Proteinuria and Renal Dysfunction after Intravitreal Injection of Bevacizumab in Patients with Diabetic Nephropathy: A Prospective Observational Study

Proliferative diabetic retinopathy (PDR) is one of the most important microvascular complications among the patients with diabetes. Intravitreal anti-vascular endothelial growth factor (anti-VEGF) agent enacts a key role in PDR. Some studies have dealt with the systemic exposure to these agents after intravitreal administration. However, renal dysfunction following this therapy has scarcely been reported. Hence, this study aimed to determine the effect of intravitreal bevacizumab treatment on the deterioration of renal function and proteinuria. This present prospective observational study was performed on 40 patients with diabetic nephropathy and PDR and/or significant diabetic macular edema as the candidates for receiving intravitreal injection of bevacizumab. To evaluate renal function, changes in the urinary albumin-to-creatinine ratio (UACR), serum creatinine (SCr), and estimated glomerular filtration rate (eGFR) one month after injection were measured. Also, changes in systolic and diastolic blood pressures (BPs), plasma VEGF level, platelet, white blood cell (WBC) counts, and hemoglobin (Hb) level were measured at the baseline and one month after treatment. The mean age of the patients was 60.3 ± 9.2 years, and 33 patients were female. The decrease in the plasma VEGF level and platelet count, as well as the increase in diastolic BP, and Hb level were significant. However, systolic BP and WBC count remained unchanged. There were no significant changes in UACR, SCr, and eGFR after the injection as compared to baseline (P>0.05). Our study indicated that intravitreal bevacizumab injection was not associated with renal dysfunction and proteinuria in patients with diabetic nephropathy. Nevertheless, diastolic BP and Hb level could increase after one month.