Bilateral Optic Neuropathy and Permanent Loss of Vision After Treatment With Amiodarone

Amiodarone is a commonly prescribed and one of the most effective anti-arrhythmic drugs available. However, its use is limited by serious toxic adverse effects including optic neuropathy. Previously, amiodarone-associated optic neuropathy has been reported at an incidence of 1.3%-1.8%. Nearly, one-third of patients with amiodarone-induced toxic optic neuropathy are asymptomatic and typically visual acuity improves after drug cessation. We describe the case of a 75-year-old woman who experienced severe optic neuropathy with bilateral optic disc edema and hemorrhages, irreversible loss of vision, and severe defects in visual fields after 1.5 months use of amiodarone. The optic disc edema resolved promptly after discontinuation of the drug, but the patient remained blind permanently. This is the first report of only 6.5 weeks of amiodarone treatment resulting in bilateral optic neuropathy with bilateral and irreversible loss of vision. To ideally establish a connection between amiodarone and optic neuropathy, re-exposure of the patient to the drug should reproduce the symptoms. As a limitation of the study, this was not done in the present case because it would have been unethical. The worldwide growth of the elderly population in number is expected to increase age-related conditions including cardiac diseases. The use of cardiovascular drugs, also anti-arrhythmic agents such as amiodarone, may increase. Thus, clinicians need to be aware of the possibility of drug-induced toxic optic neuropathy, especially if a patient receiving a regimen of amiodarone complains of visual problems.