Cataracts - A Threat To Vision

The term cataract refers to the clouding of the normally transparent lens of the eye. As the opacity thickens, it prevents light rays from passing through the lens and focusing on the retina--the light sensitive tissue lining in the back of the eye.

In the archives of the American Academy of Ophthalmology (AAO) it states that "the word cataract comes from the Greek [word] for waterfall. Until the mid-1700s, it was thought that a cataract was formed by opaque material flowing, like a waterfall, into the eye."

Now it is well known that the natural aging process is the most common cause of cataracts. In fact, according to the National Eye Institute, about 50 percent of Americans, ages 65 to 74 and about 70 percent of those 75 and over have cataracts.

Other causes of cataracts include: family history, female gender, injury to the eye. medications (i.e . steroids), some eye diseases and medical problems (i.e., diabetes), exposure to harmfill chemicals, previous eye surgery, smoking, alcohol consumption or long-term, unprotected exposure to sunlight (UV-B radiation, which causes sunburn and common skin cancers). Cataracts can also exist at birth or develop later in life.

Symptoms

Cataracts usually develop slowly without pain, redness or tearing of the eye. In fact, some cataracts never progress to the point where they seriously impair vision. In other cases, cataracts can eventually block out most or all vision in the affected eye(s). Some of the common symptoms of cataract formation include:

• Blurring, distortion and yellowed vision;
• Gradual loss of color vision;
• Problems with light, such as headlights that seem too bright at night, glare from lamps or the sun,or a halo or haze around lights;
• Double or multiple vision;
• Frequent changes in eyeglasses or contact lenses.

Remember that the above symptoms can also be a sign of other eye problems.

Detection

In a number of cases a cataract can be detected by an eye care professional just by looking at the eye. However, a comprehensive eye examination should be performed including a visual acuity test (measures distance), pupil dilation for extensive look at the retina and other eye problems) and tonometry (measures fluid pressure inside the eye).

Treatment

When first diagnosed with a cataract, an eye care professional may suggest adjusting your eyeglass prescription, using magnifying lenses or using a stronger light to improve vision. But when these methods fail and your vision is affecting everyday activities, cataract removal should' be considered. You and your eye doctor should decide what is right for you.

Cataract surgery is one of the most common operations performed in the United States today. It is also one of the safest and most effective. In preexisting eye conditions, however, your vision after surgery may not be quite as good as before the cataract appeared. Complications may occur, but most are treatable.

This removal procedure is usually done on an outpatient basis without general anesthesia at a hospital, surgery center or a clinic. General anesthesia is usually used on children and some older adults.

There are two steps involved in the actual surgery: the removal of the cloudy lens and the permanent replacement of a clear, manmade lens, known as an intraocular lens (IOL). These steps can be accomplished by one of the following two techniques:

1. phacoemulsification (phaco). A small incision is made in the eye. A special tool then sends vibrations into the eye to soften and break up the lens. These pieces are suctioned out, leaving in the posterior (back) capsule to support the replacement lens (IOL); OR
2. extracapsular extraction. A slightly larger incision is used than in phaco. A special tool then extracts the lens, leaving in the posterior capsule to support the IOL.

The implantation of the IOL is done by one of two methods known as: posterior chamber lens implant or anterior chamber lens implant.

In the posterior chamber lens implant, the new IOL becomes a permanent part of the eye. It is placed in the space behind the iris (posterior chamber) and held in place by flexible loops or tabs. Stitches may or may not be needed to close the incision.

The anterior chamber lens implant method is used when the posterior chamber lens implant method is not possible. The IOL is usually placed in the space in front of the iris called the anterior chamber. The lens is held in place by flexible loops, and again, stitches may or may not be needed to close the incision.

After surgery, your vision will be retested as your eye heals. When you have fully recovered, a new eyeglass prescription for your treated eye will be given.

Lasers are not routinely used in original cataract surgery. However, clinical studies and research are ongoing. At the present time, lasers are used in what is sometimes called "after-cataract," which can develop months to years after the original surgery. It may appear to be a reoccurrence of a cataract; but, in fact, it is not. This condition is treated by your eye doctor by using a laser beam to make a tiny hole in the capsule to let light pass through; thus, improving your vision.

Anyone considering cataract surgery should talk to their eye doctor about the benefits, risks, recovery and insurance coverage. You may also want to consider a second opinion.

Research

While patients look to surgery to restore or to improve their lost vision, vision researchers look for ways to prevent or delay cataracts as was evident at a recent conference of cataract researchers convened by Research to Prevent Blindness (RPB). Some important information that ISPB would like to pass on to you is as follows:

• Advances in genetic engineering will continue to expand basic understanding of lens development.
• Continued work with the three major proteins of the lens suggests that they help regulate lens fiber cells and play active roles in cell metabolism.
• New and controversial evidence suggests that some age-related cataracts are caused by the body's immune system going awry.
• Studies indicate that microbial eye infections may sometimes cause the body to make auto-antibodies that can damage the lens.
• Studies show that foods rich in certain vitamins and minerals-especially Vitamins A, C and E-appear to offer some protection against cataracts.

(ISPB suggests that you check with your eye care and health care professionals before embarking on a vitamin/mineral regimen.)

At the conference it was determined that the "ability to delay the onset of cataract by 10 years would eliminate the need for fully one-half of all cataract surgeries. This would provide an important saving in both cost and untold human anxiety, especially as life spans lengthen and more people reach the 'cataract age' " (Sources and for more information: "Treating your Cataracts," pamphlet by Krames Communications, Bruno, Calif.; Research to Prevent Blindness-1+800+ 621-0026; American Academy of Ophthalmology-(415) 561-8500; National Eye Institute-(301) 496-5248; The Foundation for Fighting Blindness-1+800+683-5555).

The Visionary, published as a service of the Illinois Society for the Prevention of Blindness,
is available upon request. The information contained in this issue,
taken from sources considered to be accurate,
does not replace the need for professional eye care consultations and treatments.

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