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Peer-reviewed articles

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

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 (p<0.01), with no statistically significant difference between lenses for any time point (all p>0.05). 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' (p<0.01) and for ‘overall vision clarity’ (p=0.01). No preference was indicated for distance tasks (p>0.05).

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 (p<0.05) with Day 13 (D13) end-of-day (EOD) satisfaction with comfort (rs=0.36) and dryness (rs=0.39). There were no significant correlations for delA-MF (comfort: rs=-0.06; dryness: rs=0.11; both p>0.05). Similarly, for stenA-MF, “I would like to wear SCL in the future” was significantly correlated (p<0.05) with D13 EOD satisfaction with comfort (rs=0.46) and dryness (rs=0.41). Again, there were no significant correlations for delA-MF (comfort: rs=0.03; dryness: rs=0.10; both p>0.05). 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 p<0.05). There were no statistical differences (all p>0.05) 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 p<0.001). When subjects’ data was divided according to their habitual lens modality groups (60 H-DD wearers and 60 re-useable wearers), there were also no comfort differences between the study lenses, either across time, or at insertion and 8hrs (all p>0.05). 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

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.