What is a Cataract?
One of the most common problems which can affect vision is a cataract. Almost everyone who lives a long life will eventually develop cataracts.
The term cataract is used to describe a natural lens that has turned cloudy, usually as part of the natural aging process. Cataracts are not a growth, a film, or a type of cancer. Light cannot pass through a cataract easily, so the retina only receives blurred and distorted images.
The retina is the unable to send clear signals to the brain, and vision is gradually impaired. If cataracts are not removed, blindness can eventually result.
Cataracts develop for a number of reasons, but the most common cause is aging. Age-related cataracts develop as a result of natural changes within the lens. In other cases, an injury or blow to the eye may cause a traumatic cataract. Some cataracts may also result from the use of certain drugs, exposure to harmful chemicals, excessive amounts of ultraviolet radiation, or some diseases.
In addition, a small amount of babies are born with congenital cataracts as result of unusual prenatal factors. Very infrequently, cataracts can develop during childhood. Fortunately, almost all cataracts can be successfully removed, and vision restored through modern microsurgery.
Because cataracts form in different ways, the symptoms of cataracts are variable. Most people notice that their vision gradually deteriorates--objects may begin to look yellow, hazy, blurred or distorted. Many people also find that they need more light to see clearly, or that they experience glare or haloes from lights at night. Other common problems include increasing nearsightedness, double vision, or the appearance of dark spots or shadows in the vision. In advanced cases, the cataract may be visible as a white or yellow-looking pupil.
Modern cataract surgery begins with a very small incision, between 1/8 and 1/4 of an inch, in the eye. A special kind of incision, called a no-stitch incision, is generally used. These incisions are preferable, because they seal themselves immediately after surgery and heal over the following weeks. No stitches are used, and normal daily activities can be maintained during this period. Another advantage of no-stitch incisions is that they are less likely than other incisions to cause a focusing problem known as astigmatism. In fact, depending upon where the surgeon makes the incision, no-stitch incisions can actually reduce astigmatism which existed naturally before surgery.
After the incision has been made, the surgeon gently inserts a small instrument into the eye which is used to tear a small round opening, known as a continuous curvilinear capsulorhexis, in the lens capsule. Another instrument, called a phacoemulsification tip, is then inserted through this round opening.
Phacoemulsification uses high-speed ultrasound waves, vibrating 40,000 times per second, to break the cataract into tiny pieces which are then suctioned out of the eye. Ultrasound is currently the most effective method for removing cataracts.
Once the cataract has been removed, a lens implant is placed in the lens capsule to replace the focusing power of the natural lens. Lens implants are very small and are designed to fit permanently within the lens capsule, where they fill most of the functions of the natural lens. They are made of special materials which require no care and which will not be rejected by the eye. Lens implants come in different powers, as do glasses or contact lenses, and are selected to improve the eyes focusing ability.
Many people discover that lens implants improve their vision and give them greater freedom from their glasses than they enjoyed before they developed cataracts.
A cataract operation is relatively brief--usually lasting between 10 and 20 minutes. Once the surgery has been completed, the patient is escorted into the recovery area. After being monitored by a nurse and receiving some simple instructions on eye care, people are free to leave. Most people appreciate being able to resume their regular activities immediately after surgery.
Risks and Benefits
Fortunately, cataract surgeries are highly successful procedures. The few complications which exist are becoming even more unlikely with new developments in anesthesia and surgical techniques. Potential complications include infection or hemorrhage within the eye, retinal detachment, or persistent double vision. The odds of experiencing any of these complications are very low--between one in 1,000 for hemorrhages and one in 10,000 for infections. Usually, such rare complications can be treated or controlled, either during the surgery or afterwards.
The very small risks associated with cataract surgery are more than offset by the excellent results. At Gimbel Eye Centre, over 99 percent of cataract surgery patients enjoy good vision after their surgeries when no other serious eye problems existed before the surgery. Eye diseases or problems with the retina or optic nerve may limit the potential for clear vision even when the cataract surgery itself has been successful. Furthermore, there are numerous benefits of cataract surgery, many of which cannot be measured statistically. These include:
Improved Color Vision
Colors are brighter and more vivid after cataract surgery.
Greater Clarity of Vision
Vision is crisper and sharper after cataract surgery.
Improved Quality of Life
Studies have repeatedly shown that people enjoy improved quality of life after successful cataract surgery. Many people can resume driving, thereby gaining greater independence. Favorite activities such as reading, sewing, carpentry, baking, or even using a computer are generally easier after cataract surgery. Even when retinal diseases or other problems prevent a total restoration of vision, the remaining vision is usually improved by a cataract surgery.
Greater Freedom From Corrective Lenses
Because lens implants are selected to compensate for pre-existing focusing problems, most people find that their vision improves considerably after surgery. Ideally, people are able to see clearly without glasses after surgery, although glasses may be necessary for some activities such as reading or driving. Even people who still need to use glasses most of the time can usually use thinner lenses than they relied upon in the past. The only minor drawback of this improved eyesight is that most people will need to replace their glasses after surgery, even if they only need to use them occasionally.