Subepithelial infiltrates in Acanthamoeba keratitis

Six patients had Acanthamoeba keratitis that manifested an unusual type of subepithelial corneal infiltrate late in the course of the disease. These infiltrates occurred in the anterior corneal stroma, often in a location removed from the site of infection. In four of these patients the infiltrates occurred with no other clinical signs of inflammation. Two patients had mild foreign-body sensation that resolved despite the persistence of the subepithelial infiltrates. The infiltrates resolved with topical corticosteroid therapy in three patients; however, in two of these three patients the infiltrates recurred when corticosteroid therapy was tapered or discontinued. The subepithelial infiltrates appeared and behaved similarly to those associated with viral and chlamydial corneal infections. An immunologic mechanism may be responsible for these unusual delayed-in-onset infiltrates.