Amiodarone Producing Insidious Optic Neuropathy

There was minimal residual temporal pallor of each optic disk, more pronounced on the left, a left relative afferent pupillary defect, and mild loss of retinal nerve fiber layer thickness on OCT with average thickness of 81 µm right and 75 µm left. If untreated, however, it can sometimes lead to visual loss. Since patients taking amiodarone are often older with cardiovascular comorbidities, one should differentiate AAON from non-arteritic anterior ischemic optic neuropathy (NAION). Histopathologic and animal studies suggest that intraneuronal or glial cell inclusion bodies within the optic nerve may obstruct axoplasmic flow and result in disk edema and optic neuropathy, although a direct causal relationship remains speculative.5,6 AAON typically occurs within 1 year of drug initiation.7 It is unclear if patients taking amiodarone need regular ophthalmic screening, but a detailed ocular assessment should occur if visual symptoms arise.