Clinical Ophthalmology (Apr 2021)
Activity of Deposited Lysozyme on Contemporary Soft Contact Lenses Exposed to Differing Lens Care Systems
Abstract
Miriam Heynen,1 Alan Ng,1 Elizabeth Martell,1 Lakshman N Subbaraman,1 Lyndon Jones1,2 1Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada; 2Centre for Eye and Vision Research (CEVR), Hong Kong Science Park, Hong KongCorrespondence: Miriam HeynenCentre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, CanadaTel +1 519 888 4567Fax +1 519 888 4303Email [email protected]: The amount of protein deposition on soft contact lenses and to what extent the proteins are denatured may have an impact on comfortable wearing times of contact lenses. The purpose of this study was to evaluate the effects of two lens care systems on total protein and the quantity and activity of lysozyme deposited on worn senofilcon A, silicone hydrogel contact lenses.Participants and Methods: Thirty symptomatic soft contact lens wearers were enrolled into a 4-week prospective, randomized, bilateral eye, daily-wear, crossover, double-masked study. Participants were fitted with biweekly senofilcon A lenses and were assigned either a polyquaternium-1 and myristamidopropyl dimethylamine-containing system (OPTI-FREE RepleniSH) or a peroxide-based system (CLEAR CARE). After each wear period, proteins were extracted from the lenses and analyzed for total protein, total lysozyme quantity and activity.Results: The use of either the peroxide-based system or the polyquaternium-1 and myristamidopropyl dimethylamine-containing system resulted in no difference (P> 0.05) to the amount of total protein deposited on the lenses (6.7 ± 2.8 micrograms/lens versus 7.3 ± 2.8 micrograms/lens, respectively) or to the amount of denatured lysozyme deposits (0.8 ± 0.7 versus 0.9 ± 0.7 micrograms/lens), respectively. The total amount of lysozyme deposited on the lenses was significantly lower when using the peroxide-based system (1.3 ± 0.9 micrograms/lens) compared to the polyquaternium-1 and myristamidopropyl dimethylamine-containing system (1.7 ± 1.0 micrograms/lens) (P=0.02).Conclusion: The inactivation of lysozyme deposited on senofilcon A lenses when disinfected with the peroxide-based or the polyquaternium-1 and myristamidopropyl dimethylamine-containing systems were neither statistically nor clinically significant and the overall amounts of denatured lysozyme recovered from the lenses were low (< 1 microgram/lens).Keywords: contact lens, contact lens care system, lysozyme, protein activity, silicone hydrogel
