Macular Capillary Perfusion in Chinese Patients With Diabetic Retinopathy Obtained With Optical Coherence Tomography Angiography

BACKGROUND AND OBJECTIVE: To compare the macular perfusion in the retina and choroidal layer between control subjects and Chinese patients with diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA) and to evaluate the association of OCTA characteristics with the stage of DR. PATIENTS AND METHODS: A total of 200 eyes (normal controls = 40; mild non-proliferative diabetic retinopathy [NPDR] = 40; moderate NPDR = 40; severe NPDR = 40; and PDR [proliferative diabetic retinopathy] = 40) underwent OCTA imaging. OCTA parameters were vessel densities in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris, as well as foveal avascular zone (FAZ) area (mm(2)) in the SCP. RESULTS: The reduction of macular perfusion in the SCP, DCP, and choriocapillaris was correlated with increasing severity of DR. Vessel density in the SCP, DCP, and choriocapillaris was 55.31% +/- 2.56%, 62.40% +/- 2.46%, and 66.87% +/- 1.30%, respectively, in control subjects; 50.58% +/- 3.14%, 56.31% +/- 4.24%, and 66.20% +/- 1.69%, respectively, in mild NPDR; 46.46% +/- 3.09%, 49.40% +/- 5.68%, and 64.39% +/- 1.94%, respectively, in moderate NPDR; 45.61% +/- 3.81%, 49.33% +/- 6.14%, and 63.75% +/- 2.21%, respectively, in severe NPDR; and 43.78% +/- 3.71%, 44.78% +/- 6.36%, and 61.32% +/- 6.29%, respectively, in PDR. Vessel density in DR groups decreased compared with normal controls (P <.001). FAZ area in the SCP was 0.34 +/- 0.09 mm(2) in control subjects compared with 0.48 +/- 0.17 mm2 (mild NPDR), 0.52 +/- 0.13 mm(2) (moderate NPDR), 0.62 +/- 0.24 mm(2) (severe NPDR), and 0.75 +/- 0.30 mm(2) (PDR). FAZ in the SCP of patients with DR was greater than that in control subjects (P < .001). Vessel density in the DCP shows better ability to identify the severity of DR (area under the curve, sensitivity, and specificity of 0.967, 92.5%, and 93.1%, respectively) than vessel density in the SCP and choriocapillaris. CONCLUSION: OCTA might be clinically useful to evaluate different stages of DR in a noninvasive manner. Vessel density in DCP could be an objective and reliable indicator for monitoring progression of DR.