What is Pterygium?
Pterygium is most commonly noticed from the nasal side of the sclera. When a Pterygium is on the nasal side it is usually of the suns rays passing laterally through the cornea, where it under goes under refraction and becomes more focused on the limbic area. The sunlight can pass unobstructed on the lateral side of the eye, focusing on the medial limbus after passing through the cornea. On the medial side the shadow from the nose medially reduces the intensity from the sunlight.
Cause
The exact cause is not determined but it is associated with excessive exposure to wind, UV rays(sunlight), or sand. That is why it is more likely to occur in areas near the equator, and also windy locations. They are also more likely to occur in men.
Prevention:
Since the main cause of Pterygium is sun and wind exposure, the best way to prevent them are by wearing protective sunglasses with side shields or a hat, and use artifical tears throughout the day may help the prevention and further growth. Water sports athletes and surfers should wear protective eye wear that blocks 100% UV rays.
Treatment
There are many ways of treating the Pterygium from conjunctiva auto-gratfing to amniotic membrane with sutures or glue, to irradiation. As it is a small growth, Pterygiums do not usually require surgery unless it grows to where it covers the pupil, obstructing vision, or presents acute symptoms. However some of the irritating symptoms can be treated with artifical tears. There is no reliable medical treatment to reduce or even prevent the Pterygium progression. The only way to be sure to the Pterygium is completely removed is by surgerical removal. Long term follow up is required because Pterygiums may reoccur even after the surgery has been done.