Retinal microvascular changes in patients with coronary artery disease and apnea

Optical coherence tomography angiography (OCT-A) allowed visualization of capillary level of retina; however, the relationship between coronary vascular status and retinal microvascular changes in patients with apnea is not known well. Our aim was to assess the retinal OCT-A parameters in patients with ischemia and angiographically proven microvascular disease and compare them with obstructive coronary disease in patients with apnea.Our observational study included 185 eyes of 185 patients, 123 eyes of patients with apnea (72 eyes from mild OSAS, 51 eyes from moderate to severe OSAS) and 62 eyes from healthy controls. Radial scans of the macula and OCT-A scans of the central macula (superficial (SCP) and deep (DCP) capillary plexuses) were performed on all participants. All participants had documented sleep apnea disorder within 2 years prior to coronary angiography. Patients were grouped by severity of apnea and coronary atherosclerosis (50 % stenosis cut-off value for obstructive coronary artery disease). Patients presented with myocardial ischemia and without coronary artery occlusion (<50 % diameter reduction or FFR > 0.80) constitute the microvascular coronary artery (INOCA) group.Compared to healthy controls, patients with apnea showed deterioration in vascular density in all regions of the retina, regardless of obstructive or microvascular coronary artery disease on the ischemia background. This study has provided important observations of a high prevalence of INOCA in patients with OSAS and the presence of OSAS was a significant independent predictor of functional coronary artery disease. The relative decreases in vascular densities were more pronounced in the DCP layer according to SCP layer of macula. Only FAZ area values were significantly different according to the severity of OSAS (0.27 (0.11-0.62) and 0.23 (0.07-0.50) (p = 0.012)).In patients with apnea, OCT-A can be used as a noninvasive tool to define coronary artery involvement, with similar retinal microvascular changes both in obstructive and microvascular coronary artery group. In patients with OSAS, we observed a high prevalence of microvascular coronary disease, supporting pathophysiological role of OSAS in ischemia of this group of patients.