Retinopathy and chronic kidney disease in the Chronic Renal Insufficiency Cohort (CRIC) study

Objective: To investigate the association between retinopathy and chronic kidney disease. Methods: In this observational, cross-sectional study, 2605 patients of the Chronic Renal Insufficiency Cohort (CRIC) study, a multicenter study of chronic kidney disease, were offered participation. Nonmydriatic fundus photographs of the disc and macula in both eyes were obtained in 1936 of these subjects. The photographs were reviewed in a masked fashion at a central photograph reading center using standard protocols. Presence and severity of retinopathy (diabetic, hypertensive, or other) and vessel diameter caliber were assessed by trained graders and a retinal specialist using protocols developed for large epidemiologic studies. Kidney function measurements and information on traditional and nontraditional risk factors for decreased kidney function were obtained from the CRIC study. Results: Greater severity of retinopathy was associated with lower estimated glomerular filtration rate after adjustment for traditional and nontraditional risk factors. The presence of vascular abnormalities usually associated with hypertension was also associated with lower estimated glomerular filtration rate. We found no strong direct relationship between estimated glomerular filtration rate and average arteriolar or venular calibers. Conclusions: Our findings show a strong association between severity of retinopathy and its features and level of kidney function after adjustment for traditional and nontraditional risk factors for chronic kidney disease, suggesting that retinovascular pathology reflects renal disease.