Retinal microvascular parameters are not associated with reduced renal function in a study of individuals with type 2 diabetes

Abstract

The eye provides an opportunistic “window” to view the microcirculation. There is published evidence of an association between retinal microvascular calibre and renal function measured by estimated glomerular filtration rate (eGFR) in individuals with diabetes mellitus. Beyond vascular calibre, few studies have considered other microvascular geometrical features. Here we report novel null findings for measures of vascular spread (vessel fractal dimension), tortuosity, and branching patterns and their relationship with renal function in type 2 diabetes over a mean of 3 years. We performed a nested case-control comparison of multiple retinal vascular parameters between individuals with type 2 diabetes and stable (non-progressors) versus declining (progressors) eGFR across two time points within a subset of 1072 participants from the GoDARTS study cohort. Retinal microvascular were measured using VAMPIRE 3.1 software. In unadjusted analyses and following adjustment for age, gender, systolic blood pressure, HbA1C, and diabetic retinopathy, no associations between baseline retinal vascular parameters and risk of eGFR progression were observed. Cross-sectional analysis of follow-up data showed a significant association between retinal arteriolar diameter and eGFR, but this was not maintained following adjustment. These findings are consistent with a lack of predictive capacity for progressive loss of renal function in type 2 diabetes.

Association of retinal venular tortuosity with impaired renal function in the Northern Ireland Cohort for the Longitudinal Study of Ageing

“…Several cross-sectional studies have previously reported associations between RMPs and renal dysfunction [16,18,39,40] including arteriolar narrowing in those with eGFR < 60 mL/min/1.73m 2 [41,42]. In contrast, other studies have failed to detect associations between RMPs and renal function [43,44]. We failed to detect any associations between CRAE and CKD stages 3-5 defined as eGFR < 60 mL/min/1.73m 2 .…”

A systematic review and participant-level meta-analysis found little association of retinal microvascular caliber with reduced kidney function

“…[22][23][24][25][26][27][28][29][30][31][32][33] However, the findings reported have not always been consistent. 34,35 Therefore, this meta-analysis of cross-sectional studies sought to address the hypothesis that retinal arteriolar and venular calibers are associated with CKD stages 3-5 (eGFR < 60 mL/min/1.73m 2 ) in the general population.…”

The eye, the kidney, and cardiovascular disease: old concepts, better tools, and new horizons

“…73 In contrast, large studies of both diabetic and nondiabetic CKD found no relationship between either baseline or change in Df and the presence or progression of CKD (Table 2). 69,74 The lack of a consistent retinal vascular metric for the detection of incident and prevalent CKD may reflect the heterogeneity of the study populations, underlying etiologies, metabolic abnormalities, and treatments, such as immunosuppression and erythropoietin-stimulating agents. It may also suggest that retinal photography has limited sensitivity to reveal a reliable metric among these competing influences.…”