Fluorescein Angiography Leakage Patterns in Pachychoroid Neovasculopathy: Neovascularization or Central Serous Chorioretinopathy?

INTRODUCTION: The aim of this work is to characterize fluorescein angiography (FA) leakage patterns in eyes with pachychoroid neovasculopathy (PNV) and subretinal fluid (SRF), and to evaluate their associations with clinical features and treatment response. METHODS: Retrospective observational study of consecutive patients with PNV presenting with SRF on optical coherence tomography and a clearly visible macular neovascular network on optical coherence tomography angiography at a single center. FA findings, multimodal imaging features, and clinical characteristics were analyzed. FA leakage was classified as neovascular (NV)-pattern leakage, characterized by diffuse leakage; central serous chorioretinopathy (CSC)-pattern leakage, characterized by pinpoint leakage; or an undetermined pattern. Main outcome measures were the distribution of FA leakage patterns and their associations with clinical features and treatment response. RESULTS: Seventy-one eyes from 68 patients were included. Baseline FA revealed NV pattern, CSC pattern, and mixed-pattern leakage in 43 (60.56%), 19 (26.76%), and three eyes (4.23%), respectively, while six eyes (8.45%) were indeterminate. Younger age, greater SRF height, and neurosensory retinal sagging were significantly associated with the CSC- pattern group. Among eyes that received anti-vascular endothelial growth factor (VEGF) therapy, complete SRF resolution after three loading injections occurred in 65.85% of the NV pattern group and 27.27% of the CSC pattern group (odds ratio, 5.14; 95% confidence interval, 1.18-22.49; P = 0.037). Of the seven eyes in the CSC pattern group that were observed without anti-VEGF therapy, five (71.43%) showed spontaneous resolution. Ninety-five percent of CSC leakage points (20/21) were located along the NV margin. Leakage pattern changes were observed in 19% of repeated FA examinations during follow-up. CONCLUSIONS: In the pachychoroid context, the presence of neovascularization does not necessarily indicate that accumulated fluid originates from the neovascular complex. Combined CSC and nonexudative PNV appears relatively common, with CSC leakage points typically located along the NV margin. Given its frequency, the risk of neovascular activation, and the recurrent nature of CSC, FA remains valuable for identifying the origin of SRF when indicated.