Contact lens materials and design are constantly being improved to increase the accuracy of vision correction and to improve comfort and ease of handling, for both new and habitual wearers of contact lenses.

Daily disposable contact lenses are intended to be worn during waking hours for a full day and to be discarded the same day after use. Wearing of daily disposable lenses eliminates the need for cleaning and/or disinfecting solutions, resulting in a higher compliance rate for lens replacement

Most contact lenses currently prescribed are soft contact lenses. Discontinuation of lens wear is a major problem, especially in new wearers of contact lenses. The primary reason given for discontinuation of contact lens wear was poor vision quality, followed by poor comfort, especially at the end of the day, and difficulty handling of the lens.

Verofilcon A is a highly breathable silicone hydrogel contact lens material. The core of verofilcon A lenses has a 51% water content and a modulus of 0.6 MPa, allowing for easy handling; and the surface of these lenses has a permanent level of moisture with >80% water content. These lenses were found to confer excellent visual acuity, with subjects consistently providing high ratings for vision quality, comfort, and handling.

Etafilcon A is a widely used, high-quality and well accepted conventional hydrogel contact lens material that have been marketed for a long period of time. These lenses are regarded as a benchmark for safety, efficacy, and comfort and are often used as a comparator in clinical trials with other lenses. Etafilcon A lenses contain the wetting agent polyvinyl pyrrolidone, which mimics the natural tear film, and have a water content of 58%, with an excellent safety profile. Evaluation of hypoxic stress showed that etafilcon A lenses were noninferior to two types of silicone hydrogel lenses, lotrafilcon B and comfilcon A. Etafilcon A daily disposable lenses were selected for comparison with verofilcon A lenses because of their design and replacement schedule.

The present clinical study by Miller et al was designed to compare the objective and subjective performance of verofilcon A contact lenses with those of already marketed etafilcon A daily disposable contact lenses. The primary objective of this study was to demonstrate that distance visual acuity (VA) is noninferior in subjects wearing verofilcon A contact lenses compared with the same subjects wearing etafilcon A contact lenses. The key subjective endpoints reported here by wearers of verofilcon A and etafilcon A contact lenses included overall preference, end-of-day vision (EOD), overall handling, insertion comfort and EOD comfort. Other subjective comparisons included overall quality of vision, overall comfort, vision throughout the day, lens handling at insertion, and lens handling at removal.

Successful wearers of spherical soft CLs for distance correction were prospectively randomized to wear verofilcon A or etafilcon A lenses for 1 week and crossed over to the alternative lenses. The primary study objective was a comparison of distance visual acuity (VA). Exploratory endpoints included subjective overall lens preference (5-point scale) and subjective ratings (10-point scales) of end-of-day (EOD) vision, overall handling, insertion comfort, EOD comfort, overall quality of vision, overall comfort, vision throughout the day, lens handling at insertion, and lens handling at removal.

Of 92 subjects (184 eyes), 46 each were randomized to verofilcon A or etafilcon A lenses and subsequently crossed over to the other lenses.

Evaluation of distance VA showed that verofilcon A lenses were noninferior to etafilcon A lenses.

Comparison of lens preference showed that 68 (73.9%) subjects somewhat or strongly preferred verofilcon A lenses, whereas 21 (22.9%) somewhat or strongly preferred etafilcon A lenses (p<0.0001). Mean ± SD ratings of EOD vision (8.6±1.5 vs 7.7±1.9), overall handling (8.7±1.5 vs 6.9 ±2.3), insertion comfort (9.2±1.0 vs 7.7±1.9), and EOD comfort (8.0±1.9 vs 7.0±2.2) were all significantly (p≤0.0001 each) higher for verofilcon A than for etafilcon A lenses. Mean ± SD ratings of overall quality of vision (8.9±1.2 vs 8.2±1.8), overall comfort (8.6±1.5 vs 7.4 ±1.8), vision throughout the day (8.9±1.3 vs 8.1±1.8), lens handling at insertion (9.0±1.4 vs 6.9±2.5), and lens handling at removal (8.3±2.1 vs 7.7±2.2) were also significantly higher for verofilcon A lenses. No subject experienced any ocular adverse events><0.0001).

Mean ± SD ratings of EOD vision, overall handling, insertion comfort, and EOD comfort were all significantly (p≤0.0001 each) higher for verofilcon A than for etafilcon A lenses.

Mean ± SD ratings of overall quality of vision, overall comfort, vision throughout the day, lens handling at insertion, and lens handling at removal were also significantly higher for verofilcon A lenses. No subject experienced any ocular adverse events.

In conclusion, this study showed that verofilcon A contact lenses were noninferior to etafilcon A lenses as determined by distance VA. After 1 week of wear, the study population gave significantly higher ratings to verofilcon A than etafilcon A lenses, as determined by overall preference and other subjective endpoints, including EOD vision, overall handling, insertion comfort, EOD comfort, overall quality of vision, overall comfort, vision throughout the day, lens handling at insertion and lens handling at removal. Further clinical trials are warranted to evaluate long-term use of verofilcon A contact lenses.

Source: Miller et al; Clinical Ophthalmology 2021:15 4339–4345

https://doi.org/10.2147/OPTH.S332651