Pterygium and Pinguecula
A pterygium is scar tissue that grows over the cornea (the clear front window of the eye). It may remain small or may grow large enough to interfere with vision. A pterygium most commonly occurs on the inner corner of the eye, but can appear on the outer corner as well. The exact cause is not well understood. Pterygium occurs more often in people who spend a great deal of time outdoors, especially in sunny climates. Long-term exposure to sunlight, especially ultraviolet (UV) rays, and chronic eye irritation from dry, dusty conditions seem to play an important causal role. A dry eye may contribute to pterygium.
When a pterygium becomes red
and irritated, eyedrops or ointments may be used to help
reduce the inflammation. If the pterygium is large enough
to threaten sight or grows rapidly, it can be removed
surgically.
Despite proper surgical removal, the pterygium may return,
particularly in young people. Protecting the eyes from
excessive ultraviolet light with proper sunglasses and
avoiding dry, dusty conditions and use of artificial tears
may also help.
A pinguecula is a yellowish patch or bump on the white of
the eye, most often on the side closest to the nose. It is
not a tumor, but an alteration of normal tissue resulting
in a deposit of protein and fat (similar to a scar). Unlike
a pterygium, a pinguecula does not actually grow onto the
cornea. A pinguecula may also be a response to chronic eye
irritation or sunlight.
No treatment is necessary unless it becomes inflamed. A
pinguecula does not grow onto the cornea or threaten sight.
If particularly annoying, a pinguecula may on rare
occasions be surgically removed, but the postoperative scar
may be as cosmetically objectionable as the pinguecula.