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 4.20 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.