Risk for microbial keratitis: Comparative metaanalysis of contact lens wearers and post-laser in situ keratomileusis patients.

PURPOSE: To compare the risk for microbial keratitis in contact lens wearers stratified by wear schedule with the risk after laser in situ keratomileusis (LASIK).

SETTING: Hamilton Eye Institute and Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, USA.

DESIGN: Comparative metaanalysis and literature review.

METHODS: An extensive literature search was performed in the PubMed database between December 2014 and July 2015. This was followed by a metaanalysis using a mixed-effects modeling approach.

RESULTS: After 1 year of daily soft contact lens wear, there were fewer microbial keratitis cases than after LASIK, or approximately 2 cases fewer cases per 10 000 (P = .0609). If LASIK were assumed to have essentially a 1-time risk for microbial keratitis, 5 years of extrapolation would yield 11 more cases per 10 000 with daily soft contact lens wear than with LASIK, or approximately 3 times as many cases (P < .0001). The extended use of soft contact lenses led to 12 more cases at 1 year than LASIK, or approximately 3 times as many cases (P < .0001), and 81 more cases at 5 years (P < .0001). When incorporating an estimated 10% retreatment rate for LASIK, these results changed very little.

CONCLUSIONS: Microbial keratitis is a relatively rare complication associated with contact lens use and LASIK postoperatively. The risk for microbial keratitis was similar between patients using contact lenses for 1 year compared with LASIK. Over time, the risk for microbial keratitis was higher for contact lens use than for LASIK, specifically with extended-wear lenses.