Switching Between Anti-Vegf Agents in Diabetic Macular Edema: A Narrative Review of Evidence and Clinical Practice

Background: Diabetic macular edema (DME) is a leading cause of vision impairment among patients with diabetic retinopathy. Intravitreal anti–vascular endothelial growth factor (anti-VEGF) therapy has become the first-line treatment; however, a significant proportion of patients demonstrate suboptimal response or require frequent injections, highlighting the need for alternative therapeutic strategies. Objective: To review the rationale, clinical evidence, and outcomes associated with switching between anti-VEGF agents in the management of DME, with a focus on real-world data and emerging therapies. Methods: A narrative review of the literature was conducted, including randomized controlled trials, observational studies, and meta-analyses evaluating anti-VEGF therapy and switching strategies in DME. Particular attention was given to studies assessing treatment response, predictors of outcomes, and newer agents such as faricimab. Results: Evidence suggests that a substantial proportion of patients exhibit incomplete anatomical or functional response to initial anti-VEGF therapy. Switching between agents, particularly from ranibizumab or bevacizumab to aflibercept, has been associated with improvements in retinal thickness and stabilization or modest gains in visual acuity. The introduction of faricimab, a dual inhibitor of VEGF-A and angiopoietin-2, has demonstrated comparable efficacy to aflibercept with extended dosing intervals in phase 3 trials and promising real-world outcomes. Meta-analyses confirm overall effectiveness of anti-VEGF therapy while highlighting variability in individual response. Conclusion: Switching between anti-VEGF agents represents a practical and evidence-based strategy in patients with DME who demonstrate suboptimal response to initial therapy. Emerging treatments such as faricimab further expand therapeutic options and may reduce treatment burden. Individualized treatment approaches and timely therapy modification are essential for optimizing long-term outcomes.