Long-term choroidal thickness changes based on the subtype of macular neovascularization in neovascular age-related macular degeneration (5-year follow-up)

Abstract

Purpose To evaluate the long-term choroidal thickness changes in combination with other morphological and functional outcomes during anti-vascular endothelial growth factor (VEGF) treatment for neovascular age-related macular degeneration (nAMD) based on the subtype of macular neovascularization (MNV): MNV-1 (within the subretinal pigment epithelium space) and MNV-2 (within the subretinal space). Methods This retrospective study included 58 eyes from 53 patients with naïve nAMD who received anti-VEGF therapy over a 60-month period. All eyes were treated initially with intravitreal bevacizumab following Pro re nata regimen. Main outcome measures included the following: subfoveal choroidal thickness (SFCT), best corrected visual acuity (BCVA), central macular thickness (CMT), development of subfoveal geographic atrophy (GA), and the number of injections. Results Thirty-four eyes had MNV-1 (group 1) and 24 eyes had MNV-2 (group 2). SFCT in group 1 vs group 2 was (210±45 µm vs 191±52 µm, p=0.01) before treatment and (170±47 µm vs 179±48 µm, p=0.24) after 60 months. BCVA (log MAR) in group 1 vs group 2 was (0.57±0.18 vs 0.53±0.22, p=0.47) before treatment and (0.59±0.23 vs 0.69±0.16, p=0.04) after 60 months. CMT in group 1 vs group 2 was (398±154 µm vs 382±103 µm, p=0.86) before treatment and (297±68 µm vs 283±67 µm, p=0.14) after 60 months. The number of injections per eye over a period of 60 months was signifcantly higher in group 1 (34.9±11 vs 29.0±14, p=0.04). The proportion of eyes with subfoveal GA after 60 months was signifcantly higher in group 2 (13 eyes, 54%) than in group 1 (9 eyes, 25%) (p=0.03). Conclusion Over the full 60 months of anti-VEGF treatment, eyes with MNV-1 showed a greater reduction in choroidal thickness, better visual acuity, and less development of subfoveal geographic atrophy compared with eyes with MNV-2. The signifcantly thicker choroid in eyes with MNV type 1 at baseline seems to have a positive impact on long-term outcomes.