Genetics, Risk Factors and Pathogenesis In The Spectrum of Pachychoroid Diseases

The spectrum of pachychoroid disease was first described by Warrow et al. in 2013. The characteristics of pachyoroid phenotype are dilatation of the vessels in the Haller layer (pachyvessels), thinning of the layers of Sattler and choriocapillaris. Dilated choroidal vessels, choroidal hyperpermeability, diffuse or focal choroidal thickness and associated with progressive retinal pigment epithelium (RPE) dysfunction are thought to be in the pathogenesis. Angiographic findings such as choroidal vascular hyperpermeability, especially in the region of RPE changes, and delay in choroidal filling suggest that the primary pathology is associated with choroidal vascular disturbance. However, the exact pathophysiological mechanisms of the disease are not fully known. Pachychoroid-related diseases include pachychoroid pigment epitheliopathy, central serous chorioretinopathy, pachychoroid neovasculopathy, polypoidal choroidal vasculopathy, focal choroidal excavation and peripapillary pachychoroid syndrome. These diseases are thought to be reveal different manifestations of common pathological mechanisms. This review highlights the current understanding of genetics, risk factors and pathogenesis in the spectrum of pachychoroid disease based on the current literature.