Microbial keratitis and the role of rub and rinsing.

Recent outbreaks of microbial keratitis in contact lens wearers have involved various pathogens, including Acanthamoeba and Fusarium species. Specific reasons for the marked increase in microbial keratitis, particularly those involving species typically rarely involved in contact lens infection, remain unknown. Possible contributing factors include inadequacies of various multipurpose solutions against certain pathogens; inadequate lens care hygiene, including elimination of the digital rubbing step; poor contact lens storage case hygiene; and the introduction of new soft contact lens materials that may promote adherence of certain pathogens, particularly when a digital rubbing step is eliminated. Although there is some conflict of opinion in the literature regarding the necessity for a mechanical rub during lens cleaning and disinfection, growing evidence supports the reestablishment of a digital rub component to multipurpose solution lens care systems. This article reviews the literature on whether such a process should be recommended to contact lens wearers.