Short-Term Effects of Intravitreal Ranibizumab Biosimilar Injections in Patients with Neovascular Age-Related Macular Degeneration on Retinal Nerve Fiber Layer Thickness

<b>Background/Objectives:</b> Intravitreal anti-vascular endothelial growth factor (anti-VEGF) therapy is the standard treatment for neovascular age-related macular degeneration (nAMD), but concerns remain regarding its potential effects on optic nerve structure. Evidence on the structural safety of ranibizumab biosimilars, including LucenBS^®, is still limited. This study aimed to investigate the short-term effects of intravitreal LucenBS^® injections on peripapillary retinal nerve fiber layer (RNFL) thickness in previously treated nAMD patients using optical coherence tomography (OCT). <b>Methods:</b> This retrospective, observational case series included 24 eyes from 24 nAMD patients who had previously received anti-VEGF agents other than ranibizumab biosimilar. In bilateral cases, the eye that developed nAMD earlier was selected. Patients received between one and three LucenBS^® injections, and the mean follow-up period after the final injection was 11.92 ± 4.81 weeks. Best-corrected visual acuity (BCVA), intraocular pressure (IOP), central macular thickness (CMT), and peripapillary RNFL thickness were assessed before and after each injection using spectral-domain OCT. Sectoral and global RNFL values were compared using the Wilcoxon signed-rank test. <b>Results:</b> The mean age of participants was 74.6 ± 9.0 years, and baseline BCVA and IOP were 0.83 ± 0.66 logMAR and 14.88 ± 2.80 mmHg, respectively. RNFL thickness showed no significant changes in either global or sectoral regions after any injection (all <i>p</i> > 0.05). CMT significantly decreased after the first injection (<i>p</i> = 0.007), but remained stable with subsequent treatments. BCVA remained stable after the first and second injections, but slightly worsened after the third injection (<i>p</i> = 0.012). IOP showed no significant changes at any time point. <b>Conclusions:</b> Short-term intravitreal LucenBS^® injections did not induce structural alterations in the peripapillary RNFL, supporting their short-term ocular safety in previously treated nAMD patients. Although CMT improved after the first injection, functional and anatomical responses varied with repeated dosing. Larger, long-term studies are required to further validate the structural and functional safety of ranibizumab biosimilars in nAMD management.