Mid-Phase Hyperfluorescent Plaques Seen on Indocyanine Green Angiography in Patients with Central Serous Chorioretinopathy

Abstract

(1) Indocyanine green angiography (ICG-A) shows the presence of mid-phase hyperfluorescent area in central serous chorioretinopathy (CSCR). However, their exact meaning remains uncertain. (2) The clinical and multimodal imaging findings of 100 patients (133 eyes) with CSCR, including the enhanced-depth-imaging OCT (EDI-OCT), blue-light fundus autofluorescence (BAF), fluorescein and indocyanine green angiography (FA and ICG-A) findings were reviewed. Mid-phase hyperfluorescent plaques (MPHP) were defined as fairly well circumscribed hyperfluorescent regions during the midphase of the ICG-A. The association between MPHP and other clinical/imaging parameters was assessed using a multiple logistic regression analysis. (3) MPHP were detected in 59.4% of eyes with CSCR. The chronic form of the disease, the presence of irregular pigment epithelium detachments (PED) and the retinal pigment epithelium (RPE) changes seen on FA were associated with the presence of MPHP in the multivariate analysis (p = 0.015; p = 0.018 and p = 0.002; respectively). OCT showed RPE bulges or PED in 98.7% of areas with MPHP and BAF showed changes in 57.3% of areas with MPHP. (4) MPHP were associated with a chronic form of CSCR and colocated with PED or RPE bulges. MPHP should be recognized as a sign of early RPE dysfunction before it is detected with BAF.

Keywords: central serous chorioretinopathy; choroidal hyperpermeability; indocyanine green angiography.

Figure 1

Multimodal imaging of patients with central serous chorioretinopathy (CSCR) without mid-phase hyperfluorescent plaques (MPHP) (A–E) and with MPHP (F–J). (A–E) A 35-year-old man with CSCR in the right eye. (A). The horizontal enhanced depth imaging (EDI) OCT centered on the fovea shows a macular serous retinal detachment (SRD). A dilated choroidal vessel is visualized (stars). (B). Blue-light fundus autofluorescence shows a mixed hyper- and hypo-autofluorescent area at the SRD. (C). Late-phase fluorescein angiography (FA) shows two focal leaks (arrows). (D). Early-phase indocyanine green angiography (ICG-A) is unremarkable. (E). Mid-phase ICG-A shows the two focal leaks (arrows) visualized on FA without MPHP. (F–J) A 46-year-old man with CSCR in the left eye. (F). An EDI-OCT centered on the fovea shows a macular SRD associated with dilated choroidal vessels (stars). (G). Blue-light fundus autofluorescence shows a superior hyper-autofluorescent area consistent with a previous SRD. (H). Late-phase FA shows a leaking point (red arrow) and an ill-defined hyperfluorescent area consistent with retinal pigment epithelium changes. (I). Early-phase ICG-A shows inferior dilated choroidal veins. (J). Mid-phase ICG-A shows multifocal MPHP (yellow arrows). The focal leak seen on FA is also detected on mid-phase ICG-A (red arrow).

Figure 2

Multimodal imaging of a 37-year-old man with bilateral chronic central serous chorioretinopathy. (A,B,E–G). Right eye. (A). Blue-light fundus autofluorescence (BAF) shows a superior hyper-autofluorescent area consistent with previous serous retinal detachments. (B). Mid-phase indocyanine green angiography (ICG-A) shows multifocal mid-phase hyperfluorescent plaques (MPHP) without retinal pigment epithelium (RPE) damages detected on BAF. (E). The horizontal OCT B-scan passing through the fovea shows a RPE bulge at the level of the temporal MPHP (arrow). (F,G). The horizontal OCT B-scan passing through the MPHP (green and red dotted lines) shows an irregular pigment epithelium detachment (PED, (F), green arrow) and a RPE bulge ((G), arrow). (C,D,H–J). Left eye. (C). BAF shows a hyper-autofluorescent area inferior to the optic disc that corresponds to a subretinal detachment (SRD, (H)). (D). Mid-phase ICG-A shows multifocal MPHP. (H) The horizontal OCT B-scan passing through the MPHP (red dotted-line) shows a serous retinal detachment associated with RPE irregularities (red arrow) and dilated choroidal vessels (stars). (I,J). The horizontal OCT B-scan passing through the MPHP (green and blue dotted-line) shows small irregular PED (green arrow and blue arrow). A dilated choroidal vessel is visualized behind the PED (star, (J)).

Figure 3

Manifestations of hyperpermeability in central serous chorioretinopathy. (A). Soon after injection of indocyanine green, the intravascular dye concentration is high. (B). In areas of choroidal vascular hyperpermeability there is leakage of dye into the choroidal stroma. (C). The dye is removed from the blood stream by the liver. The dye in the stroma may diffuse back into the blood or spread posteriorly between the larger choroidal vessels. This produces a silhouetting of the large choroidal vessels against a hyperfluorescent background. (D). In areas with mid-phase hyperfluorescent plaques (MPHP) there appears to be localized, shallow elevations of the RPE monolayer. In some cases, the space has reflectivity greater and more heterogeneous than what would be expected from simple fluid alone. (E). Dye leaking in areas of chorodal vascular hyperpermeability may diffuse into the choroidal stroma or into the sub-retinal pigment epithelial space. The fluorescence from the anteriorly located dye masks the visible details of the underlying choroid. (F). In the later portions of the mid-phase, there is retention of dye in the sub-RPE space. The contrast between the regions with retained dye and the lesser amounts remaining in the choroid produces the plaque-like appearance.