If you have been told that you have a cataract, don't be alarmed. Over half of those over 65 have some cataract development and most cases can be treated successfully with surgery. Despite what you may have heard, a cataract is not a skin that grows over your eye. A cataract is a clouding of part of your eye called the lens. Your vision becomes blurred or dim because light cannot pass through the clouded lens to the back of the eye.
The lens
The lens is a transparent body behind the iris, the coloured part of the eye. The lens bends light rays so that they give a clear image to the back of the eye - the retina. As the lens is elastic, it will change shape, getting fatter for close objects and thinner for distant objects.
What causes a cataract?
Cataracts can form at any age, but most often develop as people get older. In younger people they can result from an injury, certain drugs such as steroids, long-standing inflammation or illnesses such as diabetes. Diets or drugs have not been shown conclusively to slow or stop the development of the cataract in any large multi-centre studies yet, but there is a positive link between smoking and premature development of cataract, possibly due the toxins in the smoke such as cyanide.
Symptoms
You may notice that some things seem blurred round the edges, or that your glasses seem dirty or scratched.
Seeing double. The cloudiness in the lens may occur in more than one place, so that the light rays which reach the retina are split, causing a double image.
Glare in bright light. You may find that bright light such as from car headlights when driving at night or on very sunny days make it more difficult to see.
Change of colour vision. As the cataract develops its centre becomes more and more yellow, giving everything you see a yellowish tinge.
What can be done to help?
The normal treatment for cataracts is a small operation to remove the cloudy lens. This cannot be performed by laser, although laser treatment is sometimes needed afterwards. Cataract occurs because the proteins in the fibres in the lens de-nature, in a similar way to the proteins in an egg white, when they are cooked.
Oral antoxidant vitamins (eg VisionACE) may slow this process down especially in smokers, although smokers need to be careful with very high doses of vitamin A. There are antoxidant eyedrops available, which as yet have not been scientifically validated. In particular, there is no evidence of ocular penetration of the active ingrediant, L-carnosine, into the eye at significant levels. However further information can be obtained by one of their distributors, David Crystal Optometrists in Edinburgh, www.davidcrystal.co.uk, for those interested in investigating further.
What is a lens implant?
When the cloudy lens has been surgically removed it is usually replaced by a plastic lens so that the eye can focus properly.
Occasionally a doctor will decide that someone's eye is not suitable for a lens implant. In these cases contact lenses or special glasses will be prescribed instead.
When should I have the operation?
Usually, you can decide if, and at what stage to have the operation. Obviously you need to bear in mind that there may be a waiting list for this. In the past, eye specialists often waited until the cataract became `ripe' before suggesting you had it removed. Nowadays, with modern surgery the operation can be carried out at any stage of the cataract's development. If visual impairment interferes with your ability to read, to work, or to do the things you enjoy then you will probably want to consider surgery. For most people, it is possible to have your operation and go home on the same day, as long as you have someone to look after you at home. Sometimes surgery will mean a short stay in hospital.
What happens in the operation?
Just before the operation you will be given eye drops to enlarge your pupil and something to help you relax if you want this. Normally cataract surgery is performed with a local anaesthetic and some sedation. The local anaesthetic numbs the area that is being operated on. You will be wide awake but feel nothing in your eye. Usually the eye specialist will explain what is happening as the operation goes along, and a nurse will be there to hold your hand and make sure you are all right. Sometimes your doctor may decide to give you a general anaesthetic. This means that you are completely unconscious, and it will be like sleeping through the operation. The operation is performed with the aid of a microscope through a small cut in the top of the eye. This is closed using small stitches at the end of the operation. The operation generally takes up to 45 minutes. A pad or shield will probably be put over your eye to protect it from accidental rubbing and bumping after the operation. We want to reassure you that your eye is not taken out of its socket during surgery. The operation is not painful and the stitches cannot be seen.
After the operation
Your sight will usually improve within a few days, although complete healing may take several months. It is a good idea to have some help at home if you can, especially if you find it difficult to put your eye drops in. You will need to take it easy for a couple of weeks so that your eye can heal:
- Avoid rubbing your eye; wear an eyeshield if you are a restless sleeper.
- Don't do any heavy lifting, and avoid strenuous exercise and swimming.
- You can do light housework or cooking, but try to get some help if you can.
· You don't need to stay indoors but take care if it is windy, in case anything blows in your eye.
·- Wash your hair leaning backwards rather than forwards.
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- Avoid eye make-up for six weeks.
- Avoid driving until your surgeon tells you it is safe.
- New glasses are usually prescribed two to eight weeks after the operation.
· How long you are off work will depend on the job you do. Ask your eye specialist about this.
