Obstructive sleep apnoea prevalence in non-arteritic anterior ischaemic optic neuropathy

Aims The aim of this study was to show the prevalence of obstructive sleep apnoea (OSA) in non-arteritic anterior ischaemic optic neuropathy (NAION). Methods 20 patients diagnosed with NAION were included in the study. 20 age and sex matched subjects with similar risk factors for NAION, such as diabetes mellitus (DM) and hypertension (HT), constituted the control group. All cases underwent polysomnography for investigation of the presence of OSA. Cases with an Apnoea-Hypopnoea Index >5 were accepted as having OSA. Results Mean ages of the patients and controls were 60.90+/-8.14 and 61.15+/-7.23 years, respectively. There were no significant differences between the patient and control groups in terms of age, gender, body mass index, smoking/alcohol consumption or systemic diseases. In the patient group, 85% were diagnosed with OSA compared with 65% in the control group (p>0.05). Conclusions We found a high prevalence of OSA in patients with NAION but it was also high in the control group (p>0.05). This may be due to the fact that the two groups were matched for the same risk factors for NAION. The study indicates that OSA is not a risk factor for NAION in itself but is the contributing factor as it has effects on the vascular endothelium in DM, HT and atherosclerosis.