What is a Pterygium?
A pterygium is a benign elevated piece of tissue in the conjunctiva (conjunctiva is the outer layer of tissue containing the blood vessels over the outer white portion of the eye called the sclera) of the eye. The condition is a proliferation of tissue that grows from the white portion of the eye onto the cornea (clear structure of the eye).
The Anatomy of a Pterygium
A pterygium has several different anatomical portions:
- Body- the main elevated portion containing numerous blood vessels.
- Inferior and Superior Edge – upper and lower border of the growth on the cornea
- Head- the front leading edge that is elevated and can contain blood vessels.
- Stocker’s Line- a linear iron deposit ahead of the head of the pterygium.
- Fuchs’ Patches- grayish areas of tissue in front of the pterygium.
It is believed that pterygia or pterygiums develop secondary to sunlight (UV radiation), wind, dust, dirt, and dry eyes. Pterygiums are more prevalent in areas near the equator, windy climates, hereditary traits, and many work environments. People who work outdoors are much more likely to develop the eye condition, such as farmers, commercial fishermen, tennis players, golfers, and etc… Pterygiums occur more commonly on the nasal side of the eye versus the temporal side.
Redness, irritation, foreign body sensation, growth on eye, tearing, scratchy, and itchy are common symptoms.
There are numerous treatments available for removing pterygiums. If the pterygium is small and not near the pupil, it does not need to be removed. During a flare-up of symptoms, non-steroidal anti-inflammatory eye drops and/or corticosteroid eye drops can be used to treat the inflammation.
If it starts to progress toward the pupil, it needs to be surgically removed in order to keep scarring from the pterygium blurring a person’s vision.
Simple excision of the pterygium and leaving the sclera exposed has been in the past the common method for removal of the tissue growth. This technique has a high reoccurrence rate and is not used very often today.
Radiation after Removal
Radiation treatment was used to stop the reoccurrence but is not used often today secondary to the complications related to radiation treatment.
Removal and Treatment of the Area with Mitomycin C
The pterygium is removed and Mitomycin C is applied to the area of the surgery and kept in place for a few minutes. The conjunctiva is sutured back in place up to the cornea. Mitomycin C can also be used as eye drops for up to two weeks following surgery. Using the Mitomycin C has very good results and reoccurrence is not common.
The pterygium is removed with no cautery of the limbal area and Mitomycin C is injected into the conjunctiva. The conjunctiva is not sutured back in place and the eye heals without sutures. This technique has very good results as well.
Removal with Conjunctival Graft
The pterygium is removed and a conjunctival graft from under the upper lid is sutured or glued in place to cover the area where the pterygium was removed. This portion of the conjunctiva has not been exposed to the environment and is still normal tissue. The graft decreases the reoccurrence rate.
Removal of a with Amniotic Membrane Graft
The pterygium is removed and an amniotic membrane is placed over the area where the pterygium was removed. Amniotic membrane tissue is acquired from the inner layer of the human placenta. The amniotic membrane may be sutured or Tissell glue is used to keep the graft in place.
Since exposure of the eye to our environment is the major cause of a pterygium, you should protect your eyes especially if you work or live in an area where you are more likely to develop it. Always wear sunglasses outdoors and wrap-around types of sunglasses are better. Keep your eyes lubricated with artificial tears and rinse your eyes with artificial tears if any dust or dirt gets in your eyes.