Retinal nerve fibre layer thickness measurements by optical coherence tomography in patients with sleep apnoea syndrome

Background: The study aims to investigate whether retinal nerve fibre layer (RNFL) abnormalities can be detected in patients with obstructive sleep apnoea/hypopnoea syndrome with normally appearing optic disc. Design: This is an observational case-control study. Participants: One hundred and eight consecutive patients with moderate or severe obstructive sleep apnoea/hypopnoea syndrome (OSAHS) as determined by overnight polysomnography and normal looking discs and 108 age-matched healthy controls were included in the study. Methods: All patients underwent RNFL examinations by optical coherence tomography using fast retinal nerve fibre layer thickness scan. Main Outcome Measures: The main outcome measure was RNFL thickness. Results: Multivariate regression analysis results showed that the RNFL was thinner for a patient with OSAHS than that of a normal control in the average by 4.20μm (P<0.003), in the superior quadrant by 4.83μm (P=0.028) and in the inferior quadrant by 5.19μm (P=0.016). RNFL thickness did not correlate with the severity of the disease. Conclusions: RNFL thinning was detected in normal-looking discs of patients with advanced OSAHS, but the extent of this thinning did not correlate with the severity of the disease. Longitudinal follow-up is needed to clarify whether RNFL thinning in OSAHS patients with normal clinically appearing optic nerves will eventually lead to glaucoma.