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

ABSTRACT

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 4.20 µm (P < 0.003), in the superior quadrant by 4.83 µm (P = 0.028) and in the inferior quadrant by 5.19 µm (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.