TYPE 4 MACULAR NEOVASCULARIZATION

PURPOSE: To describe the clinical and multimodal imaging features of a novel form of macular neovascularization (MNV), designated Type 4 MNV, defined by mixed Type 1 and Type 2 neovascularization (NV), extensive intraretinal anastomotic NV, and central posterior hyaloid fibrosis. METHODS: This multicenter retrospective observational case series included patients with neovascular age-related macular degeneration exhibiting both Type 1 and 2 MNV and an overlying anastomotic intraretinal NV network. This was confirmed with optical coherence tomography (OCT) and OCT angiography (OCTA). Demographics, baseline visual acuity (VA), and OCT imaging biomarkers including the hyperreflective oblique band sign, central posterior hyaloid fibrosis, epiretinal membrane, and OCTA NV subtype were assessed. RESULTS: Eleven eyes from 11 patients (mean age: 76.9 years; 36.4% female) met inclusion criteria. Baseline VA was logMAR 1.56 ± 0.45 (≈20/630) and 90.9% of subjects presented with severe visual loss. All eyes showed the hyperreflective oblique band sign. Central posterior hyaloid fibrosis was observed in 81.8% (9/11 subjects). Epiretinal membrane with radial traction was present in 81.8%. OCT angiography illustrated mixed Type 1 and 2 MNV with a prominent overlying intraretinal anastomotic network extending into the preretinal space. CONCLUSION: Type 4 MNV represents a distinct age-related macular degeneration phenotype with aggressive anatomical features including mixed Type 1 and 2 MNV, inner retinal and preretinal proliferation and anastomosis and retinal disorganization. The visual prognosis is invariably poor with recalcitrance to anti-vascular endothelial growth factor therapy. The recognition of this signature NV lesion subtype further refines the MNV classification system and can affect therapeutic strategies for neovascular age-related macular degeneration.