Childhood cataract

The aim of this leaflet is to ensure that you are informed about your child’s diagnosis of cataract.

The eye is made of three parts:

1. A light focusing bit at the front (cornea and lens)
2. A light sensitive film at the back of the eye (retina)
3. A large collection of communication wires to the brain (optic nerve)

A curved window called the cornea first focuses the light. The light then passes through a hole called the pupil. A circle of muscle called the iris surrounds the pupil. The iris is the coloured part of the eye. The light is then focused onto the back of the eye by a lens – which should be transparent and approximately the same size and shape as a ‘smartie’ sweet. Tiny light sensitive cells (photoreceptors) cover the back of the eye. The covering of photoreceptors at the back of the eye forms a thin film known as the retina. Photoreceptors collect information about the images you see. Each photoreceptor sends its signals down very fine wires to the brain. The wires joining each eye to the brain are called the optic nerves. The information then travels to many different special ‘vision’ parts of the brain. All parts of the brain and eye need to be present and working for us to see normally.

What is a cataract?

A cataract is cloudiness in the normally clear lens of the eye. If the lens is not clear then not all the light can get into the eye or it may be scattered by the cataract, blurring the vision and causing visual problems with dazzle and glare.

Childhood cataract

Although we usually think of cataracts as something older people develop, children can be born with cataracts in one or both eyes, or develop them in infancy and childhood. About 5-6 per 10,000 infants and young children will be affected by cataracts. The cataract(s) may be mild and not affect the vision much, or they can be severe and need urgent treatment. The earlier in life the cataract develops, the more it interferes with normal vision development which is why all babies are screened for cataract in infancy.

What are the causes of cataract?

Cataract affecting one eye (unilateral):

Most children with a cataract in only one eye have good vision in the other. Often there is no history of childhood cataracts in the family, the child is healthy in every other way and no cause for the cataract can be found. Sometimes there are other structural problems in the eye besides the cataract, such as it being smaller than the other, which suggest that a problem occurred during the development of the eye before birth.

Cataract affecting both eyes (bilateral):

There are several groups of conditions that cause cataracts to develop in childhood:

1. inherited, genetic cataract conditions
2. untreated chronic inflammation of the eye (uveitis)
3. medical treatment such as steroid therapy or radiotherapy

What are inherited or genetic cataracts?

About one fifth of children with cataracts will have a close relative with the same condition. This is caused by a misprint in the genes responsible for the development of the lens. There are many different kinds of inherited cataract conditions. Additionally, cataracts can develop in children with chromosomal abnormalities, such as Down syndrome.

If your child has bilateral cataracts, we may examine the eyes of other members of the family in clinic, or do some gene testing to determine if there is a genetic explanation. Often no cause for bilateral cataracts can be found and these are called idiopathic cataracts.

How does cataract affect the way a child sees?

Cataracts can affect the vision in different ways depending on the child’s age and the severity of the cataract.

If the cataract is mild your child’s vision may not be affected and the ophthalmologist may decide that early surgery is not required. Your child will be prescribed glasses if necessary and will be reviewed quite frequently to ensure that his/her vision is developing normally. If the mild cataract is in one eye only, you may be asked to patch your baby’s other eye in order to prevent the eye with the cataract becoming lazy (amblyopic).

If the cataract is severe and affecting one eye only, the eye may turn in or out (squint) compared to the other or the pupil of the eye may look white or grey rather than black. Children usually do not complain of vision problems when only one eye is affected. If both eyes are affected, the child’s visual behaviour may change so they hold things closer or their reading and writing gets worse. Young children may develop a wobbly movement of their eyes (nystagmus) and a squint.

How are cataracts treated?

The ophthalmologist will make a decision about the need for surgery based on your child’s visual assessment and the appearance of the cataract. If the cataract is very mild or affects only a small portion of the lens, surgery may not be required and regular monitoring, wearing glasses and part-time patching of the better eye may be advised. If the cataract is felt to be interfering with your child’s visual development, an operation may be necessary.

What if an operation is needed?

