A 45-year-old man presents with right-sided proptosis associated with an audible bruit over the eye, corkscrew conjunctival vessels, and elevated intraocular pressure. Doppler imaging shows arterialized flow in the superior ophthalmic vein. The underlying lesion is located between which two vascular compartments?
- A Internal carotid artery and cavernous sinus ✓
- B Superior ophthalmic vein and angular vein
- C Middle meningeal artery and pterygoid venous plexus
- D Ophthalmic artery and superior ophthalmic vein
Correct answer: A. Internal carotid artery and cavernous sinus
Explanation
A direct carotid-cavernous fistula is an abnormal communication between the internal carotid artery and the cavernous sinus, classically post-traumatic, producing pulsatile proptosis with bruit, arterialization of episcleral veins, and raised intraocular pressure from elevated episcleral venous pressure. Arterialized retrograde flow in the superior ophthalmic vein is the imaging hallmark. A dural fistula between meningeal branches and the cavernous sinus gives a milder picture.
Reference: Parsons' Diseases of the Eye, 22nd ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.