Evidence and Consensus Based Imaging Guidelines in Ocular Toxoplasmosis. Multimodal imaging in Uveitis (MUV) Taskforce Report 14.

PURPOSE: To develop imaging and consensus-based guidelines for the application of multimodal imaging in ocular toxoplasmosis (OT). DESIGN: International expert consensus study using the nominal group technique (NGT) guided by systematic literature review. PARTICIPANTS: International uveitis specialists and retina experts participating in the Multimodal Imaging in Uveitis (MUV) taskforce. METHODS: A subgroup of experts reviewed the published literature on imaging in OT, along with complete multimodal imaging datasets from cases fulfilling the Standardized Uveitis Nomenclature (SUN) criteria. Imaging modalities included color fundus photography (CFP), optical coherence tomography (OCT), fundus autofluorescence (FAF), fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), and OCT angiography (OCTA). NGT sessions were conducted to identify key imaging features of typical and atypical presentations of active and inactive OT across modalities and to define imaging findings associated with disease-related complications. Consensus-based imaging descriptors and practical imaging guidelines were developed through iterative discussion. The proposed guidelines were voted on by the MUV taskforce. MAIN OUTCOME MEASURES: Identification of multimodal imaging features of active and inactive OT and development of imaging guidelines for diagnosis, activity assessment, and detection of complications. RESULTS: The experts agreed that classic OT remains primarily a clinical diagnosis. CFP was considered sufficient for diagnosing typical active OT presenting as focal or paucifocal necrotizing retinochoroiditis. OCT provided important information on lesion depth, retinal and choroidal involvement, and vitreoretinal interface abnormalities, and was particularly valuable in atypical presentations and for longitudinal disease monitoring. FAF assisted in staging lesion evolution and identifying MEWDS-like reactions. FA and ICGA were not recommended for routine use but suggested in selected cases to evaluate the presence and extent of complications. OCTA was considered sufficient for detecting choroidal neovascularization in most cases. Multimodal imaging was generally recommended for atypical OT and for assessment of complications. CONCLUSIONS: The consensus-based imaging guidelines by MUV provide a standardized and pragmatic framework for the use of multimodal imaging in OT. While the diagnosis in typical cases remains largely clinical, as outlined in the SUN classification, OCT and FAF are valuable for monitoring disease activity, and additional imaging modalities support the management of atypical presentations and complications.