Orbital pseudotumor is a swelling of the tissues behind the eye in an area called the orbit. The orbit is the bony cavity in the skull where the eye sits. It protects the eyeball and the muscles and tissue that surround it.
Unlike cancerous tumors, an orbital pseudotumor does not spread to other tissues or places in the body.
Alternative NamesIdiopathic orbital inflammatory syndrome (IOIS)
Causes, incidence, and risk factors
The cause is unknown. It most commonly affects young women, although it can still occur at any age.
- Pain in eye - may be severe
- Restricted eye movement
- Decreased vision
- Double vision
- Eye swelling (proptosos)
- Red eye (rare)
Signs and tests
Signs of pseudotumor can be seen when the eye is examined. Tests must be done to tell the difference between a pseudotumor and cancerous tumor and eye problems that can occur in people with thyroid disease.
Tests may include:
Mild cases may go away without treatment. More severe cases will usually respond to treatment with corticosteroids. Very severe cases may develop damaging pressure on the eye, and require surgical movement of the bones of the orbit to relieve pressure on the eyeball.
Most cases are mild and do well. Severe cases may be resistant to treatment and visual loss may occur. Orbital pseudotumor usually involves only one eye.
Severe cases of orbital pseudotumor may push the eye forward to the extent that the lids can no longer protect the cornea, leading to drying of the affected eye. This can lead to damage to the clarity of the cornea, or to corneal ulcer (wound). The eye muscles may not be able to properly aim the eye, and double vision may result.
Calling your health care provider
Patients with pseudotumor will be closely followed by an ophthalmologist with experience in the treatment of orbital disease.
If you experience irritation of the cornea, redness, pain, or decreased vision, call your ophthalmologist or general health care provider right away.
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Mendenhall WM, Lessner AM. Orbital pseudotumor. Am J Clin Oncol. 2010 Jun;33(3):304-6.
Karesh JW, On AV, Hirschbein MJ. Noninfectious orbital inflammatory disease. In: Tasman W, Jaeger EA, eds. Duane’s Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 35.
Glaser JS, Tse DT, Chang WJ. Orbital disease and neuro-ophthalmology. In: Tasman W, Jaeger EA, eds. Duane’s Ophthalmology. 15th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2009:chap 14.
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.