PDF Version Available

Congenital cataracts

Disclaimer: This fact sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.

A cataract is a cloudiness in the lens of the eye. This means the lens is no longer transparent. The lens is located behind the iris (the coloured part of the eye), which focuses light rays on to the retina. The retina is the inner layer at the back of the eye. For a child to be able to see, light has to pass through the transparent lens to focus on the retina.

In a normal eye the cornea and the lens focus light rays onto the retina

Lens with a cataract, blocking the light rays so the eyesight is reduced

Cataracts can occur in one or both eyes. What causes most cataracts is unknown. We do know that some cataracts are linked to metabolic and infectious diseases (like rubella) and some syndromes. In most cases, the cause cannot be identified. About one third of cataracts are hereditary. For example, the child's grandparent or parent may have been born with a cataract. The parent and child usually have a cataract in the same part of the lens, as well as the same type of cataract.

Most cataracts are invisible until they became dense enough to cause loss of sight. When the lens becomes cloudy it thickens and the pupil appears white. Congenital cataracts can vary in density. If the cataract is not dense enough to interfere with the transmission of light, it may require no treatment. The ophthalmologist will continue to monitor your child. Once the cataract reduces your child's vision, the lens will be removed. Dense central cataracts require surgery - if they go untreated, vision will not be able to develop in that eye.

Some of the symptoms of cataracts

• Glare - the same effect as car headlights through a dirty windscreen at night.
• A white pupil known as leukocoria - this is due to the cataract showing through the pupil. The pupil is just a hole or opening which also assists in the focusing of light rays.
• Poor vision - light is not getting through the lens, because it's no longer transparent.
• In the older child the eye can turn. This is called Strabismus, or commonly known as a squint. A "turn" occurs because the eye can not focus properly.

To diagnose the congenital cataract, the ophthalmologist will look at your child's eyes with an instrument called an ophthalmoscope. The pupil has to be dilated with eye drops. A dilated pupil gives a wider picture or view of the eye lens.

If your child needs surgery

Cataracts are usually treated by surgically removing the lens of the eye. The lens is removed by making a small incision in the eye. The operation usually takes about an hour. Your child may either, stay for the day or may have to stay in hospital overnight. Your child will return to the ward with an eye pad covering the operated eye. This pad will be removed the next day.

After the operation

After the operation, your child will need eye drops frequently during the day for a period of time. Because the lens is used to focus the light rays, the child won't be able to focus on objects. The doctor will either prescribe a contact lens or glasses. An intra-ocular lens can also be used in place of the eye lens, for an older child.

Contact lenses are usually the preferred choice - these lenses can stay in for a week at a time. Parents are taught how to put in and clean the contact lens. We make sure that you feel confident in handling the day- to-day care of your child's lenses.

• Cataracts are usually treated by surgically removing the lens of the eye.
• Your doctor will prescribe contact lenses or glasses.

The Children's Hospital at Westmead Tel: (02) 9845 3585 Fax: (02) 9845 3562 www.chw.edu.au	Sydney Children's Hospital, Randwick Tel: (02) 9382 1688 Fax: (02) 9382 1451 www.sch.edu.au	Kaleidoscope, Hunter Children's Health Network Tel: (02) 4921 3670 Fax: (02) 4921 3599 www.kaleidoscope.org.au