Risk of Nonarteritic Anterior Ischemic Optic Neuropathy After Cataract Extraction in the Fellow Eye of Patients with Prior Unilateral Nonarteritic Anterior Ischemic Optic Neuropathy

¹ Bascom Palmer Eye Institute, United States
² University of California San Francisco, United States

^* To whom correspondence should be addressed. E-mail: blam{at}med.miami.edu.

Accepted 2 November 2006

	Abstract

Background/Aims: To determine the risk of non- arteritic anterior ischemic optic neuropathy (NAION) after cataract extraction (CE) in the fellow eye of patients with prior unilateral NAION.

Design: Retrospective, cohort study.

Methods: Medical records of patients with NAION evaluated in our institution between January 1, 1986 and December 31, 2001 were reviewed to determine the onset of NAION and the time of CE. Cases were excluded if the date of NAION and CE was unreliable or if fellow eye CE was performed before the unilateral NAION. Statistical analysis was performed by including fellow eye CE as a time dependent covariate in a Cox proportional hazards regression model of fellow eye NAION incidence.

Results: Of the 325 eligible patients, 9 (53%) of 17 NAION patients who underwent CE in the fellow eye developed fellow eye NAION, and 59 (19%) of 308 NAION patients who did not undergo CE in the fellow eye developed fellow eye NAION. Cataract extraction in the fellow eye increased the risk of NAION occurrence in the fellow eye by 3.6 times (Cox regression, p=0.001).

Conclusions: Patients with unilateral NAION are at a significantly higher risk of developing NAION in the fellow eye after CE.

Keywords: anterior ischemic optic neuropathy, cataract extraction