Emboli causing amaurosis fugax typically originate from which artery?

Emboli causing amaurosis fugax typically originate from which artery?

• A. External carotid
• B. Vertebral
• C. Subclavian
• D. Internal carotid

Answer: (D)

Amaurosis fugax is caused by transient retinal ischemia from emboli that reach the retinal circulation via the ophthalmic artery, which is the first intracranial branch of the internal carotid artery. Because the retinal vessels are supplied through the ophthalmic artery stemming from the internal carotid, emboli originating from the internal carotid are the usual source. Emboli from the external carotid artery don’t reliably enter the retinal circulation, and those from the vertebral or subclavian arteries typically affect other vascular territories (posterior circulation or upper limbs) rather than causing transient monocular blindness.

Amaurosis fugax is caused by transient retinal ischemia from emboli that reach the retinal circulation via the ophthalmic artery, which is the first intracranial branch of the internal carotid artery. Because the retinal vessels are supplied through the ophthalmic artery stemming from the internal carotid, emboli originating from the internal carotid are the usual source.

Emboli from the external carotid artery don’t reliably enter the retinal circulation, and those from the vertebral or subclavian arteries typically affect other vascular territories (posterior circulation or upper limbs) rather than causing transient monocular blindness.