lens quiz: You decide! Canadian Association of Optometrists, Edmonton, Alberta, Canada, 2013

Jones L. Contact lens dryness: Can we help? Canadian Association of Optometrists, Edmonton, Alberta, Canada, 2013

Jones L. Current status and the future for contact lenses Prime Fitters Symposium, Rome, Italy, 2013

Jones L. Is corneal staining important? Prime Fitters Symposium, Rome, Italy, 2013

Jones L. Kids and contact lenses University of Waterloo CE Conference, Waterloo, Canada, 2013

Jones L. Short term performance evaluation of a new daily disposable silicone hydrogel contact lens Alcon US launch symposium of Dailies Total1, Dallas, Texas, 2013

Jones L. Current status and the future for contact lenses 6th Eye Health Symposium, Warsaw, Poland, 2013

Jones L. Is corneal staining important? 6th Eye Health Symposium, Warsaw, Poland, 2013

Jones L. Compliance in contact lens wearers Aarhus University Hospital, Aarhus, Denmark, 2013

Jones L. Myopia control: An update Aarhus University Hospital, Aarhus, Denmark, 2013

Jones L. Medical use of contact lenses Aarhus University Hospital, Aarhus, Denmark, 2013

Jones L. Myopia control: Dream or reality? Danish College of Optometry, Randers, Denmark, 2013

Jones L. Compliance in contact lens wearers KEA Department of Optometry, Copenhagen, Denmark, 2013

Jones L. Myopia control: An update KEA Department of Optometry, Copenhagen, Denmark, 2013

Jones L. Medical use of contact lenses KEA Department of Optometry, Copenhagen, Denmark, 2013

Jones L. So what do you want to know about contact lenses? Amersfoort, Netherlands, 2013

Jones L. Current status and the future for contact lenses Fielmann Eye Health Symposium, Hamburg, Germany, 2013

Jones L. Is corneal staining important? Fielmann Eye Health Symposium, Hamburg, Germany, 2013

Jones L. Comfortable contacts: Impossible dream or achievable reality? CIOCV Congress, Braga, Portugal, 2013

Jones L. Comfortable contacts: Fanciful dream or achievable reality? Seminar Series, Houston School of Optometry, Houston, Texas, 2013

Jones L. Contact lenses: Their role in detecting & managing disease Global Specialty Lens Symposium, Las Vegas, USA, 2013

Jones L. Clinical application of lens care Global Specialty Lens Symposium, Las Vegas, USA, 2013

Jones L, Hrynchak P. Problem-based learning (PBL) in optometry Philippine College of Optometrists, Tagaytay, Philippines, 2013

2012

Jones L. Compliance in contact lens wearers: What your patients don’t tell you! Australian National Conference, Melbourne Australia, 2012

Jones L. A commonwealth perspective on microbial keratitis and inflammatory responses in contact lens wear Australian National Conference, Melbourne Australia, 2012

Jones L. Drug delivery via contact lenses Australian National Conference, Melbourne Australia, 2012

Jones L. The great debate: Optometrists should stick with what they do best! Australian National Conference, Melbourne Australia, 2012

Jones L. 50 Fabulous facts about contact lenses East-West conference, Cleveland Ohio, 2012

Jones L. In contact with the practice of 2020 East-West conference, Cleveland Ohio, 2012

Jones L. Ocular drug delivery East-West conference, Cleveland Ohio, 2012

Jones L. Comfortable contacts: Impossible dream or achievable reality? East-West conference, Cleveland Ohio, 2012

Jones L. In contact with the practice of 2020 Western Pennsylvania Optometric Society, Pittsburgh, 2012

Jones L. What are the major challenges in dry eye and contact lens research? Summer Research Symposium, CCLR, University of Waterloo, Waterloo, Canada, 2012

Jones L. What your patients don’t tell you! University of Waterloo Continuing Education Conference, Waterloo, Canada, 2012

Jones L. What will contacts looks like in 2020? Woodruff Memorial Lecture, University of Waterloo Continuing Education Conference, Waterloo, Canada, 2012

Jones L. Is SICS really important? BCLA conference, Birmingham, UK, 2012

Jones L. The future metamorphosis of the contact lens BCLA conference, Birmingham, UK, 2012

Jones L. Toxicity versus safety – achieving a balance BioScience meeting, BCLA conference, Birmingham, UK, 2012

Jones L. Comfortable contacts: Fanciful dream or achievable reality? Abbott Medical Optics Seminar, Santa Ana, California, 2012

Jones L. Compliance – how bad is it? Johnson & Johnson educational event, Warsaw, Poland, 2012

Jones L. Frequent replacement: A modern approach Johnson & Johnson educational event, Warsaw, Poland, 2012

Jones L. Red eye and contacts: Emergency or not – your call! Johnson & Johnson educational roadshow, London, England, 2012

Jones L. Could the solution be the solution? Johnson & Johnson educational roadshow, London, England, 2012

Jones L. Red eye and contacts: Emergency or not – your call! Johnson & Johnson educational roadshow, Manchester, England, 2012

Jones L. Could the solution be the solution? Johnson & Johnson educational roadshow, Manchester, England, 2012

Jones L. Drug delivering contact lenses: The future for comfortable contacts? Dutch Contact Lens Association, Veldhoven, Netherlands, 2012

Jones L. What’s new and sexy in contacts? Dutch Contact Lens Association, Veldhoven, Netherlands, 2012

Jones L. Uptake and release of preservatives into soft contact lenses: Clinical implications Dutch Contact Lens Association, Veldhoven, Netherlands, 2012

Jones L. What you’re patients don’t tell you! Bronstein contact lens meeting, Scottsdale, Arizona, 2012

Jones L. Kids and contacts Bronstein contact lens meeting, Scottsdale, Arizona, 2012

Jones L. Ocular drug delivery update Bronstein contact lens meeting, Scottsdale, Arizona, 2012

Professional Publications

2024

Hui A. Research Review - Anti-inflammatory therapy in CLD Contact Lens Spectrum 2024;39, June: 6

Hui A. Interactions of Contact Lenses with Preservatives Contact Lens Spectrum 2024;39, January:

Hui A. Not a Dry Eye in the House: An Overview of New Drugs https://contactlensupdate.com/2024/04/16/not-a-dry-eye-in-the-house-an-overview-of-new-drugs/ 2024, 77:

Jones D, MacNeil C, Pal S, Weinstein M.. 3 Min, 49 Sec Video: How Do You Communicate to Kids & Parents as a Team?
Review of Optometric Business 2024, February: Video series - Part 4

Jones L. Everything you wanted to know about contact lens care but were afraid to ask! 2024

Luensmann D. Can we mask corneal astigmatism with soft lenses? https://contactlensupdate.com/2024/06/19/can-we-mask-corneal-astigmatism-with-soft-lenses/ 2024, 78:

Luensmann D. Fast Forward to the Future: Regaining Accommodation: Which Way to Go? Contact Lens Spectrum 2024;39, July:

Luensmann D. Practitioner Reference: Optimize Multifocal Soft Lens Fitting
https://contactlensupdate.com/2024/10/03/practitioner-reference-optimize-multifocal-soft-lens-fitting/ 2024, 80:

Mahil A, Jong M. Truth or myth: Only high levels of myopia increase the risk of ocular disease and permanent vision loss? Optician: https://www.opticianonline.net/content/features/truth-or-myth-only-high-levels-of-myopia-increase-the-risk-of-ocular-disease-and-permanent-vision-loss-answer-myth/ 2024, February 1:

Moezzi A, Ruston D. Truth or myth: Daily disposable hydrogel wearers should be refitted into DD silicone hydrogel lenses? Optician: https://www.opticianonline.net/content/features/truth-or-myth-daily-disposable-hydrogel-wearers-should-be-refitted-into-dd-silicone-hydrogel-lenses/ 2024, April 5:

Morgan P, Woods CA, Tranoudis IG, Efron N, Jones L, Faccia L, Rivadeneira D, Grupcheva CN, Jones D, Rodriguez Cely LM, Adsersen A, Santodomingo-Rubido J, Muselier-Mathieu A, Vegh M, Erdinest N, Montani G, Itoi M, Bendoriene RL, Mulder J, van der Worp E, van Mierlo T, Ystenaes AE, Romualdex-Oo J, Abesamis-Dichoso C, Gonzalez-Meijome JM, Macedo-de-Araujo RM, Johansson O, Hsiao J, Nichols JJ. International contact lens prescribing in 2023 Contact Lens Spectrum 2024;39, January/February: 20-22,24,26-28

Ng AY. AZR-MD-001 Improved Tear Film Stability and Symptoms of Meibomian Gland Dysfunction in a 6-Month Study https://contactlensupdate.com/2024/04/16/azr-md-001-improved-tear-film-stability-and-symptoms-of-meibomian-gland-dysfunction-in-a-6-month-study/ 2024, 77:

Qiu S. Fast Forward to the Future: The Rise of Empirical Fitting and Scleral Lens Customization Contact Lens Spectrum 2024;39, January/February: 36

Shokrollahi P. Fast Forward to the Future: Material science innovation Contact Lens Spectrum 2024;39, June: 34

Wolffsohn J, Craig J, Jones L. An Action Plan for Managing Dry Eye Review of Optometry 2024, May 15: 50-55

Wong S. Fast Forward to the Future: Shades Ahead Contact Lens Spectrum 2024;39, October: 17

Wong S, Ruston D. Truth or myth: Spectacle lenses provide better visual acuity than soft toric contact lenses Optician: https://www.opticianonline.net/content/features/truth-or-myth-spectacle-lenses-provide-better-visual-acuity-than-soft-toric-contact-lenses/ 2024, January 5:

Woods J. Article Review: Multifocal contact lens success predictability https://contactlensupdate.com/2024/10/03/article-review-multifocal-contact-lens-success-predictability/ 2024, 80:

Woods J, Jong M. Truth or myth: Young children are less successful in contact lenses? Optician: https://www.opticianonline.net/content/features/truth-or-myth-young-children-are-less-successful-in-contact-lenses-answer-myth 2024, March 1:

2023

Dantam J, Ng QW. Truth or myth: There is no patient benefit to correcting low astigmatism with soft contact lenses Optician: https://www.opticianonline.net/content/features/truth-or-myth-there-is-no-patient-benefit-to-correcting-low-astigmatism-with-soft-contact-lenses 2023, December 1:

Fadel D. Preventing and Managing Edema with Scleral Lenses Review of Cornea and Contact Lenses 2023, March/April: 18-21

Fadel D. Fast Forward to the Future: Envisaging the Future of Scleral Lenses Contact Lens Spectrum 2023;38, October: 46

Fadel D.. Three of a kind: Examples of challenges presented with scleral lens patients and how to overcome them. Contact Lens Spectrum 2023;38, July: 32-36, 38-40, 51

Garg P. Fast Forward to the Future: Biodegradable CLs Contact Lens Spectrum 2023;38, February:

Hui A. Recent Strategies to Manage CLD Contact Lens Spectrum 2023;38, July: 10-11

Jones D. The Role of Biometry in Myopia Management https://contactlensupdate.com/2023/04/25/the-role-of-biometry-in-myopia-management/ 2023;71

Jones D, MacNeil C, Pal S, Weinstein M. Unmet Market Needs of Children in Contact Lenses Review of Optometric Business 2023, July: Video series - Part 1

Jones D, MacNeil C, Pal S, Weinstein M. What Is the Best Way to Market CLs as a Great Choice for Children? Review of Optometric Business 2023, September: Video series - Part 2

Jones D, MacNeil C, Pal S, Weinstein M. What Are Your Practice’s Key Gains & Improvements in Myopia Management? Review of Optometric Business 2023, November: Video series - Part 3

Jones L, Wolffsohn J. CLS LIVE!: Lyndon Jones with James Wolffsohn Contact Lens Spectrum 2023;38, November: 16-17

Luensmann D, Meyler J. Truth or myth: All multifocal fitting steps are the same across different brands? Optician: https://www.opticianonline.net/content/features/are-all-multifocal-fitting-steps-the-same-across-brands/ 2023, October 6:

Morgan P, Woods CA, Tranoudis IG, Efron N, Jones L, Faccia L, Rivadeneira D, Teufl M, Grupcheva CN, Jones D, Rodriguez Cely LM, Adsersen A, Santodomingo-Rubido J, Bloise L, Erdinest N, Montani G, Itoi M, Bendoriene RL, Mulder J, van der Worp E, can Mierlo T, Romualdez-Oo J, Abesamis-Dichoso C, Gonzalez-Meijome JM, Macedo-de-Araujo RM, Johansson O, Hsiao J, Nichols JJ. International contact lens prescribing in 2022 Contact Lens Spectrum 2023;38, January: 28-35

