Pterygium is a disease that affects the conjunctiva and cornea. The conjunctiva is a thin transparent membrane that covers the sclera (the white of the eye). This is where disease begins: An overgrowth of the conjunctiva in sun-exposed portions. When raising the conjunctiva, generates dryness (since the tear can not meet this 'island' high). The normal reaction of the conjunctiva to the dryness is trying to grow even more protection. This will procude a vicious circle where more growth produces greater dryness and this in turn leads to more growth. Finally pterygium grows as a fleshy mass of the cornea - the transparent structure located opposite the iris (which gives color to the eye).
Very often, people living in tropical develop pterygium. This is because the main factor is to produce ultraviolet radiation from the sun. Those working long time in the sun and do not use UV protection (sunglasses, hat) are at an increased risk.
Dryness and roughness of the pterygium causes burning, itching and dryness in the affected eye. For many people also undesirable cosmetic appearance pterygium. There may come a point where the pterygium grows enough to approach the center of the cornea and prevent the passage of light, producing a marked decrease in vision.
In the early stages when it is light burning sensation and dryness, can be managed with lubricants and vasoconstrictor. In the advanced or when it is aesthetically annoying to the person, surgery is required to remove and replace pterygium healthy conjunctiva.