Pterygium refers to a pink colored, triangle-shaped tissue growth on the cornea. The cornea is the clear outer layer of the eye. Pterygium may start as a pinguecula (a growth resembling a yellow bump or spot on the conjunctiva). A conjunctiva is a membrane that covers the white of the eye. Pterygium grows on the side closest to the nose. It grows towards the pupil area.
Pterygium may grow slowly throughout one's lifetime. It may, however, grow large enough to cover part of the cornea. When that happens, it may interfere with vision or cause irritation. Still, pterygium may stop growing altogether. Nevertheless, it’s very rare that pterygium would grow so large as to cover the pupil of the eye. It is prevalent in sunny places or those near the equator. It is also common in men between the ages of 20 and 40. It may also affect anyone who lives in a sunny area. The disease can grow in one eye (unilateral) or both eyes (bilateral). Pterygium is not contagious. It is usually small and harmless.
Also Known As
Causes and Risk Factors
It is not clear how individuals develop pterygium. However, researchers associate it with the sun. Those likely to develop it might be frequently exposed to Ultraviolet (UV) rays. They are people who spend a significant amount of their time outdoors. Exposure to a combination of dry eyes, dust and wind can also be said to increase the likelihood of the condition. Children and teenagers who grow up near the equator are also at risk of developing pterygium.
Signs & Symptoms
The symptoms for pterygium include:
- A pinkish, whitish or reddish lesion on the eye
- Feeling that there is a foreign body in the eye
- Blurry, decreased or double vision
- Dryness in the eye
- Burning or itching sensation
- The eyes might feel gritty
A complete eye examination will be conducted. The focus is on visual acuity, changes in manifest refraction and corneal topography. The eye professional will diagnose the condition by using a slit lamp. A slit lamp is a special microscope used to check the front part of the eye. Photos may also be taken to keep a record of the growth. The pictures may help to measure if astigmatism (abnormal curvature) is developing.
Treatment is directed towards reducing the inflammation and irritation.
Lubricating or steroid eye drops may be recommended. These help reduce redness and soother irritation. Vasoconstrictor drops can also be used. Artificial tears may relieve irritation and burning. The patient can also use anti-allergy drops or tropical eye drops and ointments to reduce inflammation.
When the pterygium affects vision, a surgical excision is recommended. Surgery is also recommended if the growth is too large and uncomfortable.
A surgical procedure mitomycin-C can help prevent the formation of scar tissue.
Some people may want the pterygium removed for cosmetic reasons. However, surgery is not necessary unless it affects vision. Pterygium is likely to grow back especially in people under 40 years.
It is possible the pterygium may grow back after removal. The new growth could be more aggressive. It usually grows back within 12 months.
The surgeon may carry out a transplant. That is, use tissue from the conjunctiva and placenta to fill the empty space left by the pterygium’s removal. The filler tissue is glued or stitched onto the affected area to avoid a re-growth. Antimetabolite drugs or radiation can then be applied on the area that was operated on.
After the transplant, the patient may wear a patch for one or two days. He or she can resume normal activities in a few days. Steroid eye drops can be taken for several weeks or months. This is done to prevent the pterygium from re-growing. The steroids also help with inflammation.
The corneal extension of the pterygium should initially be measured and followed every 1 to 2 years. This is done to determine the growth rate of the disease.
Astigmatism can result from pterygium. This happens when the pterygium grows too large. The large pterygium then alters the shape of the cornea causing blurred vision. When a pterygium grows over the cornea, it may cause vision loss.
Other complications include corneal scarring and corneal perforation among others.
The following can help prevent pterygium:
- Wearing sunglasses for protection against UV rays
- Wearing goggles or glasses for protection against dust
- Putting on a wide-brimmed hat in areas with strong sunlight
- Using artificial tears when the eyes get dry