Ophthalmology

Cataracts

Cataracts are one of the oldest and most common afflictions of humankind. Most people will develop cataracts with aging, and cataract removal is the most common surgical procedure in the world. The good news about cataracts is that the treatment options are among the most successful in all of medicine. Scheie's expert cataract surgeons use proven techniques and lenses to treat cases ranging from the simple to the complex.

What is a Cataract?

The term cataract refers to a clouding or loss of transparency of the lens — normally a crystal clear structure located behind the pupil and iris, focuses light on the retina, much as the lens in a camera focuses light. As clouding progresses, light has difficulty passing through the lens. This results in dim, distorted or blurred images on the retina and decreased vision, similar to looking through a dirty window.

Cataract [A.D.A.M.]

There is no way of predicting how rapidly a cataract will progress. Some develop slowly over a period of many years, while others progress rapidly. Some cataracts decrease distance vision, while others predominantly affect near vision, and still others affect both.

At present, no treatment will slow or stop the progression of a cataract.

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Cause of Cataracts

Most cataracts seem to be the result of the aging process, and most occur in individuals over age 65. However, cataracts can occur at any age. The second most common age group affected is the very young. Their cataracts are congenital in nature. People on chronic doses of steroids (such as for asthma) and smokers are at higher risk. A cataract may be caused or accelerated by conditions such as injury, inflammation inside the eye, certain disorders of blood chemistry and some drugs.

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Symptoms of Cataracts

Many people have early cataracts and are unaware of them. Early cataracts may affect the vision more in certain lighting conditions, either bright light or darkness. Common symptoms of early cataracts include glare, halos, and a marked decrease in vision while driving at night.

The mere presence of a cataract does not mean you need surgery. Depending on your own visual needs, a developing cataract may or may not interfere with your normal lifestyle. If you see well enough to do most of the things you want to do, then you most likely do not need to have surgery. On the other hand, if your decreased vision interferes significantly with your lifestyle, surgery may be beneficial.

Cataract surgery can be done at any time and at any age. In the vast majority of cases, it is an elective procedure.

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Diagnosis

Cataracts can be diagnosed through various tests performed by an ophthalmologist. These tests may include the standard ophthalmic exam, which examines the patient's visual acuity, or the slit lamp examination, which examines the front structure of the eye. Although moderately rare, other tests may also be performed, including the glare test, contrast sensitivity test, potential visual test, and specular microscopic of the cornea.

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Cataract Surgery

New surgical techniques allow doctors to remove a cataract at any stage in which a significant visual impairment is evident.

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Removal of the Cataract

There are several ways to remove a cataract. The most commonly used method is the phacoemulsification technique where the cloudy lens is broken up, using an ultrasound probe that allows removal of the pieces through a tiny incision. A soft, plastic intraocular lens is then carefully inserted, and visual recovery is very rapid. The incision may not even require sutures.

The second, less commonly used technique, is extra capsular lens extraction. With the extra capsular technique, a larger incision is necessary, and the whole cataract is removed intact, rather than breaking it up with ultrasound. Visual rehabilitation takes somewhat longer than it does with the phacoemulsification method, because a larger incision is required. Most often, the phacoemulsification technique is used, but each technique has its advantages.

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Preparation for Surgery

A complete outpatient medical examination, including X-rays and laboratory tests, is performed during the week before surgery. On the day of surgery, the cataract is removed and the patient goes home the same day. In special circumstances, usually because of a medical illness, cataract surgery may be performed on an inpatient basis.

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Anesthesia

Most cataract surgery is done under either topical or local anesthesia with intravenous sedation. Patients may fall asleep during the operation and awake to find that the operation is finished.

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Immediately Following Surgery

Recovery is almost immediate. The eye may be patched for one or more night. Medications are used to prevent infection and to help the healing process. For about three weeks after surgery, a plastic shield must be worn at night and protective glasses during the day to prevent accidental injury to the eye.

Your surgeon will see you as an outpatient the day after surgery and perhaps three or four times more during the two months after surgery. It takes about two months to heal. During that time, your vision may vary. At home, you should observe a few precautions:

  • No heavy lifting
  • Avoid bending over with your head below your knees
  • No rubbing or scratching the operative eye
  • No sleeping on the operative eye
  • Avoid dusty areas
  • Use your eye drops on schedule

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Prognosis

Cataract surgery is successful most of the time. Unfortunately, even in cases with an excellent surgical outcome, vision after the operation is sometimes poor because of disease elsewhere in the eye. Frequently, the existence of such a condition cannot be detected before surgery because the back of the eye cannot be seen through a cataract.

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Risks of Cataract Surgery

Cataract surgery, like any other kind of surgery, involves the risk of complications. Bleeding, infection or poor healing may occur. Any of these circumstances may interfere with vision, and may even lead to blindness. The likelihood that any of these events will happen is very small, and every precaution against their occurrence is taken.

Of the many hundreds of thousands of cataract operations performed every year in this country, about 98% of patients with otherwise healthy eyes have useful vision restored.

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