Diabetic kidney disease (DKD) is a common microvascular complication of diabetes. Biomarkers that can detect DKD at an early stage may allow early intervention and improve patient outcomes. The vascular system (or vascular network) of the kidney and eye share strikingly similar structural, developmental, physiologic, and pathogenic pathways.1 Optical coherence tomography-angiography (OCT-A), which maps erythrocyte movements by comparing sequential OCT-B scans (motion contrast) at a given cross-section, was recently developed for noninvasive and depth-resolved assessment of the retinal capillary network without exogenous intravenous dye injection.