Pterygium - A pterygium grows in response to exposure to ultraviolet light. They are more common in light-skinned people living nearer the equator, particularly where outdoor activities are popular.
As the pterygium grows, it replaces the corneal epithelium, and erodes the superficial layers beneath it. These layers are Bowman's membrane, and the anterior corneal stromal lamellae. The pterygium pulls and distorts the cornea as it enlarges.
Indications for surgery:
- Growth over the corneal centre.
- Reduced vision due to corneal distortion.
- Documented growth.
- Symptoms of discomfort.