Clinical features and outcome of Acanthamoeba keratitis.

We retrospectively reviewed 11 patients with culture-proven Acanthamoeba keratitis who presented at the National Taiwan University Hospital between 1989 and 1996. We assessed predisposing factors, initial diagnosis, clinical presentation, treatment, and outcome. A history of contact lens-wear, poor contact lens hygiene, intractable eye pain, and ring infiltrates in the cornea were the most prominent characteristics and clinical manifestations. Acanthamoeba keratitis was often misdiagnosed, with herpetic keratitis (7/11) being the most common initial diagnosis from referring hospitals. These patients were usually treated on the basis of the inaccurate diagnosis for more than 1 month (range 1-8 mo) before referral. All patients ultimately received penetrating keratoplasty because of poor response to delayed medical treatment. We suggest that inadequate contact lens hygiene may be important in Acanthamoeba keratitis. This condition is often misdiagnosed and, as early diagnosis is a major factor for successful medical treatment in such patients, awareness in clinical practice is critical.