This occurs even before the pterygium itself has reached the area because of the irregular astigmatism produced by the corneal folds. Only when very extensive do they encroach on the axial area of the eye and impair vision, or mechanically interfere with eye movements. Their tendency is always to grow centripetally, especially in those that are vascular and fleshy. A pterygium is completely adherent to the surface of the cornea and can only be removed by surgery. It can not be removed by laser surgery.
Recurrence is fairly common for a pterygium after removal.
Various kinds of eyedrops and sometimes radio therapy is used post operatively to help prevent recurrence. This does not mean that the pterygium is a type of cancer. These are only ways of preventing a recurrence. The patient goes home the same day, it is not necessary to stay overnight. The eye might be red, swollen and irritable for 1 month after the operation.