A pterygium is a wedge-shaped growth of the conjunctiva, or transparent membrane covering the surface of the eye. A pterygium evolves very slowly and grows toward the cornea. There are periods of clinical calm and periods of rapid growth but in general the progression is slow. Pterygia are most common in the tropics and areas closer to the equator. A pterygium may develop when exposure to UV sunlight is a daily event and prolonged for years.
The primary risk factors in the onset of pterygia are lifestyle and profession of the patient. The patient exposed to greatest risk is the young adult, who for professional or environmental reasons, is subject to daily exposure to UV sunlight, particularly if he does not use sunglasses or protective shades. Symptoms include redness, irritation, sensitivity to light, burning sensation on exposure to cold and heat, glare and decreased vision.
Treatment for a pterygium is indicated when the pterygium has invaded the cornea, which can reduce the patient’s vision. Treatment is also indicated for refractory discomfort or intolerance to contact lenses.