Microbial keratitis and vision loss with contact lenses

PURPOSE: Microbial keratitis is the only sight-threatening adverse event that occurs with contact lens wear. This article gives a preliminary estimation of the incidence of microbial keratitis and vision loss with continuous-wear contact lenses made from highly oxygen permeable (Dk) materials. METHODS: The most up-to-date data available on microbial keratitis and vision loss are collected from a range of sources including industry, private practice, and publications and is reviewed. RESULTS: There have been 16 cases of microbial keratitis with high-Dk silicone hydrogel lenses. Of the 13 where data are available, none have lost two or more lines of best-corrected visual acuity (BCVA). CONCLUSION: First approximation indicates that the incidence of microbial keratitis with high-Dk silicone hydrogel lenses may be lower than the incidence with low-Dk soft lenses during extended wear. The rate of loss of more than two lines of BCVA is low in patients that develop microbial keratitis with low- and high-Dk soft lenses.