Clinical discussion on the relative efficacy of 2 surfactant-containing lubricating agents in removing proteins during contact lens wear

Abstract

Background This clinical study aims to evaluate the clinical efficacy of 2 popular rewetting agents, Blink-N-Clean ™, manufactured by Advanced Medical Optics (Santa Ana, California), and Clens 100 ™, manufactured by Alcon (Ft. Worth, Texas), on protein removal in a nonsymptomatic population of contact lens wearers fitted with etafilcon A soft contact lenses, Acuvue 2 ™, manufactured by Vistakon, a division of Johnson and Johnson Vision Care (Jacksonville, Florida). Methods This randomized, double-blind, crossover study was performed on 22 subjects who had been fitted successfully with etafilcon A soft contact lenses. Each subject was examined on 3 occasions, at 2-week intervals, to evaluate a number of clinical signs related to contact lens wear, with or without the use of ocular lubricants specifically designed to reduce the levels of proteins adsorbed on the lens. A washout period was observed between each of the study’s different phases. High- and low-contrast visual acuity levels were measured using the Bailey-Lovie (logMAR) chart under mesopic and scotopic conditions. Protein levels adsorbed on the lenses were determined using a modified Lowry method. Ocular health was assessed under biomicroscopy using conventional techniques. Subjective comfort was also evaluated, using a questionnaire based on a Likert scale graded from 0 to 50. Results Objectively, no significant difference in either visual acuity or comfort was found between the use or the nonuse of drops or the use of one specific product. Using Clens 100 allowed for a significant reduction in the quantity of protein on the lens surface. More than 3 subjects of 4 (77%) preferred the Clens 100 product, in large part because they found the size of drops dispensed from the Clens 100 bottle less disturbing during insertion because of the size of the drops and blur. Conclusion Among healthy contact lens wearers fitted with the same type of contact lens, a significant difference was observed in the quantity of proteins adsorbed on the lens with the use of Clens 100, as compared with the use of either Blink-N-Clean or no product at all. This difference does not seem to have had an impact because clinical signs and symptoms did not vary over the course of the study.