The prevalence of obstructive sleep apnea syndrome (OSAS) in patients with nonarteritic anterior ischemic optic neuropathy (NAION) and its influence on second eye involvement is not well known. OBJECTIVE To evaluate the prevalence of OSAS in patients with NAION and risk factors of second eye involvement. DESIGN, SETTING, AND PARTICIPANTS In this cohort study, we examined 118 patients with anterior ischemic optic neuropathy referred to a tertiary care center from January 1, 2003, through December 31, 2010. EXPOSURES Patients underwent polysomnography to detect OSAS and were prospectively followed up to assess the risk of second eye involvement. MAIN OUTCOMES AND MEASURES The prevalence of OSAS in patients with NAION and the risk of second eye involvement using survival analysis based on the presence of OSAS, indication for ventilation treatment with continuous positive airway pressure, and other potential ocular and systemic confounders. RESULTS In 89 patients with NAION who underwent polysomnography, 67 (75%) had OSAS. Second eye involvement was found in 10 (13.7%) of 73 patients at 3 years: 8 (15.4%) of 52 patients with OSAS at 3 years and 2 (9.5%) of 21 patients without OSAS at 3 years; P = .04. In multivariate analysis, nonadherence to ventilation treatment with continuous positive airway pressure in patients with severe OSAS increased the risk of second eye involvement (hazard ratio, 5.54; 95% CI, 1.13-27.11; P = .04). CONCLUSIONS AND RELEVANCE These results suggest that OSAS is common in patients with NAION and that polysomnography should be considered in these patients. These findings also suggest that patients with severe OSAS who are nonadherent to ventilation treatment with continuous positive airway pressure have an increased risk of second eye involvement.

The pharmacological approach in animals and the study of isometric exercise in humans show that IOP rises significantly and rapidly with kinetics close to those of BP, and the two values are linearly related. The absence of variation in capnia and the greater increase in BP during squatting may explain the greater increase in IOP during this exercise compared to handgripping.

This study showed unimpaired choroidal vascular reactivity in otherwise healthy men with OSA. This suggests that patients with OSA, without comorbidities, have long-term adaptive mechanisms active in ocular microcirculation.