A pterygium is a non-cancerous growth that starts in the of the clear, thin tissue (conjunctiva ) of the eye. This growth covers the white part of the eye (sclera) and extends onto the cornea. It is often slightly raised and contains visible blood vessels. The problem may occur on one or both eyes.
Causes, incidence, and risk factors
The exact cause is unknown. It is more common in people who have a lot of exposure to sunlight and wind, such as people who work outdoors.
Risk factors are exposure to sunny, dusty, sandy, or windblown areas. Farmers, fishermen, and people living near the equator are often affected. Pterygium is rare in children.
The main symptom of a pterygium is a painless area of raised white tissue that has blood vessels on the inner or outer edge of the cornea. Sometimes the pterygium has no symptoms. However, it may become inflamed and cause burning, irritation, or a feeling like there's something foreign in the eye. Vision may be affected if the grows extends far enough onto the cornea.
Signs and tests
A physical examination of the eyes and eyelids confirms the diagnosis. Special tests are usually not needed.
Treatment is usually not needed. Using artificial tears to keep the eyes moist may help prevent a pterygium from becoming inflamed. Mild steroid eye drop can be used to calm inflammation if it occurs. Surgery can be used to remove the growth for cosmetic reasons or if it block vision.
Most pterygia cause no problems and do not need treatment. If a pterygium affects the cornea, removing it can have good results.
Ongoing inflammation can cause a pterygium to grow farther onto the cornea. A pterygium can return after it is removed.
Calling your health care provider
People with pterygium should be seen by an ophthalmologist each year, so that the condition can be treated before it affects vision.
Call for an appointment with your ophthalmologist if you have had a pterygium in the past and your symptoms return.
Taking steps to protect the eyes from ultraviolet light such as wearing sunglasses and a hat with a brim may help prevent this condition.
Farjo QA, Sugar A. Pterygium and conjunctival degenerations. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, MO: Mosby Elsevier; 2008:chap 4.9.
Naidu SS, Ocampo-Goldberg AC. Corneal Topography. In: Tasman W, Jaeger EA, eds. Foundations of Clinical Ophthalmology. 2012 ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2012:vol 2; chap 112.