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Peer-reviewed articles

2024

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;18(October):2999-3008 [ 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.

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.

2023

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.

2022

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.

2020

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.

2015

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.

2013

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.

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 [ Show Abstract ][ PDF ]

Purpose: This study aimed to determine if scleral lenses (SLs), either with or without a covalently bonded polyethylene glycol-based lens surface treatment (Hydra-PEG) (Tangible Science), could improve ocular comfort and decrease dryness in symptomatic habitual soft contact lens (CL) wearers and non-CL wearers.

Methods: This prospective, randomized, double-masked, 1-month bilateral cross-over, daily wear study recruited soft CL wearers with a CLDEQ-8 score ≥12 and non-CL wearers with an OSDI score ≥13. Eligible participants were fit with SLs (Onefit MED, Blanchard Contact Lens, a CooperVision Company) and wore one pair with and one pair without lens coating (coated (C-SL)/uncoated (U-SL)) in a randomized order for 1 month each. Participants completed the CLDEQ-8 and rated their overall satisfaction with ocular comfort, dryness, and vision clarity after each wear period using a 0-10 scale (10=best). These data were compared between study SLs and habitual correction (hab-correction), which is habitual CL (hab-CL) or baseline (BL) for non-CL wearers.

Results: 38 completed all study visits and were included in the analysis (20 hab-CL, 18 non-CL). At 1 month, the CLDEQ-8 score improved with both study SLs in comparison to hab-CL (p0.05) and were better than hab-correction (p0.05) but higher with C-SL than hab-CL (p< 0.05) (Hab-CL: 7.3, C-SL: 8.4, U-SL: 7.7). For non-CL wearers, comfort was improved with both study SLs compared to BL (p0.05) (BL: 4.7, C-SL: 7.3, U-SL: 7.1). Overall satisfaction with vision clarity was similar with hab-correction and study SLs (p >0.05) (hab-correction: 7.9, C-SL: 8.2, U-SL: 7.8). However, it was significantly higher with C-SL compared to U-SL for CL wearers (p< 0.05) (C-SL: 8.6, U-SL: 7.7). At study completion, 45% of participants (9 hab-CL and 8 non-CL) expressed interest in future SL wear.

Conclusion: Symptomatic soft CL wearers and non-CL wearers could successfully be fit with Onefit MED SLs. Both study SLs performed well, and only minor differences were seen between study SLs, which were typically in favor of the coated SL. After 1 month, comfort and dryness satisfaction ratings were better with SLs than hab-correction, indicating that SLs are a good option to manage patients with dry eye symptoms, irrespective of whether they are hab-CL or non-CL wearers.

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 [ Show Abstract ]

Purpose: To determine how optometrists in Ontario, Canada are managing myopic pediatric patients over time, and identify factors affecting prescribing decisions.

Methods: In a retrospective chart review, children aged 6-10 who had eye exams between 2017-2021 at optometry practices in Ontario were included. Children were grouped based on presenting spherical equivalent refraction (SER) as myopes (≤-0.50D) or pre-myopes (≤+0.75D). A maximum of five unique charts were selected for each age and visit year for each group, for up to 250 files per practice. Demographic information, refraction and recommended interventions (categorized as standard myopia correction with single vision (SV) glasses or contact lenses (CL); myopia control (MC) treatment with MC glasses or soft CL, ortho-keratology (ortho-K), atropine, bifocals/progressives) were recorded. The present analysis examines how myopes were managed at their initial visit. Data were analyzed using a one-way ANOVA with post-hoc pairwise t-tests with Bonferroni correction.

Results: 2920 patients (1162 myopes) were included from 15 practices across Ontario. All practices offered at least 1 form of myopia control. The majority of clinicians recommended SV glasses/CL as the initial intervention across all years studied (93.8% in 2017 to 59.0% in 2021), although the proportion diminished over time. The most prevalent MC treatments prescribed per year were ortho-K in 2017 (3.9%), MC soft CL in 2018 and 2019 (11.8% and 11.7% respectively) and MC glasses in 2020 and 2021 (12.8% and 30.1% respectively). In later years, clinicians recommended myopia control at earlier levels of myopia; compared to 2017, the mean difference in SER with 2019 was 1.40±0.41D (mean±SE) less myopia, with 2020 1.05±0.41D less myopiaand with 2021 1.08±0.39D less myopia (all p.05). The mean age at which MC glasses (8.6±0.2 years) and MC soft CLs (8.9±0.2 years) were recommended was not statistically different, and similar to the age at which SV glasses/CL were first recommended (8.8±0.1 years; all p>.05). There was no significant difference in the refractive error of patients who were recommended MC glasses (-1.92±0.13D) versus MC soft CL (-2.05±0.15D; mean difference 0.13±0.16D, p>.05). Children with high myopia (< -6D) do not appear to be offered myopia control options as initial management. The lower limit of SER for those offered myopia control was -5.50D (MC glasses) as compared to -7.75D for standard myopia correction (SV glasses/CL).

Conclusion: The prescribing behaviour of clinicians in Ontario, Canada changed from 2017-2021 to incorporate myopia control and interventions are being prescribed at earlier stages of myopia. Neither age nor refractive error seem to impact whether the modality of glasses or CL is recommended for myopia control. Children with high myopia may still benefit from myopia control and are currently underserved.

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.

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 [ Show Abstract ][ PDF ]

Purpose: To evaluate whether symptomatic contact lens (CL) wearers achieve improvements in comfort and dryness when using lifitegrast 5.0% ophthalmic solution (Xiidra) for 12 weeks.

