In Vivo Visualization and Quantification of Optic Disc Microvasculature for Assessing Renal Dysfunction

Objective: To assess the relationship between optic disc microvasculature and renal function in subjects with diabetes mellitus without diabetic retinopathy (DR).Design: Prospective, cross-sectional study.Participants: A total 1629 patients with type 2 diabetes mellitus without DR were recruited from the community of Guangzhou, China.Methods: All subjects underwent 6 mm x 6 mm OCT angiography (OCTA) centered on the optic nerve head. Four state-of-the-art microcirculation parameters, including peripapillary vessel density (PVD) in the radial peripapillary capillaries (RPC), superficial capillary plexus, deep capillary plexus (DCP), and a choriocapillaris flow void density percentage (CC FVD%) were assessed via swept-source OCTA.Primary outcomes: Renal function was assessed by levels of microalbuminuria (MAU) and estimated glomerular filtration rate (eGFR).Results: Compared with non-chronic kidney disease (CKD) participants, PVD was significantly lower in subjects in the CKD group and worsened as eGFR declined. After adjustment for covariates, higher eGFR was significantly associated with higher PVD in the RPC (beta = 0.01; 95% confidence interval [CI], 0.01-0.02; P < 0.001), in the superficial capillary plexus (beta = 0.010; 95% CI, 0.002-0.019; P = 0.020), in the DCP (beta = 0.02; 95% CI, 0.01-0.03; P < 0.001), and lower CC FVD% (beta = -0.01; 95% CI, -0.03 to -0.001; P = 0.040) in the entire images. After they were fully adjusted, the parameters in the inner ring of the RPC, DCP, and CC FVD% were significantly associated with MAU (P < 0.05).Conclusion: Decrease in retinal and choroidal microcirculation in the optic nerve head was independently associated with renal dysfunction. Further longitudinal studies are needed to clarify the peripapillary vessel changes during CKD progression.