Nonarteritic anterior ischaemic optic neuropathy and its association with obstructive sleep apnoea: a health insurance database study

Background: Nonarteritic anterior ischaemic optic neuropathy (NAION) is the most common acute optic neuropathy in old age. Although there are several known risk factors, the influence of obstructive sleep apnoea (OSA) has not been completely elucidated. The aim of this study was to evaluate the association between NAION and OSA. Methods: This retrospective, longitudinal cohort study used the national health insurance database of Taiwan covering the period 1996–2013. Patients without NAION at the diagnosis of OSA or who developed NAION 1 year after the diagnosis of OSA were enrolled. The patients were followed until death or the last day of the study. Cox proportional hazard regression was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) to investigate the association between OSA and NAION. Results: There were 8488 patients in the OSA group and 33 952 in the control group (without OSA), for a ratio of approximately 1:4. The percentages of NAION were 0.36% and 0.2% in the OSA and control groups, respectively, with a statistically significant difference (p < 0.01; chi-square test), and this significant difference remained in multivariate analysis (p = 0.019) with a significantly higher HR (1.66; 95% CI: 1.08–2.55). There was significant difference in the 30–39 years age group in multivariate analysis (p < 0.01, HR: 6.30; 95% CI: 2.28–17.40). Conclusion: There was a strong association between NAION and OSA, and the patients with OSA had a higher risk of NAION. Further large-scale, prospective studies are warranted to evaluate the effect of OSA on developing NAION.