Prevalence of Fundus Pathology in the Chronic Renal Insufficiency Cohort (CRIC) Study

Abstract

Purpose: : To describe the prevalence of fundus pathology in the CRIC study, a multi-center longitudinal study of individuals with chronic kidney disease (CKD) followed for CKD progression and cardiovascular (CVD) events.

Methods: : During a CRIC annual examination, 45º digital photos of the disc and macula were obtained by non-ophthalmologic personnel using a non-mydriatic Cannon CR-Dgi fundus camera. Photographs were obtained in 1613 patients participating in 6 CRIC centers and were assessed in a masked fashion by a retinal specialist. The purpose of this review was to quickly inform patients of the need for a complete eye examination by an ophthalmologist. Mean age was: 58±11 years (± 1SD), range 21-75 years; mean systolic blood pressure: 127±21 mmHg, range 73-243 mmHg; mean diastolic pressure: 72±13 mmHg, range 35-139 mmHg; estimated mean glomerular filtration rate: 44.9±13.7 mL/min/1.73m² ; range 13.5-93.6 mL/min/1.73m². Racial distribution was: 50% Caucasian, 44.8% African American and 5.2% other. 54.3% of the participants were male. Systemic hypertension was present in 83.7%, and diabetes mellitus was present in 44.2% of the subjects.

Results: : Among the 1613 patients reviewed, 721 (45%) patients required a follow up examination by an ophthalmologist because of mild to severe pathologic fundus findings. Retinopathy (diabetic and/or hypertensive) was observed in 373 (23%) patients. Optic disc cup-to-disc ratio larger than 0.7 was observed in 144 (9%) patients. Age related macular degeneration and drusen were detected in 127 (8%) patients. Miscellaneous abnormal findings such as pigmentary changes and vitreous opacities were seen in 94 (6%) patients. Nevi were observed in 19 (1%) patients. Embolic plaques were seen in 7 patients. In 7% (50 patients) of the 721 patients with fundus abnormalities we found serious eye conditions, such as diabetic retinopathy (40 patients) and others (10 patients), that required urgent follow up.

Conclusions: : Our results show a high prevalence of fundus pathology suggesting that these patients should receive a complete eye examination. Quantitative assessment of retinopathy and retinal vascular calibers in this study will further elucidate the relationship between retinal vascular changes and CKD and CVD.

Keywords: imaging/image analysis: clinical • diabetic retinopathy • clinical (human) or epidemiologic studies: prevalence/incidence