If your child has cataracts in both eyes we usually operate on one eye at a time to reduce the very small risk of infection. Sometimes we will operate on both eyes under the same general anaesthetic if there are health concerns which might reduce your child’s tolerance to a general anaesthetic. Your child will be admitted to the children’s ward for their surgery as a day case procedure. He/she will have to fast before the anaesthetic is given. Before the operation, drops will be instilled into your child’s eye(s) to dilate the pupils. You will be able to go with your child to the anaesthetic room and be there while they fall asleep. Usually anaesthetic gas is used to put infants and young children to sleep for the operation.

The operation usually takes one-and-a-half hours. During the operation the surgeon will remove the cataract. If your baby is over seven months of age an acrylic intra-ocular lens (a lens that is implanted within the eye) may be implanted at the time the cataract is removed. If your child is under seven months or has a small eye, the intra-ocular lens is implanted as a second step, once the child is over seven months and the eye is a suitable size.

The small incision sites are carefully sewn up with dissolvable stitches. An antibiotic and anti-inflammatory medicine is injected under the conjunctiva (the thin, transparent tissue that covers the outer surface of the eye) – this often results in a raised white patch and some blood staining on the white of the eye. If the decision has been made not to implant an intra-ocular lens at the time of surgery, a contact lens will be required. This is usually put in the eye several days after the cataract operation by the surgeon or contact lens fitter in clinic.

Following the operation

After the operation your child will have a small see-through shield on his/her eye to stop him/her from rubbing it. You will be asked to start on very frequent drops during the daytime; these are very important and reduce the inflammation in the eye following surgery. Unless there are other health needs, children usually go home the day of their surgery. The surgeon will come to talk to you about the operation and post-operative care before you go home. The eye will be gritty and uncomfortable after the procedure but it is not usually very painful.

At home

Your child will need to continue on frequent drops and will be reviewed within a week in eye clinic. If you have difficulty putting in the drops, lie your child down on his/her back and drop a pool of three to four drops in the inside corner of the eye, these will run into the eye when he/she blinks. It is better to be sure and get more drops in the eye than to miss! Try to stop your child rubbing his/her eye and avoid swimming for one month.
It is important that you continue the drops until the surgical team says you can reduce or stop them – if you run out of drops before the follow up appointment, please ring the paediatric ophthalmology nurses on the number below.

The eye will look red and may be sticky for a few days; if it is difficult to open the eye in the mornings then bathe gently with sterile water or boiled cooled water and a make-up pad, not cotton wool.

Benefits

If the cataract is severe and surgery is delayed, irreversible and permanent reduction of vision can occur. Cataract surgery improves the light getting through to the back of the eye but good vision will only occur if the brain is able to recognize and use the visual information from that eye. If your child has had the cataract since they were an infant, this ability may have been affected and their vision even after surgery may be limited. However, in most cases the vision does gradually improve once the cataract is removed.

Risks

If left untreated your child will be visually impaired.

What are the risks of surgery?

1. Common: Capsular thickening (the capsule is the outer bag of the natural lens that is left behind during surgery to hold the artificial lens or implant) and membrane formation
2. Rare: Infection
3. Rare: Glaucoma
4. Rare: Retinal detachment

Infants and young children develop much more scar tissue in their eyes after surgery than adults. It is common for developing scar tissue to form on the lens implant and this may reduce the vision. In children over three years, this scar tissue can usually be removed using a laser in clinic. This is a completely painless procedure but does require the child to be still. Sometimes this needs to be repeated several times. Children who are unable to comply with this treatment usually require a short operation under general anaesthesia to remove the scar tissue instead.

Infection in the eye after surgery only occurs in less than one in 1000 cases. Unfortunately this results in very poor vision. This is the reason why one eye at a time is operated on.

Glaucoma is a high pressure in the eye, which damages the optic nerve and tends to occur years after the initial surgery. It happens rarely in children who are over six to seven months at the time of their cataract surgery. Your child will have regular measurements of his/her eye pressures in clinic. Occasionally, if we are unable to assess the eye health fully in clinic, an examination under anaesthetic might be necessary. If detected early, glaucoma can be treated with eye drops although some children do need an operation to keep the pressure controlled.

Rarely, the retina (the light sensitive film lining the inside of the eye) becomes detached. If detected quickly the retina can be re-attached surgically but usually the visual outcome is poor.

