High water content versus low water content—Does monthly replacement affect the difference?: A comparison between the Focus ® and Medalist ™ lenses under identical conditions of use

Abstract

The frequent replacement of contact lenses has developed primarily as a means of maintaining a high level of hygiene with soft lenses. To determine the differences in the performance of a low-water-content (Bausch & Lomb Medalist ™) and a high-water-content (CIBA Vision Focus ®) lens when used for monthly replacement, we carried out a 3-month, randomized, contralateral, single masked study using daily wear. There was no significant difference between the lenses in terms of ocular physiology, fitting performance, or spoilation. Handling of the high-water-content lens was judged to be better for insertion, removal, cleaning, and disinfection and determining whether the lens was inside out ( p < 0.05). Pooled subjective assessments of comfort, vision, and overall satisfaction gave a statistically significant patient preference ( p < 0.05) for the high-water-content lens. Unscheduled replacements of damaged lenses were low (<2%) and statistically insignificant between the lens types. These results imply that, with frequent replacement, the normally perceived disadvantages of handling, deposition, and fragility for high-water-content lenses, as opposed to low-water-content soft lenses, do not necessarily apply.