Background: Amiodarone, a di-iodinated benzofuran derivative, is a class III antiarrhythmic agent that primarily exerts its effect through potassium channel blockade. Initially introduced in the 1960s for the treatment of angina pectoris, it is now widely prescribed for the management of various cardiac arrhythmias, particularly atrial fibrillation. Despite its therapeutic efficacy, amiodarone is associated with multiple systemic adverse effects involving several organs, including the eyes.
Methods: This study was conducted as a case report. The patient presenting with complaints of blurred vision underwent a comprehensive ophthalmic evaluation, including measurement of best-corrected visual acuity, slit-lamp examination, funduscopy, automated perimetry, and neuroimaging of the brain and orbits with contrast-enhanced magnetic resonance imaging (MRI).
Findings:
We report a 60-year-old man who presented with progressive blurred vision while receiving amiodarone therapy for atrial fibrillation. Ophthalmologic examination revealed optic neuropathy, which in this case presented unilaterally, an uncommon finding given that most reported cases are bilateral. Corneal verticillata was also observed as an additional ocular manifestation. Following discontinuation of amiodarone, the progression of visual symptoms stabilized without further deterioration.
Conclusion: Amiodarone-induced optic neuropathy is a rare but clinically significant adverse effect that may be challenging to distinguish from non-arteritic anterior ischemic optic neuropathy (NAION). Persistent optic disc edema and a more insidious course are important distinguishing characteristics. Given the diagnostic overlap, careful evaluation is essential to exclude alternative causes of optic neuropathy. Discontinuation of amiodarone may lead to stabilization or partial improvement in visual function, although optic disc edema can persist for several months.