Other problems to consider:

1. Glasses and contact lens correction
2. Patching therapy for lazy eye
3. Wobble (nystagmus)
4. Eye misalignment (squint)

Glasses and contact lens correction

Since the eyes grow quite rapidly in the first years, your child’s glasses prescription will need to change to keep pace. If a lens implant has been used, the baby will need to grow into the implanted lens strength and will require quite thick glasses for the first few years after cataract surgery. The artificial lens implant does not change focus like a natural lens and so your child will always need glasses.

If your child has not had a lens implant inserted at the time of the initial cataract surgery, he/she will be reliant on contact lenses to focus the vision. The contact lenses are inserted by a contact lens practitioner in the clinic and are changed every few months.

Patching therapy

If the cataract affects only one eye and the other eye has good vision, the brain will continue to prefer to use the vision in the normal eye to the one that has had cataract surgery. The eye will be lazy (amblyopic). In order to improve the vision in the lazy eye, your child may need to have the normal eye patched for the majority of the time he/she is awake and patching will need to continue until the child is eight years old. This is a considerable burden on the child and family. A child only needs good vision in one eye to be able to drive and undertake most occupations in later years. Some parents decide not to go ahead with surgery for a unilateral cataract for this reason.

Wobble

Nystagmus (a to and fro movement in the eyes) is commonly seen in children who have had bilateral cataracts since infancy. It is sometimes also seen in children who have unilateral cataracts, especially if the vision in the eye is very poor. Because the eyes are constantly moving, fine detail in the vision is lost. Often the child will tilt or turn his or her head to place the eyes in a position where they wobble less to improve the vision.

Squint

Most children who have had congenital cataracts develop a squint or misalignment of the eyes. Usually one eye will tend to turn in. This is another factor that may make the squinting eye lazy and patching of the other eye may be advised. If the squint becomes a social issue, squint surgery can be performed to improve the alignment. This is usually delayed until the child starts school.

How can parents, family and teachers make a difference?

There are lots of things that you can do to help your child make the most of his/her vision. If your child has been prescribed glasses, contact lenses or a Low Visual Aid, it is important that they are encouraged to wear and use them. This will help your child see more clearly and ensure the vision parts of the brain grow and develop. If your child dislikes bright lights ask your ophthalmologist for prescription sunglasses.

Your child may have difficulty learning to read and keeping up with schoolwork. Your ophthalmologist will arrange for the visual impairment teachers to visit you at home to help you stimulate your baby’s vision and will liaise with nursery and school teachers to ensure that your child has the help they need to have a successful mainstream education.

Alternatives

Please be sure to ask about any alternatives to your child’s plan of care during their consultation.

Contacts/further information

Further information about congenital cataracts is available at:

Support is available from:

Childhood cataracts (opens in a new tab)

Childhood cataract network - parent information (opens in a new tab)

If you have any concerns about your child’s eye, the eye becomes more red and your child stops feeding, starts vomiting, or seems in pain, ring the emergency eye clinic number on 01223 216778 or contact your General Practitioner (GP) for advice.

Hospital contacts:

Consultant Paediatric Ophthalmologist
Department of Ophthalmology
Clinic 3, Box 41, Addenbrooke’s Hospital
Cambridge University Hospitals NHS Foundation Trust
Hills Road, Cambridge, CB2 0QQ
Secretary: 01223 216700

Paediatric Ophthalmology Nurses
Department of Ophthalmology
Hills Road, Cambridge, CB2 0QQ
01223 596414 Monday - Friday 08:00 - 17:00hrs
Email paedophth@addenbrookes.nhs.uk

Privacy and Dignity

We are committed to treating all patients with privacy and dignity in a safe, clean and comfortable environment. This means, with a few exceptions, we will care for you in same sex bays in wards with separate sanitary facilities for men and women.

In some areas, due to the nature of the equipment or specialist care involved, we may not be able to care for you in same sex bays. In these cases staff will always do their best to respect your privacy and dignity, eg with the use of curtains or, where possible, moving you next to a patient of the same sex. If you have any concerns, please speak to the ward sister or charge nurse.