Nonarteritic anterior ischemic optic neuropathy and tobacco smoking

Objective: To evaluate whether tobacco smoking may be a risk factor for development of nonarteritic anterior ischemic optic neuropathy (NA-AION). Design: Cohort study. Participants: Six hundred twenty-four consecutive patients with NA-AION who fulfilled our inclusion criteria. Methods: All patients provided a detailed ocular, medical, and smoking history, and underwent a comprehensive ophthalmic evaluation. For data analysis, patients were divided into current, former, and never smokers. The prevalence for current smoking in the NA-AION patients was compared to the corresponding race-, gender-, age-, and period-matched subgroup of the U.S. population. Main Outcome Measures: Association between NA-AION and tobacco smoking. Results: Of the 624 patients, 369 (59.1 %) were men, and mean (+/- standard deviation) age was 61.0 +/- 12.3 years. Of all the patients, 151 (24.2%) were current smokers, 160 (25.6%) former smokers, and 313 (50.2%) had never smoked. The prevalence of smoking in NA-AION patients was not significantly different from the prevalence in the period-matched U.S. population and the period matched Iowa population. In contrast, the prevalence of diabetes mellitus, ischemic heart disease, arterial hypertension, and cerebrovascular disease in NA-AION patients was significantly higher compared to the prevalence of these chronic conditions in the matched U.S. population (P < 0.0001). There was no significant difference in initial visual acuity (P = 0.97) or the amount of initial visual field loss (P = 0.31) among nonsmokers, former smokers, and current smokers. Current smokers had NA-AION in the first eye at a significantly younger age (57.8 +/- 11.7 years) than former smokers (64.0 +/- 10.2 years; P < 0.0001), and nonsmokers (60.4 +/- 13.5 years; P = 0.032). Comparison of the distribution of the time to develop NA-AION in the fellow eye showed no significant difference among the 3 groups (log-rank test P = 0.186). Conclusions: Our study showed no association between NA-AION and tobacco smoking.