Ng AY. Fast Forward to the Future: Going Green with Daily Disposables Contact Lens Spectrum 2023;38, June: 47

Ng AY, Jones L. CLs: Addressing core questions about sustainability Optician 2023, April 7: 16-17

Nogueira C. Fast Forward to the Future: Antibacterial coatings Contact Lens Spectrum 2023;38, April: 49

Phan C-M. Fast Forward to the Future: 3D Printing of Specialty Contact Lenses Contact Lens Spectrum 2023;38, August: 43

Powell S, Jones L. Contact lens wear over a lifetime Optometry Today: https://www.aop.org.uk/ot/life-in-practice/practitioner-stories/2023/12/07/contact-lens-wear-over-a-lifetime 2023, December 7:

Qiu S. Fitting Multifocal Scleral Lenses for Unilateral Central Corneal Scar Contact Lens Spectrum 2023;38; October, Scleral and Specialty Contact Lens Case Reports: 18

Schulze M. Fast Forward to the Future: What Happened to Super Vision? Contact Lens Spectrum 2023;38, December: 37

Schulze M, Bishop M. Truth or myth: Fitting soft multifocal CLs takes too much chair time? Optician; https://www.opticianonline.net/content/features/truth-or-myth-fitting-soft-multifocal-cls-takes-too-much-chair-time 2023, July 7:

Seo J, Meyler J. Truth or Myth. Fitting soft toric lenses takes too much chair time? Optician: https://www.opticianonline.net/content/features/truth-or-myth-fitting-soft-toric-lenses-takes-too-much-chair-time 2023, November 3:

Seo J, Moody K. Truth or myth: The preferred sighting method is the best way of measuring ocular dominance? Optician; https://www.opticianonline.net/content/features/truth-or-myth-the-preferred-sighting-method-is-the-best-way-of-measuring-ocular-dominance 2023, September 1:

Walker M, Bergmanson J, Schornack M, Fadel D. IFSLR 2023 RECAP Contact Lens Spectrum 2023;38, September: 37-41

Wong S, Meyler J,. Truth or myth: Monovision is best for presbyopic CL correction? Optician; https://www.opticianonline.net/content/features/truth-or-myth-monovision-is-best-for-presbyopic-cl-correction 2023, August 1:

2022

Bzovey B. Fast forward to the future - contact lens optical enhancements Contact Lens Spectrum 2022;37, December: 11

Bzovey B. Perspective on: Multifocal contacts benefit young adults, those with presbyopia Primary Care Optometry News 2022;April 18 [ Show Abstract ]

MCLs are used to manage myopia, based on the theories of peripheral retinal defocus and accommodative lag, by removing the signals that cause the eye to elongate.

It has been thought that center-distance designs are best for maintaining distance visual acuity (VA) and are the better choice for myopia control. This article describes that center-near MCLs can be another option that maintains distance VA.

The researchers discovered that center-near MCLs can degrade distance VA, with the higher add having a more significant degradation effect than a standard monofocal lens. They showed that young adults with accommodation (24- to 38-year-olds) overall had better VA than presbyopes with MCLs; the young adult’s distance and near VAs were maintained around 6/6. Pupil sizes showed a minimal effect on performance on either group, indicating preservation of good VA and functionality in center-near MCLs.

Accommodative lag is thought to be one of the theories of axial elongation in myopia. This report discusses how center-near MCLs allow a more accurate accommodative response, reducing accommodative lag. While additional research is required to investigate the efficacy differences of center-near vs. center-distance for myopia control, the presence of the near addition in MCLs will produce a sufficiently strong inhibitory signal to slow down myopia progression.

Bzovey B, Jones D.. Myopia measurements made easy Optician 2022, 18 March: 20-23 [ Show Abstract ]

Whether setting up a new practice, upgrading current equipment or choosing new equipment, the available choices can be overwhelming. There are many decisions to be made, including those based on cost, space and functionality. And with substantial growth opportunities within primary care practice, from services including specialty contact lens practice, dry eye and myopia management, making the right decision is important.
Practitioners looking for innovative instruments to support their myopia control practice should consider the clinical information required to manage their patients, including refractive error, keratometry and axial length. In addition, attention should be given to the footprint that any new equipment takes up.
Practitioners wishing to best utilise valuable practice space with a multi-function instrument can now consider the Myopia Master from Oculus (figures 1 and 2) as a standalone option for their myopia management practice. This sleek, all-in-one unit will check many boxes on the list of clinical measurement and functionality requirements to support this fast-moving area of clinical practice.

Chan V. Fast forward to the future - drugs & the ocular surface Contact Lens Spectrum 2022;37, June: 11

Chau J. Fast forward to the future - ocular disease and smart contact lenses Contact Lens Spectrum 2022;37, March: 12

Dantam J. Fast forward to the future - keep the microbes at bay Contact Lens Spectrum 2022;37, November: 12

Drolle E. Fast forward to the future - contact lens-based theranostics Contact Lens Spectrum 2022;37, September: 11

Guthrie S. Relationships between success factors in daily disposable multifocal lenses https://contactlensupdate.com/2022/12/21/relationships-between-success-factors-in-daily-disposable-multifocal-lenses/ 2022;69

Hui A. CL drug delivery for dry eye treatment Contact Lens Spectrum 2022;37, July: 12-13

Jones D. CAO Position Statement on Myopia Management Canadian Association of Optometrists - Position Statement; Jan 19, 2022

Jones D. Article Review: Long-term Effect of Dual-focus Contact Lenses on Myopia Progression in Children: A 6-year Multicenter Clinical Trial https://contactlensupdate.com/2022/09/01/article-review-long-term-effect-of-dual-focus-contact-lenses-on-myopia-progression-in-children-a-6-year-multicenter-clinical-trial/ 2022;67

Jones L. Contact Lens Spectrum Live! Contact Lens Spectrum 2022;37, 8: 22-23

Jones L, Walsh K, Sulley A. A lifetime of contact lens wear: How to select the right lens for the right patient at the right time! Optician 2022, July: 29-33

Lam M, Jones L. What a time to be alive: The future for contact lenses MiVision 2022;18171-72

Morgan P, Woods CA, Tranoudis IG, Efron N, Jones L, , Merchan BNL, Teufl M, Grupcheva CN, Jones D, Beeler-Kaupke M, Qi P, Tan KO, Rodriguez Cely LM, Belova S, can Beusekom M, Ravn O, Santodomingo-Rubido J, Bloise L, Plakitsi A, Végh M, Erdinest N, Montani G, Itoi M, Bendoriene RL, Mulder J, van der Worp E, Ystenaes AE, Romualdez-Oo J, Abesamis-Dichoso C, Gonzalez-Meijome JM, Macedo-de-Araujo RM, Johansson O, Sim D, Hsiao J, Nichols JJ. International contact lens prescribing in 2021 Contact Lens Spectrum 2022;37, 1: 32-38

Nagaarudkumaran N. Fast forward to the future - potential future ocular drug delivery technologies Contact Lens Spectrum 2022;37, August: 14

Ng AY. Replace your contact lenses on time. Patient handout https://contactlensupdate.com/2022/02/28/patient-handout-replace-your-contact-lenses-on-time/ 2022;64

Phan C. Smart Contact Lenses for Diagnostic and Therapeutic Applications OPTIK by VuePoint Optik 2022, May-June: 44-47

Phan CM. Fast forward to the future - diagnosing systemic diseases with smart lenses Contact Lens Spectrum 2022;37, February: 11

Schulze M. Multifocal Contact Lens Fitting: Clinical Pearls https://contactlensupdate.com/2022/12/21/multifocal-contact-lens-fitting-clinical-pearls/ 2022;69

Tan W, Jones L. Are all preservatives contraindicated in the management of dry eye disease? Ocular Surface Insight 2022;1513-16

Walker M, Bergmanson J, Fadel D, Johns L. Evidence-based Research and Clinical Practice Contact Lens Spectrum 2022;37, October: 38-43

Yang R. Fast forward to the future - treating ocular conditions Contact Lens Spectrum 2022;37, May: 10

2021

Guthrie S. Comfort and vision correlations in daily disposable multifocal lenses https://contactlensupdate.com/2021/06/15/comfort-and-vision-correlations-in-daily-disposable-multifocal-lenses/ 2021;60

Jones L. CLEAR report summary: Contact Lens Wettability, Cleaning, Disinfection and Interactions with Tears https://contactlensupdate.com/2021/06/15/contact-lens-wettability-cleaning-disinfection-and-interactions-with-tears/ 2021;60

Jones L. Pandemic-Associated Eye Problems: A Review of Five Issues for the ECP https://contactlensupdate.com/2021/12/10/pandemic-associated-eye-problems-a-review-of-five-issues-for-the-ecp/ 2021;60

Moezzi A. CLEAR report summary: Effect of Contact Lens Materials and Designs on the Anatomy and Physiology of the Eye https://contactlensupdate.com/2021/06/15/effect-of-contact-lens-materials-and-designs-on-the-anatomy-and-physiology-of-the-eye/ 2021;60

Morgan P, Woods CA, Tranoudis IG, Efron N, Jones L, Grupcheva CN, Jones D, Beeler-Kaupke M, Qi P, Tan KO, Rodriguez Cely LM, Belova S, Ravn O, Santodomingo-Rubido J, Bloise L, Plakitsi A, Végh M, Erdinest N, Montani G, Itoi M, Bendoriene RL, Mulder J, van der Worp E, Ystenaes AE, Romualdez-Oo J, Abesamis-Dichoso C, Gonzalez-Meijome JM, Belousov V, Johansson O, Hsiao J, Nicholes JJ.. International contact lens prescribing in 2020 Contact Lens Spectrum 2021;36, January: 26-32 [ Show Abstract ]

This article is our 20th consecutive annual report of international contact lens prescribing for Contact Lens Spectrum. The premise of the work is simple. As an alternative to asking a cross section of contact lens wearers about the lenses that they use and the basis on which the lenses are worn, we move upstream in the process and directly survey those who are fitting contact lenses in numerous markets around the world. This presents a more “leading edge” indicator of contact lens fitting habits; the lenses fitted today are those sold tomorrow. The aim here is to provide summary information for colleagues in clinical practice, industry, and academia about contact lens prescribing behaviors to inform their patient management, research and development, and educational curricula, respectively.

Ng AY. CLEAR report summary: Contact Lens Complications https://contactlensupdate.com/2021/06/15/contact-lens-complications/ 2021;60

Ng AY, Yang M. Why you shouldn’t neglect eye care during the pandemic The Conversation 2021;March 7 [ Show Abstract ]

Since COVID-19 emerged, access to eye care has continued to change. Lockdowns and concerns about virus exposure have caused people of all ages to cancel and delay routine appointments, raising red flags among eye-care professionals. As the pandemic continues into its second year, can ocular health be neglected any longer?

Our team of optometrists and clinical scientists at the Centre for Ocular Research & Education (CORE) hear the confusion and concerns about people’s eyes during COVID-19. Addressing the most common questions — many of which we keep up to date at COVIDeyefacts.org — can help you and your family maintain the best vision while staying safe.

Ngo W. CLEAR report summary: Anatomy and Physiology of the Anterior Eye https://contactlensupdate.com/2021/06/15/anatomy-and-physiology-of-the-anterior-eye/ 2021;60

Ngo W.. Face masks, digital screens and winter weather are a triple threat for dry eyes The Conversation 2021;December 16

Patel K, Draper M, Bull Z, Walsh K. Contact lenses: So much more than simple correction of refractive error Optician 2021, February: 25-29

Patel K, Walsh K. Soft toric contact lenses: Aligning patient expectations and eye care professional attitudes Optician 2021, March: 32-36 [ Show Abstract ]

In this article Krupa Patel and Karen Walsh examine the expectations around soft toric lenses from both the practitioner and patient’s point of view. It serves as a timely review of current toric fitting practices and how they relate to the prevalence of astigmatism, highlighting a number of opportunities for enhancing patient satisfaction and increasing practice revenue (C77594, one distance learning CET point suitable for optometrists, contact lens opticians and dispensing opticians).
Some simple facts help set the scene for this global review. It has been established that modern soft toric contact lenses are as quick and simple to fit as spherical lenses, with good visual outcomes and rotational stability across many visual tasks. However, when 400 eye care professionals (ECPs) in the US were asked, only around half agreed soft torics are as easy to fit as the equivalent spherical lens (49%), and that they have excellent rotational recovery (55%). How does this disparity between reported product performance and practitioner attitude influence fitting practices? Ultimately, what is the impact on patients, and how close does current practice come to meeting their
expectations?

