The operation to replace a clouded lens is low-risk, fast, and effective, but requires some decision making.
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Cataract surgery—which involves removing the eye's clouded lens and replacing it with a clear synthetic version—once required several days in the hospital and a long recovery period. Today it is performed under local anesthesia on an outpatient basis, and people are back to their normal lives within days. The success rate is high, and the rate of vision-threatening complications is relatively low. For people with cataracts, the decision whether to have surgery may be easy to make. However, two additional decisions might be more difficult: when to have surgery and what type of lens implant to get, says Dr. Laura Fine, an ophthalmologist at Harvard-affiliated Massachusetts General Hospital.
Why you may need cataract surgery
To a great extent, cataracts are a normal consequence of aging. Cataract formation is usually a gradual process that plays out over years. The lenses of our eyes become less transparent, less resilient, and often thicker. By age 80, half of us will have cataracts.
Cataracts can creep up on you. It may be hard to tease out the effects of a developing cataract from other age-related vision changes. In the early stages you may become more nearsighted, a problem that can be corrected with glasses. As the cataract progresses, your night vision may worsen, and colors may appear duller.
Any vision changes warrant an eye exam. However, because cataract-associated changes can be subtle, it's better not to wait until your sight is noticeably affected. Comprehensive eye exams, which can detect not just cataracts but also glaucoma and other eye conditions, are recommended every two years for adults ages 40 through 64 and annually for everyone 65 or older.
The doctor will test the sharpness of your vision by having you identify a series of symbols or letters on a chart. He or she may also dilate your pupils with drops to examine the interior of the eye. Using a slit lamp—to illuminate a small area inside the eye at a time—the doctor can see any cataract and assess how extensive the clouded areas are. Additional examinations and tests help rule out other eye disorders, such as glaucoma or retinal degeneration.
When do you need a lens replacement?
Removing and replacing the clouded lens is the only effective cure for a cataract. For most people, the question is when to undergo the procedure. "There's no rush to have cataract surgery. It isn't a life-threatening situation," Dr. Fine says. That decision is usually based on how much the cataract is interfering with your vision and daily life. You may want to delay cataract surgery until you feel that you need better vision. But you might not want to wait until you can't see stair steps clearly or fail a driving test. If you have another eye condition, such as age-related macular degeneration, your doctor may recommend cataract surgery sooner because the cataracts make it difficult to examine and manage the other problem.
If your doctor determines that you have cataracts in both eyes, he or she may recommend operating first on the eye with the denser cataract. If surgery is successful and your vision improves substantially, you may elect to forgo surgery on your other eye. However, most people get significant benefits from having the second eye operation, including better depth perception and improvements in their ability to drive and to read. People usually have the second surgery once the first eye has healed and their vision is stable. If you are extremely far-sighted or nearsighted and need cataract surgery in both eyes, you may want to have the second surgery within a month or so of the first surgery to avoid problems with double vision and depth perception due to the difference in vision from eye to eye.
What's involved in cataract surgery
Experience and technology have fine-tuned the procedure to replace the eye's lens so that it takes only about 15 minutes to perform. The approach used most often is phacoemulsification—informally known as phaco. It offers good long-term results, and 97% to 98% of all cases done by an experienced surgeon are successful and free of complications.
The recovery period
You'll spend about an hour in the recovery room as the anesthesia wears off. The doctor may place a bandage or clear shield over your eye. You'll need to have someone help you get home.
Once at home, your primary goal will be to keep your eye from getting infected. You'll need to use eye drops several times a day and to keep water out of your eye. You can go about your daily routine as long as you avoid heavy lifting or activities like jogging that can jar the new lens.
It's also fine to read and watch TV by the day after surgery. The first thing you're likely to notice is how vivid colors seem and how much more detail you can see.
Your surgeon will probably ask you to return for a check-up the day after surgery, a week later, and a few weeks after that.
Making the lens choice
"The primary goal is to improve your vision and function," Dr. Fine says. There are several things to consider when you're choosing a lens, especially these points:
What's most important to you. For most people, the monofocal implant is a good choice, Dr. Fine says. It provides the best contrast vision, so it's good for driving and most other activities. It's also a good choice for people who have cataract surgery when they are relatively young, because contrast vision is likely to diminish with age. However, many people who have monofocal lens implants still need glasses for reading or distance. Multifocal lenses may be a good choice if you do lots of close work, don't want to use glasses, and accept less visual clarity as a trade-off.
Cost. Insurance typically covers monofocal lenses, but you can expect to pay about $1,500 for each toric lens and about $3,000 apiece for other specialized lenses.
The surgeon's experience. Because specialty lenses are newer and relatively few people choose them, many surgeons have limited experience placing them. If you're considering one, find out how many such implants your surgeon has performed.
Commonly used replacement lenses
As the number of cataract surgeries has grown, so have the options for lenses. The most widely used include the following:
Fixed-focus monofocal lenses.
These lenses can help you see at a distance, but you'll need reading glasses to see up close. Alternatively, some people who get fixed-focus monofocal lenses have one eye fitted with a lens that provides near vision and the other eye with a lens that provides far vision. This com-bination is called monovision. If you are considering this option, your eye surgeon may recommend that you try out monovision with contact lenses before your cataract surgery to see how well you can adjust to the combination. Monovision is usually not an ideal option for people who require crisp, detailed vision.
Accommodating monofocal lenses
A newer option, accommodating monofocal lenses, can shift from near to far vision in response to movements of the ciliary muscles in your eye, similar to the natural lens in a younger eye. These lenses offer excellent distance and middle vision, but they aren't as reliable for near vision. Eye exercises can help you get used to them, but about half of people who receive them still end up needing reading glasses.
These specialized monofocal lenses are designed for people with astigmatism. Toric lenses offer focused vision at a single distance and correct your astigmatism, so you might not need distance glasses after surgery.
Like the bifocal or progressive lenses used in glasses, multifocal lenses have different areas designed for distance, intermediate, and near vision. The brain and eye figure out which part of the lens to use. The main drawback of multifocal lenses is they can distort bright light, creating more glare and halos at night.