Abstract: A structurally and functionally intact choroid tissue is vitally important for the retina function. Polypoidal choroidal vasculopathy (PCV) is a fundus disease characterized by choroidal anomalous branch vascular network (BVN) and polypoid expansion at the end of the vascular network. PCV is a pachychoroid disease. Conversions can occur between spectrum diseases, and there are characteristic choroidal changes between them: focal or diffuse choroidal thickening, increased proportion of choroidal macrovascular layer thickness, choroidal vascular hyperpermeability, secondary retinal pigment epithelial dysfunction or neovascular formation. Current studies have shown that PCV with different choroidal changes has differences in treatment response and prognosis. Re-understanding PCV from the perspective of choroid is helpful to judge prognosis and guide treatment. (Int Rev Ophthalmol, 2021, 45: 98-102)

Key words: polypoid choroidal vasculopathy, pachychoroid disease, choroidal thickness