Fig 3. Receiver operating characteristic curves for optical coherence tomography angiography parameters distinguishing severe from mild and moderate NPDR.

ROC analysis was performed to assess the ability of OCTA parameters to distinguish severe from mild and moderate NPDR. Superficial capillary plexus (SCP) vessel density (VD), vessel length density (VLD), and middle capillary plexus (MCP) VD were analyzed. AUC = area under curve; SN = sensitivity; SP = specificity.