By Marquis Vaughn
Scheie Vision Summer 2016
Dr. Juan Grunwald’s research for Penn under the Chronic Renal Insufficiency Cohort (CRIC) has contributed to the understanding of how abnormalities in the retina, which can be examined non-invasively, can reflect broader pathology throughout the body. CRIC is a longitudinal, multicenter study of adults suffering from chronic kidney disease (CKD). CRIC researchers explore risk factors for CKD and other chronic conditions, such as cardiovascular disease, and seek to develop therapies to manage these diseases.
CKD is characterized by the substantial loss of kidney function. The kidneys are responsible for filtering waste and other excess fluids from the blood, which are then flushed out through the urine. As CKD advances, it can prevent the kidneys from excreting these wastes, causing them to build up in the bloodstream. CKD can lead to kidney failure, which ultimately requires dialysis or even a kidney transplant to preserve life. According to the National Kidney Foundation, 26 million people in the United States are diagnosed with some form of CKD, and millions more are at risk of obtaining this disease.
Interestingly, a high percentage of patients enrolled in CRIC (who have been diagnosed with CKD and/or other chronic illnesses) also have eye pathologies. Dr. Grunwald, the Director of the Vivian S. Lasko Retinal Vascular Research Center, developed the Retinopathy in Chronic Renal Insufficiency Cohort (RCRIC) under the umbrella of CRIC, to further study this observation. RCRIC, which was carried out at the Scheie Image Reading Center, investigated the relationship between retinopathy (damage to the retinal vasculature) and kidney and other systemic diseases.
After photographing and examining the retinas of patients enrolled in the CRIC study, Dr. Grunwald and colleagues found a significant association between severe retinopathy and low glomerular filtration rate (a test of kidney function). This correlation was stronger among diabetic patients: 49% of diabetic participants had retinopathy, while only 11% of non-diabetic participants had retinopathy. The results also revealed that retinopathy was closely associated with cardiovascular disease and that patients with retinopathy have a greater chance of developing CKD and other chronic illnesses.
RCRIC’s results point toward a common mechanism underlying the retinal and renal vascular changes. The presence of retinopathy was associated with a higher risk of developing end stage renal disease and cardiovascular disease in the future. Participants that had proliferative retinopathy, the more advanced stage of retinopathy, had a nine times higher risk of developing strokes than those that did not have retinopathy.
RCRIC is one of the first studies to show that the presence of retinopathy in patients with kidney disease provides information of prognostic value regarding the future development of kidney and cardiovascular disease. Furthermore, severity of retinopathy can serve as an indicator of severity of CKD, highlighting the need for eye evaluations in patients with CKD.