Figure 4. Deep vessel density values (%) on optical coherence tomography angiography in different diabetic retinopathy stages. *Control versus NoDR, NPDR, and PDR: significant differences, with the control having higher vessel density. NoDR versus NPDR and PDR: significant differences, with NoDR having higher vessel density. NPDR versus PDR: significant difference, with NPDR having higher vessel density. OCTA - optical coherence tomography angiography, DVD - deep vessel density, NoDR - no diabetic retinopathy, NPDR - non-proliferative diabetic retinopathy, PDR - proliferative diabetic retinopathy.