Pachychoroid Disease

Pachychoroid spectrum disorders include uncomplicated pachychoroid, pachychoroid pigment epitheliopathy, central serous chorioretinopathy, pachychoroid neovasculopathy, polypoidal choroidal vasculopathy/aneurysmal type 1 neovascularisation, focal choroidal excavation and peripapillary pachychoroid syndrome. They are characterized by a thickened and hyperpermeable choroid and thinning of the choriocapillaris. The disorders are being diagnosed with increasing frequency and differentiation due to the advancement of multimodality imaging. Current understanding of the development, course, possible complications and treatment of these diseases is growing rapidly, but not all mechanisms have yet been elucidated. A correct diagnosis is important, especially the differentiation between the presence of active neovascularisation or a purely exudative stage, in order to initiate a therapy. It is also not yet clear why patients have a thickened choroid and why some of these patients develop pathological changes such as subretinal fluid, RPE changes or neovascularisation.