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

BackgroundThe 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. DesignThis is an observational case-control study. ParticipantsOne 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. MethodsAll patients underwent RNFL examinations by optical coherence tomography using fast retinal nerve fibre layer thickness scan. Main Outcome MeasuresThe main outcome measure was RNFL thickness. ResultsMultivariate regression analysis results showed that the RNFL was thinner for a patient with OSAHS than that of a normal control in the average by 4.20m (P<0.003), in the superior quadrant by 4.83m (P=0.028) and in the inferior quadrant by 5.19m (P=0.016). RNFL thickness did not correlate with the severity of the disease. ConclusionsRNFL 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.