A pterygium (pronounced ter-idge-ee-um, plural: pterygia) is a triangular-shaped lump of tissue with blood vessels that grows from the conjunctiva (the thin membrane that covers the white of the eye) on to the cornea (the clear central part of the eye). Pterygia frequently occur in both eyes, usually on the side of the eye closer to the nose. A pterygium is not a cancer. People sometimes confuse pterygia with cataracts. A cataract is a clouding of the lens inside the eye and cannot be seen easily with the naked eye.
The development of pterygia is strongly associated with exposure to ultraviolet radiation and hot, dry environments. In Australia people who spent their early childhood at latitudes less than 30? were found to have a higher risk of developing pterygia than those who grew up at higher latitudes. People who live in rural environments are approximately 5 times more likely to develop pterygia that those who live in urban areas. Pterygia are thus more common in the Northern parts of Australia and among people such as farmers and surfers who spend a lot of time outdoors, but anyone can develop a pterygium.
Pterygia are not dangerous, but they can be a problem cosmetically and can cause irritation and redness. Pterygia may also interfere with vision as their growth can cause corneal distortion. If the pterygium grows on to the central part of the cornea it can begin to block light from entering the eye. Although a pterygium is not dangerous, it should be checked to make sure that it is not something more serious. If you have any area of tissue on or around the eyes that changes rapidly or that you have not had checked previously you should make an appointment with an optometrist or eye surgeon (ophthalmologist).
In cases where the pterygium is not actively growing on to the cornea, protecting the eyes from ultraviolet light will often stabilise its growth. In many cases, provided it is not threatening vision and it remains stable, this may be all that is required.
If a pterygium causes discomfort, eye drops and ointments may be useful. Your optometrist can advise you on the use of decongestant eye drops to assist in making the eye less red, or artificial tears to make the eye more comfortable.
In cases where a pterygium is actively growing on to the cornea and threatening to distort the vision, the only effective treatment is surgical removal. This surgery is usually performed under a local anaesthetic. It is best to have surgery before the pterygium progresses to the point where it interferes with vision. Your optometrist can assess the pterygium and refer you to an eye surgeon if the pterygium requires removal.
Your optometrist will be able to advise you regarding the most suitable contact lens for your situation and will require you to attend for regular contact lens aftercare visits so that they can monitor changes in corneal shape that may indicate progression of the pterygium and check the ongoing suitability of the fit of the contact lens.
The best way to reduce your risk of developing a pterygium, or to slow the progression of an existing pterygium, is to protect your eyes from ultraviolet light. UV radiation can also cause cataracts and other eye diseases, as well as skin cancers, so reducing exposure is a wise move. The best ways of doing this are to:
- Avoid the sun: UV radiation is strongest between between 10 am and 3 pm. Staying out of the sun between those times will significantly reduce your UV exposure.
- Wear a hat: a broad-brimmed hat will not only protect your head from sunburn, but will reduce by at least half the amount of UV radiation reaching your eyes.
- Wear sunglasses: a good pair of sunglasses will reduce the amount of UV reaching your eyes and cut the amount of glare. Wrap-around sunglasses are best as they block UV radiation that can slip around the sides of conventional sunglasses.
Parents should ensure that they protect the eyes of babies and children from ultraviolet light through the use of hats and children’s sunglasses that meet the Australian Standards.
It is not uncommon for pterygia to grow back after they have been surgically removed so it is important to follow the recommendations above for the prevention of pterygia.