Comparative Study to Evaluate Efficacy and Safety of Intravitreal Injections of Bevacizumab and Ranibizumab in Patients of Diabetic Macular Edema in a Tertiary Care Hospital

Abstract

Introduction: Diabetes mellitus is a chronic metabolic disorder driven by hyperglycemia and insulin resistance which can lead to microvascular complications like diabetic macular edema (DME) - a primary cause of blindness in the working-age population. The pathophysiology of DME involves blood-retinal barrier breakdown and elevated vascular endothelial growth factor levels. While anti-VEGF therapies have transformed management, comparing agents like Bevacizumab and Ranibizumab remains clinically relevant.

Objectives: To evaluate and compare the safety and efficacy of intravitreal Bevacizumab versus Ranibizumab in patients with DME over a 16-week period. To measure the proportion of patients achieving >15 ETDRS letter improvements and assessing mean changes in central subfield thickness.

Material and Methods: A prospective, open-labelled, comparative study was conducted over 16 weeks on 130 newly diagnosed DME patients divided equally into Group A (n=65) received monthly intravitreal Bevacizumab (1.25 mg/0.05 mL) and Group B (n=65) received monthly intravitreal Ranibizumab (0.5 mg/0.05 mL). Baseline evaluations included BCVA via ETDRS charts, OCT imaging for CST and comprehensive systemic laboratory profiles. Data were analysed using SPSS 22.0 with Student's t-tests and Chi-square tests (p < 0.05).

Results: At 16 weeks both groups showed significant improvements in BCVA (p < 0.001), though Ranibizumab demonstrated better visual gains (67.5+11.0 vs. 61.2+10.4 letters; p=0.003) and a higher proportion of patients achieving >15 letter gains (47.7% vs. 27.7%; p=0.019). Mean CST decreased significantly in both groups (p < 0.001), with Ranibizumab showing a greater reduction (-152.8+48.6 μm vs. -117.8+45.3 μm; p < 0.01). Ocular adverse events were mild and transient. No severe complications or systemic/thromboembolic events reported and metabolic parameters remained stable (p > 0.05).

Conclusion: Both intravitreal Bevacizumab and Ranibizumab are safe and effective for managing DME, with Ranibizumab demonstrating better short-term visual and anatomical efficacy while Bevacizumab remains a reliable, economical alternative.