PurposeContact lens wearers today spend much time using digital display devices. Contact lens manufacturers are challenged to develop products that account for longer periods of time where blink rate is reduced and tear-film evaporation rate is increased, affecting both visual acuity and comfort. Two manufacturers recently introduced novel daily disposable contact lenses with high surface water content. The objective of the present study was to compare surface water characteristics before and after initial wear of recently introduced nesofilcon A and delefilcon A high surface water lenses with those of etafilcon A lenses.Patients and methodsTwenty healthy subjects wore each of the three lens types studied in a randomly determined order for 15 minutes. After each wearing, lenses were removed and the surface refractive index (RI) of each lens was immediately measured.ResultsThe mean RI of the unworn delefilcon A lens was 1.34, consistent with water content in excess of 80%. After 15 minutes of wear, the surface RI shifted to 1.43, consistent with its reported 33% bulk water content. In contrast, the mean surface RI of the nesofilcon A lens was 1.38, both initially and after 15 minutes of wear, and that of the etafilcon A lens was 1.41 initially and 1.42 after 15 minutes of wear.ConclusionThe surface of the delefilcon A lens behaves like a high water hydrogel upon insertion but quickly dehydrates to behave like its low-water silicone-hydrogel bulk material with respect to surface water content during wear, while both nesofilcon A and etafilcon A lenses maintain their water content during initial wear. The nesofilcon A lens appears unique among high water lenses in maintaining high surface and bulk water content during wear. This is important because changes in surface RI due to dehydration are reported to lead to visual aberration affecting user experience.

BackgroundConcerns regarding the safety of cosmetically tinted contact lenses have been reported in the literature. The purpose of this paper is to evaluate the safety of cosmetically tinted contact lenses in a large number of patients across six clinical trials that varied from 1 week to 3 months in duration.MethodsLenses tested included: Naturelle limbal ring daily disposable, Lacelle limbal ring daily disposable, Lacelle colored cosmetic daily disposable, Lacelle limbal ring planned replacement at 2 weeks, and Alamode traditional/annual colored cosmetic lens. The primary safety outcome was slit-lamp examination, including epithelial edema, epithelial microcysts, corneal staining, bulbar injection, limbal injection, upper lid tarsal conjunctival abnormalities, corneal neovascularization, and corneal infiltrates. High contrast logMAR visual acuity with lenses, and lens wearing time, movement, and centration, are also presented.ResultsA total of 871 subjects (1,742 eyes) and 23 clinical investigators participated in the six studies, with an average completion rate of 96.4% across all studies. The mean age of the patients was 26.8 ± 6.6 years, and 86.7% of participants were female. The total number of slit-lamp examinations across the six studies was 2,456 visits by eye (1,228 visits by patient). There were no slit-lamp signs > grade 2 for any finding, with the exception of corneal staining in one study. In this study, grade 3 corneal staining was noted in one eye (0.1%) at follow-up visit 1 and four (0.6%) of all eligible dispensed eyes at follow-up visit 2, with no eyes requiring medical treatment. No adverse events were reported during any of the trials.ConclusionThe cosmetically tinted lenses evaluated in this meta-analysis appear to be safe when properly prescribed by an eye care professional and used in a compliant manner.

BackgroundSustained digital display viewing reduces eye blink frequency and tear film stability. To retain water and preserve a smooth optical surface, contact lens manufacturers have integrated the humectant polyvinylpyrrolidone (PVP) into silicone hydrogel contact lenses. In this study, extended blink time (EBT) was used to assess visual stability over a prolonged blink interval of two PVP-containing silicone hydrogel lenses, samfilcon A (SAM) and senofilcon A (SEN).Materials and methodsThis randomized, bilateral, masked, crossover study assessed lens performance in ten subjects after 16 hours of wear. EBT, ie, the time elapsed between cessation of blinking and blur-out of a threshold letter on the acuity chart, was measured. At the end of the wear period, subjects reported duration of computer use and rated visual quality (VQ) and comfort while wearing the assigned lens, and the investigator evaluated lens surface wetting characteristics. Each lens was removed and immediately weighed to determine total water content.ResultsEBTs were 10.42 seconds for SAM and 8.04 seconds for SEN (p = 0.015). Subjective ratings of VQ after 16 hours of wear were 84.6 for SAM and 74.4 for SEN (p = 0.049). Comfort ratings were 85.9 for SAM and 80.2 for SEN (p > 0.05). Median times of computer use were 6–8 hours for both lens types. Post blink, 70.0% of SAM and 30.0% of SEN lenses were completely wet (p = 0.021). Total water content after wear was 43.7% for SAM and 35.5% for SEN (p < 0.001).ConclusionEBT measurement indicated more stable vision with the PVP-containing SAM polymer compared with the PVP-containing SEN polymer. The SAM polymer also demonstrated better surface wetting and maintained higher water content after a prolonged period of wear. EBT can be valuable in assessing vision stability of patients after hours of computer use.

Background: Addressing contact lens dryness continues to be a development goal of contact lens (CL) manufacturers. Objective: The objective of this study is to evaluate the clinical performance of kalifilcon A, a daily disposable silicone hydrogel (SiHy) CL, in subjects that experience dryness with their habitual planned-replacement SiHy CLs relative to a non-dry subgroup. Methods: A cohort of adapted planned-replacement SiHy CL wearers wore kalifilcon A lenses for at least 8 hours daily over two weeks. After one week of lens wear, subjects completed a survey regarding their lens wearing experience with respect to comfort and vision. Subsequently, subjects visited the clinics for the 2-week visit, during which the investigators completed a slit lamp exam and questionnaire regarding lens performance. Results: The evaluation included 180 subjects experiencing CL dryness with their habitual SiHy lenses and 213 subjects that did not. Both subgroups largely agreed with all comfort and vision attribute statements, and the dryness subgroup expressed higher levels of agreement with most comfort-related statements. Among habitual rewetting drop users, 73.9% in the dryness subgroup and 73.1% in the non-dry subgroup used drops less frequently while wearing kalifilcon A lenses. Investigators found no > Grade 2 slit-lamp findings, nor differences between subgroups. Neither subgroup showed a change in ratings between visits, except for a significantly higher proportion of improvers in the non-dry subgroup for upper lid tarsal conjunctival abnormalities. Conclusion: The kalifilcon A lens performed well among habitual planned-replacement SiHy CLs wearers. Its unique chemistry can provide a more satisfying wear experience for SiHy lens wearers experiencing CL dryness.

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