Bilateral optic disk pallor after unilateral internal carotid artery occlusion.

Bilateral pallor of the optic disks was observed in a 52-year-old man after dissection of an internal carotid artery. Diffuse pallor of the ipsilateral optic disk reflected infarction of the ipsilateral optic nerve and "bow-tie" atrophy of the contralateral optic disk reflected infarction of the ipsilateral optic tract. The findings were due to an occlusion of the internal carotid artery proximal to the origin of the ophthalmic artery, resulting also in insufficiency in the area of supply of the anterior choroidal artery.