A pterygium is a pinkish, triangular-shaped tissue growth on
the cornea. Some pterygia grow slowly throughout a person's
life, while others stop growing after a certain point. A
pterygium rarely grows so large that it begins to cover the
pupil of the eye.
Pterygia are more common in sunny climates and in the 20-40
age group. Scientists do not know what causes pterygia to
develop. However, since people who have pterygia usually
have spent a significant time outdoors, many doctors believe
ultraviolet (UV) light from the sun may be a factor. In
areas where sunlight is strong, wearing protective
eyeglasses, sunglasses, and/or hats with brims are
suggested. While some studies report a higher prevalence of
pterygia in men than in women, this may reflect different
rates of exposure to UV light.
A mass of fleshy tissue gradually grows over the cornea (the
clear front window of the eye).
Effect on Vision
A pterygium may remain small or may grow large enough to
interfere with vision.
Because a pterygium is visible, many people want to have it
removed for cosmetic reasons. It is usually not too
noticeable unless it becomes red and swollen from dust or
air pollutants. Surgery to remove a pterygium is not
recommended unless it affects vision. If a pterygium is
surgically removed, it may grow back, particularly if the
patient is less than 40 years of age. Lubricants can reduce
the redness and provide relief from the chronic irritation.