Cataract

What is a cataract ?

A cataract is a clouding of the lens in the eye and is a normal feature of ageing. Many adults aged over 65 develop cataracts, which normally build up slowly but occasionally they can worsen over a short period. Very rarely they can also develop for reasons other than normal ageing.
The presence of a cataract means that light cannot be clearly focussed on the retina and therefore the image is blurred and distorted. In addition to blurred vision, other symptoms of cataract include glare and dazzle in sunlight or from car headlights and haloes when driving at night.
In the early stages of cataract, impaired vision may be able to be improved by updating your spectacles. As the cataract progresses however, your vision may deteriorate to a level where a change of spectacles no longer gives an improvement in vision. At this stage the only way to improve your vision further is cataract surgery to remove the cloudy lens and replace it with a clear, artificial lens.

What happens during a cataract operation?

Cataract surgery is a common procedure throughout the world with excellent results with over 98% of people achieving improved vision. The surgery is usually performed under local anaesthetic either with anaesthetic drops or an anaesthetic injection around the eye. Although you will be awake, you should not feel any discomfort and you will not see the operation being performed. Occasionally a general anaesthetic may be used depending on individual patient requirements.
A small incision is made in the cornea (2.8mm in size) which is self-sealing and does not require a suture. Once the incision has been made, a round opening is made in the bag that holds the cataract to gain access to the cataract itself. Then an instrument called a phacoemulsifier is used which uses ultrasound to break the cataract into tiny pieces which are then sucked out of the eye. A folding artificial lens is then introduced into the eye and unfolds within the capsular bag which then supports the artificial lens.
The surgery itself usually last about 20 minutes and you will leave hospital a few hours after the surgery.
What types of intraocular lens are available?

Monofocal lens

Most patients have a monofocal intraocular lens which usually gives them clear distance vision without glasses but they will require reading spectacles for close work.

Toric lens

Toric lenses are used to correct astigmatism which occurs if the cornea at the front of the eye is shaped like a rugby ball rather than a football. Correcting the astigmatism with a toric lens implant means that patients with astigmatism are less likely to require spectacles for distance vision.

Multifocal lens

Some patients would like to achieve spectacle independence i.e they do not wish to wear spectacles for distance or near vision. A multifocal lens can be used in these cases and there are various types available. This type of lens is not suitable for everyone and I can discuss the advantages and disadvantages of these lenses during the consultation. There are also multifocal toric lens implants which aim to give freedom from spectacles and correct astigmatism.

What happens after the surgery?

You will be given a supply of eye drops to use for approximately one month following the operation. They are used to treat any inflammation and guard against infection. I will review you in clinic at 1-2 weeks after the operation and if necessary you can visit you optometrist for a spectacle update 4-6 weeks after the operation.

Is the operation safe?

Cataract surgery is a very common operation and achieves excellent visual results. Although it is a safe operation there is a very small risk of less than 1 in 1000 that your vision could be worse after surgery as a result of infection.