UV irradiation shows promise for contact lens disinfection

This in vitro experimental study demonstrates the efficacy of a novel ultraviolet (UV) light device against Acanthamoeba cysts and lends strong evidence to support the use of UV irradiation in a contact lens disinfecting system with no additional antimicrobial compounds.

The early results of this study are promising but further safety data will be needed before this technology is ready for commercial use.

Acanthameoba keratitis is a disease with significant ocular morbidity. Contact lens wearers are particularly at risk for developing the infection. Preventative measures, such as improved contact lens disinfection systems, are greatly needed to decrease the incidence of disease.

The investigators constructed a UV lens device to expose Acanthamoeba cysts to various levels of UV irradiation. They determined an efficacious dose of UV (130 mJ/cm²).

They applied 30 cycles of this dose to six soft contact lens materials, which produced a mean of 3.5 log reduction of Acanthamoeba cysts when applied to the case (lens and solution inside). No gross changes were observed in mechanical properties of any of the lens materials tested.

The authors conclude that further work may be needed to optimize the UV dose to prevent damage to the lens polymers if a UV-only regimen is used, as well as if a rinse or rinse/rub regimen is combined with UV treatment, and to compare efficacy to commercially available multipurpose and hydrogen peroxide solutions.