Phan C. CLEAR report summary: Contact Lens Technologies of the Future https://contactlensupdate.com/2021/06/15/contact-lens-technologies-of-the-future/ 2021;60

Schulze M. CLEAR report summary: Contact Lens Optics https://contactlensupdate.com/2021/06/15/contact-lens-optics/ 2021;60

Walsh K. BCLA CLEAR Summary https://contactlensupdate-com.s3.amazonaws.com/uploads/2021/06/BCLA-CLEAR-summary.pdf 2021;60 [ Show Abstract ]

The BCLA Contact Lens Evidence-based Academic Report (CLEAR) totals more than 300 pages across 11 papers. Coordinated by 10 committee chairs, written by 102 authors based in 16 countries, it was published in March 2021 and is available here.

BCLA CLEAR sets the standard to which eye care professionals (ECPs) can refer for the latest information in the contact lens field whilst also highlighting opportunities for future research. This summary draws on key points from the reports to help inform evidence-based practice.

Walsh K, Jones L. Covid-19 and contact lenses: Keeping it simple in the ‘new normal’ Optician 2021, March: 25-30 [ Show Abstract ]

Karen Walsh and Professor Lyndon Jones examine how Covid-19 has affected routine contact lens practice and what that means for both eye care practitioners and their patients (C77595, one distance learning CET point suitable for optometrists, contact lens opticians and dispensing opticians).

In the first quarter of 2020, routine clinical eye care underwent a temporary cessation in most regions around the world due to the coronavirus pandemic. Optometric practice is now predominantly back up and running, albeit with the occasional return to a higher alert level as the infection rates in countries ebb and flow over time. The demands
of working in a world with Covid-19 have necessitated changes to how routine practice is conducted. As a result, the attitudes and needs of eye care practitioners (ECPs) and patients related to eye care in general, and contact lenses (CLs) in particular, may have altered. Within this new shape of optometric practice, the question of where CL practice fits naturally arises. While aftercare for the routine assessment and resupply of existing wearers may seem acceptable, how does the profession approach the option of new fits and upgrades? Given the wider challenges faced by practitioners, is this really the time to focus on such areas? Is it even ‘safe’ to fit CL now, given the close contact required? However, looking at it from a different point of view, are there in fact opportunities arising from the changes dictated by Covid-19 that could be beneficial for CL practice? This article reviews the recommendations
for safe CL practice, looks at their relevance for both practitioners and patients, and addresses how CL can be accommodated into the daily clinic routine as easily as possible.

Walsh K, Jones L. Ein Jahr Covid-19 und die Auswirkungen auf die Kontaktlinsenpraxis (German translation of "COVID-19: A Year in Review and the Impact on Contact Lens Practice", as published in CL Spectrum in Feb 2021); Deutsche Optikerzeitung 2021, 06: 96-103 [ Show Abstract ]

Das Jahr 2020, in dem die Corona-Pandemie begann, hat die gesamte Weltgemeinschaft und damit das Leben jedes einzelnen Menschen verändert. Folglich sind die Auswirkungen der Pandemie auch in der augenoptischen Branche zu spüren. Die Autoren Karen Walsh, MCOptom und PGDip, und Lyndon Jones, DSc und FCOptom, ziehen Bilanz.

Walsh K, Jones L. COVID-19: A year in review and the impact on CL practice Contact Lens Spectrum 2021;36, February: E1-E6 [ Show Abstract ]

For everyone involved in eye care, 2020 was going to be a special year. The numerous “20/20” puns and articles circulating in January were full of hope and future-gazing. No one could have predicted the direction that the year would take and its resulting impact on the world at large and, for this audience specifically, on the delivery of routine contact lens care. As the end of this unprecedented year has finally come to pass, it feels right to pause and reflect on the last 12 months, to examine the journey that the profession has taken, and to summarize the situation. This article reviews what the profession has learned and asks whether enough is known to successfully navigate the months and years ahead. With no small amount of irony and a large nod to those aforementioned puns, does being approximately one year into the pandemic result in having a useful amount of “20/20 hindsight”?

Walsh K, Sulley A. Soft toric lens fitting practices not meeting patient needs Optometry Times Journal 2021;13, 2: 34-37 [ Show Abstract ]

The inclusion of astigmatic correction in spectacles is common practice. Outside of the need to reduce a high or previously uncorrected astigmatism to ease adaption, eyecare professionals (ECPs) routinely prescribe the full toric correction in spectacles. Historically, the lack of availability of consistently performing, comfortable soft toric contact lens designs resulted in different prescribing practices for astigmats compared to those wearing spectacles, with spherical lenses often recommended over toric lenses for low to moderate levels of astigmatism.

Modern soft toric designs are significantly different from early non-planned replacement versions of 20 or more years ago. Their overall performance—which includes ease of fitting, comfort, rotational stability, vision performance, and consistent manufacturing in a range of designs and materials—enables them to be fit successfully to a wide range of astigmatic patients.

This review provides an overview of current soft toric prescribing, comparing and contrasting different fitting practices around the globe, and explores patient expectations and the opportunities that exist to meet their needs.

Wong S. CLEAR report summary: Evidence-Based Contact Lens Practice https://contactlensupdate.com/2021/06/15/evidence-based-contact-lens-practice/ 2021;60

Yang M. CLEAR report summary: Medical Use of Contact Lenses https://contactlensupdate.com/2021/06/15/medical-use-of-contact-lenses/ 2021;60

Yang R. Progression of myopia in school-aged children after COVID-19 home confinement: a review https://contactlensupdate.com/2021/12/10/progression-of-myopia-in-school-aged-children-after-covid-19-home-confinement-a-review/ 2021, 63:

2020

Fadel D, Walsh K.. COVID-19, quando l'uso delle lenti è sicurio B2Eyes 2020;March. [ Show Abstract ]

Recentemente alcuni articoli di giornali sul possibile contagio da coronavirus tramite lenti a contatto e alcune organizzazioni sanitarie che consigliano il passaggio in questa fase agli occhiali anziché l’uso delle lenti a contatto sollevano facilmente la preoccupazione che l'utilizzo delle lac potrebbe non essere sicuro durante la pandemia da Covid-19. Questa inondazione di informazioni fuorvianti ha portato ricercatori di spicco nel panorama internazionale, da Canada, Regno Unito e Stati Uniti, a rispondere. Lyndon Jones, direttore del Center for Ocular Research & Education (CORE) presso l'Università di Waterloo (Canada), Philip Morgan, direttore di Eurolens Research presso l'Università di Manchester (Regno Unito), e Jason Nichols, vicepresidente associato di ricerca e docente all'Università dell'Alabama presso la Birmingham School of Optometry (Stati Uniti) e direttore editoriale di Contact Lens Spectrum, hanno fornito le seguenti informazioni sulla sicurezza dell'uso delle lenti a contatto.

Jones D. Myopia Management: What Are the Options? Optometric Management 2020;June [ Show Abstract ]

There have been alarming predictions regarding the rate of increase of myopia for the next three decades. Of particular concern is the predicted increase in high myopia, with reports that almost 10% of the world’s population will exhibit myopia in excess of -5.00 D by 2050. Given the abundance of evidence in the literature that shows myopia progression can be reduced, practitioners need to be proactive with their young patients and introduce the concept of myopia control as soon as there is evidence of a myopic refractive error. Additionally, practitioners need to be familiar with the treatment options available.

Jones D. Measure Axial Length to Guide Myopia Management Review of Myopia Management 2020;March 1. [ Show Abstract ]

Myopic patients must be managed and monitored closely. Myopia can no longer be considered as a benign refractive error, and it cannot be managed by traditional optical means. With the growing prevalence of myopia, and the increased risk of ocular pathology associated with high myopia, eye care professionals (ECPs) need to assess their patients for risk factors that may lead to its onset.

Jones D. What Myopia Management Is and What It Is Not Review of Myopia Management 2020;July [ Show Abstract ]

Almost without exception, a paper or article written about myopia starts with the alarming statistics and predictions regarding the prevalence of myopia worldwide. Globally, clinicians and researchers are hopefully well aware by now of the projection that by 2050, 50 percent of the world’s population will be myopic. While this traditionally sets the scene for the need for action to combat this epidemic, what exactly does the term myopia management mean, and how can it be put into practice?

Jones L, Walsh K. Future of optics: The ultimate contact lens. Optician 2020;262, 2783: 24-25 [ Show Abstract ]

Twenty years ago, two of the most prominent contact lens (CL) researchers in the world (Professors Brien Holden and Debbie Sweeney) predicted what the ultimate CL would look like moving forward. Sadly, Professor Holden, the most visionary CL researcher in the history of our profession, passed away in July 2015. When their article was written back in January 2000, the biggest news was the commercialisation of silicone hydrogel (SiHy) materials by Bausch + Lomb and CIBA-Vision just one year prior. Daily disposable lenses were in their relative infancy, having been launched in the mid-1990s, and there were around half the number of CL wearers globally compared to best estimates today (80 million vs 150 million). With the luxury of hindsight, it is now possible to assess how close their predictions were, while also attempting the same feat with a look forward to what the CL practitioner of today may expect to be fitting in 2040.

Jones L, Walsh K, Willcox M, Morgan P, Nichols J. Key considerations for contact lens practitioners during the coronavirus pandemic. Optician 2020;April, 19-25: [ Show Abstract ]

A novel coronavirus (CoV), the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), results in the coronavirus disease 2019 (COVID-19). The World Health Organisation (WHO) declared the rapid spread of cases of COVID-19 a pandemic on March 11, 2020. The global response to COVID-19 has resulted in substantial changes to business and social practices around the world. With concerns existing around the pandemic, many reports relating to how best limit the chance of infection have been shared via various news outlets and on social media, with significant amounts of misinformation and speculation being reported. Among these, recent rumours have circulated stating that contact lens wear is unsafe, that wearers of contact lenses are more at risk of developing COVID-19, that certain contact lens materials are ‘riskier’ than others and that contact lens wearers should immediately revert to spectacle wear to protect themselves. How true are these statements, and are they supported by evidence? Importantly, are contact lens wearers increasing their risk of contracting COVID-19 by wearing contact lenses? Furthermore, what are the ramifications of a potential reduction in the availability of local ophthalmic care for contact lens wearers during this pandemic?

Jones L, Walsh K, Willcox M, Morgan P, Nichols J. Key considerations for contact lens practitioners during the coronavirus pandemic. Contact Lens Spectrum 2020;June, 19-26: [ Show Abstract ]

A novel coronavirus (CoV), the Severe Acute Respiratory Syndrome Coronavirus-2 (SARSCoV-2), results in the coronavirus disease 2019 (COVID-19). The World Health Organization (WHO) declared the rapid spread of cases of COVID-19 a pandemic on March 11, 2020.
The global response to COVID-19 has resulted in substantial changes to business and social practices around the world. With concerns existing around the pandemic, many reports relating to how to best limit the chance of infection have been shared via various news outlets and on social media, with significant amounts of misinformation and speculation being reported. Among these, recent rumors have circulated stating that contact lens wear is unsafe, that wearers of contact lenses are more at risk of developing COVID-19, that certain contact lens materials are more “risky” compared with others, and that contact lens wearers should immediately revert to spectacle wear to protect themselves. How true are these statements, and are they supported by evidence? Importantly, are contact lens wearers increasing their risk of contracting COVID-19 by wearing contact lenses? Furthermore, what are the ramifications of a potential reduction in the availability of local ophthalmic care for contact lens wearers during this pandemic?

Jones,L., Walsh,K.. COVID-19 and contact lenses - Practice re-entry considerations Optician 2020;August22-28 [ Show Abstract ]

A return to contact lens practice after the COVID-19 lock down requires an enhanced awareness of the risks and possibilities of contamination in the practice, and how to manage these. Patients can be triaged via a survey and telehealth before the appointment, and then precautions taken to assure distancing and protection as far as possible during their time in the practice. Staff need to be trained in new procedures and protected from exposure via screens and masks. Regular, rigorous cleaning of surfaces and equipment needs to be carried out between appointments and re-useable diagnostic lenses will need to be disinfected according to rigorous guidelines. However, with adequate guidance and care, contact lens wear continues to be a good option for patients.

Morgan P, Jones L, Gifford K.. Orthokeratology for myopia control in Covid-19 era Optician 2020, August: 12-14 [ Show Abstract ]

The year 2020 was affectionately termed ‘the year of optometry’ but the new decade has brought numerous challenges to the profession as the ongoing Covid-19 pandemic has seen normal clinical practice greatly disrupted. As the lockdown begins to ease, many aspects of normal optometric and optical functions are being reconsidered.

