Case Presentation: Demanding prompt evaluation, carotid-cavernous sinus fistula (CCF) is a rare etiology of the “red eye.” Despite the risk for vision loss, this diagnosis can be missed due to its subtle and nonspecific presentation. We present the case of progressively worsening conjunctivitis and exophthalmos in an elderly woman following a fall who was found to have CCF, a rare but interesting neuroophthalmological finding.Patient is a 77-year-old female with past medical history of hypertension and diabetes who presented following a mechanical fall. Physical exam revealed right eye with subconjunctival hemorrhage but was grossly unremarkable otherwise. Computed tomography (CT) head revealed scattered subarachnoid hemorrhage, hemorrhagic contusion of the right frontal temporal lobe, and subdural hematoma along the right frontal temporal region. After inpatient consultation with neurosurgery and ophthalmology, the patient was discharged with recommendation for close follow-up in the outpatient setting. During the patient’s ophthalmology appointment, there was concern for proptosis of the right eye and increased intraocular pressure (IOP). Repeat CT facial bones demonstrated interval enlargement of the right superior ophthalmic vein, exophthalmos of the right eye, and enlargement of the right extraocular muscles. Notably, in the setting of trauma and right frontal temporal hematoma, these findings were consistent with right CCF. The patient underwent successful embolization of the CCF by interventional radiology (IR). Interval angiogram one month later revealed resolution of the CCF. Repeat ophthalmologic evaluation showed improved IOP and intact vision.
Discussion: Often masqueraded as conjunctivitis or uveitis, CCF is a rare but serious condition. CCF is classified as direct or dural. Direct CCFs involve a tear in the internal carotid artery within the cavernous sinus while dural arteriovenous shunts involve abnormal communications between the cavernous sinus and the meningeal branches of the internal or external carotid arteries. Risk factors for development of CCF include trauma, as in the case with our patient, but also hypertension, atherosclerotic vascular disease and Ehlers-Danlos syndrome. Presentation depends on location, type and size of the fistula. Symptoms, though, can be vague, including proptosis, double vision, or a red eye. Ophthalmologic exam may reveal only increased IOP. However, misdiagnosis can lead to vision loss. Diagnosis is with CT head and angiogram. Treatment is with IR-guided endovascular embolization.
Conclusions: CCF should be considered when evaluating the patient with the “red eye” to ensure successful management of this serious but reversible condition.