I always try to remove as much of the scar as possible with a diamond burr as what we see under the microscope at the end of the surgery is what the patient usually will see for the rest of his or her life.
It is clear that the older a patient is, the more likely the full scar tissue cannot be removed and a more obvious white scar will remain. Younger patients usually have a superficial pterygium and a plane of tissue which includes the white scar can be removed or burred away.
Either way we know that pterygia are common, abnormal growth of clear covering (conjunctiva) of eye’s white part (sclera) over the cornea (window of the eye). If severe & causing discomfort or red, can be removed w/ surgery. It is generally benign (very rarely it can masquerade a cancer). It is due to excess sun/UV exposure. Prevention is key remedy. Avoid sun (sunglasses/hat); avoid smoking.
Those are the key issues.