Background: Conventional procedures for contact lens disinfection, based on solutions with aggressive chemical ingredients, not only affect microorganisms but operate likewise damaging towards the epithelial eye surface.
Objective: The aim of this study was to evaluate the applicability of an alternative or complementary disinfection procedure for contact lenses based on irradiation within the visible wavelength range.
Methods: Suspensions of S. auricularis, B. subtilis and E. coli were exposed to 405 nm irradiation, for determining the disinfection efficacy. Surviving rates were analyzed by membrane filtration as well as a semi-quantitative analysis using DipSlides.
Results: A significant antibacterial effect of the 405 nm irradiation is verifiable for all probed bacteria. Using S. auricularis, there has been no colony forming after an irradiation exposure of 2 hours.
Conclusion: The hitherto existing results give reason for the assumption that violet LEDs integrated in contact lens cases will provide a subsidiary disinfection activity and maybe even offer the reduction of chemical ingredients in lens cleaning solutions to become gentler to the eye. In addition the danger of a rerise of the germ concentration after the completion of the disinfection procedure will be reduced.
Keywords: 405 nm; Contact lens disinfection; porphyrin; violet LED; visible irradiation.