Imaging features of branching vascular network in polypoidal choroidal vasculopathy

Abstract

Objective To observe the imaging features of branching vascular network (BVN) in polypoidal choroidal vasculopathy (PCV).Methods Eighty PCV patients (90 eyes) were enrolled in this study.The patients included 58 males and 22 females.The age was ranged from 49 to 85 years,with a mean age of 61.4 years.All the patients were examined for fundus photography,fundus fluorescein angiography (FFA),indocyanine green angiography (ICGA) and optical coherence tomography (OCT).The fibrovascular retinal pigment epithelium detachment (PED) was defined as a well-demarcated subretinal heterogeneous plaque with increasing fluorescence on FFA.The late lichenoid hyperfluorescent plaque was defined as a well-demarcated lichenoid hyperfluorescent plaque on late phase ICGA.The double-layer sign on OCT was defined as a wide range of shallow PED from Bruch membrane.Results BVN were found on early ICGA in 76 eyes among the 90 eyes (84.4％).Among these 76 eyes,18 eyes (23.7％) demonstrated the subretinal reddish-orange branches corresponding to BVN.Fifty-six eyes (73.7％) demonstrated all or part of the BVN on early FFA.Three eyes (3.9％) demonstrated branching transmitted fluorescence corresponding to BVN throughout the FFA.Seventy-three eyes (96.1％) were manifested by occult choroidal vascularization on FFA,and 21 eyes (27.6％) of them were fibrovascular PED.Among the 76 eyes with BVN,all BVN appeared earlier than polypoidal lesions on ICGA.Polypoidal lesions located on the terminal of BVN in 62 eyes (81.6％).Sixty-nine eyes (90.8％) on ICGA demonstrated the late lichenoid hyperfluorescent plaque,whose area was equal to or greater than the area of BVN shown on early ICGA.Seventy-two eyes (94.7％) had the double layer sign.Among these 72 eyes,15 eyes (20.8％) had lumen like structure within the double-layer sign.Sixty-five eyes (90.3％) had punctate and linear hyperreflectance within the double-layer sign.Two eyes (2.8％) demonstrated a hyporeflective short segment and a gap of Bruch membrane on OCT corresponding to the origin of the BVN.Sixty-three eyes (87.5％) had an area of double-layer sign that matched the area of late lichenoid hyperfluorescent plaque on ICGA.Conclusions BVN in PCV can be noted as reddish-orange branches on fundus examination.Most of the BVN are shown as early branching transmitted fluorescence but collectively an occult choroidal vascularization on FFA,as lichenoid hyperfluorescent plaque on late ICGA,and as double-layer sign on OCT whose area matches late lichenoid hyperfluorescent plaque. Key words: Choroid diseases/diagnosis; Fluorescein angiography; Tomography, optical coherence; Diagnostic imaging