Tomographic features of branching vascular networks in polypoidal choroidal vasculopathy

To identify the tomographic features of the branching vascular networks in patients with polypoidal choroidal vasculopathy (PCV).

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.

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.

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.