CATARACT

You have been told that you have a cataract. This pamphlet has been prepared in order to give you information on what this means for you and what can be done to help you.

A CATARACT is clouding of the natural lens of your eye. To some degree, it affects half of the people aged over 65 years. Your lens, just like the lens of a camera, helps focus the image of whatever your eye is looking at. The lens sits behind the pupil of your eye and is normally transparent. It comprises symmetrically aligned cells (lens fibres) enclosed in a thin, elastic membrane (capsule). With cataract formation the lens becomes cloudy and the image that it forms becomes progressively less distinct. Cataracts therefore cause progressive, painless loss of eyesight. Often glare becomes troublesome and the focus of the eye changes. Usually both eyes are involved but one gives symptoms before the other.

CAUSES: Most cataracts develop naturally over many years as part ageing. Metabolic changes in the fibre-like cells that make up the lens cause these cells to swell and lose their precise alignment; the lens becomes cloudy and so obscures your sight. Less commonly, injury, certain diseases (such as Diabetes), particular medications (such as prednisone) and birth defects can contribute to cataract formation.

THERAPY: To date, cataracts cannot be reversed. Spectacles may improve the clarity of vision for a while but eventually surgery is needed: the cloudy lens is removed and replaced with an implanted artificial lens.

The cataract is not a "film/skin over the eye" that can be "peeled off". Neither can drops, drugs or diets be used to "dissolve" a cataract. Lasers are not used as a substitute for an operation: lasers do have a place in the aftercare of cataract patients when a fibrous membrane forms inside the eye following successful surgery - more on this later. Your past or present use of your eyes in no way contributes to cataract formation and so there is no place for "saving sight" by not reading or whatever.

Surgery to remove the clouded lens is the only treatment for cataracts. The right time to have surgery is when your vision becomes too blurred for you to continue your usual activities. You are the one who decides when a cataract is significantly handicapping you. The cataract does not need to be "ripe/mature" before it is ready for surgery. Surgery is carried out on the worse eye first so that your better eye can be relied upon during the convalescence period. You will undergo eye measurements (for the implant lens) prior to surgery and, in some situations, medical tests may be required. Ensure that your surgeon knows of all of your medications and of any drug allergies that you have experienced.

OPERATION: Cataract surgery involves removing the cloudy part of the lens through two small incisions made through the outer coat of the eye. The cataractous lens is replaced with a plastic implant lens. This implant lens stays in position permanently and cannot be seen by others. Most times stitches are not required. The operation is carried out under a special operating microscope using a sophisticated jackhammer (phako-emulsifier) and tiny instruments. The operation takes 20-25 minutes but you will be in the operating theatre longer for the necessary pre and post-operative tasks. The anaesthetic comprises anaesthetic eye-drops and local anaesthetic infused around your eye. Most cataract operations are out-patient procedures meaning that you only stay in the hospital long enough to have the surgery (about 1½ hours). Antibiotic/steroid eye-drops are required for a week following surgery. Ensure that you have your first follow-up appointment and a supply of eye-drops before heading home.

AFTERCARE: It is not a painful operation - during or after surgery. You should stay active. You can continue your usual activities as long as they do not include vigorous or forceful effort nor anything that exposes you to the risk of something poking your eye. Avoid political arguments! Reading and TV watching do not hurt the eye. Resume driving when you feel confident to. After six weeks your eye is healed enough for your glasses to be updated as necessary

COMPLICATIONS: Although these are unusual, you must be aware that not all operations follow the expected course and the possibility of your being worse off following surgery exists. Usually all goes well if both surgeon and patient obey the rules. Please use your medications as instructed, don't injure the eye (especially by poking your glasses into your eye) and please let your surgeon or GP know if your eye does not feel right (viz. increasing pain, redness or blurriness). Your eye should feel a little better with each new day but don't expect your sight to be great from the beginning as the focusing improves only as the eye heals.

The most common complication is raised eye pressure following the operation (glaucoma) but it usually settles after a brief period of treatment. If all of the cataract cannot be removed in the first operation, a further procedure may be required. Swelling of the central retina (cystoid macular oedema) sometimes follows routine cataract surgery but mostly settles after some months. Rupture of the wound can follow injury. Infection is the most serious complication as it can leave the eye blind. Every care is taken to minimise this risk.

If there is some other disease in the eye the vision improvement may be disappointing. Age-related retinal degeneration, retinal blood-vessel disease and glaucoma, for example, can coexist with cataract. These conditions are usually noted before surgery.

A small percentage of patients will notice that their vision begins to fade some months or years after surgery from thickening of the membrane (Posterior Capsule) that fixates the implant lens. This membrane is easily perforated with LASER treatment and does not recur.

It is important to be aware that 95% of patients who have cataract surgery do achieve a substantial improvement in their vision.

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