OCTA Observed The Changes Of Blood Flow Density In The Choroid And Retina Of Macular Area In Patients With Type Ⅱ Diabetes At Different Stages

Objective To observe the changes of choroidal and retinal blood flow density in the macular area of type 2 diabetic patients at different stages by optical coherence tomography angiography(OCTA).Methods A total of 150 eyes of 150 patients with type 2 diabetes mellitus in the First Affiliated Hospital of Bengbu Medical College were included in the study.According to the severity grading standard of diabetic retinopathy(DR),the eyes were divided into five groups: non-DR group,mild,moderate and severe non-proliferative diabetic retinopathy(NPDR)groups and proliferative diabetic retinopathy(PDR)group,30 eyes of 30 patients in each group.OCTA was performed on the macular area(6mm×6mm)to measure the blood flow density of the superficial retinal layer,deep retinal layer and choroid capillary layer and the foveal avascular zone(FAZ)area of the superficial capillary plexus.The changes of choroidal and retinal blood flow density and FAZ area in different stages of DR patients were observed,and the correlation between blood flow density and the degree of DR was analyzed.Results With the increase of the severity of DR,the blood flow density of the superficial retina,deep retina and choroid capillary layer decreased significantly(all P < 0.001),and the FAZ area increased significantly(P < 0.001).In both the superficial and deep layers of the retina,the density of blood flow in different quadrants decreases with the progression of DR.There was a strong positive correlation between the blood flow density of the superficial retinal layer,the deep retinal layer and the choriocapillaris layer(all P < 0.001).The ability of deep retinal blood flow density to identify the severity of DR(sensitivity and specificity were 92.5% and93.1%,respectively)was better than that of superficial retinal and choriocapillaris.Conclusion OCTA can accurately observe the changes of choroidal and retinal blood flow density in different stages of DR,and the deep retinal blood flow density can be used as a sensitive indicator to monitor the progress of DR.