The implications of subretinal fluid in pachychoroid neovasculopathy

This study aimed to identify the clinical characteristics and longitudinal changes in exudative pachychoroid neovasculopathy (PNV) and non-exudative PNV. This retrospective cohort study involved 81 eyes of PNV diagnosed by multimodal imaging including optical coherence tomography angiography. At baseline, they were divided into exudative PNV group and non-exudative PNV group depending on the presence of subretinal fluid. The clinical features of both groups and the longitudinal changes were investigated and compared. There were 55 eyes with non-exudative PNV and 26 eyes with exudative PNV. Individuals with non-exudative PNV were older, more frequently asymptomatic and had a higher prevalence of polypoidal choroidal vasculopathy in the opposite eye (all P’s < 0.05). Whereas individuals with exudative PNV showed thicker choroid and more frequent history of central serous chorioretinopathy (all P’s < 0.001). During about 12 months of longitudinal observation, the transformation into polypoidal choroidal vasculopathy was noted in 4 eyes of non-exudative PNV group, whereas in none of the exudative PNV group. Exudative PNV and non-exudative PNV seem to be separate entities with different epidemiological parameters. Non-exudative PNV, which is frequently found without symptoms at an older age, is suspected to be the significant precursor lesion of polypoidal choroidal vasculopathy. In contrast, exudative PNV may share the same pathophysiology as central serous chorioretinopathy.