Abstract
Purpose :
Susac syndrome, a rare microangiopathy of retina, cochlea and the brain, often evades early diagnosis due to fluctuating and incomplete clinical manifestation. We outline pathognomonic OCTA and fluorescein angiographic (FA) features enhancing timely diagnosis and therapeutic follow-up.
Methods :
Multimodal retinal imaging of two cases of Susac syndrome (Case1: 44y/o w/f; Case2: 35y/o w/f) was carried out over follow-up periods of 1 and 4 years, including SD-OCT, OCTA and FA. Over the course of different therapeutic approaches, these examinations were frequently repeated to monitor disease progression.
Results :
At first presentation FA in Case1 showed a paracentral branch retinal artery occlusion in the symptomatic left eye along with a singular focal vasculitic leakage in midperiphery in each eye. Case2 showed an old local branch artery occlusion in the symptomatic left eye, on FA a pair of obliterated vessel branches; localized peripheral ischemia contralaterally. On OCTA, the temporal region of the macula showed reduced blood flow in the superficial an deep layer in both cases. In the course of the disease, Case1 developed new segmental vasculitic retinal branch artery occlusions in the temporal and nasal periphery of the right eye, along with arterio-arterial collaterals, while Case2 showed new ischemia of the temporal inferior macula of the right eye, also detected in OCTA, and segmental vasculitic signs (arteries) and occlusive changes (arteries and veins) of the great vessel arcades. Both cases showed prolonged, relapsing courses and only stabilized under therapy escalation (Case1: oral and IV steroids, cyclophosphamide, plasmapheresis and IV immunoglobulins; Case2: IV steroids, azathioprine, rituximab, mycophenolate mofetil and IV immunoglobulins).
Conclusions :
Pathognomonic signs (relapsing segmental vasculitic branch artery occlusions, retinal arterio-arterial collaterals) on wide field FA allowed for early diagnosis, which is mandatory in Susac syndrome for the timely start of antiinflammatory treatment. Otherwise significant sequelae can lead to severe visual, neurological and hearing impairment. OCTA examination in particular is beneficial for early detection of microvascular changes at first presentation and allows monitoring them under treatment. We recommend implementing OCTA at baseline and follow-ups with additional scans covering the temporal mid-periphery.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.