Bilateral multifocal retinal pigment epithelium detachment and pachychoroidopathy

Idiopathic bilateral multifocal retinal pigment epithelial detachment (RPED) is an extremely rare condition and is often observed as an incidental clinical finding. The exact pathophysiology and natural course of this disease is not known. We observed a case of multifocal RPED in otherwise asymptomatic middle-aged female. Multimodal imaging confirmed the diagnosis of RPED associated with pachychoroid features, which were not described before, and foci of central serous chorioretinopathy. The benign nature of this entity and role of multimodal imaging has been emphasized in this case. Case Report A 52-year-old woman after presbyopic correction, presented to retina clinic for routine fundus evaluation. The best-corrected visual acuity of both eyes was 20/20 and had no major systemic illness. Fundus examination of both eyes showed multiple retinal pigment epithelial detachments (RPEDs) distributed throughout the fundus and concentrated more in the posterior pole [Fig. 1a and b] which shows hyperautofluorescence on blue reflectance [Fig. 1c and d]. Spectral-domain optical coherence tomography (SD-OCT) revealed serous nature of the PEDs with underlying pachychoroid features [Fig. 2e and j]. A small pocket of subretinal fluid was noted along superior arcade of the right eye, which showed central serous chorioretinopathy (CSR)-like leak on fundus fluorescein angiography (FFA) [Fig. 3]. All the PEDs were initially hypofluorescent followed by hyperfluorescent on FFA and varied cyanescence on indocyanine green angiography (ICGA) [Fig. 2a-d, f-i] with no evidence of choroidal neovascular membrane (CNVM) or polypoidal choroidal vasculopathy (PCV).Figure 1: Color fundus photo of right (a) and left (b) eye showing well-circumscribed multiple retinal pigment epithelial detachments throughout the macula, which are hyperautofluorescent (c and d)Figure 2: Fundus fluorescein angiography of both eyes shows progressive filling of dye in all pigment epithelial detachments (a and d, right eye; e and g, left eye) whereas indocyanine green angiography shows initial hypocyanescence of pigment epithelial detachments and in late phases it shows mixed hypo- and hypercyanescence (c and d, right eye; h and i, left eye). Optical coherence tomography passing through macula shows pigment epithelial detachment with internal hyporeflectivity suggestive of serous nature and the presence of pachyvessels (cross star) (arrow head and arrow show pigment epithelial detachment with hypo- and hypercyanescence at late phase indocyanine green angiography in image d). Subfoveal choroidal thickness OD: 338 μ, OS: 364 μ and pachyvessel diameter: 229 μFigure 3: Fundus fluorescein angiography shows central serous chorioretinopathy-like leak along superior arcade (a, early phase; b, late phase) and corresponding indocyanine green angiography shows underlying pachyvessel (c) with leakage at late phase (d) optical coherence tomography passing through that region shows the presence of subretinal fluid (cross star) and underlying pachyvessel (arrowheads)Discussion Idiopathic RPED is a rare condition for which pathogenesis and natural course is poorly understood. Widespread primary defect in adhesion between RPE and Bruch's membrane was assumed to be the cause for multiple RPEDs. Gass et al.[1] described the presence of inflammatory infiltrates in the choroidal layer and that of large choroidal vessels in histopathological section. Though majority are asymptomatic, they can develop complications such as hemorrhagic PED,[2] CNVM,[1] and CSR as in our case. The diagnosis is simple and OCT confirms serous nature of PEDs, but other differentials that should be borne in mind but not difficult to diagnose include photoreceptor-RPE diastasis, which predominantly presents as multifocal CSR[3] and nonbest multifocal vitelliform maculopathy in which yellow lesions are located in subretinal space and Doyne's honeycomb dystrophy which is distinguished by temporal distribution of drusen and family history.[4] Evaluation of this condition should include SD-OCT, FFA, and ICGA to rule out the presence of associated treatable conditions such as CNVM, PCV, and CSR. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Conclusion Multifocal RPED can be associated with pachychoroid features and foci of central serous chorioretinopathy. Multimodal imaging helps confirm the diagnosis and rule out simulating conditions. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.