To evaluate the extent of macular microvascular changes in diabetic retinopathy according to progression of diabetic retinopathy using optical coherence tomography angiography (OCTA).

We retrospectively analyzed 46 diabetic patients and 10 normal patients who underwent OCTA. Diabetic patients were classified as mild, moderate, severe non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR) according to international clinical diabetic retinopathy severity classification fundus findings. OCTA was performed on a 3 × 3 mm region centered on the fovea and parafoveal areas to measure the width of the fovea avascular zone (FAZ) of the superficial and deep capillary plexuses.

Among the control group, NPDR, and PDR, the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of the FAZ increased with progression of diabetic retinopathy. In the SCP ( p <0.001) and DCP ( p <0.001), there was a significant difference in size between the NPDR and PDR groups. In the NPDR group, there were meaningful differences in SCP ( p =0.011) and DCP ( p =0.038) size between the moderate and severe NPDR groups.

In this study, OCTA was used to measure the FAZ, and we aimed to determine if there was a significant difference in FAZ between the NPDR and the PDR groups and between the moderate and severe NPDR groups in terms of the degree of progression of diabetic retinopathy. The results suggest that the size of the FAZ could be a marker of progression of diabetic retinopathy, and noninvasive OCTA can be used to confirm such progression.