Purpose: Recent reports of disproportionate outbreaks of microbial keratitis caused by Fusarium solani have led to the removal of the Bausch & Lomb multipurpose lens care solution ReNu With MoistureLoc ("MoistureLoc") from the global market. Previous studies have shown an increased risk of contact lens-related corneal infection in connection with overnight wear, noncompliant lens wearing and lens care behaviors, specific treatment regimens, and other patient-related and non-patient-related factors. The purpose of the laboratory evaluations reported in this article were to observe the effects of levels of simulated lens care noncompliance on the antimicrobial efficacy of multipurpose solutions following recent reports of F. solani keratitis.

Methods: Two multipurpose contact lens care solutions, MoistureLoc and ReNu MultiPlus multipurpose solution ("ReNu MultiPlus"), were tested under conditions that attempted to simulate the possible effect of the noncompliant behaviors reported to Bausch & Lomb as part of the investigation into cases of Fusarium keratitis. Testing conditions included simulated multiple reuse of solutions and evaporation of solutions.

Results: The biocidal efficacy of MoistureLoc and other tested solutions was reduced under conditions that simulated the possible impact of solution reuse. Further investigation of MoistureLoc and ReNu MultiPlus suggests that although efficacy with ReNu MultiPlus was maintained across a variety of noncompliant conditions, the MoistureLoc formula could be rendered less effective under certain conditions.

Conclusions: Under conditions simulating the possible impact of noncompliance, the MoistureLoc solution showed reduced biocidal efficacy. In contrast, ReNu MultiPlus retained a higher level of biocidal activity under the same conditions.