Quantitative retinal vascular complications in obstructive sleep apnoea: A follow up study investigating the response to CPAP therapy

Brendon Wong1,2, Jessica Tong1, Angela Schulz1, Stuart Graham1,3, Claude Farah4, Clare Fraser1

Meeting:  2019 RANZCO


Date:      -

Session Title: FREE PAPERS

Session Time:      -

Purpose: Obstructive sleep apnoea (OSA) is associated with systemic vascular dysregulation that can increase the risk of diabetes, hypertension and stroke. It was recently shown that quantifiable retinal vascular changes occur in patients with OSA, which correlate with disease severity. In this follow‐up study, we examine the response of retinal vascular changes in OSA patients receiving continuous positive airway pressure (CPAP) treatment.

Methods: Participants of the original study were adult patients who underwent diagnostic polysomnography. They were stratified into four groups according to Apnoea‐Hypopnoea Index (AHI); controls, mild, moderate and severe OSA. At baseline and follow up, static retinal vascular calibre was derived from fundus photos and dynamic vascular pulsation amplitudes were measured on video fundoscopy. In the patients prescribed CPAP, data regarding duration and compliance to treatment was obtained from their CPAP machines.

Results: 79 patients participated in this follow up study; 9 controls, 18 mild, 21 moderate and 31 severe. 25 patients had commenced CPAP after the original study. In the severe group, patients not on treatment showed progressive narrowing of retinal arteries from baseline, while those on CPAP showed a slight improvement (mean 171.3 μm to 165.1 μm and 171.2 μm to 174.0 μm respectively, P = 0.012). Results for mild/moderate severity were less pronounced (mean 178.0 μm to 177.6 μm for non‐CPAP and 177.6 μm to 179.1 μm for CPAP, P = 0.46). CPAP did not appear to have a significant impact on vascular pulsatility.

Conclusion: In patients with OSA, CPAP may attenuate progressive retinal arterial narrowing. The effect seems more pronounced with more severe OSA.