Acanthamoeba keratitis associated with disposable contact lenses.

Two patients developed Acanthamoeba keratitis associated with the use of disposable extended-wear hydrogel contact lenses. Both patients removed, irrigated, and reinserted the contact lenses without disinfecting them. One patient wore the lenses on a daily basis, rinsed the lenses in tap water, stored them overnight, and discarded them weekly. Both infections were treated successfully. In a third patient, Acanthamoeba species was cultured from two pairs of disposable lenses that had been stored in cases rinsed with well water. Potential benefits from disposable contact lens wear are negated when patients do not comply with a continuous wearing schedule.