Idiopathic orbital inflammatory syndrome (IOIS)
Orbital pseudotumor is the swelling of tissue behind the eye in an area called the orbit. The orbit is the hollow space in the skull where the eye sits. The orbit protects the eyeball and the muscles and tissue that surround it. Orbital pseudotumor does not spread to other tissues or places in the body.
The cause is unknown. It mostly affects young women, although it can occur at any age.
Symptoms may include:
- Pain in eye, and it may be severe
- Restricted eye movement
- Decreased vision
- Double vision
- Eye swelling (proptosis)
- Red eye (rare)
Exams and Tests
The health care provider will examine your eye. If you have signs of pseudotumor, additional tests will be done to make sure you don't have other conditions that may look like pseudotumor. The two most common other conditions are:
- A cancer tumor
- Thyroid eye disease
Tests may include:
Mild cases may go away without treatment. More severe cases most often respond well to corticosteroid treatment. If the condition is very bad, the swelling may put pressure on the eyeball and damage it. Surgery may be needed to remove part of the bones of the orbit to relieve the pressure.
Most cases are mild and outcomes are good. Severe cases may not respond well to treatment and there may be some loss of vision. Orbital pseudotumor most often involves only one eye.
Severe cases of orbital pseudotumor may push the eye forward so much that the lids cannot cover and protect the cornea. This causes the eye to dry out. The cornea may become cloudy or develop an ulcer. Also, the eye muscles may not be able to properly aim the eye which can cause double vision.
When to Contact a Medical Professional
People with this condition need regular follow-up care with an eye doctor who is familiar with the treatment of orbital disease.
Call your provider right away if you have any of the following problems:
- Irritation of the cornea
- Decreased vision
McNab AA. Orbital infection and inflammation. In: Yanoff M, Duker JS, eds. Ophthalmology. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 12.14.
Wang MY, Rubin RM, Sadun AA. Ocular myopathies. In: Yanoff M, Duker JS, eds. Ophthalmology. 5th ed. Philadelphia, PA: Elsevier; 2019:chap 9.18.
Yanoff M, Cameron JD. Diseases of the visual system. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 423.