Effect of obstructive sleep apnoea on retinal microvascular function: a randomised controlled trial

Abstract

Purpose Retinal microvascular endothelial dysfunction is thought to be of importance in the development of ocular vascular diseases. Obstructive sleep apnoea (OSA) causes macrovascular endothelial dysfunction, but the effect of OSA on retinal microvascular endothelial function is not known. We aimed to determine the effect of OSA on retinal microvascular function. Methods We conducted a multi-centre, double-blind, randomised, parallel, controlled trial in patients with known moderate-to-severe OSA, established on continuous positive airway pressure (CPAP). Participants were randomised to 14 nights of either continued CPAP or sham CPAP to generate a return of OSA. Retinal vascular responses to flickering light were measured using dynamic vessel analysis both at baseline and after 14 nights of intervention. The primary outcome was the change from baseline to follow-up in the area under the curve of the arteriolar response to flickering light, sham CPAP versus continued CPAP. Results Nineteen patients were randomised to sham CPAP, and 18 patients were randomised to continued CPAP. There was no significant effect of CPAP withdrawal and return of OSA on retinal responses, with a change in the area under the curve of the arteriole response to flickering light of + 3.8 arbitrary units (95% CI − 10.6 to + 18.2, p = 0.59), sham CPAP versus continued CPAP. Conclusions CPAP withdrawal and a return of OSA had no significant effect on retinal microvascular responses. This contrasts with the effect of CPAP withdrawal on macrovascular endothelial function and suggests that OSA has different effects on macrovascular and microvascular endothelial function. ISRCTN 78082983, 23/10/2014, Prospectively registered.

The effect of obstructive sleep apnea on retinal arterial and venous oxygen saturations: further evidence from a randomised study

“…Thirty-seven participants were included in this study, with 18 randomised to continuing CPAP (controls) and 19 to sham. Baseline characteristics were comparable between groups, as reported previously [4].…”

“…We report an exploratory analysis of a multi-centre, double-blind, randomised controlled study of the OSA effects on retinal microvascular function. Full methodology and main outcomes have been published previously [4]. Briefly, participants had known OSA established on continuous positive airway pressure (CPAP) treatment, with no history of diabetes mellitus or pre-existing eye disease.…”

Automated Retinal Vessel Analysis Based on Fundus Photographs as a Predictor for Non-Ophthalmic Diseases—Evolution and Perspectives

“…When undergoing DVA analysis, individuals with untreated moderate-to-severe obstructive sleep apnea but without overt cardiovascular disease exhibited delayed reaction time in response to flicker, as well as decreased dilation amplitude, dilation slope, and postflicker constriction, which can be early indicators for future vascular complications [79]. However, continuous positive airway pressure (CPAP) withdrawal did not affect retinal vascular responses to flickering light, suggesting that there are different effects on macrovascular and microvascular endothelial function [80].…”