Choroidal perfusion abnormalities associated with Acute Posterior Multifocal Placoid Pigment Epitheliopathy: a case report

BACKGROUND: Indocyanine Green Angiography (ICG-A) and Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography (EDI-OCT) are essential imaging techniques for diagnosis, management and understanding of the pathophysiology of many chorioretinal diseases. Herein, we report the ICG-A and EDI-OCT findings from a case of Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE), in which these imaging techniques enable the visualization of more diagnostic details than those observable with other widely used diagnostic tools. CASE PRESENTATION: A 60-year-old white female presented with bilateral blurred vision for few days. Fundus examination showed multiple, yellow-white placoid lesions at the posterior pole of both eyes. The placoid lesions were also evident on Spectral-Domain Optical Coherence Tomography (SD-OCT), Fluorescein Angiography (FA), Fundus Autofluorescence (AF), and ICG-A. A complete ophthalmologic examination was performed and the diagnosis of APMPPE was made based on imaging and clinical features. Notably, all the lesions detected by FA, AF and OCT corresponded to focal areas of hypofluorescence seen on ICG-A, whereas several additional hypofluorescent areas that were not associated with FA, AF or OCT abnormalities, were also detected with ICG-A. On follow-up, the regression of outer retinal abnormalities detected on OCT preceded the restoration of choroidal perfusion abnormalities in the corresponding locations on ICG-A. This long-standing choroidal perfusion defect could not be detected with OCT. EDI-OCT scans revealed characteristic choriocapillaris changes beneath the placoid lesions and an increase in choroidal thickness during the acute phase, with subsequent decrease in the inactive stage of the disease. CONCLUSION: Our findings show that ICG-A and EDI-OCT provide detailed morphologic information of choroidal abnormalities in APMPPE and allow accurate evaluation of definitive resolution of the lesions. Moreover, they support the acute choroidal hypoperfusion as the primary mechanism overlying the pathogenesis of the disease, and suggest that the non-perfused areas may extend beyond the damage of the outer retina.