Purpose: To identify the tomographic features of the branching vascular networks in patients with polypoidal choroidal vasculopathy (PCV).
Methods: We prospectively performed third-generation optical coherence tomography (OCT) and fluorescein angiography for 44 eyes of 42 patients (mean age +/- SD, 67.1 +/- 9.1 years) with PCV. All eyes had branching vascular networks and polypoidal lesions that were confirmed by indocyanine green angiography.
Results: OCT showed double reflective layers that consisted of retinal pigment epithelium (RPE) and another highly reflective layer beneath the RPE ("double-layer sign") in the area of the branching network vessels in 26 (59%) of 44 eyes. The remaining 18 eyes had no double-layer sign, but 17 (94%) of 18 eyes had a slightly elevated RPE. A serous retinal detachment was present in 23 (88%) of 26 eyes with a double-layer sign, while only 1 (6%) of 18 eyes without the sign had a serous retinal detachment.
Conclusions: In PCV, the double-layer sign is seen frequently in the area of the network vessels, particularly in eyes with a serous retinal detachment. The sign may reflect fluid accumulation between RPE and Bruch membrane resulting from leakage from the network of abnormal vessels.