Arteriolarization from Carotid-Cavernous Fistula

This 63-year-old woman's primary care physician had referred her to an ophthamologist because of her persistently red eye. She had been treated unsuccessfully for almost 3 weeks with several different antibiotic eyedrops. Her vision had begun to worsen, and she started to hear “swishing” noises. Pertinent medical history included a carotid endarterectomy on the same side as the red eye about 1 month before onset of the symptoms.

Ophthamologic evaluation revealed decreased visual acuity, conjunctival injection from arteriolarization of the conjunctival blood vessels, pulsing proptosis, and an audible bruit that was synchronous with the pulse (as detected with a stethoscope placed over the patient's eye). Leonid Skorin, Jr, DO, of Dixon, IL, reports that these findings suggest a fistula between the carotid artery and the cavernous sinus. Although some carotid-cavernous fistulas may occur spontaneously, most arise secondary to trauma or surgery, as in this case.

The most serious complication of this condition is vision loss. It may result from increases in episcleral venous pressure, which can lead to glaucoma; anterior segment ischemia; corneal decompensation from exposure; cystoid macular edema or hemorrhage in the macula; and retinal artery occlusion.

Spontaneous resolution of these fistulas rarely occurs. Repair of the fistula is indicated if:

• There is loss of vision.
• Intractable or incapacitating periocular pain develops from any underlying ischemia or corneal exposure.
• The patient is disturbed by the continuous noise from the intracranial bruit or is concerned with his or her appearance.