Direct Carotid-Cavernous Fistula Superimposed on Acute Anterior Uveitis in Ankylosing Spondylitis: A Case Report

Abstract

Background: Acute anterior uveitis is the classic extra-articular manifestation of ankylosing spondylitis (AS), but acute vascular events such as high-flow carotid-cavernous fistula (CCF) can mimic anterior ocular inflammation, delaying diagnosis and risking vision-threatening secondary glaucoma.

Objective: To describe the clinical course, diagnostic pitfalls and endovascular treatment of a spontaneous direct CCF that presented as acute anterior uveitis in a patient with AS.

Methods: A 40-year-old HLA-B27-positive man with AS presented with unilateral acute anterior uveitis, followed by rapid orbital deterioration. He was assessed at four time points (T0 baseline; T1 day 5; T2 day 12; T3 day 90) with Goldmann tonometry, Hertel exophthalmometry, contrast-enhanced orbital computed tomography, catheter digital subtraction angiography (DSA) and systemic inflammatory biomarkers.

Results: Topical corticosteroids failed to halt the orbital swelling. By day 5 he had pulsatile exophthalmos (axial asymmetry +7.0 mm), bullous chemosis and secondary ocular hypertension (intraocular pressure [IOP] 36.5 mmHg). DSA showed a direct high-flow Barrow type A CCF draining retrogradely into dilated superior (6.4 mm) and inferior ophthalmic veins. Transarterial microcoil embolization achieved immediate occlusion. At day 90, IOP was 13.5 mmHg (−63.0%), proptosis had resolved (−100.0%) and best-corrected visual acuity had recovered from 20/100 to 20/20, with no neurological deficit. Serum matrix metalloproteinase-2 and -9 were elevated, consistent with intrinsic arterial wall vulnerability in AS.

Conclusion: A direct CCF can mimic refractory acute uveitis in AS. Rapid onset of pulsatile proptosis, chemosis and high IOP calls for urgent neurovascular angiography and endovascular embolization to preserve vision.