History

• 63-year-old male presented with a two-month history of left eye swelling
• Associated with pain and horizontal diplopia
• Also reports decreased vision for the past few months

Exam Findings

• VAcc: 20/25-1; 20/50+1
• Pupils: Round and Reactive OU, no RAPD
• IOP: 10; 26
• EOM: Full OD; -3 abduction OS otherwise full EOM in all other directions OS

Differential Diagnosis

• Vascular
• Cavernous sinus thrombosis
• Carotid-cavernous fistula
• Neoplastic
• Cavernous sinus tumors
• Orbital tumors
• Inflammatory
• Thyroid orbitopathy
• Idiopathic Orbital Inflammation
• Sarcoidosis
• Infectious
• Orbital cellulitis
• Mucormycosis

Additional Investigations

• A CT/CTA of the patient’s brain was performed, given high suspicion for a cavernous sinus lesion (Note: MRI was not performed since patient has a pacemaker).
• Cerebral angiogram was performed and showed a left carotid cavernous fistula fed by branches of the left external carotid artery and, to a lesser degree, the right external carotid artery and left internal carotid artery.

Diagnosis

• Dural carotid cavernous fistula

Pathophysiology

• Direct carotid cavernous fistula – Arise most commonly secondary to a traumatic tear of internal carotid artery within the cavernous sinus. It can also rarely arise secondary to a spontaneous aneurysm rupture.
• Dural carotid cavernous fistula – Arise from connections between dural branches of the internal or external carotid arteries and the cavernous sinus. Pathophysiology is somewhat unknown. Two major hypotheses:
  1. Associated with occlusion of adjacent draining venous dural sinuses. This results in arterialization of venous blood flow and subsequent formation of an arteriovenous shunt.
  2. Arise from congenital arteriovenous shunts that are normal variants. Often in the setting of hypertension / atherosclerotic disease, these congenital shunts proliferate into a carotid cavernous fistula.

Treatment

• The patient was started on Cosopt (dorzolamide hydrochloride-timolol maleate)for the elevated IOP in the left eye
• Neurosurgery was consulted for angiography and embolization of the left carotid cavernous fistula

Prognosis and Future Directions

• The overall prognosis for dural CCF is very good. There is very minimal increase in mortality rates and generally 20 to 50 percent of cases spontaneously resolve.
• Patients with mild ocular symptoms can be closely monitored with regular ophthalmology exams (checking visual acuity, IOP, EOM and dilated fundus exam).
• Patients with mild exposure keratopathy can be treated with aggressive lubrication.
• Patients experiencing diplopia can be treated with prism or occlusion therapy and IOP-lowering medications can be started if IOP is substantially elevated.
• The main indications for intervention with angiography are: visual deterioration, intolerable diplopia, elevated IOP despite maximal medical therapy, proliferative retinopathy, proptosis with untreatable corneal exposure and patients with cortical venous drainage.
• Transvenous embolization is typically used when intervention is necessary. In difficult cases, retrograde cannulation of superior or inferior ophthalmic vein can be performed to access the CCF for coiling.
• Successful closure is reported to occur in 80 to 100 percent of cases following embolization.

References

• Miller NR. Neurosurg Clin N Am. 2012 Jan;23(1):179-92.
• Barrow DL, Spector RH, Braun IF, et al. Classification and treatment of spontaneous carotid-cavernous sinus fistulas. J Neurosurg.1985 Feb;62(2):248-256.
• Miller NR. “Carotid-Cavernous Sinus Fistulas,” Walsh and Hoyt’s Clinical Neuro-Ophthalmology, 6th ed. (Baltimore: Lippincott, Williams & Wilkins, 2005) pp. 2263-2296.
• Ang M, Sng C, Milea D. Optical coherence tomography angiography in dural carotid-cavernous sinus fistula. BMC Ophthalmol. 2016 Jul 7;16:93.
• Debrun GM, Viñuela F, Fox AJ, et al. Indications for treatment and classification of 132 carotid-cavernous fistulas. Neurosurgery. 1988 Feb;22(2):285-9.
• Ishijima K, Kashiwagi K, Nakano K, et al. Ocular manifestations and prognosis of secondary glaucoma in patients with carotid-cavernous fistula. Jpn J Ophthalmol. 2003;47:603-8.

Contact

• Jonathan Kim, MD, Associate Professor of Clinical Ophthalmology, jonkim@chla.usc.edu
• Nadim Rayess, MD, PGY-2 Ophthalmology Resident, nadim.rayess@med.usc.edu

Section Editors

• Vivek Patel, MD, Associate Professor of Clinical Ophthalmology, Program Director, vivek.patel@med.usc.edu
• Jesse Berry, MD, Assistant Professor of Clinical Ophthalmology, Associate Program Director, jesse.berry@med.usc.edu

Produced by: Monica Chavez, John Daniel, Joseph Yim and Dr. Vivek Patel