A pterygium is a triangular-shaped fold of the tissue on the white of the eye. This growth of tissue usually begins on the inner corner of the eye and spreads toward the center. A pterygium is the result in which the conjunctiva (a thin transparent membrane which lines the surface of the eyelids and covers the white parts of the eye) grows onto the cornea (the transparent tissue covering the central front of the eye).
The complete cause of a pterygium is not fully understood, however, long term exposure to sunlight and chronic irritation from dry conditions seem to contribute to the development and growth.
The symptoms of a pterygium are usually not severe but may include blurry vision, dryness, and eye irritation. Patients often report symptoms of itching, burning, and scratchiness. At the time a pterygium is growing it appears red and swollen. Pterygiums progress slowly, but if it grows over the center of the cornea vision loss occurs.
If a pterygium becomes red and swollen eye drops or ointments are used to reduce inflammation. Surgery can be an option for cosmetic reasons but not necessary. Once removed pterygiums have a tendency to return, especially in younger people.