Cataract surgery

Definition

A cataract is the clouding of the normally clear lens of your eye. In cataract surgery, an eye doctor (ophthalmologist) removes the clouded lens from your eye and, in most cases, replaces the lens with an artificial lens. Cataract surgery is usually successful — more than 90 percent of people who have a cataract removed enjoy improved vision after the procedure.

Why it's done

If a cataract is making it difficult for you to carry out your normal activities, your doctor may suggest cataract surgery. Even if your visual acuity isn't severely affected, you might want cataract surgery to remove a cataract that's causing problems with glare or double vision.

When a cataract interferes with the treatment of another eye problem, such as age-related macular degeneration, diabetic retinopathy or retinal detachment, prompt cataract removal also may be advisable. In younger people or people with diabetes, cataracts may progress rapidly, making the need for surgery more urgent.

In most cases, waiting to have surgery won't harm your eye, so you have time to consider your options. If your vision is still quite good, you may not need cataract surgery for many years, if ever. Approach the decision with these questions in mind:

• Can you see to do your job and drive safely?
• Do you have problems reading or watching television?
• Is it difficult to cook, shop, do yardwork, climb stairs or take medications?
• Do vision problems affect your level of independence?

Risks

Complications after cataract surgery are uncommon, and most can be treated successfully.

Cataract surgery risks include:

• Inflammation
• Infection
• Bleeding
• Swelling
• Retinal detachment
• Glaucoma
• Second cataract

Your risk of complications is greater if you have another eye disease or a serious medical condition affecting any part of your body. Occasionally, cataract surgery fails to improve vision because of underlying eye damage from conditions such as glaucoma or macular degeneration. It's important to evaluate and treat such eye problems, if possible, before making the decision to proceed with cataract surgery.

How you prepare

A week or so before your surgery, your doctor performs a painless ultrasound test to measure the size and shape of your eye. This helps determine the proper power of the lens implant.

Your doctor may advise you to temporarily stop taking any medication that could increase your risk of bleeding during the procedure. Antibiotic eyedrops may be prescribed for use one or two days before the surgery. You may be instructed not to eat or drink anything 12 hours before the procedure.

Normally you can go home on the same day of your surgery, but you won't be able to drive, so arrange for a ride home. Also line up help around home, if necessary, because your doctor may limit activities, such as bending and lifting, for a few days after your surgery.

What you can expect

During the procedure
Cataract surgery, usually an outpatient procedure, takes an hour or less to perform. Eyedrops placed in your eye dilate your pupil. You'll have local anesthetics to numb the area, and you may be given a sedative to help you relax. If you're given a sedative, you may be awake but groggy during surgery. Rarely does anyone require general anesthesia for cataract surgery.

Typically, two things happen during cataract surgery — the clouded lens is removed, and a clear artificial lens is implanted. In some cases, however, a cataract may be removed without implanting an artificial lens.

Surgical methods used to remove cataracts include:

• Phacoemulsification (fak-o-e-mul-sih-fih-KA-shun). In phacoemulsification, your surgeon removes the cataract but leaves most of the back layer of the lens (lens capsule) in place. To do this, your surgeon makes a small incision — about 1/8 inch, or 3 millimeters (mm), long — where the cornea meets the conjunctiva and inserts a needle-thin probe. Your surgeon then uses the probe, which transmits ultrasound waves, to break up (emulsify) the cataract and suction out the fragments. The lens capsule remains in place to provide support for the lens implant.
• Extracapsular cataract extraction. If your cataract has advanced to the point where phacoemulsification can't break up the clouded lens, your surgeon may do an extracapsular cataract extraction. This procedure requires a larger incision, about 2/10 inch (10 mm), where the cornea and sclera meet. Through this incision your surgeon opens the lens capsule, removes the center (nucleus) of the lens in one piece and vacuums out the softer outer lens, leaving the capsule in place.

Once the cataract has been removed by either phacoemulsification or extracapsular extraction, a clear artificial lens is implanted into the empty lens capsule. This implant, known as an intraocular lens (IOL), is made of plastic, acrylic or silicone. You won't be able to see or feel the lens; it requires no care and becomes a permanent part of your eye.

Some IOLs are rigid plastic and implanted through an incision that requires several stitches (sutures) to close. However, many IOLs are flexible, allowing a smaller incision that requires no stitches. The surgeon folds this type of lens and inserts it into the empty capsule where the natural lens used to be. Once in place the lens unfolds to about 1/4 inch (6 mm) in diameter.

Recent advances in IOLs include blue-blocking lenses, which filter out ultraviolet light. Other types of IOLs provide multifocal vision — being able to see things both near and at a distance. Multifocal lenses offer reasonably good near and distance vision. However, vision at the intermediate range is sometimes less than satisfactory. Glare is reportedly a problem with multifocal lenses, but design improvements are ongoing.

After the procedure
With phacoemulsification and foldable lens implants, surgical incisions are very small, and sutures may not be necessary. If all goes well, you'll heal fast and your vision will start to improve within a few days.

You'll typically see your eye doctor the day after your surgery, the following week and then again after a month to monitor healing.

It's normal to feel itching and mild discomfort for a couple of days after surgery. Avoid rubbing or pressing on your eye. Clean your eyelids with tissue or cotton balls to remove any crusty discharge. You may wear an eye patch or protective shield the day of surgery. Your doctor may prescribe eyedrops or other medication to prevent infection and control eye pressure. After a couple of days, all discomfort should disappear. Often, complete healing occurs within eight weeks.

Contact your doctor immediately if you experience any of the following:

• Vision loss
• Pain that persists despite the use of over-the-counter pain medications
• Increased eye redness
• Light flashes or multiple spots (floaters) in front of your eye
• Nausea, vomiting or excessive coughing

You're likely to need glasses after cataract surgery, both for reading and to correct astigmatism, a focusing problem caused by uneven curving of the cornea. Although astigmatism is often unavoidable, it's not likely to be a significant problem if your surgeon is able to remove the cataract through a very small incision. Your doctor will let you know when your eyes have healed enough for you to get a final prescription for eyeglasses.

If you have cataracts in both eyes, your doctor typically schedules a second surgery a month or two later to remove the cataract in your other eye. This allows time for the first eye to heal before the second eye surgery takes place.

Anatomy of the eye

Anatomy of the eye

Your eye is a complex, compact structure measuring about 1 inch in diameter. In an instant, it can receive millions of pieces of information about the outside world, which are quickly processed by your brain.

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Cataract surgery

Cataract surgery

During phacoemulsification — the most common type of cataract surgery — the rapidly vibrating tip of the ultrasound probe breaks up the cataract, which your surgeon then suctions out (top). After removing the cataract, your surgeon inserts the lens implant into the empty capsule where the natural lens used to be (bottom).

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Results

Cataract surgery successfully restores vision in the majority of people who have the procedure done.

Months to years after cataract surgery, you have a 25 percent risk of developing a condition known as posterior capsule opacification (PCO), or second cataract. This happens when the back of the lens capsule — the part of the lens that wasn't removed during surgery and that now supports the lens implant — becomes cloudy and impairs your vision. The gradual clouding is the result of cell growth on the back of the capsule.

To treat PCO, you need a painless, five-minute outpatient procedure called YAG (yttrium-aluminum-garnet) laser capsulotomy. In YAG laser capsulotomy, a laser beam is used to make a small opening in the clouded capsule to let light pass through.

After the procedure, you typically stay in the doctor's office for about an hour to make sure your eye pressure doesn't increase — a potential complication if you have glaucoma or are extremely nearsighted. Other complications are rare but can include swelling of the macula and retinal detachment.