Role of aspirin in reducing the frequency of second eye involvement in patients with non-arteritic anterior ischaemic optic neuropathy

Purpose To retrospectively evaluate in patients with non-arteritic ischaemi c optic neuropathy (NAION) whether aspirin reduces the frequency of second eye involvement. Methods In 52 patients who presented with NAION between 1984 and 1997 adequ ate information was available regarding use of aspirin, presence of risk fa ctors and second eye involvement. Results Second eye involvement was noted in 8 of 16 patients (50%) who did not receive aspirin, in 3 of 8 patients (38%) who received 100 mg/day aspir in and in only 5 of 28 patients (18%) who received aspirin 325 mg/day. More over, mean time to second eye involvement was 63 months in patients who did not receive aspirin versus 156 months in patients who received aspirin 325 mg/day. Conclusion Our results strongly suggest that aspirin at 325 mg/day may be e ffective in reducing the frequency of second eye involvement with NAION.