Proptosis is protrusion of the eyeball. Exophthalmos means the same thing, and this term is usually used when describing proptosis due to Graves disease. Disorders that may cause changes in the appearance of the face and eyes that resemble proptosis but are not include hyperthyroidism without infiltrative eye disease, Cushing disease, and severe obesity.

Proptosis

Etiology

The most common cause is Graves disease (see Table 9: Symptoms of Ophthalmologic Disorders: Some Causes of Proptosis), which causes edema and lymphoid infiltration of the orbital tissues.

Table 9
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Some Causes of Proptosis Cause Suggestive Findings Diagnostic Approach Graves disease Eye symptoms: Eye pain, lacrimation, dry eyes, irritation, photophobia, ocular muscle weakness causing diplopia, vision loss caused by optic nerve compression Systemic symptoms: Palpitations, anxiety, increased appetite, weight loss, insomnia, goiter, pretibial myxedema (see Thyroid Disorders: Symptoms and Signs) Thyroid function tests Carotid-cavernous sinus or dural-cavernous sinus fistula Pulsating proptosis with an orbital bruit Magnetic resonance angiography Cavernous sinus thrombosis Ophthalmoplegia, headache, ptosis, decreased visual acuity, fever CT or MRI Congenital glaucoma and unilateral high myopia Tearing, blepharospasm, redness Intraocular pressure measurement and funduscopy by ophthalmologist Orbital cellulitis Redness, fever, pain, impaired visual acuity, impaired or painful extraocular movements Usually unilateral CT or MRI Orbital tumors (eg, lymphoma, hemangioma, vascular malformations) Decreased visual acuity, diplopia, pain MRI or CT Retrobulbar hemorrhage Decreased visual acuity, diplopia, pain, ophthalmoplegia, risk factors Immediate CT or treatment based on clinical findings Spheno-orbital meningioma Pain, headache, visual field defects, ophthalmoplegia MRI or CT

Evaluation

Rate of onset may provide a clue to diagnosis. Sudden unilateral onset suggests intraorbital hemorrhage (which can occur after surgery, retrobulbar injection, or trauma) or inflammation of the orbit or paranasal sinuses. A 2- to 3-wk onset suggests chronic inflammation or orbital inflammatory pseudotumor (non-neoplastic cellular infiltration and proliferation); slower onset suggests an orbital tumor.

Ocular examination findings typical of hyperthyroidism but unrelated to infiltrative eye disease include eyelid retraction, eyelid lag, temporal flare of the upper eyelid, and staring. Other signs include eyelid erythema and conjunctival hyperemia. Prolonged exposure of larger-than-usual areas of the eyeball to air causes corneal drying and can lead to infection and ulceration.

Red flags

The following findings are of particular concern:

• Eye pain or redness
• Headache
• Loss of vision
• Diplopia
• Fever
• Pulsating proptosis
• Neonatal proptosis

Testing

Proptosis can be confirmed with exophthalmometry, which measures the distance between the lateral angle of the bony orbit and the cornea; normal values are < 20 mm in whites and < 22 mm in blacks. CT or MRI is often useful to confirm the diagnosis and to identify structural causes of unilateral proptosis. Thyroid function testing is indicated when Graves disease is suspected.

Treatment

Lubrication to protect the cornea is required in severe cases. When lubrication is not sufficient, surgery to provide better coverage of the eye surface or to reduce proptosis may be required. Systemic corticosteroids (eg, prednisone 1 mg/kg po once/day for 1 wk, tapered over ≥ 1 mo) are often helpful in controlling edema and orbital congestion due to thyroid eye disease or inflammatory orbital pseudotumor. Other interventions vary by etiology. Graves exophthalmos is not affected by treatment of the thyroid condition but may lessen over time. Tumors must be surgically removed. Selective embolization or, rarely, trapping procedures may be effective in cases of arteriovenous fistulas involving the cavernous sinus.

Key Points

• The most common cause of bilateral proptosis is Graves disease.
• Acute unilateral proptosis suggests infection or vascular disorder (eg, hemorrhage, fistula, cavernous sinus thrombosis).
• Chronic unilateral proptosis suggests tumor.
• Do CT or MRI and thyroid function testing when Graves disease is suspected.
• Apply lubrication to exposed cornea.

Last full review/revision November 2012 by Kathryn Colby, MD, PhD