Validation of an Angiographic Scoring System for Longitudinal Monitoring of Susac Syndrome: A Standardized Approach

BACKGROUND: In Susac syndrome, there is no standardized scoring system for the interpretation of fluorescein angiography (FA). The objective of this study was to standardize the angiographic evaluation of these patients by applying an angiographic score validated for uveitis to the specific context of Susac syndrome. METHODS: Retrospective analysis of patients diagnosed with Susac syndrome was conducted. Angiograms were evaluated using a structured scoring system based on predefined angiographic features and their localization by retinal quadrants. The presence of these items was summed to generate a total score. Interobserver agreement was assessed between 2 independent graders for the angiographic scoring system. RESULTS: From July 2015 to May 2024, 10 patients (mean age 32 ± 13 years; 60% male) were included. A total of 83 bilateral FA (166 eyes) were analyzed, with each patient undergoing between 2 and 17 examinations (median = 8) over a mean follow-up of 42.6 ± 30.2 months. Arterial leakage was present in 60% of patients, and capillary nonperfusion or arterial occlusion in 70% of patients at first visit. The development of new signs of arterial leakage and/or nonperfusion was documented in 33.13% of follow-up angiograms. Most items showed excellent interobserver agreement, with weighted Cohen kappa values above 0.8, and all but 1 item exceeding 0.7. CONCLUSIONS: This angiographic scoring system demonstrates validity and repeatability for assessing Susac syndrome. Further prospective studies are needed to assess its application in larger cohorts, explore treatment response, and evaluate its role in guiding therapy decisions.