Real-World outcomes of intravitreal treatment switching in retinal diseases: Analysis of 3,038 treated cases

Purpose To evaluate the frequency and patterns of intravitreal therapy (IVT) switching in retinal diseases and describe associated visual acuity outcomes in real-world clinical practice. Materials and Methods This retrospective, monocentric study evaluated consecutive IVT-treated cases at a tertiary retina unit. Demographic data, diagnoses, initial agent, injection number, and treatment switches were recorded. Best-corrected visual acuity (BCVA, LogMAR) was assessed at baseline and final follow-up. Switching was defined as a change to another anti-VEGF agent or intravitreal dexamethasone (DEX) implant for inadequate functional and/or anatomical response. BCVA changes were compared using appropriate tests, stratified by indication (diabetic macular edema [DME], neovascular age-related macular degeneration [nAMD], retinal vein occlusion [RVO]). Results A total of 3,038 IVT-treated cases (11,345 injections) were analyzed. The main indications were DME (55.5%), nAMD (36.4%), and RVO (6.0%). Overall, 22.9% of treated cases underwent treatment switching, most frequently in DME (24.8%) and nAMD (20.8%). Within-group analyses showed significant BCVA improvement after switching in DME (p = 0.001), RVO (p = 0.032), and nAMD (p = 0.009), while non-switched groups showed no significant change. Aflibercept was the most commonly selected second-line agent (81.7%), and the aflibercept subgroup showed significant within-group BCVA improvement ( p < 0.001). Because treatment choice was not randomized, this finding should not be interpreted as evidence of superiority over other second-line agents. Conclusions In this retrospective real-world cohort, treatment switching was common in routine retinal practice, and switched cases showed within-group BCVA improvement in some diagnostic subgroups. These findings should be interpreted as descriptive associations rather than evidence of a causal treatment effect.