Fluorescein Angiography Findings in Susac Syndrome: A Multicenter Retrospective Case Series

Area of Science:

• Ophthalmology
• Neurology
• Rheumatology

Background:

• Susac syndrome is a rare vasculopathy characterized by the triad of branch retinal artery occlusion (BRAO), inner ear ischemia, and brain ischemia.
• Understanding the diagnostic markers for Susac syndrome is crucial for timely intervention and management.

Purpose of the Study:

• To characterize fluorescein angiography (FA) findings in Susac syndrome.
• To evaluate the sensitivity of ancillary tests, including FA, MRI, and audiometry, in detecting disease activity and relapse.

Main Methods:

• A multicenter, retrospective case series of patients diagnosed with Susac syndrome between 2010 and 2020.
• Patients underwent fluorescein angiography (FA), contrasted MRI of the brain, and audiometry.
• Medical records were reviewed for clinical data, symptoms, and test results to define clinical relapse and assess diagnostic sensitivity.

Main Results:

• Of 31 patients, 20 (64%) had the complete triad; median age was 43.5 years, and 70% were women.
• Fluorescein angiography (FA) revealed nonspecific leakage in all patients, indicating previous arteriolar damage.
• FA demonstrated the highest sensitivity (81.8%) in detecting active disease during episodes of relapse compared to MRI (18.2%) and audiometry (72.7%).

Conclusions:

• New leakage on FA is the most sensitive marker for active Susac syndrome.
• Persistent leakage on FA indicates prior damage, while new leakage signifies ongoing disease activity.
• Detection of new leakage on FA warrants consideration for modifying immunosuppressive therapy.