Due to their application to the ocular surface, the use of contact lenses has faced particular scrutiny and some media reports have advocated the cessation of contact lens use despite the absence of clear evidence for an increased risk of Covid-19 infection or any increase of eye touching during lens wear. Indeed, a recent review of the literature found no relationship between lens use and Covid-19 infection 1 and a separate report indicated that coronaviruses such as SARS-CoV-2 (the virus which causes Covid-19) are unlikely to bind to ocular surface cells to initiate infection.2 Related to this, although there are a number of reports of conjunctivitis occurring prior to symptoms of Covid-19, 3,4 a United Kingdom report of over 20,000 hospital patients with the disease found that only 0.3% presented with conjunctivitis. 5 Although more work is required to fully understand this area and new information is becoming available daily, it appears that the ocular surface is not a major point of ingress for the virus 6 and overall, contact lens wear continues to be safe.

Professional bodies and regulatory agencies including the College of Optometrists, 7 the British Contact Lens Association8 and the United States Centers for Disease Control and Prevention 9 concur that there is no association between contact lens use and Covid-19 infection. However, all these groups stress the need for hygienic contact lens use at this time, a recommendation which in part may relate to the need to minimise the requirement for contact lens wearers to seek clinical advice at a time where optometric services may not be fully operational and other healthcare facilities are also offering a reduced service. Furthermore, contact lens wearers should ideally refrain from attending emergency departments where they may be exposed to the virus.

Morgan P, Woods CA, Tranoudis IG, Efron N, Jones L, Merchan B, Grupcheva CN, Jones D, Beeler-Kaupke M, Krasnanska J, Belova S, Ravn O, Santodomingo-Rubido J, Taste P, Malet F, Plakitsi A, Végh M, Erdinest N, Montani G, Itoi M, Bendoriene J, Ramos Gómez RL, Pintor R, Mulder J, Van Der Worp E, Lam W, Ystenæs AE, Romualdez-Oo J, Abesamis-Dichoso C, González-Méijome J, Gierow P, Pettersson LA, Hsiao J, Nichols JJ . International Contact Lens Prescribing in 2019 Contact Lens Spectrum 2020;35, January: 26-32 [ Show Abstract ]

Since the turn of the century, we have presented annual overviews of contact lens prescribing trends in Contact Lens Spectrum. The work was initiated to help eyecare practitioners who are active in contact lenses to benchmark their fitting habits against their peers as well as to provide context to researchers in the field working on next-generation products. The database of lens fits collected over this period now exceeds 400,000, and the information has been collected across 71 markets.

In each targeted market, we supply survey forms and request that practitioners complete generic information about the first 10 contact lens fits conducted after receipt. This fundamental approach has remained unchanged since the first survey was conducted in the United Kingdom in 1996, with only minor changes to the form to account for new products becoming available on the market. For example, an option for “anti-myopia” (now termed “myopia control”) lenses was introduced in the 2011 survey to allow us to track developments in that area.

The distribution of the survey form varies. Some markets continue to use paper forms with a reply-paid envelope; others distribute and collect the same form via e-mail or a web-based questionnaire. The work is coordinated in each market by national coordinators who are listed as co-authors of this paper.

The survey forms request information about the age and sex of each contact lens patient fitted in addition to data about the material, design, replacement frequency, and wearing modality of the fitted lenses; anticipated weekly usage; and care system type. Each fit is weighted based on the estimated annualized number of fits for each practitioner. The data are finally collated at both the University of Manchester in the United Kingdom and at the University of Waterloo in Canada.

Phan C. Contact lens biosensors: Can we sense our tears? https://contactlensupdate.com/2020/02/06/contact-lens-biosensors-can-we-sense-our-tears/ 2020;February.

Phan C. Beyond 20/20 vision: the Mojo smart lens https://contactlensupdate.com/2020/02/06/beyond-20-20-vision-the-mojo-smart-lens/ 2020;February.

Schulze M. Blink Mechanics: Why it Matters Review of Cornea and Contact Lenses 2020;January/February

van der Worp E, Wolffsohn J, Jones L. Dropping the dropout rate Contact Lens Spectrum 2020;35, May: 36-43 [ Show Abstract ]

A review of soft lens types and fitting strategies that can help reduce the dropout rate among soft lens wearers.

At the 2020 Global Specialty Lens Symposium (GSLS), specialty lens topics from A to Z naturally dominated the program. However, soft lens fitting relating to all of its aspects is also one of the topics that the meeting covers, because the vast majority of contact lenses fitted worldwide are standard soft lenses, as confirmed by the annual Eurolens Research Survey published each year in the January issue of Contact Lens Spectrum.

Walsh K. Artificial tears: preserved or non-preserved, that is the question New Zealand Optics 2020, September: 26-27

Walsh K. A Year in Review: A Global Perspective on the Most Extraordinary of Years in Clinical Practice https://contactlensupdate.com/2020/12/09/a-year-in-review-a-global-perspective-on-the-most-extraordinary-of-years-in-clinical-practice/ 2020;December.

Walsh K. COVID-19 and contact lens wear: what do eye care practitioners and patients need to know? https://contactlensupdate.com/2020/03/16/covid-19-and-contact-lens-wear-what-do-eye-care-practitioners-and-patients-need-to-know/ 2020;March.

Walsh K. Face coverings and mask to minimise droplet dispersion and aerosolisation: a video case study https://contactlensupdate.com/2020/12/09/face-coverings-and-mask-to-minimise-droplet-dispersion-and-aerosolisation-a-video-case-study/ 2020

2019

Guthrie S. Summary: IMI Report on Experimental Models of Emmetropization and Myopia ContactLensUpdate.com 2019

Guthrie S. Report on Experimental Models of Emmetropization and Myopia - An article review ContactLensUpdate.com 2019

Jones D. Summary: IMI – Clinical Myopia Control Trials and Instrumentation report ContactLensUpdate.com 2019

Jones L. Summary: IMI – Industry Guidelines and Ethical Considerations for Myopia Control Report ContactLensUpdate.com 2019

Jones L., Jones D., Jones R. Contact lenses: Beyond 2020 Pharma (Australia) 2019, Dec: 12-13

Jones L., Woods J., Walsh K., Luensmann D. Happy 20th, silicone hydrogels! Review of Cornea and Contact Lenses 2019, Jan/Feb: 12-13

Lievens C, Jones L. The compelling case for hydrogen peroxide Contact Lens Spectrum 2019;34, 6: 30,32,33,36

Luensmann D. Summary: IMI Interventions for Controlling Myopia Onset and Progression Report ContactLensUpdate.com 2019

Morgan P, Woods CA, Tranoudis IG, Efron N, Jones L, Aighamdi W, Nair V, Merchan B NL, Teufl M, Grupcheva CN, Jones D, Beeler-Kaupke M, Lan W, Qi P, Tan KO, Krasnanska J, Pult H, Ravn O, Santodomingo-Rubido J, Tast P, Malet F, Plakitsi A, Végh M, Erdinest N, Chande PK, Montani G, Itoi M, Bendoriene, Ramos Gómez RL, Pintor R, Van Der Worp E, Lam W, Ystenæs AE, Romualdez-Oo J, Abesamis-Dichoso C, González-Méijome JM, Belousov V, Sim D, Stabuc Silih M, Gierow P, Pettersson LA, Hsiao J, Nichols JJ. International Contact Lens Prescribing in 2018 Contact Lens Spectrum 2019;34, January: 26-32

Ng AY. Summary: IMI Myopia genetics report ContactLensUpdate.com 2019

Phan C., Walther H., Jones L. Development of a polymeric eye model for foreign body removal Optometric Education 2019;45, 1: 1-6

Schulze M. Summary: IMI Myopia Control Reports Overview and Introduction ContactLensUpdate.com 2019

Walsh K. Summary: Defining and Classifying Myopia: A Proposed Set of Standards for Clinical and Epidemiological Studies ContactLensUpdate.com 2019

Walsh K. Clinical pearls from GSLS New Zealand Optics 2019, March: 16-19

Walsh K. Canadian Dry Eye Summit: Conference review
https://contactlensupdate.com/2019/12/11/canadian-dry-eye-summit-conference-review/ 2019;December.

Walsh K. Canadian Dry Eye Summit: On the subject of nutrition https://contactlensupdate.com/2019/12/11/canadian-dry-eye-summit-on-the-subject-of-nutrition/ 2019;December.

Walsh K. Canadian Dry Eye Summit: Getting started in practice https://contactlensupdate.com/2019/12/11/canadian-dry-eye-summit-getting-started-in-practice/ 2019;December.

Walsh K. Canadian Dry Eye Summit: Questioning the questionnaires https://contactlensupdate.com/2019/12/11/canadian-dry-eye-summit-questioning-the-questionnaires/ 2019;December.

Walsh K, Dantam J, Luensmann D. Contact Lens Wear and Its Disruption of the Tear Film Review of Cornea & Contact Lens 2019;May/June: 38-42.

Walsh K, Jones L, Woods J, Moody K. Evidence-based contact lens recommendation Contact Lens Spectrum 2019, Nov: 21-26

Walsh K, Lenz Y, Behrens R. Get the support you need: Freely available information can complement basic contact lens practice Contact Lens Spectrum 2019;34, 9: 32-37

Walsh K., Jones L. Aligning clinical practice with professional beliefs Optometry Today 2019, Dec: 71-75

Woods J, Jones L. Lens care compliance Contact Lens Spectrum 2019;34, 4: 36-40

Woods J, Jones L. Patients should comply with the proper use of hydrogen peroxide and multipurpose solution care regimens Contact Lens Spectrum 2019;34, April: 38-42

Yang M. Summary: IMI – Clinical Management Guidelines Report ContactLensUpdate.com 2019

2018

Elder M. Evaluation of Interprofessional Education and Collaboration in Optometry ContactLensUpdate.com 2018

Elder M, Srinivasan S. Tear Osmolarity: an overview Optician 2018;257, 6637: 30-33

Elder M, Srinivasan S. Meibography overview Optician 2018;257, 6634: 26-30

Elder M, Srinivasan S, Jones L. Tear ferning: an overview Optician 2018;258, 6671: 29-32

Jones D, Woods J. Maximize the opportunity for part-time contact lens wear Contact Lens Spectrum 2018;33, December: 12-13

Jones D, Woods J. Soft torics: Putting things straight Contact Lens Spectrum 2018;33, September: 12-13

Jones D, Woods J. Accommodating presbyopes: Who does it best? Contact Lens Spectrum 2018;33, June: 12-13

Jones D, Woods J. North America - Independence or not? Contact Lens Spectrum 2018;33, March: 14-15

Jones L. “Doc, I think I'm allergic to these new lenses…” Contact Lens Spectrum 2018;33, May: 44-46, 51

Jones L. Coping with Contact Lens Discomfort Review of Cornea & Contact Lenses 2018, January/February: 26-29

Jones L. Myth 1: Daily Disposable Silicone Hydrogels-Necessary or Not? ContactLensUpdate.com 2018;December.

Jones L, Berg A. Allergies to and with contact lenses New Zealand Optics 2018;10:24-25

Jones L, Karpecki P, Nichols K, O'Dell L. Frontline ocular surface disease care Review of Optometry 2018;155, 4: 36-43

Jones L, Walsh K. The evolution of silicone hydrogel daily disposables Optician 2018, 4 May: 25-32

Morgan P, Woods C, Tranoudis I, Helland M, Efron N, Jones L, Merchan N, Teufl M, Van Beusekom M, Grupcheva C, Jones D, Beeler-Kaupke M, Krasnanska J, Pult H, Ravn O, Santodomingo-Rubido J, Tast P, Malet F, Plakitsi A, Végh M, Erdinest N, Jafari A, Montani G, Itoi M, Bendoriene J, Ziziuchin V, Van Der Worp E, Lam W, Ystenæs A, Romualdez-Oo J, Abesamis-Dichoso C, González-Méijome J, Sim D, Stabuc Silih M, Hsiao J, Nichols J. International Contact Lens Prescribing in 2017 Contact Lens Spectrum 2018;33, January: 28-33

Schulze M. Blink animation software to improve blinking and dry eye symptoms ContactLensUpdate.com 2018

Srinivasan S. Dry eye update: new diagnostic and management strategies ContactLensUpdate.com 2018

Subbaraman L. The Tear Film: More complex than you may realize Review of Cornea & Contact Lenses 2018;January/February:22-25

Walsh K. Myth 3: It is not worth correcting low astigmats with toric contact lenses ContactLensUpdate.com 2018

Walsh K. Myth or reality? ContactLensUpdate.com 2018

Walsh K, Srinivasan S, Jones L. Lid margin health: the forgotten part of contact lens discomfort? Optician 2018, 7 September: 28-32

Woods J. Myth 2: Fitting soft multifocal lenses is complex, takes up a lot of chair time and never meets patient needs ContactLensUpdate.com 2018

Yang M. Are contact lenses safe for children? ContactLensUpdate.com 2018

Yang M. Myopia: A Global Problem with a Local Solution Optik 2018, September: 38-42

