What is a cataract?

The lens of the eye is normally transparent. A cataract is an opacity (cloudiness) in the lens, which is positioned behind the iris and pupil. The lens sits within a clear membrane called the lens capsule. A cataract therefore develops inside the eye and does not grow across the front of the eye. Such an opacity can vary from being quite minor to being so marked as to prevent adequate vision by scattering or blocking the light.

Cause of cataracts

There are many causes of cataracts but the most common in New Zealand is age related (as a person ages the lens slowly grows cloudy and turns yellow). A cataract is more common in each successive decade of life. Years may pass before you notice your reduced vision.

Treatment of cataracts

Only cataracts which cause symptoms need treatment. Modern cataract surgery is effective in restoring vision in most patients and the technique involves removing the clouded lens through a small incision in the eye (a technique called phacoemulsification - the most commonly used method).

An intraocular (plastic) lens is then placed in the eye to replace the cataractous lens. The operation takes 20 to 60 minutes and there is usually no need to be kept in hospital overnight, unless you are recommended to stay because of other medical problems.

Anaesthesia

Cataract surgery is performed in an operating theatre under sterile conditions. The surgery can be performed under general or local anaesthesic, but local anaesthetic with light sedation is far more commonly used. The type of anaesthesia is chosen after discussion with the patient and the anaesthetist.

Postoperative care

After surgery, you’ll rest in a recovery area for a few hours. The after-effects of sedation and local anaesthetic are usually only slight. Even though you may feel fine, you should take it easy. Your eye specialist or nurse will let you know what you should and shouldn’t do once you get home. Also, arrange to have someone to take you home after surgery.

If you had general anesthesia, it may take a day or more to fully recover. So, for at least the next 24 hours: do not drive or use machinery or power tools; do not drink alcohol; and do not make any major decisions.

You may be told to wear some form of eye protection, or shield, on the first day or two. If the light is too bright when you take off the shield (this is common) you can wear sunglasses. Also, you should remember to take any eyedrops or other medicine your eye specialist prescribes. Eye drops need to be instilled into the eye; the technique for this is easily learned:

• Tilt your head back
• Pull your bottom eyelid down
• Squeeze one drop into your eye - do not touch your eye with the bottle tip
• Close your eyes for a few seconds.
• Spend your first day relaxing at home (watching TV and reading are OK and won’t harm your eye).
• Don't press or rub your eye
• Don't do anything that makes you jar or strain the eye (eg, heavy lifting)
• Don't drink alcohol within the first 24 hours.
• You may be able to get back to much of your routine in the first day. But with some tasks, your eye specialist may ask you to wait.
• Driving: you can drive again in five to seven days
• Bathing: you can shower again in two to three days
• Exercising: You can exercise again in 14 days.

Risks and complications

There are risks and complications with any surgery but cataract surgery has an excellent safety record. If there are any problems or concerns following surgery you should consult your eye specialist via the phone numbers given to you at the time of surgery.

It is normal to have the following:

• Scratchy, sandlike feeling in the eye for two weeks
• Tired feeling, especially during the first 24 hours
• Headache, upset stomach
• Bruised or bloodshot eye for one week.

You should call your eye specialist if:

• You have a fever of more than 38 degrees
• You have chills
• You have increasingly blurred or distorted vision
• You have increasing redness of the eye
• You have excessive coughing
• Your pain is not relieved by over-the-counter medicine (eg, paracetamol)
• You have nausea or vomiting
• Any other concerns about your surgery.

Common questions about cataract surgery.

1. Can cataract surgery be performed by laser surgery?

No. There are no institutions in the world currently using lasers to remove cataracts. Experimental lasers are being developed which may be of use.

2. Can cataracts regrow after surgery?

No. Once a cataract is removed another cataract will not form. Sometimes the capsule securing the intraocular lens thickens following surgery and may require laser treatment. This is performed during a short outpatient visit.

3. Will I need glasses after surgery?

Most patients will require spectacles for fine visual tasks. Some people can get by without glasses for certain duties.

4. What if I have other eye disease - will cataract surgery help?

There are many diseases, which affect the eye and limit the visual improvement. Most diseases, which reduce the success of surgery, can be diagnosed preoperatively. Your eye specialist will discuss any additional problems with you.

For further information and support talk to an optometrist or eye specialist. Optometrists are listed in the 'Yellow Pages' of your telephone book. Eye specialists are listed with registered medical practitioners at the front of the white pages of your telephone book.

Original material provided by Auckland Eye and edited by everybody.