The Relationship between Central Retinal Artery Resistive Index and Measures of Renal Function in Type 2 Diabetes

Background: Renal and ocular vessels are some of the major vessels affected in patients with diabetes, and the involvement of these vessels is independent risk factors for other complications. Hemodynamic flow in arteries may be assessed by using measures such as resistive index, which is a non-invasive measure of the resistance in vessels. The association between retinopathy and nephropathy has been conflicting. This study assessed the relationship between resistive index of the central retinal artery and indices of nephropathy in type 2 diabetes. Method: This cross-sectional study examined 74 Nigerian diabetics who were selected consecutively from the out-patient diabetic clinic of a tertiary hospital in South-West Nigeria. Doppler ultrasound was used to determine the resistive index of the central retinal artery along with the right renal artery. The urinary and serum biochemical parameters were also done to determine the urinary albumin excretion and the glomerular filtration rate. Results: The mean age of participants was 59.62 ± 9.55 years. The mean central retinal artery resistive index (CRARI) was 0.77 ± 0.06, with 65 (87.8%) of the participants having elevated CRARI. There was no statistical difference between patients with normal CRARI and elevated CRARI in respect of their urinary albumin excretion (p = 0.796). There was no significant correlation between CRARI and estimated glomerular filtration rate (r = 0.120; p = 0.309) and right renal artery resistive index (r = 0.068; p = 0.564). Conclusion: This study demonstrates that central retinal artery resistive index (CRARI) may not be a predictor of renal function in diabetics.