2017

Elder M. Summary: Epidemiology report ContactLensUpdate.com 2017

Elder M, Srinivasan S, Jones L. A new look at tears Optician 2017, June 2nd: 34-36

Luensmann D. Summary: Iatrogenic report – Dry eye disease caused by a medical treatment or procedure ContactLensUpdate.com 2017

Moezzi A. Summary: Pain and sensation report ContactLensUpdate.com 2017

Morgan P, Woods C, Tranoudis I, Helland M, Efron N, Jones L, Van Beusekom M, Grupcheva C, Fico F, Jones D, Beeler-Kaupke M, Qi P, Tan K, Krasnanska J, Pult H, Ravn O, Santodomingo-Rubido J, Végh M, Fan C, Erdinest N, Jafari A, Montani G, Itoi M, Chu B, Bendoriene J, Ziziuchin V, Van Der Worp E, Lam W, Ystenæs A, Romualdez-Oo J, Abesamis-Dichoso C, González-Méijome J, Belousov V, Cierow P, Stabuc Silih M, Hsiao J, Nichols J. International Contact Lens Prescribing in 2016 Contact Lens Spectrum 2017;32, January: 30-35

Ng AY. Summary: TFOS DEWS II Diagnostic methodology report ContactLensUpdate.com 2017;October, 38:

Schulze M. Summary: Pathophysiology report ContactLensUpdate.com 2017

Srinivasan S. Summary: Sex, gender and hormones report ContactLensUpdate.com 2017

Srinivasan S. Research update column Ocular Surface News 2017;May, Issue 90:

Srinivasan S. Research update column Ocular Surface News 2017;June, Issue 93:

Srinivasan S. Research update column Ocular Surface News 2017;July, Issue 95:

Srinivasan S. Research update column Ocular Surface News 2017;August, Issue 97:

Srinivasan S. Research update column Ocular Surface News 2017;September, Issue 99:

Srinivasan S. Research update column Ocular Surface News 2017;October, Issue 101:

Srinivasan S. Research update column Ocular Surface News 2017;November, Issue 103:

Srinivasan S. Research update column Ocular Surface News 2017;December, Issue 105:

Stahl U. Summary: Clinical trial design report ContactLensUpdate.com 2017

Subbaraman L. Summary: Tear film report ContactLensUpdate.com 2017

Walsh K. Three days of the latest in education, innovation and best practice Optik 2017

Walsh K. Building a bigger basket with your contact lens wearers Optik 2017

Walsh K. The astigmat in contact lenses: their experience and your opportunity Optik 2017

Walsh K. Material protection: UV and contacts Optik 2017

Walsh K. Hurry up and fit them while they’re young Optik 2017

Walsh K. A glimpse of a future contact lens practice Optik 2017

Walsh K. Pupil diameter, working distance and illumination during habitual tasks. Implications for simultaneous vision contact lenses for presbyopia - An article review ContactLensUpdate.com 2017

Walsh K. Summary: Definition and classification report ContactLensUpdate.com 2017

Wong S. A review of contact angle techniques ContactLensUpdate.com 2017

Yang M. Summary: Management and therapy report ContactLensUpdate.com 2017

2016

Guthrie S, Dumbleton K, Jones L. Is there a Relationship Between Care System and Compliance? Contact Lens Spectrum 2016;31, April: 40-43

Jones D. Global trends in myopia management: A review ContactLensUpdate.com 2016

Jones L. Avoiding contact lens discomfort and dropout EyeCare Update 2016;1(2):2-3

Jones L, Ng AY, Thompson B. Keeping up with ocular fatigue in the digital era Contact Lens Spectrum 2016;31(6):Supplement

Morgan P, Woods C, Tranoudis I, Helland M, Efron N, Jones L, Teufl M, Grupcheva C, Lemos R, Jones D, Beeler-Kaupke M, Qi P, Tan K-O, Belikova J, Pult H, Ravn O, Santodomingo-Rubido J, Malet F, Plakitsi A, Vegh M, Erdinest N, Jafari A, Montani G, Itoi M, Sun B, Bendoriene J, van der Worp E, Pintor R, Monroy J, Chia J, Awasthi S, Lam W, Romualdex-Oo J, Abesamis-Dichoso C, Gonzalez-Meijome J, Gierow P, Stabuc Silih M, Hsiao J, Nichols J. International contact lens prescribing in 2015 Contact Lens Spectrum 2016;31(1):24-29

Ng AY. Ocular surface implications of cosmetic products Optometry Today 2016, January:

Srinivasan S. Research update column Ocular Surface News 2016;January, Issue 67:

Srinivasan S. Research update column Ocular Surface News 2016;March, Issue 69:

Srinivasan S. Research update column Ocular Surface News 2016;April, Issue 71:

Srinivasan S. Research update column Ocular Surface News 2016;May, Issue 73:

Srinivasan S. Research update column Ocular Surface News 2016;June, Issue 75:

Srinivasan S. Research update column Ocular Surface News 2016;July, Issue 77:

Srinivasan S. Research update column Ocular Surface News 2016;August, Issue 81:

Srinivasan S. Research update column Ocular Surface News 2016;September, Issue 83:

Srinivasan S. Research update column Ocular Surface News 2016;October, Issue 85:

Srinivasan S. Research update column Ocular Surface News 2016;November, Issue 87:

Srinivasan S. Research update column Ocular Surface News 2016;December, Issue 89:

Subbaraman L. Is contact lens deposition good or bad? ContactLensUpdate.com 2016

Subbaraman L, Pruitt J, Jones L. Measuring Contact Lens Friction Contact Lens Spectrum 2016;31, January: 40-43

Walsh K. Contact lens aftercare: an opportunity to deliver great customer experience Optik 2016

Walsh K. Not all contact lens deposits are bad Optik 2016

2015

Luensmann D, Jones L. Clinical performance of a new silicone hydrogel colored contact lens Optometry Times 2015;June

McCanna D. Being “SunSmart”: Finding the right life-light balance ContactLensUpdate.com 2015

Morgan P, Woods CA, Tranoudis IG, Helland M, Efron N, Jones L, Dávila-Garcia E, Magnelli P, Teugl IM, Grupcheva CN, Jones D, Beeler-Kaupke M, Tan K, Pesinova A, Pult H, Ravn O, Santodomingo J, Malet F, Plakitsi A, Végh M, Erdinest N, Chande PK, Itoi M, Bendoriene J, van der Worp E, Pintor R, Moroy JL, Chia J, Awasthi S, Lam W, Romualdez-Oo J, Abesamis-Dichoso C, González-Méijome JM, Belousov V, Gierow P, Stabuc Silih M, Hsiao J, Nichols JJ. International contact lens prescribing in 2014 Contact Lens Spectrum 2015;30, 1: 28-33

Ngo W. Article Review:Identifying Demodex in the eyelash follicle without epilation ContactLensUpdate.com 2015

Ngo W. Meibomian Gland Dysfunction and Contact Lens Wear Contact Lens Spectrum 2015;30, March: 40, 42, 43

Sivak A. The significance of eyelid conditions for patients ContactLensUpdate.com 2015

Srinivasan S. Maintaining Ocular Surface Wellness Contact Lens Spectrum 2015;30, July: 34-36, 38, 40, 42

Srinivasan S. Research update column Ocular Surface News 2015;January, Issue 44:

Srinivasan S. Research update column Ocular Surface News 2015;February, Issue 46:

Srinivasan S. Research update column Ocular Surface News 2015;March, Issue 48:

Srinivasan S. Research update column Ocular Surface News 2015;April, Issue 50:

Srinivasan S. Research update column Ocular Surface News 2015;May, Issue 52:

Srinivasan S. Research update column Ocular Surface News 2015;June, Issue 54:

Srinivasan S. Research update column Ocular Surface News 2015;July, Issue 56:

Srinivasan S. Research update column Ocular Surface News 2015;August, Issue 58:

Srinivasan S. Research update column Ocular Surface News 2015;September, Issue 60:

Srinivasan S. Research update column Ocular Surface News 2015;October, Issue 62:

Srinivasan S. Research update column Ocular Surface News 2015;November, Issue 64:

Srinivasan S. Research update column Ocular Surface News 2015;December, Issue 66:

Srinivasan S. Subbaraman L. Current Innovations in Contact Lens Materials Review of Optometry 2015;February 15

Woods J. Conjunctival Responses to Contact Lens Wear Contact Lens Spectrum 2015;30, August: 34-36, 38

2014

Guthrie S, Dumbleton K, Jones L. Financial Implications of Patient Compliance Contact Lens Spectrum 2014;29, December: 42-45

Luensmann D. A meta-analysis of studies on cosmetically tinted soft contact lenses ContactLensUpdate.com 2014

Morgan P, Bright F, Cavet M, Dobson C, Efron N, Jones L, Papas E. A closer look at fluorescein. Global Contact Lens Care symposium supplement. Supplement to Optician 2014;March; 247, (6440):

Ng AY. Variations in tea tree oil concentrations Optician 2014;248, 6478: 11

Ng AY. Makeup and your eyes: friend or foe? ContactLensUpdate.com 2014

Ng AY. Summary: Report of the Definition and Classification Subcommittee ContactLensUpdate.com 2014

Ng AY, Bitton E, Jones L. Demodex infestation of the eyelashes Contact Lens Spectrum 2014;29, 12: 36-41

Ngo W. Summary: Report of the Management and Therapy Subcommittee ContactLensUpdate.com 2014

Panjwani F. Summary: The Economic Cost of Myopia in Adults Aged Over 40 Years in Singapore ContactLensUpdate.com 2014

Panjwani F. Summary: Report of the Subcommittee on Epidemiology ContactLensUpdate.com 2014

Schulze M. Summary: Report of the Clinical Trial Design and Outcomes Subcommittee ContactLensUpdate.com 2014

Schulze M. Review of "In vivo 3D meibography of the human eyelid using real time imaging Fourier-Domain OCT" ContactLensUpdate.com 2014

Sivak A. Conference Synopsis: Myopia in China (ARVO 2014) ContactLensUpdate.com 2014

Sivak A. Conference synopsis: New technology in contact lens research ContactLensUpdate.com 2014

Srinivasan S. Research update column Ocular Surface News 2014;September 18, Issue 35:

Srinivasan S. Research update column Ocular Surface News 2014;August 21, Issue 33:

Srinivasan S. Research update column Ocular Surface News 2014;July 24, Issue 31:

Srinivasan S. Research update column Ocular Surface News 2014;June 26, Issue 29:

Srinivasan S. Research update column Ocular Surface News 2014;May 29, Issue 27:

Srinivasan S. Research update column Ocular Surface News 2014;May 01, Issue 25:

Srinivasan S. Research update column Ocular Surface News 2014;April 03, Issue 23:

Srinivasan S. Research update column Ocular Surface News 2014;March 06, Issue 21:

Srinivasan S. Research update column Ocular Surface News 2014;February 06, Issue 19:

Srinivasan S. Research update column Ocular Surface News 2014;January 09, Issue 17:

Srinivasan S. Research update column Ocular Surface News 2014;October 16, Issue 37:

Srinivasan S. Research update column Ocular Surface News 2014;November 13, Issue 39:

Srinivasan S. Research update column Ocular Surface News 2014;December 11, Issue 41:

Srinivasan S. Overview: 2013 report from the Tear Film & Ocular Surface Society’s Workshop on Contact Lens Discomfort ContactLensUpdate.com 2014

Stahl U. Summary: Report of the Contact Lens Interactions with the Tear film Subcommittee ContactLensUpdate.com 2014

Subbaraman L. Summary: Report of the Contact Lens Materials, Design and Care Subcommittee ContactLensUpdate.com 2014

Varikooty J. Summary: Report of the Subcommittee on Neurobiology ContactLensUpdate.com 2014

Yang M. Summary: Report of the Contact lens Interactions with the Ocular Surface and Adnexa Subcommittee ContactLensUpdate.com 2014

2013

Dumbleton K, Luensmann D. Corneal Infiltrates with Silicone Hydrogel Contact Lens Wear and the Role of Compliance Optometry Rounds 2013;1, 5:

Fonn D. Clinical relevance of contact lens lubricity Contact Lens Spectrum 2013;28(13)

Fonn D. Assessing end of day comfort Contact lens Spectrum 2013;28(7)

Jones L. Hydrogel contact lens materials: Dead and buried or about to rise again? ContactLensUpdate.com 2013

Jones L. Measuring friction and lubricity of soft contact lenses: A review. Contact Lens Spectrum 2013;28(13)

Morgan P, Bright F, Cavet M, Dobson C, Efron N, Jones L, Papas E. A closer look at fluorescein Contact 2013;Dec1-16

Sivak A. New developments in contact lens materials: A conference synopsis ContactLensUpdate.com 2013

Srinivasan S. Research update column Ocular Surface News 2013;November 21, Issue 15:

