The Chrysanthemum Phenotype of Idiopathic Multifocal Choroiditis.

Abstract

To describe the clinical characteristics and multimodal imaging (MMI) features of a distinctive subtype of active idiopathic multifocal choroiditis (iMFC) lesions with grey-yellow chorioretinal lesions surrounded by smaller satellite dots, a presentation referred to as "chrysanthemum lesions". Retrospective, observational, multi-center case series of eyes with active iMFC and chrysanthemum lesions. Multimodal imaging features were reviewed and presented. Twenty-five eyes from 20 patients (12 women and 8 men), with a mean age of 35.8±17.0 years (range, 7 - 78 years) were included. Chrysanthemum lesions were equally located in the macula (48.0%) or the mid/far-periphery (52.0%). The number of lesions per eye varied from 1 (16.0%) to more than 20 (56.0%). On optical coherence tomography (OCT), chrysanthemum lesions showed typical features of iMFC, including subretinal hyperreflective material splitting the retinal pigment epithelium/Bruch's membrane (RPE/BrM). Chrysanthemum lesions were hypoautofluorescent on fundus autofluorescence imaging, hyperfluorescent on fluorescein angiography, hypofluorescent on indocyanine green angiography, and associated with choriocapillaris flow signal deficit on OCT-angiography. Active iMFC may present with findings resembling chrysanthemum lesions. The distinctive lesion morphology on ophthalmoscopic examination, the high number of lesions, and the high prevalence of exclusive mid- and far-peripheral involvement may represent a distinctive phenotype of iMFC.