A pterygium is a common condition where changes occur on the white of the eye just separate from the coloured area, or iris. A pingueculum is often seen as a yellow, fatty looking, slightly raised are that may or may not be slightly blood shot. A pingueculum is very common and nearly everyone who spends time outside will have some pingueculae formation.
If the pterygium continues to grow, it will cover the pupil and lead to blindness; however not all pterygia need removal. They need to be removed if they are actively growing, causing marked discomfort, distortion of vision or perhaps for cosmetic reasons.
Surgery is usually undertaken in the clinic or in hospital. The pterygium is removed with microscopic instruments and cautery is used to stop the bleeding. To try and prevent recurrence, a flap of normal conjunctiva is brought from below and possibly also from above to try and build a barrier of normal tissue in front of the pterygium remnants, and this is sutured in place with microscopic nylon sutures so small that they cannot usually be felt.