Pterygium is a growth that develops across the clear cornea of the eye that can affect people who spend a lot of time outside in the sun.
The pterygium is usually pink and fleshy and forms on the side of the eye nearest to the nose.
Pterygium can cause discomfort, and interfere with vision if the growth is allowed to continue.
Symptoms of pterygium
Sometimes, a pterygium causes no symptoms other than its appearance. An enlarging pterygium, however, may cause redness and inflammation.
In some cases, a pterygium can grow onto the centre of the cornea (the clear, outer layer of the eye covering the iris and pupil) and interfere with vision. It may also distort the shape of the cornea, causing a condition called astigmatism. The result can be blurred vision.
Symptoms of pterygium may include:
- Gritty feeling
- Sensation of a foreign body in the eye
- Blurred vision
Causes of pterygium
It's not clear what causes a pterygium to develop. But most experts believe that significant risk factors include:
Pterygium occurrence is much greater among people who live near the equator. But it also can develop in anyone who lives in a sunny climate. It's most often seen in young adults aged 20 to 40. It appears to be more common in men than in women.
Pterygium is often preceded by a related non-cancerous condition called pinguecula (pin-GWEK-yoo-la). This is a yellowish patch or bump on the conjunctiva near the cornea. The conjunctiva is the thin, moist membrane on the surface of the eye.
Treatment of pterygium
Seek medical advice or see your optometrist if you have symptoms of pterygium. It can be diagnosed by examining the front part of your eye with a special microscope called a slit lamp.
The majority of pterygia in the United Kingdom are very slow growing , cause only mild symptoms and do not require surgical removal. If a temporary worsening of the inflamed condition causes redness or irritation, it can be treated with:
- Lubricating eyedrops ('artificial tears') or ointments
- Occasional use of vasoconstrictor eyedrops
- Short course of steroid eyedrops
If the lesion causes persistent discomfort or interferes with vision, it can be surgically removed during an outpatient procedure. The operation can be performed under local anaesthesia (awake) or general anaesthesia (asleep). The choice is based on anticipated length of surgery, the size of the pterygium, the surgeon's advice and the patient's own preferences.
Surgery has a risk of complications, such as the recurrence of a more aggressive lesion. So surgery is usually considered only if:
- Conservative treatments have failed
- The patient's eyesight is at risk
The type of surgery most commonly used today uses a graft from the patient's own conjunctiva (surface eye tissue) or preserved amniotic membrane (the thin tissue forming the sac in which a foetus grows) to fill the empty space created by the removal of the pterygium. In this procedure, the pterygium is removed and the conjunctiva or amniotic membrane is glued or stitched onto the affected area.