Fig. 12.

Diagrams of choroidal vasculature in a normal eye and eyes with pachychoroid spectrum diseases. Normal: superior and inferior vortex veins are symmetric at horizontal watershed zone. Vortex veins taper toward the posterior pole. CSC: asymmetric dilatation of superior and inferior vortex veins with loss of watershed. Venous anastomosis is seen at watershed in most cases (green). PNV: choroidal neovascularization arises at the site of anastomosis (red). Overlying choriocapillaris shows filling delay. PCV: The tip of choroidal neovascularization shows aneurysmal dilatation. CSC = central serous chorioretinopathy, PNV = pachychoroid neovasculopathy, PCV = polypoidal choroidal vasculopathy