Long-term outcome of neovascular age-related macular degeneration: association between treatment outcome and major risk alleles

Aims To evaluate the long-term functional and anatomical outcomes of neovascular age-related macular degeneration (nvAMD) treated with intravitreal anti-vascular endothelial growth factor (anti-VEGF) for up to 10 years, and to identify associated risk factors. Methods Clinical and optical coherence tomography findings were retrieved for nvAMD cases treated with intravitreal anti-VEGF compounds using a treat-and-extend protocol. In addition, the major risk alleles for AMD in the CFH (rs1061170), HTRA1 (rs1200638) and C3 (rs2230199) genes were genotyped. Results From 276 eligible eyes in 206 patients, 80 eyes (29%) in 66 patients (32.0%) had a follow-up period of ≥8 years and were included in this study. Over a 10-year period, 73.3±28.0 (mean±SD) anti-VEGF injections were administered. Best-corrected visual acuity (BCVA; LogMAR) deteriorated from 0.55±0.53 at baseline to 1.00±0.73 at 10 years (p<0.0005). Central subfield thickness (CST) decreased from 415.8±162.1 μm at baseline to 323±113.6 μm (p<0.0005) after three monthly injections and remained lower than baseline throughout the follow-up period. Visual outcome was associated with BCVA and intraretinal fluid (IRF) at baseline, macular atrophy, and macular thinning at follow-up. The decrease in CST was inversely correlated with the number of CFH and/or C3 risk alleles carried by the patient (Pearson's r: -0.608; p=0.003). Conclusions Patients with nvAMD who received anti-VEGF therapy for 10 years developed substantial vision loss associated with the presence of IRF at baseline and macular atrophy. Major risk alleles for AMD in two complement genes were associated with a reduced long-term reduction in macular thickness.