Amantadine Corneal Toxicity:Case Report and Review of the Literature

Purpose: To report a case of bilateral corneal edema in a patient with a history of cocaine abuse and bipolar-depression treated with amantadine for 6 months, and to review the literature on amantadine corneal toxicity. Methods: The clinical record of a patient with amantadine corneal toxicity and the existing literature on this subject were extensively reviewed for prevalence, clinical presentation, pathogenesis and therapy. Results: A 27 year-old male who suffered from depression and cocaine abuse presented with sudden visual loss (20/150 OD and 20/200 OS) caused by bilateral corneal stromal edema without ocular inflammation. Corneal edema was related to amantadine therapy (200 mg per day) for 6 months. Visual acuity improved to 20/20 OU and corneal edema resolved after one month of cessation of therapy. Corneal endothelial cell density after 3 months of discontinuation of amantadine therapy was 636 ± 359 cells/mm² in the right eye and 1,176 ± 238 cells/mm² in the left eye. There was also increased pleomorphism (45.3% 6A cells OD, 56.4% 6A cells OS) and polymegatism (coefficient of variation, 39.04 ± 6.38 OD and 34.76 ± 2.68 OS). Conclusions: Amantadine therapy has become popularized for the treatment of many neurologic and behavioral disorders at all ages. It has been associated with reversible corneal edema but may cause irreversible endothelial cell damage after prolonged administration. This report summarizes the information currently available in the literature regarding amantadine corneal toxicity.