BACKGROUND: Two recent studies reported over 70% of the patients with non-arteritic anterior ischaemic optic neuropathy (NAION) had sleep apnoea syndrome (SAS) diagnosed by overnight polysomnography. The current study used the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ) to evaluate this association. METHODS: A matched case-control study was conducted among 73 cases of NAION matched on age and gender to 73 controls without a history of NAION. Information regarding demographics, medical conditions, health behaviours and SAS was obtained via a telephone questionnaire that included the SA-SDQ. Conditional logistic regression was used to calculate odds ratios (OR) and the 95% confidence intervals (CI) for the association between NAION and the SA-SDQ. RESULTS: Cases were significantly more likely to report symptoms and characteristics consistent with SAS than controls (OR 2.62; 95% CI 1.03 to 6.60) when adjusted for medical and health behaviour characteristics. CONCLUSIONS: The results of this study suggest that patients with SAS are at increased risk of NAION. Additional research in a larger population is needed to confirm the observed results and validate the use of the SA-SDQ in patients with NAION.