Sudden-onset Blindness from a Spontaneous Carotid-cavernous Fistula with Secondary Central Retinal Artery Occlusion and Posterior Ischemic Optic Neuropathy

ABSTRACT

Our case describes a patient diagnosed with a carotid-cavernous fistula (CCF) secondary to a spontaneously ruptured cavernous carotid aneurysm, presenting with sudden vision loss, and a concomitant central retinal artery occlusion as visualized by a cherry-red spot in the macula and posterior ischemic optic neuropathy. Computed tomography of the brain and orbits showed mild hydrocephalus, orbital fat haziness, and proptosis with concern for fluid in the basal cisterns. Cerebral angiography confirmed the suspected diagnosis of CCF. After angiography, a Magnetic resonance imaging of the brain demonstrated abnormal diffusion restriction in the posterior right optic nerve confirmed on the apparent diffusion coefficient map, consistent with ischemia of the optic nerve in this location. Two weeks after discharge, outpatient fundus photography showed resolution of her cherry-red spot, and optical coherence tomography showed thinning of the entire retinal nerve fiber layer as compared to the contralateral eye. In CCFs, congestive symptoms of proptosis, pain, and even central retinal vein occlusion findings are frequently described. However, our patient’s no light perception vision and imaging findings suggest associated central retinal artery occlusion and ischemic optic neuropathy. These findings underscore the multitude of serious visual effects of high flow CCFs.