Inner Choroidal Fibrosis: An Optical Coherence Tomography Biomarker of Severity in Chronic Central Serous Chorioretinopathy.

PURPOSE:To describe a potential biomarker termed as inner choroidal fibrosis in cases of chronic central serous chorioretinopathy (CSCR) presenting to a tertiary referral center. DESIGN:Observational case series. METHODS:Five eyes of 4 patients with CSCR were noted to have a gray-white subretinal lesion in the macula, which was analyzed with multimodal imaging. RESULTS:The lesions were hypofluorescent on autofluorescence, fundus fluorescein angiography, and indocyanine angiography. In all cases, a characteristic heterogeneous, hyperreflective lesion in the inner choroid was seen on optical coherence tomography (OCT), corresponding to the white subretinal lesions. The lesion was distinct from the adjacent choroid, with greater reflectivity and greater thickness than the adjacent compressed choroidal vasculature. The dilated outer pachyvessels were pushed outward or sideways in all cases. On OCT-angiography, the corresponding lesion showed flow void areas. We have termed this zone of inner choroidal hyperreflectivity "inner choroidal fibrosis." Upon analyzing the clinical course, 3 of the patients had a history of choroidal neovascularization. The contralateral eye in 2 of these 3 patients also developed choroidal neovascularization. Three of the eyes had an overlying focal choroidal excavation. CONCLUSIONS:We report a potential biomarker of CSCR termed "inner choroidal fibrosis" in 4 cases of chronic CSCR. It can best be identified on enhanced depth or swept source OCT as a region of heterogeneous hyperreflectivity in the inner choroid. This fibrosis could be regarded as a degenerative process secondary to more severe disease in the past.