Abstract
Purpose:
To describe the associations between non-diabetic retinopathy (NDR) and chronic kidney disease (CKD) in a multiethnic Asian population without diabetes.
Methods:
We examined 7228 adults of Chinese, Malay and Indian ethnicity aged 40-80 years who participated in the population-based Singapore Epidemiology of Eye Disease (SEED) study, and who were free of diabetes mellitus. Diabetes was defined as having a random blood glucose of ≥ 11.1 mmol/L, a known history of diabetes or diabetic medication use. Digital fundus photographs of both eyes were taken using a retinal camera and assessed by trained graders for the presence of retinopathy using the modified Airlie House classification system. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73m2. eGFR was also analyzed as a continuous variable and in categories (<60, 45-59, <45). The associations between CKD, eGFR and NDR were examined using multivariate logistic regression models adjusted for traditional cardiovascular risk factors.
Results:
There were 7088 (98.1%) participants with gradable fundus photographs and complete eGFR data, of which 647 (9.1%) had CKD and 359 (5.1%) had NDR. The presence of CKD was significantly associated with increased odds of NDR (Odds ratio [OR] 1.46; 95% Confidence Interval [CI] 1.02, 2.09), hemorrhages and/or microaneurysms (OR 1.53; 95%CI 1.06, 2.19) and hard exudates (OR 5.98; 95%CI 1.22, 29.42) in multivariate models. In analysis stratified by ethnicity, the association between CKD and NDR was consistently present in all three ethnic groups. In separate multivariate models, lower eGFR (<45) compared to having no CKD (eGFR>60) was associated with increased odds of NDR (OR 2.19; 95% CI 1.27, 3.75), hemorrhages and/or microaneurysms (OR 2.51; 95%CI 1.47, 4.27) and hard exudates (OR 19.49; 95%CI 3.37, 112.92). Likewise, the odds of having NDR were 1.25 (95%CI 1.10, 1.43) per standard deviation decrease in eGFR.
Conclusions:
CKD is a significant risk factor for retinopathy in persons without diabetes. This suggests common pathophysiological mechanisms involving the microvasculature in the kidney and eye in the general population.
Keywords: 688 retina •
464 clinical (human) or epidemiologic studies: risk factor assessment