"Eye Bumps" - Pinguecula and Pterygium
The most commonly encountered "bump" on the eye concerning patients is a fleshy-appearing
growth called a pinguecula (ping-gwek-u-lah). They may be yellow, gray, white, or colorless.
They are usually found on the white part of the eye in the space between the eyelids, almost
always on the side closest to the nose. Pingueculae are more common in middle-aged or older
people but they can also be found in younger people and even children.
Causes
Overlying the white part of the eye (sclera) is a transparent mucous membrane called the conjunctiva. The conjunctiva also lines the inside of the eyelids. A pinguecula is a slow growth caused by the degeneration of the conjuctiva's collagen fibres. Thicker yellow fibres, or in some cases calcified deposits, eventually replace the original transparent fibres. In rare cases, the conjunctiva can also become red and irritated. Pingueculae can be found in one or both eyes and do not affect vision.
The exact cause or causes of this disorder is unknown, but it occurs more frequently in people who live in sunny and windy climates and people whose jobs expose them to ultraviolet (UV) light (for example, farmers and arc welders). The frequency of pingueculae increases with age lending credence to the idea that they are primarily the result of prolonged exposure to UV, infrared light and irritation.
Signs and Symptoms
There are often no symptoms of a pinguecula other than a cosmetic concern. Dry eye can sometimes contribute to increased irritation, resulting in a "foreign-body" sensation and inflammation.
Treatment
Most people with pingueculae do not require treatment unless their symptoms are severe. Lubricating eye drops are normally recommended to relieve irritation and foreign-body sensation. Steroidal eye drops may be prescribed if significant inflammation and swelling are present. Everyone with pingueculae should wear UV-blocking sun protection to help reduce the irritation that contributes to the formation and progression of pingueculae. Surgical removal of pingueculae is sometimes considered if they are large or result in the the inability of contact lens wearers to wear their lenses.
Pterygium
A less commonly encountered "bump" on the eye is a pterygium. A pterygium is a triangular
or wing-shaped growth on the white part of the eye that also extends onto the clear front
window of the eye called the cornea. A pterygium contains blood vessels and can be of
greater cosmetic concern than the typical pinguecula. In extreme cases, pterygia may
grow far enough onto the cornea to interfere with vision. A pterygium can result
from the progression of an initial pinguecula. As with pingueculae, prolonged
exposure to ultraviolet, wind and dry conditions seem to play a significant role.
Symptoms
Many people with a pterygium are asymptomatic but others can experience a significant foreign-body sensation. Because a pterygium can stretch and distort the cornea, some people acquire astigmatism from a pterygium. When the astigmatism induced by the pterygium is significant, reduced visual acuity can be the result.
Treatment
Usually, no treatment is needed. Artificial tears can be used to relieve the sensation of a foreign body in the eye and to protect against dryness. Surgery to remove the pterygium is advisable when the effect on the cornea causes visual defects or when the thickening is causing excessive and recurrent discomfort or inflammation. surgical removal can also performed for cosmetic reasons.
Patients frequently ask their eye doctor about surgery to remove a pinguecula or pterygium. It
is important to realize that healing from this type of surgery, although usually painless,
takes many weeks, and there is a high rate of recurrence (as high as 50-60% in some regions).
Accordingly, surgery is usually not recommended unless discomfort is significant or vision is
affected.
Prognosis
Most pingueculae and pterygia grow slowly and almost never cause significant damage, so the prognosis is excellent. Diagnosis should be made by an eye doctor to rule out other more serious disorders.
Prevention
There is nothing that has been clearly shown to prevent these disorders, or to prevent a pinguecula from progressing to a pterygium. However, the presence of pingueculae and pterygia have been linked to exposure to UV radiation. For that reason, UV exposure should be reduced. The American Optometric Association (AOA) suggests that sunglasses should block 99-100% of UV-A and UV-B rays. Patients should speak to their eye care professionals about protective coatings on sunglasses or regular spectacles. Protecting the eyes from sunlight, dust, and other environmental irritants is a good idea.
Sources:
- National Eye Institute
- American Optometric Association
