Changes in Retinal Nerve Fiber Layer Thickness in Obstructive Sleep Apnea/Hypopnea Syndrome: A Meta-Analysis

To evaluate and compare changes in retinal nerve fiber layer (RNFL) thickness in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS).

The Cochrane Library, Medline, and Embase were screened using our key words. Results were carefully reviewed to ensure that the included studies met the inclusion/exclusion criteria, and the quality of the studies was assessed using the Newcastle-Ottawa Scale. All included studies categorized patients with OSAHS into 3 groups (mild, moderate, and severe), and measured average and 4-quadrant (temporal, superior, nasal, and inferior) RNFL thickness. All studies included a healthy control group. The weighted mean differences and 95% confidence intervals were calculated for the continuous outcomes.

Ten case-control studies were included in the meta-analysis, consisting of a total of 811 OSAHS group and 868 healthy eyes. A meta-analysis of the data showed that the average RNFL thicknesses in the mild, moderate, and severe OSAHS groups were significantly decreased compared to healthy controls. Additionally, RNFL thickness was significantly reduced in all but the temporal quadrant in the moderate and severe OSAHS groups when compared to healthy controls.

On the basis of these results, we suggest that peripapillary RNFL thickness as measured by optical coherence tomography could be a useful tool to monitor and assess the severity of OSAHS in patients. Further studies are required in order to differentiate these RNFL changes from glaucomatous changes. This has not been properly examined in any of the studies we were able to identify.