Distinguishing features of acute Vogt-Koyanagi-Harada disease and acute central serous chorioretinopathy on optical coherence tomography angiography and en face optical coherence tomography imaging

Abstract

Background: The aim of this study is to determine the differences in optical coherence tomography angiography (OCTA) features of acute Vogt-Koyanagi-Harada disease (VKH) and acute central serous chorioretinopathy (CSC). Clinical and imaging data of patients with acute CSC and VKH in a tertiary-care institute were analyzed. Multimodal imaging including fluorescein angiography, indocyanine green angiography (ICGA), and enhanced-depth imaging OCT were performed. OCTA images were analyzed for alterations in retinochoroidal microvasculature.

Results: Thirty-four eyes (24 patients; 10 with VKH and 14 with CSC) were included. OCTA en face images showed apparent areas of choriocapillaris flow void due to shadowing effect from overlying subretinal fluid and pigment epithelial detachment in CSC. However, eyes with VKH showed presence of true choriocapillaris flow void on OCTA that corresponded to choriocapillaris ischemia on ICGA.

Conclusions: OCTA is a useful tool to assess choriocapillaris ischemia in VKH and is helpful to differentiate it from CSC in the acute stage.

Keywords: Central serous chorioretinopathy; EDI-OCT; Indocyanine green angiography; Multimodal imaging; Optical coherence tomography angiography; Vogt-Koyanagi-Harada syndrome.

Fig. 1

Multimodal imaging of a patient with acute central serous chorioretinopathy (CSC) (subject #6). Fundus photograph (a) of the left eye shows presence of subretinal fluid (SRF) in the macula. Fluorescein angiography (FA) in the early phase (b) shows pin-point hyperfluorescence superonasal and inferotemporal to the fovea. The late phase FA (c) shows expanding dot sign with pooling of the dye. The en face optical coherence tomography angiography (OCTA) (d) shows the presence of mottled dark areas which corresponded to the dark areas representing signal loss on the corresponding structural en face OCT at the level of the choriocapillaris (e) and the outer retina (f). Horizontal (g) and vertical (h) cross-sectional OCT B-scan shows the presence of SRF in the macula

Fig. 2

Multimodal imaging of a patient with acute central serous chorioretinopathy (CSC) (subject #8). Fundus photograph of the right eye (a) shows presence of multiple pigment epithelial detachments (PEDs) in the macula. (b) On fluorescein angiography (FA), there is hyperfluorescence corresponding to the PEDs. (c) The en face optical coherence tomography angiography (OCTA) shows presence of dense dark areas at the level of the choriocapillaris. (d) The structural en face OCT shows hyporeflectance suggestive of loss of signal transmission in the areas of PEDs. The horizontal (e) and vertical (f) cross-sectional OCT B-scans show dome-shaped PEDs

Fig. 3

Fundus photography, combined fluorescein angiography (FA) and indocyanine green angiography (ICGA), and optical coherence tomography angiography (OCTA) of a patient with acute Vogt-Koyanagi-Harada (VKH) disease (subject #3). Fundus photograph (a) shows presence of vitritis with multiple yellowish choroiditis lesions in the posterior pole. Combined FA and ICGA in the early frame (b) shows early pin-point hyperfluorescence on FA and multiple hypocyanescent lesions on ICGA. In the late frame (d), there is progressive hyperfluorescence with pooling of the dye on FA and persistence of hypocyanescent lesions on ICGA suggestive of choriocapillaris ischemia. The en face OCTA (c) at the level of choriocapillaris shows presence of multifocal dark spots which are variably sized and corresponded to the hypocyanescent lesions on ICGA. Few such dark foci have been demarcated with yellow dashed line. The structural en face OCT scan shows only mild signal loss in the area of subretinal fluid but no loss in the areas of dark spots (e). The corresponding cross-sectional OCT B-scan (f) shows presence of subretinal fluid

Fig. 4

Comparison between the superficial and deep retinal plexus (SCP and DCP) and outer retinal slab of optical coherence tomography angiography (OCTA) of patients with central serous chorioretinopathy (CSC) (a–c) and Vogt-Koyanagi-Harada (VKH) disease (d–f). The OCTA image and the corresponding structural en face image at the SCP and DCP of patients with CSC and VKH (a, b, d, and e) do not show any abnormalities. The avascular outer retinal slab in CSC and VKH (c, f) shows few dark areas (yellow arrows) due to the signal loss from subretinal fluid as visualized in the corresponding structural en face OCT