Cataract Operation
Definition
The eye contains a lens which focuses the image on to the back of the eye in a similar fashion to the lens within a camera. The lens of the eye is normally clear and transparent. A cataract is a clouding of the normally clear lens of the eye.
Incidence/age
Cataracts rarely occur in new born babies. They can occur at any age secondary to facts such as trauma or other medical problems. The majority of cataracts however occur as a normal ageing change in later life.
Causes
The most common cause of cataracts is an ageing change of the lens in an otherwise healthy patient. Other causes of cataracts can occasionally include trauma to the eye, medical problems including diabetes, medications including steroids, and other eye conditions including chronic iritis. Cataracts rarely occur in new born babies (congenital cataracts). Approximately 1/3 of congenital cataracts are hereditary with a history of such cataracts in other members of the family.
Signs/symptoms
Cataracts lead to gradual blurring of the vision with fading or dulling of colours. Reading and watching television become more difficult. Cataracts may lead to problems with glare. This can be particularly noticeable when driving if the sun is low in the sky or when driving at night facing oncoming car headlights. Cataracts occasionally give rise to symptoms of double vision in one eye. Some early cataracts lead to the need for frequent changes of spectacle prescription.
Complications of disorder
The complications of cataracts are usually related to a deterioration in vision of the affected eye.
Tests
Examination by an ophthalmologist (eye doctor) will detect the presence of a cataract in addition to checking for other causes of the deterioration in vision of the affected eye. At the time of the examination the pupil of the eye will be dilated with drops leading to a further temporary (a few hours) blurring of the vision of that eye. This allows examination of the back of the eye to exclude other causes of a deterioration in vision of the affected eye such as ageing changes of the retina at the back of the eye (macula degeneration). An ultrasound examination of the back of the eye may be undertaken if the cataract is particularly advanced.
Treatment
Medical
In the early stages of a cataract vision may be improved by a change of spectacles and by using improved lighting for reading. There is no known way however of preventing or slowing the development of cataracts. No medications (including eye drops), dietary supplements or eye exercises have been shown to cure or prevent the development of cataracts.
Surgical
Cataract surgery should be considered when the vision deteriorates to a level at which the individual has difficulty carrying out daily activities. It is not necessary to wait for the cataract to be ripe or to have reached an advanced stage before cataract surgery is performed. With modern surgical techniques the operation can be performed at any stage depending upon each person's individual visual requirements.
Cataract surgery is usually performed under local anaesthetic. The cloudy lens is removed from the eye and replaced with an artificial lens implant. The lens implant is permanent and it is intended that this lens should remain within the eye for the remainder of the patient's life.
Outcome
The speed at which a cataract develops and the vision deteriorates varies considerably between different individuals. The majority of cataracts develop relatively slowly over a period of months or years. Some cataracts, and particularly those associated with trauma or medical conditions such as diabetes, may progress more quickly.
Cataract surgery results in improved vision for over 90% of individuals providing there are no problems with the health of the rest of the eye.
Further resources
Books
Your operation: Cataract, J Smith & T James. Headway. Hodder & Stoughton 1999
Contact
European Society of Cataract and Refractive Surgery (ESCRS)
10 Hagan Court
Lad Lane
Dublin 2
Ireland
Tel: (00 353) 1 676 0928
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