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.

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.

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.

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., 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. 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.

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

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.

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., 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.

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.

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.

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.

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.

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.

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

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.

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.

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.

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., 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.

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.

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.