Tissue that grows from the conjunctiva onto the surface of the cornea.

Causes, incidence, and risk factors

A pterygium is a non-malignant growth that frequently grows onto the cornea from conjunctiva on the inner side of the eye. It may less frequently also occur on the outer side if the cornea. One or both eyes may be involved. The cause is unknown, but it is more frequent in people with excess exposure to sun light. Risk factors are exposure to sunny, dusty, sandy, or windblown areas. Farmers, fishermen, and people living near the equator are commonly involved. It is rare in children.

Signs and tests

A physical examination of the eye and lids confirms the diagnosis. No special tests are usually necessary.

Treatment

No treatment is required unless the pterygium encroaches on the pupillary area and obstructs vision; then it should be surgically removed. Protective glasses and a hat with a brim should be worn to prevent recurrences in people who work outdoors.

Expectations (prognosis)

Most pterygia cause no problem and need no treatment. If pterygium encroaches on the pupillary area of the cornea, results are usually good after removal.

Complications

Recurrence after removal.

Calling your health care provider

People with pterygium should be seen by an ophthalmologist annually, so that encroachment on the pupil can be recognized and treated before interference with vision. Call for an appointment with your ophthalmologist if you have had a pterygium in the past and symptoms recur.

Prevention

Eye protection from ultraviolet light may have a preventive effect.