IMPORTANCE Polypoidal choroidal vasculopathy (PCV) is a major cause of visual loss worldwide, particularly in Asia, and the appropriate understanding of the structures in PCV previously described as polypoidal lesions is important for understanding their pathogenesis, diagnosis, and prognosis. OBJECTIVE To report the morphologic characteristics of polypoidal lesions and their association with branching vascular networks (BVNs) in eyes with PCV using swept-source optical coherence tomographic angiography (SS-OCTA). DESIGN, SETTING, AND PARTICIPANTS This cross-sectional observational study included 20 participants recruited from Shanghai General Hospital with a diagnosis of PCV based on the presence of focal hyperfluorescent spots on indocyanine green angiography (ICGA). Data were collected from

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Subretinal fibrosis results in local destruction of retinal structures and permanent vision loss, representing the end stage of neovascular age-related macular degeneration (AMD). Histological examination of fibrotic specimens from AMD patients has uncovered a wide range of cellular and acellular components. However, their origins and roles in fibrosis remain largely unexplored. Using a laser-induced photocoagulation model with collagen 1α1-GFP reporter mice, we demonstrate, by cell-lineage tracing, that pericytes associating with choroidal microvasculature are activated upon injury and infiltrate into the subretinal space as significant components of fibrotic lesions. In contrast to their choroidal precursors, infiltrating pericytes acquire stellate-like structures, upregulate expression of fibrogenic molecules and colocalize with extracellular fibrotic scar. Collectively, our results identify the choroidal perivascular niche as a novel source of subretinal fibrosis after photocoagulation, and suggest that collagen 1-expressing pericytes are potential targets for therapeutic intervention to suppress subretinal fibrosis and preserve vision.