ABSTRACT
Purpose: This study was conducted to evaluate and compare the in vitro disinfection efficacies of six commercial lens cleaning and disinfecting products for planned replacement soft contact lenses. Methods: Disinfection efficacies of five multi-purpose solutions (MPSs) and one hydrogen peroxide solution (HPS) as control were evaluated in the presence of organic soil according to the International Organization for Standardization (ISO, Geneva, Switzerland) ISO 14729 stand-alone test protocol. The five specified compendial organisms, three bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, and Serratia marcescens) and two fungi (Candida albicans and Fusarium solani) were incubated with each solution under standard conditions, after which microbes were recovered and quantified. Results: Each of the solutions evaluated met or exceeded the standard's primary criteria (3-log reduction of bacteria and 1-log reduction of fungi) after incubation for the manufacturer-recommended soaking time, except for COMPLETE MPS, which achieved only 0.4 ± 0.1 average log reduction for C. albicans. However, differences in efficacy between the solutions were noted. Average log reduction across all microbes for Biotrue Hydration Plus (4.6 ± 0.1) was comparable to that for CLEAR CARE PLUS HPS (4.3 ± 0.1) and greater than those for OPTI-FREE puremoist (3.6 ± 0.1), OPTI-FREE Replenish (4.0 ± 0.2), ACUVUE RevitaLens (3.9 ± 0.03), and COMPLETE MPS (3.6 ± 0.1). Biotrue Hydration Plus was especially effective at reducing the population of C. albicans (4.2 ± 0.7-log reduction). Conclusion: Products marketed for planned replacement soft CL disinfection generally meet the ISO 14729 standard's primary criteria for reducing populations of compendial organisms, with larger differences between solutions noted with C. albicans.
ABSTRACT
PURPOSE: 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.
ABSTRACT
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 senofilcon A (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.
