Cataract Questions and Answers
What is a cataract?
The human eye has a compound lens system similar to that found in a camera. This system consists of the cornea (the curved clear window of the eye), an iris diaphragm to control the light entering the eye, and a crystalline or transparent lens located just behind the iris. When the crystalline lens becomes cloudy or opaque, the patient is said to have a cataract. As the density of those opacities increases, the patient's vision becomes progressively more blurred. When this blurring of vision becomes severe enough to interfere with the individual's daily activities, then cataract surgery will be necessary to restore visual function.
Of course, other factors may be present that contribute to visual loss and the eye must be carefully examined preoperatively to determine if other conditions exist and how they affect the visual acuity. Particular attention must be given to the retina and macula to make sure that degeneration of that tissue is not contributing significantly to the loss of vision. Also, the cornea must be inspected for disease, intraocular pressure measured and the optic nerve inspected for evidence of glaucoma.
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What causes cataracts to form?
Various conditions may cause cataracts to form. Heredity is the determining factor in congenital and juvenile cataracts. Toxic substances, certain eye injuries, chronic systemic diseases (such as diabetes) or other specific eye diseases all may cause cataracts. By far, the most common cause is simply the aging process. As we grow older, the lens gradually loses its flexibility and increases in density. These natural processes may set the stage for cataract formation.
By age 65, according to some estimates, nearly 50% of the population develops the beginnings of cataracts. Some degree of cataract formation is expected in virtually everyone over age 70. The time required for development of the cataract is anywhere from a few months to many years. It may stop at an early stage of development and vision is then not significantly affected. In other cases, the cataract continues to develop and interferes with vision.
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What are some of the symptoms?
Blurred vision that worsens over a period of months or even years is the key symptom. Some people notice that things seem dim with one eye and brighter with the other, and printed images may seem distorted. Colors become less distinct and many patients are bothered by glare. No pain, itching, or redness is associated with cataract formation; these symptoms may indicate other forms of eye disease or infection. Cataracts usually develop bilaterally - in both eyes - but progress at different rates, so vision in one eye is often significantly better than in the other.
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Can cataracts be prevented? Is there a cure?
Although a large amount of research is currently underway, no preventive measures are known for cataracts that develop with the aging process. Sunglasses with ultraviolet light filtering may offer some protection against the formation of cataracts. No diets, drugs or medicines have been proven to delay or cure the developing cataract. But, a safe surgical procedure, coupled with the appropriate corrective lenses has preserved or restored sight for millions.
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When should surgery be performed?
Under ordinary circumstances, cataract surgery is not an emergency situation. There are only a few rare instances where immediate action is indicated. Examples of these emergencies might be if the cataract causes glaucoma or if an eye is severely inflamed. Otherwise, the choice of whether or not to have surgery is up to the patient. If he or she decides to have the operation, the choice of when to have it is also his or hers to make.
Cataracts usually form slowly. The time required for development of the cataract is anywhere from a few months to many years. In the past, surgeons usually waited until the cataract reached a mature or "ripe" stage to remove it. However, modern surgical advances have now made it possible to perform this operation at any stage, usually as soon as the clouded lens begins to interfere with the patient's comfort and normal daily activities.
The time to have surgery depends on your visual requirements. If you wish to drive a car and cannot see the road; if you sew, embroider, do much reading or other close work with increasing difficulty; or are employed in any kind of job requiring good vision, the decision will probably be made that it's time to take action and have the cataract treated.
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What can I expect from cataract surgery?
More than 500,000 patients who have cataracts removed each year in this country, over 95% report significant improvements in their vision. Your eye doctor will be able to tell you how much improvement you can expect from cataract surgery.
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What surgical techniques are used?
The lens may be removed from the eye by intracapsular (ICCE) or extracapsular (ECCE) cataract extraction or by phacoemulsification.
Extracapsular cataract extraction is the most common technique in use today. The surgeon makes a small incision in the front of the eye and removes the front portion of the lens capsule and the entire lens nucleus. The back portion of the capsule remains in the eye.
Phacoemulsification, a form of ECCE, allows a somewhat smaller incision. Through this incision the surgeon inserts a tiny, hollow probe. The tip of the probe vibrates at ultrasonic speed to break up (emulsify) the lens. Then, by means of suction (aspiration), the lens fragments are removed, leaving the capsule intact.
For Intracapsular cataract extraction, a similar incision is made and the surgeon removes both the lens and the capsule in which it is contained. Each of these techniques is safe and effective; your doctor will decide which one best suits your needs.
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Will I have to wear glasses after I've had surgery?
If you needed glasses to read before the surgery you will still require them after the surgery. The "intraocular lens implant" offers a significant advantage over glasses or contact lenses. The intraocular lens, which is made of plastic, is placed inside the eye at the end of a routine cataract extraction. It is left there permanently and never has to be inserted or removed by the patient. Following implant surgery, vision usually begins to improve within a few days.
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Will I have to stay in the hospital?
In most cases, cataract surgery is performed in our outpatient facility/surgery center and does not require a hospital stay. However, there may be situations that require hospitalization, and your physician will discuss these with you.
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What happens in surgery?
Before surgery, you may receive some medication to help you relax. Eye surgery is often performed using local anesthetics with some sedation. General anesthesia is available on a standby basis. Your doctor, of course, will decide what type of anesthesia is suitable for you. In any case, you will feel no pain during surgery.
First, the area around the eye will be cleansed and sterile drapes will be put over much of your face. You do not need to worry about blinking during the operation because the eye will be held open with an eyelid holder. The surgeon will use a powerful surgical microscope to help him see the delicate structures within your eye. You can expect the operation to take less than an hour. Then a patch or shield will be placed over your eye to protect it from accidental rubbing or bumping.
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What postoperative care is required?
Advanced techniques are used during your operation so that you will be spared the ordeal that cataract patients once had to endure. However, some care is necessary to ensure proper healing. After surgery, you should be able to resume most activities almost immediately. Your doctor may caution you against heavy lifting and strenuous exercise to avoid putting unnecessary strain on tiny sutures as your eye heals. You will be given an eye-shield to wear at night for the first few weeks and eye drops to use daily according to your doctor's instructions. Vision usually improves within a few days, but complete healing of the eye takes several months. Vision continues to improve as the eye heals. DO NOT LEAVE COLORADO EYE ASSOCIATES WITHOUT YOUR MEDICATION. THE MEDICATION IS TO BE USED AT HOME EXACTLY AS DIRECTED.
If you have any questions about the medications and how they are to be used, be sure to get a clear understanding before you leave. The medication routine is very important. You must use the drops faithfully - exactly as directed.
Medical follow-up is very important during the first few weeks after surgery, regardless of the comfort of your eye or the promptness of visual restoration. For this reason, you will be given appointments for a series of postoperative examinations.
Your vision usually requires a few weeks for the eye to be healed sufficiently to prescribe the first glasses. It is not unusual for corrective lenses to need a power change some time during the postoperative year as the eye completes its healing.
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Are there any complications?
Regardless of the procedure used, the possibility of complications can exist. These are relatively rare and when they do occur, the condition can usually be corrected. However, unexpected serious complications such as infection or hemorrhage can occur and cause permanent decreased vision.
Fortunately, these serious complications are rare, but it is necessary that you know the possibilities. At some time prior to the scheduled surgery, you will be asked to sign a medical informed consent document for your operation indicating that you understand your diagnosis, the surgical procedure which you are about to undergo and the possibility of complications. If you do not understand, please ask your doctor to explain anything about which you might have questions.
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