ANTI-VEGF THERAPY SWITCHING IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION

PURPOSE: To evaluate the efficacy of switching from bevacizumab to ranibizumab or aflibercept in neovascular age-related macular degeneration (nAMD) using automated volumetric retinal fluid analysis. METHODS: This retrospective study included 186 eyes with nAMD showing inadequate response after ≥3 bevacizumab injections. Patients were switched to a second-line anti-VEGF agent and categorized as early (3-5 injections) or late (≥6 injections) switchers. Optical coherence tomography (OCT) scans were analyzed using the Notal-OCT Analyzer (NOA), an AI-based algorithm for retinal fluid quantification. Parameters included total retinal fluid (TRF), intraretinal fluid (IRF) volume, subretinal fluid (SRF) volume, pigment epithelial detachment (PED) volume, central subfield thickness (CST), and visual acuity (VA), assessed at baseline, after bevacizumab, and after three injections of the new agent. RESULTS: Early switchers showed an increase in TRF from 105 nL to 158 nL after bevacizumab, then a reduction to 20 nL postswitch ( P < 0.001); PED volume decreased postswitch ( P = 0.010). Late switchers showed fluid reductions both after bevacizumab and postswitch (TRF: P < 0.001; PED: P = 0.007). CST significantly improved only in early switchers ( P = 0.004), while VA changes were not statistically significant. CONCLUSION: Automated fluid analysis reliably quantifies treatment response in nAMD. Early switchers showed worsening after bevacizumab, while late switchers had partial responses. These findings highlight the potential of automated analysis to support more individualized, data-driven treatment strategies. Prospective studies are required to confirm impact on patient outcomes.