PURPOSE

Assessment of the indices of macular capillary blood flow and subfoveal choroidal thickness (SCT) using optical coherence tomography angiography in patients with retinal manifestations of ocular ischemic syndrome (RMOIS) associated with atherosclerotic internal carotid artery stenosis.

MATERIAL AND METHODS

The study included 34 patients (68 eyes): 21 men, 13 women with RMOIS in one eye. All patients were divided into 2 groups depending on the severity of atherosclerotic internal carotid artery stenosis and ophthalmoscopic picture of the fundus. To obtain objective information we analyzed the degree of decrease in the main indices characterizing macular microcirculation and SCT depending on the severity of RMOIS.

RESULTS AND DISCUSSION

Analysis of the results showed relationship between the severity of RMOIS and the deficit in macular microcirculation. The macula of the patients with mild RMOIS was characterized by a decrease in the density of superficial vascular plexus (SVP) and the density of deep capillary plexus (DCP) by 13.5% and 10.5% compared to the controls, respectively; in moderate RMOIS — by 19.7% and 14.6%; in severe RMOIS — by 35.9% and 28%, respectively. With an increase in the severity of RMOIS, the area of the foveal avascular zone increased too: in mild degree RMOIS — by 19%, in moderate — by 38.6%, in severe — by 51%. In proportion to the severity of RMOIS, SCT was reduced: in mild degree RMOIS — by only 8%, in moderate — by 22%, and in severe — by 29.8% of the control.

CONCLUSION

The conducted research indicates that pathological changes in RMOIS extend to the entire capillary network of the macula and SCT. With increase in the degree of RMOIS, ischemic changes in all capillary layers of the central parts of the retina proportionally increase in comparison with the control group by 1.15 times in mild degree, by 1.24 times in moderate degree, and by 1.5 times in severe RMOIS.