Pterygium

Definition:
Pterygium is a raised, wedge-shaped growth of the conjunctiva. It is most common among those who live in tropical climates or spend a lot of time in the sun.

Pathology:
Pterygium in the conjunctiva is characterized by elastotic degeneration of collagen and fibrovascular proliferation. It has an advancing portion called the head of the pterygium, which is connected to the main body of the pterygium by the neck. Sometimes a line of iron deposition can be seen adjacent to the head of the pterygium called Stocker's line. The location of the line can give an indication of the pattern of growth.
Anatomically, the pterygium is comprised of several segments:

• Fuchs' Patches (minute gray blemishes that disperse near the pterygium head).
• Stocker's Line (a brownish line composed of iron deposits).
• Hood (fibrous nonvascular portion of the pterygium).
• Head (apex of the pterygium, typically raised and highly vascular).
• Body (fleshy elevated portion congested with tortuous vessels).
• Superior Edge (upper edge of the triangular or wing shaped portion of the pterygium).
• Inferior Edge (lower edge of the triangular or wing shaped portion of the ptyerygium).

Symptoms:
Symptoms of pterygium include

1. Persistent redness
2. Inflammation
3. Foreign body sensation
4. Dry and itchy eyes.
5. In advanced cases the pterygium can affect vision as it invades the cornea with the potential of induced astigmatism and corneal scarring.

Treatment:
The majority of pterygia are inactive and can be treated with topical drops. Decongestant eye drops to make the eye appear less red and artificial tear drops to make the eye more comfortable when the pterygium flares up, can be used. If these are sufficient to maintain comfort and cosmesis then surgery is not indicated.
If this fails:

1. The 90 Sr plaque is a concave metal disc about 1-1.5cm in diameter which is hollow and filled with an insoluble strontium salt. The side placed on the eye is a very thin and delicate silver film that will contain the strontium but allow the beta particles to escape. The dose of radiation to the conjunctiva is controlled by the time that the plaque is left in contact with the surface. The integrity of the plaque surfaces is paramount to prevent exposure to patients and so is wipe tested to see if radioactive matter is escaping.
2. Conjunctival auto-grafting is a surgical technique that is effective and safe procedure for pterygium removal. When the pterygium is removed, the conjunctiva is also extracted, which is replaced from another peice of conjunctiva from the same patient.