Cataracts: Who’s at Risk?

(This article appeared in the September/October 2008 issue of The American Postal Worker magazine.)

Joyce B. Robinson, Research & Education Department Director

A cataract is a clouding of the normally clear crystalline lens inside the eye. Cataracts are usually associated with aging, but may also be a consequence of a disease such as diabetes, a side effect of medication, or the result of trauma.

Most age-related cataracts progress gradually over a period of years. However, cataracts in younger people and people with diabetes may develop rapidly.

Causes, Symptoms, Detection

No one knows for sure why the lens in the eye changes as we age. We do know that the change results in cataracts, and some studies suggest that exposure to ultraviolet light from the sun is at least one cause. Ophthalmologist recommend wearing sunglasses and a wide-brimmed hat to lessen the likelihood of damage fromexposure to sunlight. There are four different kinds of cataracts; each kind can occur in just one or both eyes:

• Age-related – More than 50 percent of all Americans over the age of 65 have cataracts;
   
• Congenital – Cataracts can form as early as at birth;
   
• Traumatic – An eye injury can lead to the formation of cataracts, either directly following the injury or years later; and
   
• Secondary – Steroid use or a condition such as diabetes can lead to the development of cataracts.

Traumatic and secondary risk factors for cataracts include cigarette smoke, air pollution, heavy alcohol consumption and a family history of such eye trouble.

The three types of cataracts are defined by their location on the lens:

• A nuclear cataract is located in the center of the lens and is the kind that typically occurs with aging.
   
• A cortical cataract is usually associated with patients suffering from diabetes, resembles the spokes of a wheel.
   
• Subcapsular cataracts, which develop at the back of the lens capsule, are typically found in patients who take steroids (or suffer from diabetes).

Cataracts can be detected during a thorough examination that includes pupil dilation, which gives the ophthalmologist an optimal view of the lens and retina; a visual acuity test that measures your visual ability at different distances; and tonometry, a test that measures the fluid pressure within the eye.

The most common symptom of cataracts is deterioration of eyesight. Other symptoms include:

• Blurring of vision;

• Double vision in one eye;

• Poor night vision;

• Sensitivity to strong light such as the glare from oncoming headlights;

• Difficulty reading; and

• The perception that colors are faded or yellowed.

Treatment

The initial treatment for cataracts typically is just a change in the eyeglasses prescription and a recommendation to avoid excessive sunlight and wear sunglasses more often to possibly slow down the inevitable progression of the problem.With advancing cataracts, however, a change in glasses may not be enough; surgery may be necessary.

Cataracts do not need to be “ripe” before they can be removed, nor do they need to be removed just because they are present. Surgery should be considered when cataracts cause enough loss of vision to interferewith daily activities. The surgery itself involves the removal of the natural, clouded lens of the eye, and its replacement with a clear, artificial one.

In extracapsular surgery, the lens of the eye is removed but the capsule — the transparentmembrane that surrounds the lens — is left in place. During intracapsular surgery, the entire lens of the eye, including the capsule, is removed, whichmeans a greater risk of complications, including glaucoma, nerve damage and blindness. This procedure also increased the possibility of a detached retina, which may cause extensive bleeding in the back of the eye.