Srinivasan S. Research update column Ocular Surface News 2013;October 25, Issue 13:

Srinivasan S. Research update column Ocular Surface News 2013;September 26, Issue 11:

Srinivasan S. Research update column Ocular Surface News 2013;August 29, Issue 09:

Srinivasan S. Research update column Ocular Surface News 2013;August 02, Issue 07:

Srinivasan S. Interview on “Breaking New Ground in Meibography” Review of Ophthalmology 2013;20, 7: 14-17

Srinivasan S. Research update column Ocular Surface News 2013;July 05, Issue 05:

Srinivasan S. A review of “Lid Wiper Epitheliopathy in Contact lens wearers" ContactLensUpdate.com 2013

Srinivasan S. Research update column Ocular Surface News 2013;June 07, Issue 03:

Srinivasan S. Research update column Ocular Surface News 2013;May 01, Issue 01:

Srinivasan S. Corneal staining and infiltrative keratitis – Is there evidence of link? Contact Lens Spectrum 2013;28, 5: 34-37

Srinivasan S. Contact Lens Wear and Meibomian Gland Dysfunction ContactLensUpdate.com 2013

Subbaraman L, Sivak A. Characterizing the surface properties of a contact lens: A review ContactLensUpdate.com 2013

Subbaraman L, Srinivasan S. A Lens Fit for Dry Eye Review of Cornea and Contact Lenses 2013 17-21

Woods J, Woods C, Fonn D, Jones L. Potential acceptance of a daily disposable silicone hydrogel multifocal lens in emmetropic presbyopes Optom Vis Sci 2013;88: E-Abstract 135100

2012

Djalal Y, Bitton E, Jones L. Tearing the tears apart Contact Lens Spectrum 2012;27, 5: 46-50

Hui A. Contact lenses for drug delivery – overview and recent developments ContactLensUpdate.com 2012

Hui A. Complications when you least expect them Contact Lens Spectrum 2012;27, Sept: 30-55

McCanna D. How safe is your lens case? ContactLensUpdate.com 2012

Nguyen D, Hui A, Weeks A, Heynen M, Martell E, Sheardown H, Jones L. Release of Ciprofloxacin-HCl and Dexamethasone phosphate by soft contact lens materials loaded with Hyaluronic Acid Materials 2012;5684-698

Phan C. Delivering cyclosporine A from contact lenses: An article review ContactLensUpdate.com 2012

Sivak A. Barriers to drug delivery via contact lenses: A report from the 2012 BCLA meeting ContactLensUpdate.com 2012

Sivak A. Meibomian gland dysfunction: An update from the 2011 meeting of the American Academy of Optometry ContactLensUpdate.com 2012

Srinivasan S. Contact lens wear and meibomian gland dysfunction ContactLensUpdate.com 2012

Varikooty J, Stahl U. Visualization of limbal/conjunctival folliculitis associated with soft contact lens wear ContactLensUpdate.com 2012

Woods C. Presbyopia: a pause in focus ContactLensUpdate.com 2012

2011

Bitton E, Jones L. Don’t flip over lens inversion markers Contact Lens Spectrum 2011;26, 2: 51-52

Guthrie S. Effect of dual-focus soft contact lens wear on axial myopia progression in children - An article review ContactLensUpdate.com 2011

Hui A.. The Future of Fitting: Predictions and contact lens innovations right around the corner Optometric Management 2011, August:

Jones L. The University of Waterloo’s Centre for Contact Lens Research The Ocular Surface 2011;9, 4: 242-244

Jones L, Papas E. The next 25 years: The future of contact lenses Contact Lens Spectrum 2011;26, 6: 14-15

K Dumbleton, L Jones. Non-compliance: So what? ContactLensUpdate.com 2011

Luensmann D. Physiological response to protein and cholesterol deposition on silicone hydrogel contact lenses - An article review ContactLensUpdate.com 2011

Sivak A. Strategies for improving patient compliance ContactLensUpdate.com 2011

Srinivasan S, Menzies K, Sorbara L, Jones L. Meibography of the upper lid Optician 2011;242, 6318: 12-15

Srinivasan S, Sorbara L, Jones L, Sickenberger W. Imaging the structure of the meibomian glands Contact Lens Spectrum 2011;26, 7: 52-53

2010

Dumbleton K, Jones L. Why wouldn’t you fit your astigmatic patients with toric silicone hydrogel lenses? Silicone Hydrogels Website 2010, March :

Dumbleton K, Woods C, Jones L, Fonn D. How compliant are today’s lens wearers? Contact Lens Spectrum 2010;25, 6: 34-37

Hall B, Jones L. Countering noncompliance with lens care and case technology Contact Lens Spectrum 2010;25, 12: 50-51

Hui A, Jones L. Contact lenses offer effective drug delivery Optometry Pharma 2010, Sept: 26-27

Jones L. New options for enhancing contact lens wetting Refractive Eyecare 2010, August: 9-11

Jones L, Epstein A, Holden B, Szczotka-Flynn L. The current realities of silicone hydrogel lenses Contact Lens Spectrum 2010, Oct: 1-15

Jones L, Menzies K, Subbaraman L. Comfortable contact lenses: A case of Mission Impossible? Contact Lens Spectrum 2010;25, 7: 45-48

Richter D, Dumbleton K, Guthrie S, Woods C, Jones L, Fonn D. Patient and practitioner compliance with silicone hydrogel and daily disposable lens replacement in Canada Canadian Journal of Optometry 2010;72, 1: 10-19

Srinivasan S, Jones L. Tear osmolarity measurements using novel osmometers Optician 2010;240, 6270: 50-52

2009

Bitton E, Sorbara L. Canadians are alive and well at the AAO in Anaheim 2008 Canadian J Optom 2009;70, 1:

Dalton K, Subbaraman L, Rogers R, Jones L. Physikalische eigenschaften von pflegelosungen fur weiche kontaklinsen Die Kontaklinse 2009;415-20

Dumbleton K, Jones L. Silicone hydrogels – no longer for just a select few Contact Lens Spectrum 2009;24, 4: 20

Dumbleton K, Jones L. The evolution of contact lens wetting agents Contact Lens Spectrum 2009;24, 10: 20

Dumbleton K, Jones L. What contact lens materials are patients wearing? Contact Lens Spectrum 2009;24, 8: 21

Dumbleton K, Jones L. Don’t compromise with your teenagers Contact Lens Spectrum 2009;24, 2: 24

Dumbleton K, Jones L. The quest for all-day comfort Contact Lens Spectrum 2009;24, 12: 17

Efron N, Morgan PB, Woods CA. Trends in Australian contact lens prescribing 2009 Australian Optometry (contact lens supplement) 2009;30, 10: 2-4

Epstein A, Andrasko G, Jones L, Kading D, Lebow K, Schachet J, Townsend W. New perspectives on patient satisfaction: The science of comfort, part 3. Ensuring wettability and comfort Contact Lens Spectrum 2009, July: 3-6

Epstein A, Andrasko G, Jones L, Kading D, Lebow K, Schachet J, Townsend W. New perspectives on patient satisfaction: The science of comfort, part 2. Keeping lenses clean Contact Lens Spectrum 2009, April: 3-7

Epstein A, Andrasko G, Jones L, Kading D, Lebow K, Schachet J, Townsend W. New perspectives on patient satisfaction: The science of comfort, part 1. Biocompatible disinfection Contact Lens Spectrum 2009, January: 3-10

French K, Jones L. Zehn jahre silikon-hydrogellinsen Die Kontaklinse 2009;320-27

Jones L. Silicone hydrogel deposition Contact Lens Spectrum 2009;24, 11: 14-15

Jones L. Solution-induced corneal staining does matter Contact Lens Spectrum 2009;24, 2: 18

Jones L. Essential fatty acids and dry eye: What do we know? Contact Lens Spectrum 2009;24, 7: 14-15

Jones L. Drug delivering contact lenses: A dream worth chasing? Contact Lens Spectrum 2009;24, 3: 18-19

Jones L, Dumbleton K. Contact lens deposits - patient or material driven? Contact Lens Spectrum 2009;24, 6: 19

Keir N. Why contact lens groups? SiliconeHydrogels.org 2009

Luensmann D, Jones L. Albuminablagerungen auf kontaklinsen-materialien: Ein uberblick Die Kontaklinse 2009;518-23

Sorbara L. Report on the Global Specialty Lens Symposium Contact Lens Spectrum 2009, March:

Subbaraman L, Jones L. What influences contact lens related dry eye? Contact Lens Spectrum 2009;24, 7: 39-43

Sulley A, Jones L, French K. Silicone hydrogels - ten years on Dispensing Optics 2009;24, 8: 4-12

Woods CA, Morgan PB, Sivak A. Market utilisation of dilicone hydrogel lenses Silicone Hydrogels Website 2009, June:

Woods J, Woods C, Fonn D. Practical guide for fitting soft centre near design multifocal contact lenses Contact Lens Spectrum 2009

Woods J, Woods CA, Fonn D. Managing the emerging presbyopic contact lens wearer Optometry Today 2009;49, 12: 32-35

2008

Dumbleton K. Why haven’t SiH contact lenses conquered the world (yet)? 2008

Efron N, Morgan P, Woods CA. Trends in Australian contact lens prescribing Australian Optometry 2008;293-5

French K, Jones L. A decade with silicone hydrogels: part 1 Optometry Today 2008;48, 16: 42-46

French K, Jones L. A decade with silicone hydrogels: part 2 Optometry Today 2008;48, 18: 38-43

Jones L. The past present and future of soft contact lenses Eye-Zone 2008, 21: 41-42

Jones L, Christie C. Soft contact lens solutions review part 2: Modern generation care systems Optometry in Practice (UK) 2008;943-62

Jones L, Lorentz H. The new comfilcon A material Review of Optometry 2008, April: 2-5

Jones L, Woods C. An eye on the world's first silicone hydrogel daily disposable contact lens The Optician 2008;236, 6172: 33-34

Jones L, Woods C. Compromises’ end? The introduction of a silicone hydrogel daily disposable lens Silicone Hydrogels Website 2008

Peterson R, Sorbara L. Contact Lenses IV: Lens fit Optometry Today 2008;48, 8: 66

2007

Efron N, Morgan PB, Woods C. Trends in Australian contact lens prescribing 2006 Australian Optometry 2007;28, 5: 9-11

Efron N, Morgan PB, Woods C. Australian contact lens prescribing 2007 Australian Optometry 2007;28, 12: 3-5

Jones L. Understanding the link between wettability and lens comfort: Improving ocular health and comfort with silicone hydrogel contact lenses Contact Lens Spectrum 2007;22s4-s6

Jones L, Dumbleton K. Comfilcon A: a new silicone hydrogel material Contact Lens Spectrum 2007;22, 8: 23

Jones L, Dumbleton K. A silicone hydrogel material gets an upgrade Contact Lens Spectrum 2007;22, 12: 18

Jones L, Dumbleton K, Woods J. A made-to-ofer silicone hydrogel lens Optician 2007;233, 6104: 45-47

Jones L, Dumbleton K, Woods J. Fitting a challenging case with a custom silicone hydrogel Contact Lens Spectrum 2007;22, 6: 17

Jones L, Dumbleton K, Woods J. Fitting and evaluating a custom silicone hydrogel lens Contact Lens Spectrum 2007;22, 4: 19

Jones L, Dumbleton K, Woods J. Introducing a made-to-order silicone hydrogel lens Contact Lens Spectrum 2007;22, 2: 23

Jones L, Dumbleton K, Woods J. A made to order silicone hydrogel lens Optician 2007;233, 6104: 45-47

Jones L, Senchyna M. Soft contact lens solutions review part 1: Components of modern care regimens Optometry in Practice 2007;845-56

Keir N. Have silicone hydrogels improved contact lens-related discomfort and dryness? SiliconeHydrogels.org 2007

2006

Dumbleton K. Expect the Unexpected-Refitting from Conventional Hydrogels 2006

Fonn D. 10 contact lens highlights from the last two decades Contact Lens Spectrum 2006;21, 6: 48

Fonn D. Silicone hydrogels - making the choice Optician 2006;232, 6067: 22-24

Fonn D. Ten contact lens highlights from the last two decades Contact Lens Spectrum 2006;21, 6: 48

Fonn D. Silicone hydrogels - making the choice The Optician 2006;232, 6063: 22-24

Fonn D, Dumbleton K, Jalbert I, Sivak A. Benefits of silicone hydrogel lenses Contact Lens Spectrum 2006;21, 2s: 38-44

Fonn D, Dumbleton K, Sivak A. Benefits of silicone hydrogel lenses Contact Lens Spectrum 2006;21, 2s: 38-44

