A Hypothesis: Can Erythropoietin Administration Affect the Severity of Retinopathy in Diabetic Patients With Renal Failure?

Before the clinical availability of erythropoietin, diabetic retinopathy was known to stabilize on dialysis. Recently erythropoietin has been shown to be a potent angiogenic factor. Therefore, we chose to examine whether severity and progression of diabetic retinopathy has been accelerated by the administration of recombinant erythropoietin to patients with chronic renal failure. Records of the patients followed by the Hypertension Nephrology, Dialysis, and Transplantation Clinic, the regional nephrology referral center for Eastern Alabama, from 1982 through 2005 were reviewed. Funduscopic examination at the time of ESRD was ranked according to the proposed international scale for severity of clinical diabetic retinopathy. Forty-five patients from the era before the availability of erythropoietin were matched to 45 patients from 2002 to 2004 who had been given erythropoietin but had similar prevalence of proliferative retinopathy, neuropathy, and years of diabetes before the onset of end-stage renal disease. Progression of retinopathy was compared according to multivariate analysis with 2-tailed Pearson correlation coefficient. There was significantly greater deterioration of retinopathy at 1 year in the patients who had received erythropoietin (P=0.004). Although the presence of retinopathy at ESRD correlated with known traditional risk factors such as years of diabetes, age, and serum cholesterol, the deterioration of retinopathy after the initiation of hemodialysis correlated only with hematocrit (P=0.042) and most significantly total dose of erythropoietin (P=0.001). The prevalence and severity of proliferative retinopathy appear to have increased and are most closely associated with the erythropoietin dosing.