A pterygium is an abnormal, non-cancerous growth of the conjunctiva. The conjunctiva is a thin membrane lining the inside of the eyelid and part of the eyeball. It is located between the sclera, or the "white of the eye" which surrounds the eyeball, and the cornea, the dome-shaped window covering the front of the eye which is responsible for the refraction of light.

Excessive growth of the conjunctiva leads to a pterygium, which appears as a fleshy spot—whitish in color and containing blood vessels—extending onto the surface of the eye. If a pterygium continues to grow, it may spread onto the cornea. A pterygium that grows large enough may eventually distort the corneal surface and blur vision.

The Conjunctiva

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The exact cause of pterygium is unknown. The most common factors that contribute to pterygium include:

  • Excessive exposure to sunlight
  • Sex: male
  • Increasing age
  • Working outdoors
  • Excessive exposure to harsh environmental conditions such as dust, dirt, heat, wind, dryness, and smoke
  • Excessive exposure to allergens such as industrial solvents and chemicals

Risk Factors

A risk factor is something that increases the chances of developing a disease or a condition.

Risk factors for pterygium include:

  • Work in occupations with excessive exposure to environmental conditions (sunlight, dust, dirt, heat, dryness, wind, smoke)
  • Work in occupations with excessive exposure to solvents or chemicals
  • Family members with pterygium


The symptoms of pterygia vary from person-to-person. In some people, pterygia remain small and do not affect vision. These pterygia are noticed only because of their abnormal cosmetic appearance. In other people, pterygia grow quickly and cause severely blurred vision. Pterygia do not cause pain.

Symptoms include:

  • Redness
  • Dryness
  • Irritation
  • Tearing
  • Sensation of something in the eye
  • Blurred vision

If you experience any of these symptoms do not assume it is due to pterygium. These symptoms may be caused by other eye conditions. If you experience any one of them, see your eye doctor.


Your eye doctor will ask about symptoms and medical history, and perform a complete eye examination. Tests may include the following:

  • Visual acuity—a test to measure your ability to see and read the smallest letters on an eye chart mounted 14 to 20 feet away
  • Slit lamp examination—a bright light with magnification used to view the eye
  • Corneal topography—a computerized test that maps changes to the curvature of the cornea
  • Photo documentation—photography to record the degree of growth of a pterygium


The main goals of treating a pterygium are to:

  • Evaluate size
  • Prevent inflammation
  • Prevent infection
  • Aid in the healing process, if surgery is performed

Treatment options include:


  • Periodic eye examination, usually when the pterygium causes no or minimal symptoms
  • If symptoms increase, additional treatments may include:
    • Medications—prescription antibiotics to prevent infection; corticosteroids to reduce inflammation;ocular lubricants, such as artificial tears
    • Radiation therapy]]> to stop pterygium cells from reforming


If vision becomes severely blurred, the pterygium may need to be surgically removed. This is commonly done on an outpatient basis. On occasion, a pterygium can return. Steps may be taken during the operation to prevent this from happening.

In rare cases a pterygium causes serious scarring of the cornea. If this happens, a corneal transplant may be needed.

Mitomycin C to aid in healing and prevent recurrence, once the pterygium has been surgically removed.

Talk with your doctor about the best treatment plan for you.


To help reduce your chances of developing a pterygium, take the following steps:

  • Wear dark glasses with UV protection to shield the eyes from sun, dust, and wind
  • Avoid harsh environmental factors to slow the growth or regrowth of pterygium