Fonn D, Kerby K, Simpson T, Bitton E, Rajani N, Jones L, Berthiaume L, Miranda T, Caffrey B, Lutzi D, Maroun F, Leinweber G. Round table discussion on dry eye Can J Optom 2006;68, 5: 189-200

Ghormley R, Jones L. Managing lipid deposition on silicone hydrogel lenses Contact Lens Spectrum 2006;21, 1: 21

Jones L. Hidrogeles de silicona y eleccion de la pauta de mantenimiento Journal of the Spanish College of Optometrists 2006;40666-68

Jones L, Subbaraman L, Rogers R, Dumbleton K. Surface treatment, wetting and modulus of silicone hydrogels Optician 2006;232, 6067: 28-34

Morgan P, Efron N, Woods C, Jones D, Grin HJ, Tranoudis Y, Itoi M, van der Worp E, Phillips G, Belousov V, Helland M, Ghunholm-Henriksson IL, Yeo A, Barr J. What contact lenses are fitted today (and tomorrow)? Global Contact Lens 2006;4212-15

Morgan P, Efron N, Woods C, Jones D, Pesnova A, Grein HJ, Tranoudis Y, Chandrinos A, Itoi M, van der Worp E, Phillips G, Belousov V, Helland M, Thunholm-Henricksson IL, Ong A, Hung L, Monatani G, Barr J. International contact lens prescribing in 2005 Contact Lens Spectrum 2006;21, 1: 35-39

Morgan PB, Efron N, Woods CA, Jones D, Pesinova A, Grein HJ, Tranoudis IG, Chandrinos A, Itoi M, van_der_Worp E, Phillips G, Belousov V, Helland M, Thunholm-Henriksson IL, Ong A, Hung LK, Barr JT. International contact lens prescribing in 2005 Contact Lens Spectrum 2006;21, 1: 35-39

Sweeney D, Fonn D, Evans K. Silicone hydrogels: the evolution of a revolution Contact Lens Spectrum 2006;21, 2s: 14-19

Sweeney D, Fonn D, Evans K. Silicone hydrogels: the evolution of a revolution Contact Lens Spectrum 2006;21, 2: 28-38

Woods CA. 2005: the year in contact lenses Contact Lens Spectrum 2006;21, 2: 28-38

2005

Dumbleton K. Daily wear performance of silicone hydrogel lenses 2005

Fonn D, Dumbleton K, Papas E. Conjunctival appearance related to silicone hydrogel lens wear Contact Lens Spectrum 2005;20, 9: 46

Fonn D, Holden B, Bonanno JA, Cavanagh D. O2 measurement and needs Contact Lens Spectrum 2005;20, 8s: 12-15

Fonn D, Holden B, Bonanno JA, Cavanagh D. 0 2 measurements and needs Contact Lens Spectrum 2005;20, 8s: 12-15

Fonn D, Holden B, Hill R, Cavanagh D, Wilson GS. Achieving normoxia Contact Lens Spectrum 2005;20, 8s: 4-7

Fonn D, Papas E, Cavanagh D, Wilson GS. Sustaining limbal health Contact Lens Spectrum 2005;20, 8s: 10-11

Fonn D, Sivak A. Benefits and challenges of high-Dk/t materials Contact Lens Spectrum 2005;20, 2: 28-31

Fonn D, Sweeney D, Holden B, Hill R, Papas E, Cavanagh D. Measuring oxygen uptake Contact Lens Spectrum 2005;20, 8s: 8-9

Jones L, Dumbleton K. Silicone hydrogels, part one: Technological developments Optometry Today 2005;2823-29

Morgan PB, Efron N, Woods CA, Jones D, Grein HJ, Tranoudis Y, Monatani G, Marani E, Itoi M, van der Worp E, Phillips G, Helland M, Thunholm-Henriksson IL, Yeo Chee Hong A, Barr JT. International contact lens prescribing 2004 Contact Lens Spectrum 2005;20, 1: 34-37

Sorbara L. Contacts by Design Optical Prism 2005, March: 15-20

Woods CA, Phillips G. Contact lens prescribing in Australia and New Zealand 2004 Australian Optometry 2005;26, 5: 10-11

2004

Cullen A, Jones L. Diseases of the ocular adnexa and anterior segment: Diseases of the cornea Institute of Optometry web-based course 2004, Sept:

Cullen A, Jones L. Diseases of the ocular adnexa and anterior segment: Diseases of the lacrimal system Institute of Optometry web-based course 2004, Sept:

Cullen A, Jones L. Diseases of the ocular adnexa and anterior segment: Diseases of the conjunctiva Institute of Optometry web-based course 2004, Aug:

Cullen A, Jones L. Diseases of the ocular adnexa and anterior segment: Diseases of the lids and lashes Institute of Optometry web-based course 2004, Aug:

Dumbleton K. Silicone Hydrogels for Daily Wear: Comparison of Complications with Extended Wear 2004

Fonn D. On the importance of silicone hydrogel contact lenses Refractive Eyecare for Opthalmologists 2004;8, 10: 11-14

Jones L. Understanding incompatibilities Contact Lens Spectrum 2004, July: 4-7

Jones L, Dumbleton K. Silicone hydrogels: Will they displace conventional lenses? Optometry Today 2004, Aug: 34-41

Jones L, Tighe B. Silicone hydrogel contact lens materials update – Part 2 Silicone Hydrogel Web-Site 2004, July:

Jones L, Tighe B. Silicone hydrogel contact lens materials update – Part 1 Silicone Hydrogel Web-Site 2004, July:

Moezzi A, Fonn D. Corneal thickness measurement Contact Lens Spectrum 2004

2003

Dumbleton K. Refractive Error and Corneal Curvature Issues with Silicone Hydrogel Lens Wear 2003

Jones L. Contact lens materials update: part one Optician 2003;225, 5891: 24-31

Jones L. Contact lens materials update: part two Optician 2003;225, 5895: 30-32

2002

du Toit R, Sweeney D, Fonn D, Stern J. Managing silicone hydrogel complications Contact Lens Spectrum 2002;17, 5: 34-40

Dumbleton K, Jones L. Introducing silicone-hydrogel contact lenses: part 1 - Material properties and patient selection Optician 2002;223, 5836: 16-22

Dumbleton K, Jones L. Introducing silicone-hydrogel contact lenses: part 3 - Follow-up and management Optician 2002;223, 5845: 34-43

Fonn D. Preventing contact lens dropouts Contact Lens Spectrum 2002;17, 8: 26-32

Fonn D. Observations of corneal staining with MPS and silicone hydrogel lenses Contact Lens Spectrum 2002;17, 11: 32

Fonn D, du Toit R, Sweeney D. Managing silicone hydrogel complications Review of Contact Lenses 2002;7, July: 18-20

Fonn D, Dumbleton K, Jones L, du Toit R, Sweeney D. Silicone hydrogel material and surface properties Contact Lens Spectrum 2002;17, 3: 24-28

Jones L. How to equip your contact lens practice Optician 2002;223, 5854: 24-27

Jones L. Modern contact lens materials: A clinical performance update Contact Lens Spectrum 2002;17, 9: 24-35

Jones L, Dumbleton K. Introducing silicone-hydrogel contact lenses: part 2 - fitting procedures and in-practice protocols Optician 2002;223, 5840: 37-45

Jones L, Dumbleton K. Practitioner attitudes to continuous wear and daily disposable CLs Optician 2002;223, 5485: 30-32

Jones L, Dumbleton K. Silicone-hydrogel contact lenses. part 1: Evolution and current status Optometry Today (UK) 2002;42, 18: 26-32

Jones L, Senchyna M. Protein and lipid deposition of silicone-hydrogel contact lens materials Silicone Hydrogel Web-Site 2002, Oct:

Krishnakumar R, Sukumar S, Subbaraman LN, Srinivasan S. Variability in the measurement of Interpupillary Distance The Indian Optician 200268-70

Simpson TL . Clinical grading: towards standardization The Official Site of Silicone Hydrogels 2002

van der Worp E, Morgan P, Efron N, Helland M, Jones L, Tranoudis Y, Woods CA. A survey of contact lens fitting: an international perspective (Enquete contactlensaanpassingen International 2001) Visus 2002;115-19

2001

Jones L. Management and diagnosis of the red eye in clinical practice 2001 [ Show Abstract ]

Distance continuing education article for Vision Express (UK Optical Chain)

Jones L, Christie C. Contact lens care: part 9 - rigid lens care systems: an overview Optician 2001;222, 5830: 22-27

Jones L, Christie C. Rigid lens care systems: An overview Optician 2001;222, 5830: 22-27

Morgan P, Efron N, Helland M, Jones L, Woods CA, van der Worp E. How does the UK market compare with other countries? Optician 2001;222, 5799: 26-32

Pritchard N. How can I avoid CL dropouts? Optician 2001;222, 5825: 14-18

van der Worp E, Morgan P, Efron N, Helland M, Jones L, Woods CA. Contactlens aanpassingen International Visus 2001;1151-157

2000

Cullen A, Jones L. Flare, cells & KP Optician 2000;219, 5756: 28-31

Cullen A, Jones L. Secrets of the sclera Optician 2000;219, 5756: 26-28

Fonn D. Silicone hydrogel website - resource for practitioners Int Contact Lens Clin 2000;27188-190

Jones L. Acquired strabismus Optician 2000;220, 5778: 16-25

Jones L. Ocular therapeutics: is it really worth the effort? Optician 2000;219, 5745: 40-42

Jones L, Cullen A. Diagnosis and management of common corneal complications - part 1 Optician 2000;220, 5767: 22-28

Jones L, Cullen A. Diagnosis and management of common corneal complications - part 2 Opticia 2000;220, 5772: 26-31

Sorbara L. Kids and contacts: when to start Visual Eyes 2000;3, 2: 23-26

Sweeney D, Fonn D, Guillon M. Silicone hydrogels - clinical performance, factors affecting success and tear exchange - multiple-choice answers Optician 2000;219, 5733: 16

1999

Cullen A, Jones L. Disorders of the conjunctiva Optician 1999;217, 5698: 19-26

Fonn D. Factors affecting the success of silicone hydrogels Optician 1999;218, 5730: 27-29

Jones L. Persistent corneal infiltrates Practical Optometry 1999;10, 2: 83-85

Jones L. "TRUE" extended wear hydrogel lenses: practical considerations Contactologia 1999;21104

Jones L, Cullen A. Anterior segment eye disease: part 1 - disorders of the lids and ocular adnexa Optician 1999;217, 5693: 23-32

Jones L, Eperjesi F, Evans B. Binocular vision evaluation in practice Optometry Today (UK) 1999;39, 4: 33-36

Sorbara L, Luong J. Contact lens fitting guidelines for the keratoconic patient using videokeratographic data Practical Optometry 1999;10, 6: 238-243

1998

. Assessment of corneal staining in clinical practice CE Optometry 1998;153-55

Higazy MT, Fonn D, Sorbara L. Rigid gas permeable contact lens fitting in keratoconus Bull Ophthalmol Soc Egypt 1998;91, 6: 985-988

McMillan R, Stevenson L, Ferguson L, Jones L. CL record cards: their use with clinical grading scales Optician 1998;216, 5667: 36-38

1997

. Chronic blepharitis - a case study CE Optometry 1997;122-23

. Dimple-veil staining - a case study CE Optometry 1997;120

. Toric calculations made simple (product review) Optician 1997;213, 5587: 34

Hickson-Curran S, Nason R, Dubow B, Jones L, Lofstrom T, Pace P. Enhanced Acuvue under trial Optician 1997;214, 5626: 36-42

1996

Fonn D. Discontinuation of contact lens wear and its effect on the growth of the business Contact Lens Spectrum 1996;11, 9: 4s-5s

Potvin RJ, Fonn D, Sorbara L. In vivo comparison of corneal topography and keratometry systems Int Contact Lens Clin 1996;23, 1: 20-26

1995

. Currently available disposable contact lens systems Optician 1995;209, 5500: 16-22

Jones L, Jones D. Three and nine O'clock corneal staining Optician 1995;210, 5526: 20-22

Jones L, Jones D. Blepharitis Optician 1995;210, 5522: 32-33

Jones L, Jones D. RGP lens binding (adherence) Optician 1995;210, 5517: 28-29

Jones L, Jones D. SMILE staining and dehydration Optician 1995;210, 5513: 24-25

Jones L, Jones D. Dimple-veil staining Optician 1995;210, 5509: 32

Jones L, Jones D. Superior epithelial arcuate lesions Optician 1995;209, 5500: 32-33

Jones L, Jones D. Corneal staining assessment Optician 1995;209, 5496: 30-32

Jones L, Jones D. Meibomian gland dysfunction Optician 1995;209, 5491: 30-31

Jones L, Jones D, Langley C. The comparative performance of two aspheric rigid gas permeable lens designs Optician 1995;210, 5526: 28-36

