Efficacy of the MicroBlockTM Antimicrobial Lens Case Against Clinical Isolates and ATCC Solution Challenge Panel Strains

Abstract

Abstract: : Purpose:Microbial contamination of lens cases may occur despite the effectiveness of currently marketed contact lens disinfection systems. Microorganisms isolated from contact–lens–associated corneal ulcers are often identical to those isolated from the patient’s associated lens case. A number of patients with contaminated lens cases also report having problems wearing their contact lenses, such as eye dryness, itching, and redness. In an attempt to reduce the degree of contamination of lens cases, the MicroBlock^TM antimicrobial lens case was developed. Efficacy of the MicroBlock^TM case against clinical isolates and ATCC solution challenge panel isolates was assessed. Performance of the MicroBlock^TM case versus standard market lens cases also was examined. Methods:Bowls of MicroBlock^TM and competitor lens cases were directly challenged with 10³ CFU/mL suspensions of clinical isolates, including one from a microbial keratitis patient, and ATCC solution challenge panel isolates of bacteria and yeast in phosphate buffered saline. This challenge level was chosen to more closely mimic real world lens case contamination levels. Sample efficacy was assessed after 24 hrs incubation. Results:The MicroBlock^TM case demonstrated significant bactericidal efficacy against clinical and ATCC isolates. The MicroBlock^TM case’s performance was superior to all competitor cases evaluated for each strain tested, including those cases with some inherent antimicrobial activity. Conclusions:The MicroBlock^TM case is efficacious against clinical isolates and solution challenge panel strains. It is a promising device for reducing the incidence of microbial lens case contamination.

Keywords: contact lens • microbial pathogenesis: experimental studies • antibiotics/antifungals/antiparasitics