Microwave treatment of contact lens cases contaminated with Acanthamoeba

Purpose. Microbially contaminated contact lens cases are a predisposing ris k factor for Acanthamoeba keratitis. Several findings have shown that micro wave irradiation kills the six Food and Drug Administration test challenge microorganisms. We aimed to determine what effect microwave irradiation has on Acanthamoeba trophozoites and cysts. Methods. Different types of contac t lens cases were contaminated with trophozoites and cysts of three differe nt Acanthamoeba species (A. comandoni, A. castellanii, A. hatchetti) and we re exposed to microwave irradiation for 3, 5, and 8 minutes, respectively. Results. Trophozoites, as well as cysts of the different Acanthamoeba strai ns, were effectively killed, even by only 3 minutes of microwave irradiatio n, and there were no negative effects of irradiation on the contact lens ca ses themselves. Conclusion. We demonstrate that microwave treatment is a ve ry effective, easy, and cheap method to keep contact lens cases free of Aca nthamoeba, thus considerably reducing the risk of an Acanthamoeba keratitis .