<i>Acanthamoeba </i>Keratitis and Contact Lens Disinfecting Solutions

<i>Objectives:</i> To report cases of culture-proved <i>Acanthamoeba</i> keratitis in Greece over a 10-year period and to evaluate the effectiveness of the commonly used commercial contact lens disinfecting systems in clinical cases of <i>Acanthamoeba </i>keratitis. <i>Material and Methods:</i> During the years1994–2004, 45 contact lens wearers and 3 non-contact lens wearers presenting with symptoms and signs of keratitis underwent corneal sampling. The scrapings obtained were inoculated directly onto appropriate culture media for bacteria, fungi and <i>Acanthamoeba.</i> All proved positive for <i>Acanthamoeba</i>. The contact lenses and contact lens disinfecting solutions (16 one-step 3% hydrogen peroxide and 3 multipurpose solutions) of 19/45 patients with culture-proven <i>Acanthamoeba</i> keratitis were cultured for bacteria, fungi and <i>Acanthamoeba.</i><i>Results:</i><i>Acanthamoeba </i>was isolated from contact lenses and contact lens disinfecting solutions in all 19 cases of <i>Acanthamoeba</i> keratitis studied. <i>Conclusions:</i> The main risk factorfor corneal infection in contact lens wearers isthe use of contact lens disinfecting systems ineffective at killing <i>Acanthamoeba</i> cysts and trophozoites, as well as bacteria and fungi. Improvement or development of new contact lens disinfecting systems by manufacturers is needed to prevent <i>Acanthamoeba</i> keratitis