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

PURPOSE: This study analyzes the temporal relationship between intraocular lens surgery and nonarteritic anterior ischemic optic neuropathy (NAION). DESIGN: 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). CONCLUSION: Our data indicate that intraocular lens surgery is associated with the occurrence of NAION. (C) 2003 by Elsevier Inc. All rights reserved.