Material and Methods: Patients with a diagnosis of CAD are divided into 3 stages according to the results of coronary angiography. Stage 1) Normal coronary artery; stage 2) Non-critical narrowing of coronary arteries (<70% stenosis); stage 3) 70% and above critical narrowing in coronary arteries. The diameters of retinal vascular structures were measured by Optical Coherence Tomography. The relationship between retinal arteriole, venule diameters and arterio-venous ratio (AVR) with CAD stage was evaluated.

Results: One hundred six eyes of 106 CAD patients (36 patients in stage 1, 40 patients in stage 2, and 30 patients in stage 3) were studied (P = 0.539). Demographic characteristics of the groups were similar (P> 0.05). In stage 1, the mean diameter of the retinal arterioles was 119.77 ± 7.24, and the venules were 142.44 ± 7.10; 118.77 ± 6.69 um and 143.01 ± 6.67 in stage 2, 104.60 ± 5.17 and 144.73 ± 12.45 um in stage 3, respectively. There was a signifi cant difference between stage 1-3 and stage 2-3 (P = 0.730; P <0.001; P <0.001, respectively). There was no signifi cant difference in venule diameter between the groups (P>0.05). The mean AVR was 0.84 ± 0.04 in stage 1, 0.83 ± 0.02 in stage 2, 0.72 ± 0.01 in stage 3, and there was a signifi cant difference between stage 1-3 and stage 2-3 (P = 0.301; P<0.001; P <0.001, respectively). It was found that there was a negative and signifi cant correlation between arteriolar diameter and AVR with CAD stage (r = -0.665, P <0.001, r = -0.717, P <0.001, respectively).

Conclusions: It was found that as the CAD stage increased, there was a signifi cant decrease in arteriole diameter and AVR value and a tendency to increase in venule diameter. Keywords : Coronary Artery Disease, Optical Coherence Tomography, Retinal Vessel Diameter