A comparison of the efficacy of four units for the physical disinfection of contact lenses

Abstract

Four contact lens disinfection units were challenged with saline suspensions of Pseudomonas aeruginosa, Staphylococcus aureus, Serratia marcescens, Escherichia coli and a clinical isolate of Candida albicans. The disinfection units all relied on physical disinfection methods and included the Sonasept unit which uses ultrasound and heat, the Aquasteril unit which uses ultraviolet radiation, the Bausch and Lomb Heat unit and the OPSM Thermos flask, both of which act through moist heat. Both the Sonasept and Aquasteril units performed poorly under most circumstances, causing little reduction in the number of viable organisms and in some cases there was an increase in the number of viable organisms following a disinfection cycle. The Bausch and Lomb Heat unit and the OPSM Thermos flask killed the challenge organisms under all test conditions.