Kira Manusis, MD
Assistant Professor of Ophthalmology
Co-Director, Cataract, Cornea and Refractive Surgery
New York Eye and Ear Infirmary of Mount Sinai
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If you are fortunate to live long enough, you will probably develop a cataract, the leading cause of vision loss in the United States.
According to the National Eye Institute, more than half of all Americans develop a cataract by age 80. As our nation's senior population expands, the number of people aged 40 or older with cataracts is expected to double from 24.4 million to about 50 million by 2050.
Cataract Basics
A cataract is a clouding of the eye's lens, the normally transparent structure that focuses light onto the back of the eye, allowing us to see. Rather than a disease, most cataracts develop as part of the aging process. You can't prevent them, but reducing exposure to ultraviolet light from the sun, quitting smoking and improving blood sugar control if you are diabetic may help slow their progress.
Cataracts develop gradually, causing vision problems starting generally around age 60. Symptoms may include dimmed or blurred vision, glare, "halos" around lights and dulled colors. Depending on your vision needs, you may not have symptoms or may notice them sooner than other people. For instance, artists might notice earlier that colors are not as vibrant, or voracious readers that their vision is blurry, even with glasses.
If the quality of your vision starts interfering with everyday life, you should see an eye care professional, preferably an ophthalmologist. Cataracts are not difficult to diagnose; the key is to make sure your eyes are otherwise healthy and there are no other causes of visual dysfunction.
Standard Cataract Surgery
Surgery to remove the cloudy lens (the cataract) and replace it with an artificial lens is the only effective treatment, and one of the most commonly performed procedures in the United States. But a diagnosis of a cataract is not enough to indicate surgery. As long as you can function and do not have such complaints as, "I can't drive. I can't read. I can't watch TV," there is no need for treatment, just regular checkups.
Standard cataract surgery is done under local anesthesia while you are awake and lightly sedated for comfort. In this painless, 30-minute outpatient procedure, called phacoemulsification, the surgeon manually makes a small incision in the eye, and uses ultrasound energy to break the cataract into tiny pieces, which are suctioned out. Then, a clear, artificial lens is implanted in place of your original lens.
The plastic implant is like a permanent contact lens for the eye. If you wore corrective lenses before the operation, the standard implant can correct for distance or close-up vision, helping you see clearly enough to reduce your dependence on glasses.
New Technologies Now Available
Beyond the standard lens, some exciting technological advances have recently increased options for patients.
Astigmatism Correction
One new type of lens implant addresses astigmatism, a common visual problem caused by an irregularly shaped cornea, the eye's outermost layer. Once treatable only with glasses, contacts, or small incisions made on the cornea itself, astigmatism can now also be corrected by the same lens inserted into the eye during cataract surgery, reducing or even eliminating your need for glasses.
Correction for Both Nearsightedness and Farsightedness
Starting around age 40, our natural ability to focus up close starts to decline, and we often require reading glasses. Standard implants can correct for this or for distance vision, but not both. The newest type of implant can correct two distances--both near and far.
Laser-Assisted Technology
The newest approach in cataract surgery is laser-assisted technology, which employs a femtosecond laser, the same technology used in LASIK vision correction surgery. The surgeon uses the laser to make all the incisions and crush the cataract into tiny particles, which are then removed.
Laser surgery takes about three minutes and is done while you are awake. It is more precise, and safer in some cases, than phacoemulsification. For patients with very dense cataracts, it reduces the amount of energy needed to remove the cataracts, leading to faster recovery times.
The Future of Cataract Surgery
In the future, we are sure to see most cataract surgeries assisted by laser technology. Also on the horizon is a single standard lens that, instead of being customized before it is inserted into the eye, is fine-tuned with the laser after implantation, allowing the most precise vision possible. One such lens, called a "Calhoun" lens, was commercially introduced in Europe in 2008 and is now in a Phase III clinical trial in the United States, meaning it will probably be available here within five years.
If you are a candidate for cataract surgery, be sure to discuss all the available treatment options with your ophthalmologist. Being well informed will help you choose the best technology and lens implant for your needs and give you a lifetime of high-quality vision.