To report a rare case of corneal edema caused by amantadine.

A 35-year-old man was diagnosed with hypoxic brain damage caused by ventricular fibrillation. The patient showed Parkinsonism and was started on treatment with amantadine. Thirty-seven months after the commencement of amantadine treatment, the patient suffered a corneal ulcer in his right eye, which healed with opacity and thinning after medical treatment. After healing, slit-lamp examination revealed a bilateral, epithelial and stromal edema without obvious guttae and keratic precipitates. The corneal edema did not improve with topical treatment of 5% NaCl and 0.02% fluorometholone in both eyes. Three months after leaving the hospital, the patient's corrected visual acuity decreased to 0.2 (-2.0 Dsph -0.5 Dcyl Ax 90) in the right eye and 0.4 (-0.75 Dsph -2.0 Dcyl Ax 90) in the left eye. Amantadine medication was discontinued after discussion with the patient's neurologist. At the 1-month follow-up, corneal examination revealed resolution of the epithelial and stromal edema in both eyes. Corrected visual acuity was improved to 0.5 (-1.5 Dsph) in the right eye and 0.7 (-1.0 Dsph -1.0 Dcyl Ax 90) in the left eye.

In cases of corneal edema without an obvious causative disease, the patient's systemic medication list must be reviewed and amantadine should be considered as a possible cause.