In early cataracts, vision can usually be improved by changing the eyeglass prescription, using a magnifying lens for close work, or using stronger lighting. If the cataract interferes with vision to the point where daily activities such as driving, working, or reading become difficult, the cataract may need to be surgically removed.
Cataract removal is one of the most commonly performed and effective surgical procedures in the United States. Approximately 90 percent of patients who undergo cataract removal experience improved vision afterward. Two procedures can be used to remove a cataract: phacoemulsification and extracapsular surgery.
Phacoemulsification (phaco) is the most commonly used procedure. A small incision is made on the side of the cornea and a tiny probe is inserted into the eye. This probe emits an ultrasound wave that softens and breaks up the cataract. The debris is then removed by suction.
Extracapsular surgery requires a longer incision in the cornea. The hard center of the lens is removed in one piece and the rest of the lens is suctioned out. The natural lens is then replaced with an intraocular lens (IOL), a clear, artificial lens that becomes a permanent part of the eye. The IOL is made of silicone, a plastic called PMMA, or acrylic. Light is then able to pass to the retina, improving vision. The artificial lens does not require additional care and the eye looks and feels normal.
Patients who are unable to have an IOL inserted because of eye disease or other complications can use soft contact lenses or glasses with powerful magnification.
Once the eye has healed, patients with an IOL usually update their lens prescription. The IOL is a single focus lens, meaning that it cannot change shape (accommodate) in order to see both near and far objects clearly. The IOL selected enables the patient to see distances clearly, therefore glasses are generally needed for reading and close work. Another option is to have one IOL focused for near vision and the other for distance, eliminating the need for eyeglasses. This is known as monovision. The drawback to this system is that it can compromise vision and depth perception.
A third option is to use a multifocal IOL which has both distance and near power within one IOL. The multifocal IOL allows better depth perception and compromises overall vision less than monovision.
Following surgery, patients often see a blue tint around everything. A cataract blocks colors such as the blues and violets at the lower end of the color spectrum. When the cataract is removed, these colors once again become vivid.
Complications after Cataract Surgery
Part of the natural lens, the lens capsule that is not removed may become cloudy and hinder vision months or years after surgery. This is called an after-cataract, a common, long-term complication of cataract surgery. To treat the condition, YAG laser capsulotomy is performed. In this procedure, a laser makes a tiny hole in the remaining lens capsule to allow light to pass through. The use of specially coated and designed IOLs may help reduce the incidence of after-cataracts.
Prevention of Cataracts
Some cataracts cannot be prevented, especially those that occur because of aging. However, measures can be taken to slow their progression, minimize their severity, and in some cases, prevent them.
Avoid prolonged exposure to sunlight by wearing a good pair of sunglasses and a wide-brimmed hat to protect the eyes. Long-term exposure to ultraviolet light has been linked to cataract formation.
Avoid smoking and excessive alcohol consumption. Both have been linked with an increased rate of cataract formation.
Increasing consumption of fruits and vegetablessuch as spinach, tomatoes, cruciferous vegetables (e.g., broccoli, cauliflower), citrus fruits, and melonssignificantly reduces the risk for cataracts. These fruits and vegetables contain carotenoids, which offer the eyes some degree of protection.
Taking vitamin supplements can reduce the risk for nuclear cataracts, and long-term vitamin supplementation lowers the risk for both nuclear and cortical cataracts. Folate and B12 may protect against cortical cataracts; vitamin A protects against nuclear cataracts; and thiamin protects against both types.
Vitamin C also may help prevent cataracts. A promising study from Tufts University found that older women who take vitamin C supplements for 10 years or more had a 77% lower prevalence of early lens clouding and an 83% percent lower prevalence of moderate lens clouding. The best results are obtained by taking 400800 mg a day.
Hormone replacement therapy (HRT) in postmenopausal women may decrease the risk for cataract formation. The benefits and risks of this therapy should be discussed with a physician.
Many medications have been associated with cataracts. Changing medication or finding alternative ways to control a condition may help prevent cataracts.
Good prenatal care can prevent congenital cataracts. Avoid using steroids and exposure to radiation during pregnancy. Giving up smoking, alcohol, and recreational drugs before becoming pregnant helps ensure better health for the baby.
Wearing protective eye gear when engaging in sports and recreational activities can prevent eye injury.