What is a Pterygium?
A Pterygium is a benign growth on the surface of the eye. It originates from the conjunctiva which is the outer layer of tissue containing blood vessels that covers over the white portion of the eye called the sclera and grows onto the cornea of the eye (clear portion of the front of the eye). Some people call it pterygium eye. It occurs on the surface of the eye between the eyelids. It is mostly likely caused by ultra-violet light, wind, dry eyes, dust, and dirty environments. It also occurs more often on the side of the eye toward the nose. There appears to be some genetic component to the development and severity of this condition.
Anatomy of a Pterygium
Stocker’s Line —- a brown colored linear deposit of iron
Fuchs’ Patches —- grey colored deposits that are in front of the head of the growth
Head —- elevated portion of the apex of the advancing pterygium
Hood —- the larger thick portion of the pterygium containing fibrous and non-vascular tissue
Body —- the main portion of the pterygium containing the blood vessels
People confuse a pinguecula with a pterygium. A pinguecula is a whitish-yellow lesion located on the surface of the conjunctiva. It does not extend onto the cornea like a pterygium. A pinguecula also is located on the conjunctiva between the eyelids. It is felt that it is caused by the same things as a pterygium. They can become inflamed at times but usually do not give any symptoms. Pinguecula treatment is not necessary unless the person is concerned about it cosmetically.
There are a variety of treatments for pterygiums. Observation, sunglasses that wrap around the eye for sun and wind protection, lubrication, and treatment of ocular allergies if present are for pterygiums that are not approaching the visual pathway or pupil. If the pterygium is going to cause loss of vision as it grows into the visual axis, then surgery needs to be performed.
Pterygiums are surgically removed. Up to this point, the surgical techniques are similar. There are other options used to keep this benign growth from returning. The exposed sclera from where the growth was removed can be left bare, conjunctival graft applied, conjunctiva sutured back over the area, and an amniotic membrane placed on the eye. Mitomycin is now used very commonly to keep pterygiums from returning. Other less common procedures is to place a strontium plaque over the area of surgery. Beta radiation has been used on rare occasions.
If you have a pterygium that is growing towards the pupil or your vision center, you should have it removed. If it is painful or cosmetically not acceptable, it can be removed as well. It does take 3 to 4 weeks to heal in many people after the surgery.