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.

Trial registration: ClinicalTrials.gov NCT01188291.

Keywords: glaucoma; obstructive sleep apnoea/hypopnoea syndrome; optical coherence tomography; retinal nerve fibre layer.