Methods: CL wearers who rated their CL end-of-day dryness as ≥40 on a 0-100 visual analog scale (VAS; 100 = worst) and who met Young’s criteria for contact lens related dryness symptoms were classified as symptomatic CL wearers and qualified for the study. Eligible participants were asked to use lifitegrast twice/day for 12 weeks while continuing to wear their habitual contact lenses and refraining from using any other eye drops. The performance of lifitegrast was assessed after 2, 6 and 12 weeks (2W, 6W, 12W) by comparing to baseline (BL) measures for end-of-day dryness and end-of-day discomfort VAS ratings (0-100 scale; 100 worst) and the CLDEQ-8 questionnaire. Total and comfortable wear times were collected at baseline and at all study visits.

Results: A total of 40 participants completed the study (33F; mean age 30.8 ± 12.1 years). Reusable CLs were habitually worn by 35% of participants, while 65% wore daily disposable CLs. Mean (±SD) subjective ratings of CL wear-related dryness (BL: 66 ± 25; 2W: 42 ± 26; 6W: 31 ± 26; 12W: 21 ± 22) and discomfort (BL: 61 ± 27; 2W: 41 ± 27; 6W: 30 ± 26; 12W: 20 ± 22) improved over time, with significant differences after 2, 6 and 12 weeks of lifitegrast use for both end-of-day dryness and discomfort (all p< 0.01). All participants (100%) scored at least 40/100 for CL end-of-day dryness rating at baseline (inclusion criterion), and this percentage (count) dropped to 55% (22) at 2W, 25% (10) at 6W and 17% (7) at 12 weeks of lifitegrast use. CLDEQ-8 scores at 2W (16 ± 5), 6W (13 ± 6) and 12W (11 ± 6) were all significantly lower (all p0.05), there was a significant improvement (all p< 0.01) in comfortable wear time at 2 weeks (8 ± 3 hours), 6 weeks and 12 weeks (both 9 ± 3 hours) compared to baseline (6 ± 2 hours).

Conclusion: Using lifitegrast for as little as 2 weeks resulted in significant improvements in symptoms of end-of-day of discomfort and dryness and a longer comfortable wear time. Lifitegrast may be a suitable alternative for symptomatic CL wearers who are unable to achieve satisfactory comfort and dryness with alternate CLs or over-the-counter comfort enhancing drops.

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 [ Show Abstract ]

Purpose: It is important for eye care professionals to have confidence when switching multifocal (MF) contact lens (CL) wearers to a new lens, knowing the results will be predictable and not involve excessive chair time, whether updating a prescription, selecting a different lens material or replacement frequency, or moving to a new optical system. A 2-add (High & Low) MFCL is being changed to a 3-add (High, Medium & Low) lens with a different binocular progressive system. This study was to evaluate the ease and predictability of fit and success when switching existing 2-Add wearers to the 3-Add system.

Methods: 5 US sites recruited presbyopic habitual MF wearers for a bilateral, daily wear, crossover (fixed order), subject-masked study. Subjects were fit and dispensed with clariti 1 day multifocal 2-add (somofilcon A, CooperVision, Inc.) with power optimizations after 3-7 days; optimal powers were worn for 2-weeks. Then subjects were fit with clariti 1 day multifocal 3-add and worn with the same visit schedule. LogMAR visual acuity and subjective ratings (0–10 scale;10=best) were collected after each lens wear period; preference ratings were recorded on study exit (5-point Likert).

Results: Fifty-eight participants (mean age 53.5±6.2 years, 46F:12M) completed the study. Mean refraction -1.11±2.44DS [-4.75 to +3.50], -0.27±0.25DC [0.00 to -0.75] and near addition +2.05±0.36D [+1.25 to +2.50]. There were no differences between lenses for 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 the 3-Add system was preferred (p=0.03). After 2-weeks, LogMAR acuity was significantly better with the 3-Add system for distance (p< 0.01) and near (p=0.02), but not for intermediate (p=0.10). When strictly following the fitting guides, the 3-Add was significantly more successful with the first pair of lenses compared to the 2-Add (80% vs 59% respectively, p=0.03); 98% of both MFCLs were successful after 1 refinement, and 100% with two.

Conclusion: The 3-Add MFCL performance matched or exceeded that of the 2-Add lens for visual acuity, subjective ratings and preference, and had a higher success rate with the first lens pair. The fit success rate for first lens pair aligns with that with MyDay multifocal (stenfilcon A, CooperVision, Inc.) that uses the same 3-Add Binocular Progressive System. This clinical study indicates that switching 2-Add wearers to the 3-Add system was generally successful, and the 3-Add lens was well accepted.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

2018

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.

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 ]

Stahl U, Keir N, Guthrie S, Jones L. Effect of monocular lens wear on ocular comfort TFOS conference, Montpelier, France, 2016

2015

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 ]

2014

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

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

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

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

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, 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

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

2008

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

2006

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

Professional Publications

2022

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

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

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

2016

Guthrie S, Dumbleton K, Jones L. Is there a Relationship Between Care System and Compliance? Contact Lens Spectrum 2016;31, April: 40-43

2014

Guthrie S, Dumbleton K, Jones L. Financial Implications of Patient Compliance Contact Lens Spectrum 2014;29, December: 42-45

2011

Guthrie S. Effect of dual-focus soft contact lens wear on axial myopia progression in children - An article review ContactLensUpdate.com 2011

2010

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

Books

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.

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

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, 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.

2016

Jones L, Sorbara L, Stahl U, Thom M, Guthrie S. Contact Lens Compendium: Contact Lenses and Solutions Available in Canada. Vol 42 2016.

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.