A pterygium is a degenerative change of the conjunctiva (the clear skin that covers the white of the eye). The exact reason why pterygiums form is unknown. There is a higher incidence found in people who live closer to the equator and thus we believe exposure to UV light is thought to be the likely source. It is common that patients with pterygium have a history of increased "outdoor activity" (farmers, construction workers, etc) and/or work in dryer climates.
Pterygium should be monitored yearly for growth. Measurements detailing the size and growth onto the cornea (the clear windshield of the eye), corneal topography which helps to analyze potential changes in corneal shape and slitlamp photographs can all be used to monitor pterygium growth and the effects they may be having on vision.
Treatment is indicated when the pterygium is causing:
- decreased best corrected vision due to irregular astigmatism
- coming close to the center of the cornea with risk of permanent scar tissue
- consistent irritation to the ocular surface
Historically pterygium were removed with simple excision but with too high of a recurrence rate simple excision alone is no longer the treatment of choice. Today simple excision is used to remove the pterygium and a conjunctival autograft (piece of healthy conjunctiva or skin from a different location on the eye) is glued or sutured into place where the pterygium had been. This technique has severely reduced the incidence of recurrence and provides a much more acceptable cosmetic result after a few months of healing.