Amaurosis fugax caused by a dural arteriovenous fistula from the ophthalmic artery.

A 52-year-old man presented with transient monocular blindness that was both spontaneous and exacerbated by exertion. Dynamic orbital CT revealed a delay in the perfusion of the left optic nerve head suggestive of a steal phenomenon. Subsequent selective arteriography demonstrated an arteriovenous fistula between the falx artery originating from the ophthalmic artery and the superior sagittal venous sinus. In the proper clinical setting, a hemodynamic steal should be considered in the differential diagnosis of amaurosis fugax.