Appearance of Polypoidal Lesions in Patients With Polypoidal Choroidal Vasculopathy Using Swept-Source Optical Coherence Tomographic Angiography

Abstract

Polypoidal choroidal vasculopathy (PCV) is a major cause of visual loss worldwide, particularly in Asia, and the appropriate understanding of the structures in PCV previously described as polypoidal lesions is important for understanding their pathogenesis, diagnosis, and prognosis. To report the morphologic characteristics of polypoidal lesions and their association with branching vascular networks (BVNs) in eyes with PCV using swept-source optical coherence tomographic angiography (SS-OCTA). This cross-sectional observational study included 20 participants recruited from Shanghai General Hospital with a diagnosis of PCV based on the presence of focal hyperfluorescent spots on indocyanine green angiography (ICGA). Data were collected from December 1, 2017, to September 1, 2018, and analyzed from June 1 through September 30, 2018. Polypoidal lesions in eyes with PCV were characterized using multimodal imaging that included fundus photography, fluorescein angiography, ICGA, SS-OCT, and SS-OCTA, and the images were anatomically aligned. Subfoveal choroidal thickness was manually measured as the distance between the Bruch membrane and the sclerochoroidal interface on the SS-OCT images. Of the 20 Asian patients, 5 (25%) were women and 15 (75%) were men. The mean (SD) age was 61.1 (7.6) years, and the mean (SD) logMAR visual acuity was 0.358 (0.294) (Snellen equivalent, 20/50 [20/40]). Twenty-three eyes underwent imaging and were diagnosed with PCV. Indocyanine green angiography identified 43 polypoidal lesions, and all corresponded to the structures that appeared as clusters of tangled vessels on SS-OCTA images. In addition, SS-OCTA detected 16 tangled vascular structures not seen on ICGA. Branching vascular networks were detected on SS-OCTA imaging in all eyes, but ICGA identified BVNs in only 17 of 23 eyes (74%). Of the 43 tangled vascular structures, 40 (93%) were located at the edge of a BVN and 3 (7%) were associated with type 2 neovascularization. In eyes with PCV undergoing SS-OCTA imaging, previously described polypoidal lesions may appear as tangled vascular structures associated with BVN or type 2 neovascularization. The identification of polypoidal lesions in patients with PCV as neovascular tangles rather than actual polypoidal lesions or aneurysmal dilatations may help facilitate understanding of their pathogenesis and response to treatment.