Comparative Effectiveness of Intravitreal Bevacizumab and Grid Laser Photocoagulation in Diabetic Macular Edema

Abstract

Objective: To compare visual and anatomical outcomes six months after intravitreal bevacizumab or grid laser photocoagulation in adults with center-involving diabetic macular edema and a central subfield thickness below 400 µm. Methods: This prospective, non-randomized cohort study was carried out between September 2024 and March 2025. Adults with treatment-naive, center-involving edema and a central subfield thickness of 350 to <400 µm received either bevacizumab or conventional grid laser, as decided by the treating clinician and the patient. The primary outcome was the change in best-corrected visual acuity at six months, measured in Early Treatment Diabetic Retinopathy Study letters. Secondary outcomes were the change in retinal thickness, response rates, number of procedures, and adverse events. Results: Of 128 patients enrolled (64 per group), 120 (60 per group) completed six months of follow-up and were analyzed. Mean visual gain was 10.0±8.0 letters with bevacizumab and 3.0±7.0 letters with laser, a difference of 7.0 letters (95% confidence interval 4.3–9.7; p<0.001). Central subfield thickness fell by 88±45 µm and 39±43 µm, respectively (p<0.001). A gain of at least 10 letters was seen in 56.7% and 20.0% of patients (p<0.001). Bevacizumab involved more procedures (4.3±1.2 versus 1.4±0.5). No endophthalmitis or retinal detachment occurred. Conclusion: Bevacizumab was associated with greater visual improvement and retinal thinning than grid laser over six months. Laser involved fewer procedures but provided smaller average gains. Treatment selection, follow-up capacity, and baseline retinal characteristics remained relevant when interpreting these findings and planning locally accessible diabetic eye care.