Contact Lens Care Products Effect on Corneal Sensitivity and Patient Comfort

Abstract

PURPOSE: To evaluate the possible effect of two leading soft contact lens care products on corneal sensitivity, relative comfort, and superficial corneal staining in adapted disposable soft contact lens wearers. METHODS: Eight disposable soft contact lens wearers equally divided between habitual users of OPTI-FREE Express Lasting Comfort No Rub formula (Alcon Laboratories, Fort Worth, TX) and ReNu MultiPlus (Bausch & Lomb, Rochester, NY) were enrolled in this crossover study. The habitual lens care product was designated the first crossover period. Patients completed a visual analog scale rating of midday and end-of-day comfort, underwent slitlamp examination for staining, and had corneal sensitivity measured by Cochet-Bonnet esthesiometry before and after being switched to the alternative lens care product. The lens care product used was masked from the investigator. RESULTS: Patients habitually using OPTI-FREE Express reported higher comfort ratings than did patients using ReNu MultiPlus. On crossover, patients who initially used ReNu MultiPlus experienced similar comfort when using OPTI-FREE Express, but OPTI-FREE Express users experienced a substantial decrease in comfort when switched to ReNu MultiPlus. Esthesiometry showed significant differences in average sensitivity in favor of OPTI-FREE Express (P=0.0041). Statistical trends supported observed increases in corneal sensitivity when switching to OPTI-FREE Express and decreased corneal sensitivity when switching to ReNu MultiPlus. ReNu MultiPlus was also associated with slightly more corneal staining. CONCLUSIONS: ReNu MultiPlus, a biguanide-based contact lens care product, was associated with decreased comfort during midday and end-of-day periods. ReNu MultiPlus was also associated with significant reduction in relative corneal sensitivity compared to Polyquad-based OPTI-FREE Express. Disturbance to normal corneal sensitivity may play a role in contact lens-related dry eye and discomfort. Further investigation is warranted.