Optic Nerve Head Capillary Network Quantified by Optical Coherence Tomography Angiography and Decline of Renal Function in Type 2 Diabetes: A Three-Year Prospective Study

To assess the association of optic capillary perfusion with decline in the estimated glomerular filtration rate (eGFR) and to clarify its added value.Prospective, observational cohort study.T2DM patients without diabetic retinopathy (non-DR) underwent standardized examinations annually during a three-year follow-up period. The superficial capillary plexus (SCP), deep capillary plexus (DCP), and radial peripapillary plexus (RPC) were visualized using OCTA, and the perfusion density (PD) and vascular density (VD) were quantified for the whole image (wi) and circumpapillary (cp) regions of the ONH.A total of 906 patients were included for 3 × 3 mm2 OCTA analysis. After adjusting for other confounders, each 1% decrease in baseline whole en face PD in SCP and RPC was associated with accelerated rates of decline in eGFR by -0.53 (95% CI: -0.17, -0.90; P = 0.004) mL/min/1.73/m2 per year and -0.60 (95% CI: 0.28, 0.91) mL/min/1.73/m2 per year, respectively. Adding both wiPD in SCP and wiPD in RPC to the conventional model increased the AUC from 0.696 (95% CI: 0.654, 0.737) to 0.725 (95% CI: 0.685, 0.765; P = 0.031). Another cohort of 400 eligible patients with 6 × 6 mm2 OCTA imaging validated the significant associations between ONH perfusion and rate of eGFR decline (P < 0.05).Reduced capillary perfusion of ONH in T2DM patients is associated with a greater eGFR decline, and it has additional predictive value for detecting an early stage and progression.