Diabetic macular edema (DME) is one of the microvascular complications of diabetes and also coexists with diabetic retinopathy. The present study aims to investigate the effectiveness of single-dose biosimilar Razumab injection in diabetic macular edema. In this retrospective, non-randomized, clinical review on patients (n=50), 50 eyes with diabetic macular edema were selected and treated with a single dose of 2.3mg/0.23mL Razumab injection intravitreally. Visual acuity (VA) and macular thickness (MT), were evaluated for a period of up to 45 days after injecting biosimilar Razumab and were used to assess the effectiveness after treatment for 45 days. The results of the study showed that there was a significant increase in visual acuity and a marked reduction in macular thickness and the intraocular pressure (IOP) and anterior segment (AS) examination reverted to normal after the injection (Day 45). This study concludes that a single dose of biosimilar Razumab injection was effective in improving visual acuity and reducing macular thickness with no ocular concerns in diabetic macular edema patients. © 2023 Elsevier B.V., All rights reserved.