Jones L, Jones D, Langley C, Houlford M. The subjective response of 100 consecutive patients to 1-day disposable lenses Optician 1995;211, 5536: 28-32

1994

. Disposable lenses for daily wear Irish Optician 1994;4, 4: 22-24

. BCLA continuing education questionnaire Optometry Today 1994, January: 16-20

Dumbleton KA, Efron N. A multicentre clinical trial of a new disposable lens Optician 1994;208, 5458: 20-24

1993

Dumbleton KA, Efron N. Clinical performance of three soft lens care systems Optician 1993;206, 5426: 19-26

Williams-Lyn D, MacNeill K, Fonn D. The effect of rigid lens back optic zone radius and diameter changes on comfort Int Contact Lens Clin 1993;20, 11/12: 223-229

1992

. Daily-wear Acuvue disposable lenses - a review Die Kontaklinse 1992;2112-16

Broughton R, Jones L. Clinical investigation of the young DOCET module for a distance learning package in "Children's Visual Problems" for the British College of Optometrists 1992

Efron N, Henriquez A, Merkx J, Alfonso E, Bouron P, Fonn D, Nishida T, Ostlund K, Schnider CM, Tan KC. A discussion paper on contact lens maintenance systems Optician 1992;204, 5358: 16-20

Efron N, Henriquez A, Merkx JTM, Alfonso E, Bouron P, Fonn D, Nishida T, Ostlund K, Schnider CM, Tan KC. Contact lens maintenance systems Int Contact Lens Clin 1992;19, 7/8: 153-156

Efron N, Henriquez A, Merkx JTM, Alfonso E, Bouron P, Fonn D, Nishida T, Ostlund K, Schnider CM, Tan KC. Why fit contact lenses? Optician 1992;204, 5367: 12-14

Efron N, Henriquez A, Merkx JTM, Alfonso E, Bouron P, Fonn D, Nishida T, Ostlund K, Schnider CM, Tan KC. Why wear contact lenses? Optician 1992;204, 5371: 23-24

Holden B, Fonn D, Sweeney D, Gauthier C, Sorbara L, Efron N. International Association of Contact Lens Educators expands globally Int Contact Lens Clin 1992;19, 7/8: 174-181

Jones L, Woods C. Contact lens fitting and design Optician 1992;203, 5354: 16-22

1991

. Disposable and planned replacement systems - a review Optometry Today 1991, July: 16-20

Cox I, Fonn D. Interference filters to eliminate the surface reflex and improve contrast during fluroescein photography Int Contact Lens Clin 1991;18, 9/10: 178-181

Efron N, Henriquez A, Merkx JTM, Alfonso E, Bouron P, Fonn D, Nishida T, Ostlund K, Schnider CM, Sweeney DF, Tan KC. Disposable contact lenses Int Contact Lens Clin 1991;18, 7/8: 127-129

Fonn D. Presbyopia and the contact lens wearer Vista 50 Plus 1991, Spring:

Jones L, Jones D. Persecon 92E: design and clinical performance Optician 1991;203, 5333: 16-23

1990

. A review of techniques for analysing hydrogel lens deposition J BCLA 199036-41

Fonn D, Gauthier C. Aftercare of RGP lens wearers Contact Lens Spectrum 1990;5, 9: 71-81

Fonn D, Gauthier C, Sorbara L. Adverse response rates in concurrent short-term extended wear and daily wear clinical trials of hydrogel lenses Int Contact Lens Clin 1990;17, 9/10: 217-223

Sorbara L. Testing for the contact lens dry-eye patient, expert opinion Contact Lens Forum 1990;15, 2: 9

1988

Jones L. High water content lenses used daily J Brit Contact Lens Assoc 1988;Scientific Meetings26-31

1982

Fonn D. South Africa: Low status for vision care Contact Lens Forum 1982;7, 7: 45-53

Jones L. Silicone hydrogels and care regimen choice Contacto ;214-7

Jones L. A new silicone hydrogel lens comes to market Contact Lens Spectrum ;22, 10: 23

Woods CA. Multipurpose solutions: safe, efficacious and simple Contact Lens Spectrum ;2315

Books

2023

Jones L, Walsh K, Ng AY, Schulze M. Diagnostic Instruments In: Contact Lens Practice; 4th Ed. Elsevier, Oxford, UK. 2023.

2022

Scleral lenses in special cases 2022.

Jabeen A, Jones L. Lag of accommodation with DOT spectacle lenses 2022.

Jones L, Stahl U, Guthrie S, Yang M, Moezzi A, Thom M. Contact Lens Compendium: Contact Lenses & Solutions Available in America. Vol 3 2022.

2021

Jones L, Stahl U, Guthrie S, Yang M, Moezzi A, Thom M. Contact Lens Compendium: Contact Lenses & Solutions Available in America. Vol 2 2021.

Jones L, Stahl U, Guthrie S, Yang M, Moezzi A, Thom M. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 47 2021.

Ranch KM, Shukla MR, Maulvi FA, Desai DT. Chapter 7: Carbon-based nanoparticles and dendrimers for delivery of combination drugs In: Nanocarriers for the Delivery of Combination Drugs , ed. Baboota S, Ali J. Elsevier Inc.. 2021.

2020

Jones L, Stahl U, Guthrie S, Yang M, Yee A, Thom M. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 46 2020.

Jones L, Stahl U, Guthrie S, Yang M, Yee A, Thom M. Contact Lens Compendium: Contact Lenses & Solutions Available in America. Vol 1 2020.

2019

Dumbleton K., Jones L. Overnight Contact Lens Wear In: Clinical Manual of Contact Lenses 5th Edition , ed. Bennet ES, Henry VA. Wolters Kluwer. 2019.

Jones L, Stahl U, Guthrie S, Luensmann D, Yang M, Thom M. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 45 2019.

2018

Jones L, Dumbleton K. Soft Contact Lens Fitting In: Contact Lenses; 6th Edn , ed. Speedwell L, Phillips A. Elsevier, Oxford, UK. 2018.

Jones L, Sorbara L, Stahl U, Yang M, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 44 2018.

2017

Jones L, Sorbara L, Stahl U, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 43 2017.

Jones L, Srinivasan S, Ng AY, Schulze M. Diagnostic Instruments In: Contact Lens Practice; 3rd Ed. Elsevier, Oxford, UK. 2017.

2016

Jones L, Sorbara L, Stahl U, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 42 2016.

Liu S, Jones L, Gu F. Nanotechnology and Nanomaterials in Ophthalmic Drug Delivery In: Nano-Biomaterials for Ophthalmic Drug Delivery , ed. Pathak Y, Sutariya V, Hirani A. Springer International Publishing. 2016.

2015

Dumbleton K, Jones L. Overnight Contact Lens Wear In: Clinical Manual of Contact Lenses: 4th Edn , ed. E Bennett and V Henry. Lippincott, Williams and Wilkins. 2015.

Jones L, Sorbara L, Stahl U, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 41 2015.

2014

Jones L, Sorbara L, Stahl U, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 40 2014.

2013

Jones L, Sorbara L, Stahl U, Guthrie S, Menzies K, Rossy J, Thom M. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 39 2013.

Srinivasan S, Jones L. Contemporary dry eye tests In: Dry Eye Syndrome: Basic and Clinical Perspectives. , ed. Yokoi N. Future Medicine Ltd. 2013.

Verma M, Liu S, Jones L, Gu F. Dextran-based nanoparticles for sustained drug delivery: applications in dry eye treatment and cancer therapy In: Dextran: Chemical Structure, Applications and Potential Side Effects , ed. GP Figgs. 2013.

2012

Jones L. Nutrition and dry eye 2012.

2010

Jones L, Srinivasan S. Clinical Instruments In: Contact Lens Practice 2nd Edition. Butterworth-Heinemann. 2010.

Sorbara L, Fonn D, Woods C, Sivak A, Boshart B. Correction of Keratoconus with GP Contact Lenses Bausch and Lomb. 2010.

2009

The IACLE Contact Lens Course IACLE. 2009.

Jones L, Dumbleton K. Contact Lenses In: Optometry: Science, Techniques and Clinical Management. Elsevier. 2009.

Williams L, Sorbara L. Care and Maintenance of GP lenses In: The IACLE Contact Lens Course , ed. Fonn D. IACLE. 2009.

2008

Bennet ES, Sorbara L. Lens Design, Fitting and Evaluation In: Clinical Manual of Contact Lenses 3rd Edition , ed. Bennet ES, Henry VA. Lippincott Williams and Wilkens. 2008.

Jones L, Dumbleton K. Extended and Continuous Wear In: Clinical Manual of Contact Lenses. Lippincott Williams and Wilkens. 2008.

2007

Jones L, Jones D. Common Contact Lens Complications: Recognition and Management Elsevier. 2007.

Sorbara L, Fonn D, Woods C, Sivak A, Boshart B. Correction of Presbyopia with GP Contact Lenses Bausch and Lomb. 2007.

Sweeney D, Stretton S, Fonn D, Swarbrick HA, Holden BA. Extended and continuous wear lenses In: Contact Lenses (5th Edition) , ed. Phillips AJ, Speedwell L, Morris,J. Butterworth-Heinemann. 2007.

2006

Jones L, Dumbleton K. Soft contact lens fitting In: Contact Lenses 5th Edition , ed. Speedwell L, Phillips A. Butterworth-Heinemann. 2006.

Jones L, Dumbleton K. Soft Extended Wear and Complications In: Manual of Contact Lens Prescribing and Fitting , ed. Hom M, Bruce A. Butterworth-Heinemann. 2006.

2005

Brennan N, Fonn D. The Physiological Effects of Hypoxia on the Anterior Eye In: Silicone Hydrogels 2nd Edition , ed. Sweeney D. Butterworth-Heinemann. 2005.

Jones L, Dumbleton K. Soft Contact Lens Extended Wear and Continuous Wear In: Manual of Contact Lens Prescribing and Fitting , ed. Milton H. Hom. Butterworth Heinemann. 2005.

2004

Brennan N, Fonn D. Corneal Hypoxia In: Silicone hydrogels: Continuous-wear contact lenses , ed. Sweeney, DF. Butterworth-Heinemann. 2004.

Fonn D and Sorbara L. Problem Solving In: Clinical Contact Lens Practice (2nd Edition) , ed. ES Bennett and BA Weissman. J.B. Lippincott. 2004.

Fonn D, Sorbara L. Progress Evaluation Procedures In: Clinical Contact Lens Practice (2nd Edition) , ed. Bennett ES, Weissman BA. Lippincott Williams and Wilkens. 2004.

2002

Dumbleton K. Clinical Performance and Observation – Lens Fit The Official Site of Silicone Hydrogels. 2002.

Dumbleton K. Clinical Performance: Comfort and Dryness The Official Site of Silicone Hydrogels. 2002.

Dumbleton K. The Physical and Clinical Characteristics of Silicone Hydrogel Lenses – How they work The Official Site of Silicone Hydrogels. 2002.

Dumbleton K. The Vascular Response to Silicone Hydrogels The Official Site of Silicone Hydrogels. 2002.

Jones L. Clinical Instruments In: Contact Lens Practice , ed. Nathan Efron. Butterworth-Heinemann. 2002.

2001

Jones L, Jones D. Slit Lamp Biomicroscopy In: The Cornea , ed. Nathan Efron. Butterworth-Heinemann. 2001.

2000

Bennett ES, Sorbara L. Lens Design, Fitting and Evaluation In: Clinical Manual of Contact Lenses Second Edition , ed. Bennett ES, Henry VA. Lippincott Williams and Wilkens. 2000.

Fonn D, Pritchard N, Dumbleton K. Factors affecting the success of silicone hydrogels In: Silicone hydrogels: The rebirth of continuous wear contact lenses , ed. Sweeney DF. Butterworth Heinemann. 2000.

Jones L, Jones D. Common Contact Lens Complications: Recognition and Management Butterworth-Heinemann. 2000.

1999

Simpson T. Binocular Refractive Procedures: A CD ROM text In: Examination of the Eye , ed. Williams L, Alexander J. ICEE. 1999.

Simpson T. Monocular Refractive Procedures: A CD ROM text In: Examination of the Eye , ed. Williams L, Alexander J. ICEE. 1999.

1991

Fonn D. Progress Evaluation Procedures In: Clinical Contact Lens Practice , ed. Bennett ES, Weissman BA. J.B. Lippincott. 1991.

1990

Morris J, Jones L. Soft lens fitting techniques and design In: Contact Lens Yearbook. 1990.

.

Sheardown H, Subbaraman L. Opthalmic Coatings In: Coatings for Biomedical Applications , ed. Mike Driver. Woodhead Publishing Ltd. .