Comparison of choriocapillary flow density between fellow eyes of polypoidal choroidal vasculopathy and neovascular age-related macular degeneration

Mingyue Luo,Xinyu Zhao,Mingzhen Yuan,Youxin Chen,Jingyuan Yang,Nan Zhao,Rongping Dai

doi:10.1186/s12886-020-01386-0

Abstract

BackgroundTo compare the choriocapillary flow density (CFD) among the fellow eyes of polypoidal choroidal vasculopathy (PCV), neovascular age-related macular degeneration (nAMD), and healthy controls using spectral-domain optical coherence angiography tomography (SD-OCTA).MethodsThis is a cross-sectional study that includes the fellow eyes of 38 patients with unilateral PCV, 36 patients with unilateral nAMD, and 36 eyes from 36 healthy volunteers. The PCV group was further classified into polypoidal CNV (P-CNV) and typical PCV (T-PCV) for subgroup analysis. The age, subfoveal choroidal thickness (SFCT), Age-Related Eye Disease Study (AREDS) classification, and fellow eye diagnosis were acquired. All subjects underwent SD-OCTA with a 6.0-mm scan pattern. Circles with radius of 1.00, 1.50, and 3.00 mm were manually selected in the choriocapillaris (CC) slab, and the CFD was calculated as the percentage of the flow area to the whole selected area as CFD-1.00, 1.50, and 3.00, respectively. Univariate and multivariate analysis were performed to study the correlation between the aforementioned factors with CFD.ResultsThe mean CFD-1.00, 1.50, and 3.00 of the nAMD group were 61.51, 63.18, and 66.20, respectively; these were significantly lower than those of the PCV group (65.90, 66.89, and 67.94; P < 0.001, P < 0.001, and P = 0.010; respectively) and control group (66.28, 66.96, and 68.42; P < 0.001, P < 0.001, and P = 0.001, respectively), and no difference was detected between the PCV and control group or between PCV subtypes. The AREDS classification and fellow eye diagnosis were correlated with CFD in univariate analysis; however, only the fellow eye diagnosis showed a significant correlation after multiple linear regression.ConclusionsThe CFD of nAMD fellow eyes was significantly lower than that of PCV and control eyes, and no difference was detected between PCV and control group, indicating that CC loss plays a different role in the early pathogenesis of nAMD and PCV.

Highlights

To compare the choriocapillary flow density (CFD) among the fellow eyes of polypoidal choroidal vasculopathy (PCV), neovascular age-related macular degeneration, and healthy controls using spectraldomain optical coherence angiography tomography (SD-optical coherence tomography angiography (OCTA))
Polypoidal choroidal vasculopathy (PCV) is characterized by orange-red nodules in fundus examinations, polypoidal lesions during indocyanine green angiography (ICGA), and tremendous bleeding at the posterior pole. Since it was first described by Yannuzi in the 1980s [1], there has been many controversies, especially the pathogenesis and whether PCV is a subtype of neovascular age-related macular degeneration, or a distinct disease within the pachychoroid disease spectrum [2], owing to the obvious heterogeneity that lies in their clinical, pathophysiological and epidemiological features and treatment responses to anti-vascular endothelium growth factor (VEGF) agents [3]
With optical coherence tomography angiography (OCTA), a novel imaging modality that reflects the choroid flow with higher accuracy and resolution compared to traditional dye-based ophthalmic angiography [4], emerging evidence suggests that the classical polypoidal lesions manifest as tangled vessels at the edge of branching vascular network (BVN) [5]

Summary

Introduction

To compare the choriocapillary flow density (CFD) among the fellow eyes of polypoidal choroidal vasculopathy (PCV), neovascular age-related macular degeneration (nAMD), and healthy controls using spectraldomain optical coherence angiography tomography (SD-OCTA). With optical coherence tomography angiography (OCTA), a novel imaging modality that reflects the choroid flow with higher accuracy and resolution compared to traditional dye-based ophthalmic angiography [4], emerging evidence suggests that the classical polypoidal lesions manifest as tangled vessels at the edge of BVN [5]. This finding further complicates our understanding of whether there is an actual difference between PCV and nAMD because the characteristic lesions of PCV and choroidal neovascularization (CNV) in nAMD are essentially both vascularization in nature and there might be no “polyps” or “aneurysmal vessels” [6]

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