Focal choroidal excavation:a preliminary interpretation based on clinic and review

<b>AIM:</b>To describe the clinical and imaging characteristics associated with focal choroidal excavation (FCE), analyze the possible complication, and interpret its probable etiopathogenesis.<b>METHODS:</b>Retrospective descriptive case series of 37 eyes of 32 patients with FCE. Findings of spectral-domain optical coherence tomography (SD-OCT), fluorescein angiography, indocyanine green angiography, and clinical features were analyzed.<b>RESULTS: </b>All patients were Chinese. Five patients (15.6%) were bilaterally involved. Patients’ ages ranged from 7 to 66y. Refractive error ranged between +2.0 D and −11.0 D. Mean best-corrected visual acuity was 0.6 (range, 0.1 to 1.2). Fundus examinations exhibited mild-moderate localized pigmentary disturbances in the corresponding area of 17 eyes. Fluorescein angiography performed in 18 patients showed varying degrees of hyperfluorescence and hypofluorescence related to a range of retinal pigment epithelium (RPE) alterations. Indocyanine green angiography performed in 7 patients showed hypofluorescence at the excavation. SD-OCT demonstrated choroidal excavation in all 37 eyes. Twenty-nine eyes showed a single lesion of FCE, and three eyes showed 2-3 separated lesions. Fifteen eyes showed separation between the photoreceptor tips and RPE consistent with nonconforming FCE. Central serous chorioretinopathy (CSC, <i>n</i>=1) and choroidal neovascularization (CNV, <i>n</i>=1) developed during follow-up.<b>CONCLUSION:</b>FCE could be interpreted as congenital focal choroidal dysplasia involving the RPE, choriocapillaris, and photoreceptor associated with the faulty anatomy. The abnormal anatomy of FCE was similar to anatomy at risk of CSC and CNV