Focal Scleral Nodule : A New Name for Solitary Idiopathic Choroiditis and Unifocal Helioid Choroiditis

Purpose: To evaluate multimodal imaging findings of solitary idiopathic choroiditis (SIC; also known as unifocal helioid choroiditis) to clarify its origin, anatomic location, and natural course. Design: Multicenter retrospective observational case series. Participants: Sixty-three patients with SIC in 1 eye. Methods: Demographic and clinical data were collected. Multimodal imaging included color fundus photography, OCT (including swept-source OCT), OCT angiography (OCTA), fundus autofluorescence, fluorescein and indocyanine green angiography, and B-scan ultrasonography. Main Outcome Measures: Standardized grading of imaging features. Results: Mean age at presentation was 56 ± 15 years (range, 12–83 years). Mean follow-up duration in 39 patients was 39 ± 55 months (range, 1 month–25 years). The lesions measured a mean of 2.4 × 2.1 mm in basal diameter, were located inferior (64%) or nasal to the optic disc, and appeared yellow (53%). No systemic associations were found. The lesions all appeared as an elevated subretinal mass, with OCT demonstrating all lesions to be confined to the sclera, not the choroid. On OCT, the deep lesion margin was visible in 12 eyes with a mean lesion thickness of 0.6 mm. Overlying choroidal thinning or absence was seen in 95% (mean choroidal thickness, 28 ± 35 μm). Mild subretinal fluid was observed overlying the lesions in 9 patients (14%). Retinal pigment epithelial disruption and overlying retinal thinning was observed in 56% and 57%, respectively. OCT angiography was performed in 13 eyes and demonstrated associated choroidal and lesional flow voids. Four lesions (6%) were identified at the macula, leading to visual loss in 1 patient. One lesion demonstrated growth and another lesion showed spontaneous resolution. Conclusions: In this largest series to date, multimodal imaging of SIC demonstrated a scleral location in all patients. The yellow and white clinical appearance may be related to scleral unmasking resulting from atrophy of overlying tissues. Additional associated features included documentation of deep margin on swept-source OCT, trace subretinal fluid in a few patients, and OCTA evidence of lesional flow voids. Because of the scleral location of this lesion in every patient, a new name, focal scleral nodule, is proposed.