Nonarteritic anterior ischemic optic neuropathy and surgery of the anterior segment: temporal relationship analysis.

Objective: This study analyzes the temporal relationship between intraocular lens surgery and nonarteritic anterior ischemic optic neuropathy (NAION).

Methods: Retrospective cohort study. Methods: Eighteen cases of NAION in 17 subjects occurring within 1 year after lens-related surgery were identified with a retrospective review of patients diagnosed with NAION. The temporal relationship between NAION onset and surgery was evaluated by using an exact chi-square test of goodness of fit to compare the observed with a uniform distribution, which would be expected if intraocular surgery were not causal.

Results: All 18 cases occurred within 6 months of surgery (mean interval, 35 days; range, 1-130 days), which is significantly different from a uniform distribution (P <.001).

Conclusions: Our data indicate that intraocular lens surgery is associated with the occurrence of NAION.