New strategies to prevent Pseudomonas keratitis

Abstract

Purpose: To review the options for preventing the development of microbial keratitis during contact lens wear.

Methods: A sequence of events that result in the production of microbial keratitis is presented. A review of published material was conducted using key words such as antimicrobial, silver, antibiotic, antibacterial, and contact lens(es). Results of the searches were examined, and strategies for reducing microbial keratitis were identified and classified into various groupings.

Results: Ways of minimizing bacterial adhesion to and colonization of contact lenses were considered the only viable preventative strategies currently being investigated by research groups and industry. The mechanisms that are being trialed include alternative disinfecting systems in contact lens cleaning and disinfecting multipurpose solutions and silver-containing contact lens cases that have been reported to reduce bacterial colonization of cases. In addition, and importantly for extended wear of lenses, industry and research groups have been investigating antimicrobial contact lenses. Strategies include the use of the antimicrobial agents silver, chitosan, polyquats, cationic peptides, furanones, and selenium.

Conclusions: Although many strategies are being investigated, to date there are no published studies examining the effectiveness of any of these strategies to reduce the rate of microbial keratitis. Such studies are likely to occur only once the strategies are available commercially because of the low rate of microbial keratitis, even during extended wear. However, it is possible that studies examining the rate of microbially driven adverse responses, such as contact lens-induced red eye, may yield valuable information of success of these proposed interventions.