Amiodarone-Associated Simultaneous Bilateral Ischemic Optic Neuropathy: A Case Report
Abstract:
Introduction: Amiodarone is a widely used antiarrhythmic agent associated with multiple systemic adverse effects, including rare but potentially vision-threatening optic neuropathy. Amiodarone-associated optic neuropathy (AAON) remains a controversial entity, with clinical features that may overlap with nonarteritic anterior ischemic optic neuropathy (NAION).
Case Report: We report the case of a 56-year-old man with arterial hypertension who developed painless, bilateral sequential visual loss three months after initiation of amiodarone therapy for arrhythmia control. Ophthalmologic examination revealed reduced visual acuity, bilateral optic disc edema with peripapillary splinter hemorrhages, and inferior altitudinal visual field defects with relative macular sparing. Neuroimaging, cerebrospinal fluid analysis, and inflammatory markers were unremarkable. Given the temporal association between drug exposure and symptom onset, amiodarone was discontinued. Optic disc edema persisted for approximately three months, followed by bilateral optic disc pallor. At six-month follow-up, visual acuity and visual field defects remained unchanged, without improvement or further deterioration.
Discussion: Amiodarone is a highly lipophilic drug that accumulates within lysosomes, interferes with lipid metabolism, and may disrupt axoplasmic flow through biochemical and mechanical mechanisms. Duration of exposure appears to be a more relevant risk factor than daily dosage. Visual outcomes after drug discontinuation are variable, ranging from improvement to permanent visual impairment.
Conclusion: This case highlights the importance of considering AAON in patients receiving amiodarone who present with optic disc edema and visual field defects. Early recognition and appropriate management are essential to optimize visual outcomes.
