Andre J. Witkin
A 71-year-old man was referred to our practice for evaluation of a
chronically red left eye for the past 3 months. There was no associated
discharge or pain. He also initially noted blurry vision in the left eye while
watching a football game 3 months ago. Since that point, he feels the blurry
vision has progressively worsened. Two months prior to presentation, he
developed binocular diplopia on upgaze, which has persisted. There was no
history of trauma.
The patient’s ocular history was significant for open-angle
glaucoma in his left eye, which was currently being treated with Xalatan
(latanoprost, Pfizer). For the past few months, IOP had been slightly elevated
in his left eye.
His medical history included hypertension, mitral valve prolapse,
gastroesophageal reflux disease and chronic headache. He was initially
evaluated for a headache and a swishing sound in his left ear by neurology 1
year ago. After an extensive evaluation including an MRI, he was diagnosed with
hypertension and started on lisinopril, and his headache improved.
On examination, the patient’s best corrected visual acuity was
20/25 in the right eye and 20/40 in the left eye. His pupils were reactive with
no afferent pupillary defect. Ocular motility showed mild restriction of upgaze
in his left eye. His color vision with Ishihara color plates was full in both
eyes, and Hertel exophthalmometry showed 3 mm of relative proptosis of the left
eye. His IOPs were 21 mm Hg in the right eye and 28 mm Hg in the left eye.
|Figure 1. Left eye:
Dilated corkscrew-shaped conjunctival vessels and chemosis.
Images: Nandakumar N, Marx J
Anterior segment examination showed dilated conjunctival vessels in a
corkscrew configuration and chemosis in the left eye (Figure 1). The right eye
had a normal anterior segment exam.
Posterior segment examination showed drusen in both eyes, mildly
tortuous retinal veins in the left eye and healthy-appearing optic nerves. On
auscultation, there was an audible bruit heard over the left eye.
What is your diagnosis?
Red eye, chemosis
Our patient presented with a red eye, chemosis, exophthalmos and
increased IOP in his left eye.
The differential diagnosis includes vascular lesions such as
carotid-cavernous fistulas (direct and indirect), arteriovenous malformations
and cavernous sinus thrombosis. Autoimmune and inflammatory processes such as
thyroid eye disease, scleritis and orbital pseudotumor can also be considered.
Other etiologies, including processes that elevate episcleral venous pressure
such as Sturge-Weber, are also in the differential diagnosis. Chronic
conjunctivitis and blepharitis, while unlikely, can also be considered.
Carotid-cavernous fistulas (C-C fistulas) are abnormal communications
between the internal or external carotid arteries and the cavernous sinus. They
can be classified based on velocity of blood flow (high vs. low), anatomy
(direct vs. dural) and etiology (traumatic vs. spontaneous). Direct C-C
fistulas are connections between the intracavernous portion of the internal
carotid artery and the cavernous sinus. They are high-flow fistulas that are
commonly caused by a traumatic tear in the arterial wall. On the other hand,
dural C-C fistulas are low-flow fistulas that have connections between the
meningeal branches of the internal or external carotid arteries and the dural
veins. They can occur spontaneously or from hypertension, diabetes or other
vascular disorders. Ocular manifestations of C-C fistulas include chemosis,
bruit, exophthalmos, corkscrew-shaped conjunctival vessels and glaucoma
secondary to elevated episcleral venous pressure. Ocular motility disturbance,
optic nerve ischemia and tortuous retinal veins can also be seen.
Most intracranial arteriovenous malformations are congenital and can
vary substantially in size. They may manifest as a headache or seizure or have
focal neurological symptoms based on their location; however, they are often
Thyroid eye disease can present in a number of ways, including bilateral
proptosis, eyelid retraction, restrictive myopathy resulting in diplopia, lid
lag, conjunctival injection and chemosis. Compressive optic neuropathy has been
reported in less than 5% of cases, and patients may present with decreased
color vision, a relative afferent pupillary defect and/or visual field defects.
A CT scan often shows enlargement of the extraocular muscles sparing the
Orbital pseudotumor may also have a number of different ocular
presentations. It is usually a unilateral process that can manifest as
proptosis, diplopia, increased IOP, lid erythema and edema, ocular pain and/or
lacrimal gland enlargement. A B-scan ultrasonogram of the eye may demonstrate a
T-sign and thickening of the sclera. As opposed to thyroid eye disease, a CT
scan will show enlargement of both the extraocular muscles and tendons.
Patients with scleritis often present with pain, photophobia and a red
eye. Ocular findings may include diffuse or sectoral areas of deep conjunctival
injection, tenderness to touch, chemosis, peripheral keratitis, thickened and
inflamed posterior sclera, chorioretinal folds, retinal edema and elevated IOP.
Sturge-Weber syndrome may present with dilated tortuous conjunctival and
episcleral vessels, increased IOP, heterochromia irides, diffuse choroidal
hemangiomas and serous retinal detachments. Extraocular findings include port
wine stains, mental retardation and seizures.
Further workup included an MRI/MRA, thyroid function tests and
gonioscopy. The MRI demonstrated a dural C-C fistula that was better visualized
on the MRA (Figure 2). Thyroid function tests were within normal limits.
Gonioscopy showed open angles without blood in Schlemm’s canal or
neovascularization of the angle.
|Figure 2. MRA with arrow demonstrating the
cavernous carotid fistula.
Diagnosis and management
Based on the history, examination and radiological findings, a diagnosis
of a carotid-cavernous dural fistula was made. Treatment options included
observation, conservative medical management with blood pressure control,
carotid compression, angiography and endovascular embolization, or
neurosurgery. After extensive discussions with several physicians, the patient
elected to undergo angiography and endovascular embolization of the fistula.
The criteria for undergoing angiography with endovascular embolization
of a C-C fistula include glaucoma, diplopia, intolerable bruit or headache, and
severe proptosis causing exposure keratopathy. Risks of the procedure include
ischemic or hemorrhagic stroke, occlusion of the superior ophthalmic vein
leading to a central retinal vein occlusion, no improvement in proptosis, red
eye or high IOP, and reopening of the fistula.
Figure 3. Angiogram and treatment.
Our patient successfully underwent embolization of the C-C fistula
(Figure 3), and we continue to closely follow him postoperatively.
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- Namrata Nandakumar, MD, and Jeffrey Marx, MD, can be reached at New
England Eye Center, Tufts University School of Medicine, 750 Washington St.,
Box 450, Boston, MA 02111; 617-636-4219; fax: 617-636-4866; Web site:
- Edited by Mark E. Patron, MD, and Andre J. Witkin, MD. Drs. Patron
and Witkin can be reached at New England Eye Center, Tufts University School of
Medicine, 750 Washington St., Box 450, Boston, MA 02111; 617-636-4219; fax:
617-636-4866; Web site: www.neec.com.