Amiodarone keratopathy. Correlation to dosage and duration.

Amiodarone hydrochloride, a benzofurane derivative used for the treatment of cardiac arrhythmias, is known to cause a verticillate epithelial keratopathy, which has been classified into three stages. Patients receiving low dosages of 100 to 200 mg of amiodarone daily retain clear corneas or show stage 1 changes only, regardless of duration of treatment or total amount of substance ingested. Patients receiving higher dosages of 400 to 1,400 mg/day show stage 2 and 3 changes, depending on duration of treatment. This keratopathy progresses, even with reduced dosage; however, complete regression occurs once administration of medication is discontinued.