The Efficacy of Acanthamoeba Cyst Kill and Effects Upon Contact Lenses of a Novel Ultraviolet Lens Disinfection System

Abstract

To assess the efficacy of a novel ultraviolet (UV) lens device on the killing of Acanthamoeba cysts and the impact of efficacious doses of UV upon soft contact lens parameter and material characteristics. Prospective, in vitro, experimental study of a device. A UV lens device was constructed and used to expose Acanthamoeba cysts to various levels of UV irradiation. Once an efficacious dose, as defined by a greater than 3 log reduction, was determined (130 mJ/cm(2)), 6 soft contact lens materials (etafilcon A, senofilcon A, galyfilcon A, lotrafilcon A, polymacon, and comfilcon A) were exposed to that dose for 30 cycles and tested for visual parameters, mechanical parameters, and cytotoxicity. The UV device produced an average log reduction of over 3.5 log of Acanthamoeba cysts when the lens and solution inside of the inset case was irradiated with 130 mJ per cm(2) of UV or greater. After 30 cycles of 130 mJ per cm(2) UV dose each, no gross changes were observed in mechanical properties or cytotoxicity tests in any soft contact lenses tested. In visual parameters, polymacon and lotrafilcon A exhibited a shift in sphere power and diameter, respectively. The novel UV lens device was able to provide a marked log reduction to Acanthamoeba cysts, one of the most resistant ocular disease-causing organisms found in lens cases, without a detrimental effect on many lens materials.