Effect of intravitreal bevacizumab on visual acuity, optical coherence tomography, and mfERG parameters in treatment-naïve center-involving diabetic macular edema: A 3-month prospective longitudinal study

Purpose: The study was conducted to evaluate the functional and anatomical outcomes of intravitreal injection of bevacizumab in patients with treatment-naïve center-involving diabetic macular edema (CI-DME), as measured by best-corrected visual acuity (BCVA), optical coherence tomography (OCT), and multifocal electroretinogram (mfERG). Materials and Methods: A prospective observational study comprising 52 CI-DME patients receiving intravitreal injection of bevacizumab (1.25 mg/0.05 mL) for 3 months. BCVA, central macular thickness (CMT), and mfERG amplitudes were measured at baseline, 1 month, and 3 months. Statistical analysis was done using SPSS v27 and Excel. Results: A significant improvement reported in BCVA which improved to 0.65 ± 0.10 ( P < 0.001) at 3 months and to 0.62 ± 0.10 at 1-month follow-up from the baseline value of 0.47 ± 0.11. CMT reduced to 330.1 ± 31.8 µm ( P < 0.001) at 3 months and 338.6 ± 34.1 µm at 1 month from the baseline value of 399.6 ± 83.5 µm. mfERG amplitude improved to 21.6 ± 1.3 nV/deg² ( P < 0.001) at 3 months and to 20.9 ± 1.2 nV/deg at 1 month from the baseline value of 20.0 ± 1.3 nV/deg. There was a strong correlation between mfERG improvement and CMT reduction ( r = −0.52, P < 0.001). Conclusion: Injections of intravitreal bevacizumab significantly improves BCVA, CMT, and mfERG within 3 months follow-up. mfERG complements OCT to evaluate the treatment response.