A pterygium is a fleshy tissue growth on your eye's conjunctiva, which is the transparent membrane covering the outer surface of your eyeball. In some cases, the growth can remain small, or it can grow large enough to cover part of the cornea, which can affect your vision. It's a benign or noncancerous growth often shaped like a wedge and is more often found on the nasal (inner) side of the cornea. Larger pterygia can alter the shape of the cornea which produces astigmatism and causes blurred vision. Pterygia are believed to be caused by ultraviolet light crossing into the eye from the more exposed lateral (outer) side and absorbing onto the nasal side. Other causes may include dry eyes and exposure to wind, dust, sand, or smoke.
It's possible to confuse pterygia with pinguecula. Similar to a pterygium, a pingueculum grows on the conjunctiva, but a pingueculum does not grow over the cornea. It looks like a yellowish patch or bump and is a benign degeneration of the conjunctiva that occurs as people get older. Pinguecula are also caused by damage due to exposure to ultraviolet light, but they are different than pterygia.
Causes, Risk Factors
UV radiation from sunlight is considered to be the most common cause of pterygia. Therefore, this condition is more prevalent in warmer climates and regions closer to the equator, and it is sometimes referred to as "surfer's eye". Other causes include dry eyes and exposure to wind and sand. In addition, pterygia are twice as likely to occur in men than women. They are associated with early exposure to the sun, especially during childhood and teen years.
Wearing sunglasses with 100% UV protective lenses and side shields can help protect your eyes from sunlight, dust, and wind. Also, wearing wide-brimmed hats can help keep sunlight from harming your eyes. Frequently using artificial tears and taking omega-3 fatty acid supplements to treat dry eyes may help to prevent pterygia from forming. Once a pterygium has developed, however, seeking professional treatment may be required to resolve the condition.
The main symptom of a pterygium is an area of raised white tissue that has visible blood vessels on the inner or outer edge of the cornea. Other symptoms can range in severity, and in some cases, there are no symptoms. However, the growth may become inflamed, and ongoing inflammation can cause it to grow farther into the cornea. Some symptoms may include:
- • Persistent redness and/or swelling.
- • Tearing, burning, dry, or scratchy feeling.
- • Blurry vision.
- • Obstruction of vision (in advanced cases).
To diagnose a pterygium, your eye doctor may be able to perform a straightforward physical examination using a slit lamp. With magnification and bright lighting, your doctor can use this lamp to see the growth more clearly. However, if your eye doctor needs to do additional tests, they may include a visual acuity test (i.e., reading letters on an eye chart), corneal topography (measuring curvature changes in your cornea), or photo documentation (taking pictures of your eye to track the growth rate of the pterygium).
In mild cases, the use of lubricating or steroid tear drops or ointments combined with vigilant use of sunglasses and hats may be adequate to treat the symptoms of a pterygium. Surgery is considered to remove the growth when irritation is not relieved with artificial tear drops or ointments, or to remove a pterygium for cosmetic reasons. Surgery is highly recommended if the pterygium has grown to the extent that it causes blurred and/or obstructed vision. At New Vision Eye Center, surgery is a comfortable experience. The patient is lightly sedated and the eye is thoroughly numbed. The patient does not see the surgery being performed and does not feel discomfort during the procedure. As the pterygium is removed, an amniotic graft is placed on the area and medicine is applied to help prevent regrowth. The latest advancements in pterygium surgery have made the procedure highly successful.