Abstract
Purpose: :
To report 294 cases of amiodarone–associated optic neuropathy (AON), representing the largest number of cases reported with this toxicity.
Methods: :
Reports of AON were identified from the Food and Drug Administration’s Adverse Event Reporting System (FDA–AERS) and published cases identified through Medline search.
Results: :
A total of 294 cases of AON were identified: 214 from the FDA–AERS, 57 from published case reports, and 23 from adverse events reports for patients enrolled on clinical trials. Based on a priori criteria, 80 cases were characterized as having definitive AON. The mean age was 63 (± 10) years and 84% were male. The mean duration of amiodarone therapy before vision loss was 9 months (range 1–84 months). Insidious onset AON (44%) was the most common presentation. Other presentations included acute onset optic neuropathy (21%), retrobulbar optic neuropathy (29%), pseudotumor cerebri/raised intracranial pressure (8%), and delayed–progressive onset optic neuropthay (6%). In some cases, ocular presentation varied between eyes in the same patient. Nearly one–third of the patients were asymptomatic. Optic disc edema was present in 85% of cases, with median duration of 3 months (range, 1 to 8 months). Visual acuity at presentation ranged from 20/15 to light perception. In follow–up, 58% had improved visual acuity, 21% had unchanged visual acuity, and 21% had further decreased visual acuity. Legal blindness (20/200 or worse) was noted in at least one eye in 20% of cases.
Conclusions: :
The clinical presentations of AON can be acute onset and unilateral, and does not have to be insidious and bilateral. Visual improvement occurs in 58% of cases following amiodarone discontinuation.
Keywords: drug toxicity/drug effects • neuro-ophthalmology: optic nerve • visual impairment: neuro-ophthalmological disease