Analysis Focusing on Plasma Von Willebrand Factor in Pachychoroid Neovasculopathy and Age-related Macular Degeneration

Pachychoroid neovasculopathy (PNV) is a new disease concept. Some cases diagnosed as age-related macular degeneration (AMD) have been re-diagnosed as PNV. However, the biological features of PNV are still uncertain. The purpose of this study was to compare PNV and AMD by an analysis focusing on von Willebrand factor (VWF) and complement factor H (CFH). Ninety-seven patients who were previously diagnosed with treatment naïve AMD were enrolled in this study. They were re-classified PNV and AMD based on the clinical criteria and 33 patients were classified as PNV and 64 patients as AMD. We examined the clinical data and performed VWF multimer analysis and genetic polymorphisms in the CFH. PNV group was significantly younger than AMD group. The presence of unusually large VWF multimers (UL-VWFMs) and subretinal hemorrhage was significantly higher in PNV than in AMD. In the CFH I62V, allele A tended to be more frequent in PNV group and recessive homozygous (AA) was found only in PNV group. Thus, the genetic alternations in CFH may result in the residual UL-VWFMs and platelet thrombosis in the choriocapillaris of PNV. In conclusion, our results suggest the biological differences between PNV and AMD.