Current View of the Spectrum of Pachychoroid Diseases. A Review

Introduction: The term "pachychoroid" (greek pachy- [παχύ] - thick) was first used by Warrow et al. in 2013. It is defined as an abnormal and permanent increase in choroidal thickness ≥ 300 μm, which is caused by dilatation of the choroidal vessels of the Haller's layer, thinning of the Sattler's layer and the choriocapillaris layer. Methodology: Literary research focused on the current view of pachychoroid spectrum diseases, including clarification of the pathophysiological theories of the formation of "pachychoroid". Results: It is assumed that “pachychoroid” disease has an autosomal dominant type of heredity. Depending on the further activity of various exogenous and/or endogenous factors, pachychoroid diseases may appear. According to the current knowledge, the spectrum of pachychoroid disease covers six clinical entities: pachychoroid pigment epitheliopathy, central serous chorioretinopathy, pachychoroid neovasculopathy, polypoid choroidal vasculopathy, focal choroidal excavation and peripapillary pachychoroid syndrome. In this study, we describe the clinical symptoms and objective findings of focal choroidal excavation and peripapillary pachychoroid syndrome. The current pathophysiological theory of pachychoroid diseases is based on impaired venous outflow from the choroid ("venous overload choroidopathy") and thickening of the sclera in the eyes of affected patients. Conclusion: Pachychoroid diseases should be included in the differential diagnosis of characteristic features observed during multimodal imaging analysis of choroidal changes.