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William Reindel,1 Gary Mosehauer,1 Marjorie Rah,1 Howard Proskin,2 Robert Steffen1 1Vision Care, Bausch & Lomb Incorporated, Rochester, NY, USA; 2Howard M. Proskin & Associates, Rochester, NY, USACorrespondence: Marjorie RahVision Care, Bausch & Lomb Incorporated, Rochester, NY, USATel +1 585-413-6397Email Marjorie.Rah@bausch.comPurpose: The objective of this study was to evaluate and compare the clinical performance of samfilcon A, a unique, polyvinylpyrrolidone (PVP)-containing, silicone hydrogel contact lens with that of the balafilcon A silicone hydrogel contact lens when worn on a 7-day extended wear basis.Subjects and Methods: A total of 669 subjects completed this 12-month, controlled, parallel group, masked, randomized study; of these, 340 wore samfilcon A lenses and 329 balafilcon A lenses. Subjects wore their respective assigned lenses bilaterally on a 7-day extended wear basis. On the seventh night of each wearing week, lenses were removed, cleaned, and disinfected using Biotrue multi-purpose solution (MPS), then re-inserted the following morning. Lenses were replaced with new lenses monthly. At each follow-up visit, investigators completed a slit lamp evaluation, and subjects rated lenses based upon a predefined set of performance criteria.Results: The samfilcon A lens performed comparably to the balafilcon A lens in terms of most graded and ungraded slit lamp findings, differing significantly only for corneal staining Grade 2 or greater, which favored samfilcon A, and anterior segment abnormalities, which favored balafilcon A. Subjects rated both lenses highly when queried about various lens-wearing characteristics. When comparing the number of subjects with findings on either eye on at least one follow-up visit, the two lenses were comparable in many aspects but favored samfilcon A with respect to cleanliness upon removal, overall comfort, comfort at end of day, dryness, vision, vision in low light, vision at end of day, and overall impression (all p < 0.05).Conclusion: While subjects rated both highly, samfilcon A lenses worn for 7-day extended wear and replaced on a monthly basis performed comparably to or better than balafilcon A lenses when worn for the same 7-day wear time and replacement cycle.Keywords: PVP, contact lens, extended wear

Jeffery Schafer,1 William Reindel,1 Robert Steffen,1 Gary Mosehauer,1 Joseph Chinn2 1Vision Care, Bausch and Lomb Incorporated, Rochester, NY, USA; 2J Chinn LLC, Lafayette, CO, USA Background: Sustained 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 senofilconA (SEN).Materials and methods: This 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.Results: EBTs 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).Conclusion: EBT 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. Keywords: polyvinylpyrrolidone, PVP, digital video display, extended blink time, EBT, visual quality, VQ, lens hydration