Orbital arteriovenous fistula presenting with choroidal pulsations on optical coherence tomography

Purpose: To describe a case of orbital arteriovenous fistula diagnosed based on choroidal pulsations on optical coherence tomography (OCT).

Observations: A 69-year-old female originally referred for evaluation of macular degeneration. During acquisition of OCT images, choroidal pulsations of the right eye were noted on the B-scan on the instrument display. The pulsations were not noted on gross or funduscopic examination. Fluorescein angiography was unremarkable. Indocyanine green angiography revealed engorged choroidal vasculature in the right eye. OCT angiography revealed relative tortuosity and dilation of the superficial and deep vascular complexes respectively. B-scan ultrasonography revealed orbital pulsations on the right. MRI imaging of the brain and orbits was unremarkable. Findings were attributed to a low-flow orbital arteriovenous fistula. The patient subsequently developed mild stasis retinopathy for which anti-VEGF therapy was initiated.

Conclusions and importance: Arteriovenous fistulas of the brain and orbit classically present with gross pulsatile proptosis among other clinical features. Low flow orbital fistulas may present with subtle choroidal pulsations only detectable on OCT.