Successful medical treatment of Acanthamoeba keratitis

Purpose: To describe the outcome of a series ofAcanthamoeba keratitis treated with a similar regimen. Methods: All cases diagnosed with Acanthamoeba keratitisin a referral centre from June 1994 through June 1997 wereincluded. Diagnosis of Acanthamoeba keratitis was based inclinical presentation and laboratory results. Positive laboratoryidentification of Acanthamoeba from corneal scraping or contactlens was required, unless the patient had very characteristicsymptoms (severe pain) and signs of the infection, includingperineural infiltrates. Initial intensive treatment includedtopical polyhexamethylene biguanide (PHMB) 0.02%, propamidineisothionate 0.1% and broad-spectrum antibiotics. The treatmentwas gradually tapered. After documented response toanti-acanthamoeba therapy, topical steroids were introduced; theywere discontinued before cessation of the anti-Acanthamoebaregimen. Results: Six males and four females, with a meanage of 30.0 ± 7.4 years were included in this study. Allcases weared contact lenses. On presentation all cases had severepain, and epitheliopathy was associated with stromal infiltratein most (seven of ten) cases. Four patients had anterior uveitis.Perineural infiltrates were present in three cases and ringinfiltrate in one patient. Anti-amoebic treatment was started12.7 ± 7.2 days after beginning of symptoms. The clinicalresponse to therapy was very satisfactory in all patients. Withintwo to three weeks all patients had remarkable lessening of painand photophobia, and improvement of clinical signs. At two tothree months, visual acuity had improved in all patients. Twopatients required penetrating keratoplasty for visualrehabilitation. Conclusion: The use of PHMB and propamidinecured all cases of Acanthamoeba keratitis. Cautious introductionof steroids was associated with expedited resolution ofinflammation and provided symptomatic relief.