Flat irregular pigment epithelium detachment in central serous chorioretinopathy: Correlation with choroidal neovascular membrane.

A 47-year-old male presented with complaints of metamorphopsia and diminished vision in right eye for 4--5 months (visual acuity 20/30). Fundus examination showed presence of neurosensory detachment (NSD) along with multiple retinal pigment epithelium (RPE) irregularities at the macula and subretinal yellowish deposits temporal to fovea. Swept source optical coherence tomography (SS-OCT) showed NSD [Fig. 1] along with dilated large choroidal vessels, suggestive of central serous chorioretinopathy (CSCR). Horizontal raster scan showed flat irregular pigment epithelium detachment (FIPED) temporal to fovea with hypereflectivity [Fig. 1a – arrowhead] below it, whereas a FIPED with hyporeflectivity [Fig. 1b – arrow] below it was seen superior to fovea on a vertical scan. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICG) showed choroidal neovascular network (CNVM) corresponding to the site of hypereflective FIPED [Fig. 2a and b – arrowhead]. However, stippled hyperfluorescence [Fig. 2a – arrow] on FFA and hypercyanescence [Fig. 2b – arrow] on ICG was seen corresponding to hyporeflective FIPED suggestive of RPE defects. A well-defined network of vessels [Fig. 2c – arrowhead] corresponding to the site of hypereflective FIPED was seen on optical coherence tomography angiography (OCTA) as well.

Figure 1

Swept source optical coherence tomography of right eye (SS-OCT) showing neurosensory detachment at the macula and dilated large choroidal vessels. Horizontal raster scan showing a hypereflective (a) arrowhead with magnified projection at right top corner) flat irregular pigment epithelium detachment (FIPED) temporal to fovea and vertical raster scan showing a hyporeflective FIPED (b) arrows with magnified projection at right top corner) superior to fovea

Figure 2

FFA (a) showing a subtle network of vessels with a poorly delineated hyperfluorescence (arrowhead) temporal to fovea and window defects (arrow) superior to the fovea corresponding to hypereflective and hyporeflective FIPED on SS-OCT, respectively. ICG (b) showing CNVM (arrowhead) temporally corresponding to hypereflective FIPED on SS-OCT and hypercyanescence superior to fovea (arrow) suggestive of choroidal hyperpermeability. OCTA (c) showing choroidal neovascular network at the level of outer retina and choriocapillaries (arrowhead) corresponding to hypereflective FIPED temporal to fovea

Discussion

Association of type 1 CNVM and CSCR has been well known in the literature.[1] However, due to chronic RPE changes and leak patterns of chronic CSCR on angiography as well as the OCT findings (subretinal fluid/intraretinal fluid/FIPED) simulating that of a type 1 CNVM, early diagnosis of CNVM in CSCR becomes a challenge. FIPED resides within a spectrum of diseases, including pachychoroid-related entities[2] and type 1 CNV.[3] Bousquet et al.[4] have reported that hyporeflective FIPED on OCT were avascular on OCTA in cases of CSCR while were partially hypereflective when associated with CNV. Also, the presence of hypereflectivity between the undulating RPE and underlying bruch membrane has been distinctly correlated with the presence of underlying neovascular tissue complex in pachychoroid spectrum of diseases.[5] In this case, we were able to analyze the reflectivity pattern (hyporeflective and hypereflective) of FIPED on SS-OCT and correlate it with the presence of underlying CNVM at the site of hypereflective FIPED using other imaging modalities consorting with the above analysis. A sound understanding and interpretation of the reflective patterns of FIPED on OCT can aid in early diagnosis and effective management of cases of CSCR associated with CNVM.

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Conflicts of interest

There are no conflicts of interest.