What Is Eye Web (Pterygium)?
A pterygium (pronounced tare-IJ-ee-um), sometimes referred to as “eye web”, is an elevated, pink-red lesion growing from the conjunctiva (the clear Saran Wrap-like layer that covers the white part of the eye) onto the cornea (the clear central windshield of the eye). A pterygium may grow from one or both sides onto the cornea, though the nasal side is more common. It often has a wing-like shape.
Mild cases of a pterygium may not cause issues, but larger growths can cause symptoms ranging from blurry vision, eye irritation, and tearing. Occasionally, they may become inflamed, causing significant eye redness and pain.
If the pterygium invades the cornea area in a significant manner, it may end up distorting the shape of the eye’s surface and causing more issues, such as astigmatism.
What Causes a Pterygium?
The exact cause of a pterygium is unknown. It is thought to be a lesion that forms when the eye has been exposed to prolonged sunlight and wind over the course of many years. A higher rate of these lesions is seen in patients who live or have lived closer to the equator. UV radiation has also been associated with this condition.
How Is a Pterygium Diagnosed?
An eye exam will be given to test how well you can see. The eye doctor will also examine the eyes using special equipment to visualize the cornea and conjunctiva to assess the pterygium. Diagnostic imaging and photographs may also be useful in determining the severity of the condition.
How Is a Pterygium Treated?
For patients with a mild pterygium, conservative treatment with eye drops and glasses or contact lenses may be required. Periodic follow up may be necessary to monitor the lesion(s).
For patients with a pterygium that is growing onto the central cornea, causing significant eye irritation/pain and/or reducing the vision due to induced astigmatism, surgical removal of the pterygium may be required. Some patients may require excision of both a nasal and temporal pterygium in the same eye at the time of surgery.
Surgical therapy may include one or more of the following:
- Pterygium Excision – The pterygium that is growing onto the cornea is removed. The underlying corneal surface is polished until a good cosmetic result is noted during the time of surgery.
- Use of Mitomycin C – After removal of the pterygium, this medication may be applied to the area of the previous pterygium for 30-120 seconds. This has been shown to reduce the rate of recurrence.
- Use of Amniotic Membrane Tissue – After removal of the pterygium, a special membrane tissue may be glued onto the area of the previous pterygium. This also has been shown to reduce the rate of recurrence.
- Use of Conjunctival Autograft – For advanced or recurrent pterygium, a small flap of healthy conjunctiva from the superior part of the eye may be used to cover the area of the previous pterygium. This also has been shown to reduce the rate of recurrence.
Modern techniques for removal of pterygium are very successful. However, there is a 10% chance that the pterygium may grow back, and the surgery may need to be repeated in the future.
Your doctor will further discuss with you the risks, benefits, and alternatives for the management of your pterygium.