Vortex Vein Anastomosis at the Watershed in Pachychoroid Spectrum Diseases

Abstract

Purpose: To evaluate the vascular changes in vortex veins at the posterior pole in pachychoroid spectrum diseases, including central serous chorioretinopathy (CSC), pachychoroid neovasculopathy without polypoidal lesions (PNV), and pachychoroid neovasculopathy with polypoidal lesions (polypoidal choroidal vasculopathy [PCV]).

Design: Retrospective case-control study.

Participants: Ninety-two eyes of 89 patients with CSC, 61 eyes of 59 patients with PNV, 63 eyes of 61 patients with PCV, and 25 healthy control eyes of 25 age- and gender-matched participants for each pachychoroid spectrum disease.

Methods: Clinical records of patients with pachychoroid spectrum diseases and healthy controls were reviewed. Multimodal images of each group were analyzed. Swept-source OCT was performed to obtain B-mode and en face images in patients with pachychoroid spectrum diseases and healthy controls. All patients underwent fluorescein angiography, indocyanine green angiography, and OCT.

Main outcome measures: Vortex vein anastomosis at the watershed, determined using en face OCT, and central choroidal thickness (CCT), measured using B-mode OCT, were examined in patients and healthy controls. Patient ages also were taken into consideration.

Results: Patients with CSC were the youngest, followed by patients with PNV, and then those with PCV (P < 0.01, CSC vs. PNV and PNV vs. PCV), whereas CSC eyes showed the highest CCT values, followed by the PNV and then the PCV eyes (P < 0.01, CSC vs. PNV; P < 0.05, PNV vs. PCV). Central choroidal thickness was significantly greater in pachychoroid spectrum diseases than in healthy controls. No significant CCT differences were found among healthy controls. Anastomosis between superior and inferior vortex veins was observed in more than 90% of eyes with pachychoroid spectrum diseases, making this finding significantly more frequent than in healthy controls (P < 0.01, each pachychoroid spectrum disease vs. control). Polypoidal choroidal vasculopathy showed a significantly higher rate of anastomosis than CSC (P < 0.05).

Conclusions: Anastomosis between superior and inferior vortex veins was found to be a common feature in pachychoroid spectrum diseases. Longstanding vortex vein congestion may lead to the development of pachychoroid spectrum diseases. Choroidal congestion may be compensated for by new drainage routes formed via vortex vein anastomosis.