Short-term changes in renal function after repeated intravitreal bevacizumab in patients with diabetic macular edema: a preliminary study

Purpose: The aim of this study was to evaluate short-term changes in renal function after repeated intravitreal bevacizumab injections in treatment-naive patients with diabetic macular edema (DME) in a preliminary retrospective cohort.Materials and Methods: This preliminary retrospective observational study included 100 patients with DME who received at least three monthly intravitreal bevacizumab injections (1.25 mg/0.05 mL) between 2023 and 2026. Serum urea and creatinine concentrations and estimated glomerular filtration rate (eGFR), calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation recorded by the institutional laboratory, were obtained before the first injection and within one month after the final injection. Results: The mean age was 68.07 ± 9.43 years, 52 patients (52.0%) were female, and the mean number of injections was 4.03 ± 2.72. Mean eGFR decreased from 76.76 ± 21.67 to 71.88 ± 22.71 mL/min/1.73 m². Serum urea increased from 40.86 ± 16.23 to 45.79 ± 18.58 mg/dL, and serum creatinine increased from 0.96 ± 0.35 to 1.02 ± 0.39 mg/dL. Injection number was not significantly correlated with either baseline or follow-up eGFR.Conclusions: In this preliminary study, repeated intravitreal bevacizumab treatment was temporally associated with modest short-term changes in renal function parameters.