Retinoblastoma is a rare type of eye cancer that can affect young children, usually under the age of 5.

If it's picked up early, retinoblastoma can often be successfully treated. More than 9 out of 10 children with the condition are cured.

Retinoblastoma can either affect 1 or both eyes. If it affects both eyes, it's usually diagnosed before a child is 1 year old. If it affects 1 eye, it tends to be diagnosed later (between the ages of 2 and 3).

Signs and symptoms of retinoblastoma

Signs and symptoms of retinoblastoma include:

• an unusual white reflection in the pupil – it often looks like a cat's eye that's reflecting light and may be apparent in photos where only the healthy eye appears red from the flash, or you may notice it in a dark or artificially lit room
• a squint
• a change in the colour of the iris – in 1 eye or sometimes only in 1 area of the eye 
• a red or inflamed eye – although your child will not usually complain of any pain
• poor vision – your child may not focus on faces or objects, or they may not be able to control their eye movements (this is more common when both eyes are affected); they may say they cannot see as well as they used to

These symptoms may be caused by something other than retinoblastoma. But you should get them checked by your GP as soon as possible.

It's unusual for retinoblastoma to progress unnoticed beyond the age of 5. 

Signs in older children include the eye appearing red, sore or swollen, and some loss of vision in the affected eye.

Causes of retinoblastoma

Retinoblastoma is cancer of the retina. The retina is the light-sensitive lining at the back of the eye.

During the early stages of a baby's development, retinal eye cells grow very quickly and then stop growing.

But in rare cases, 1 or more cells continue to grow and form a cancer called retinoblastoma.

In about 4 out of 10 (40%) of cases, retinoblastoma is caused by a faulty gene, which often affects both eyes (bilateral).

The faulty gene may be inherited from a parent, or a change to the gene (mutation) may occur at an early stage of the child's development in the womb.

It's not known what causes the remaining 60% of retinoblastoma cases. In these cases, there's no faulty gene and only 1 eye is affected (unilateral).

Around 45 children are diagnosed with retinoblastoma in the UK each year.

Diagnosing retinoblastoma

Your GP will carry out a red reflex test in a darkened room using an ophthalmoscope (a magnifying instrument with a light at one end).

When a light is shone into your child's eyes, your GP will see a red reflection if the retina is normal.

If the reflection is white, it may be a sign of an eye condition such as cataracts, retinal detachment or retinoblastoma.

In this case, your child will be urgently referred (within 2 weeks) to an eye specialist (ophthalmologist) for further investigation.

The eye specialist (ophthalmologist) will examine your child's eyes, and they may carry out another red reflex test.

Eyedrops will be used to increase the size of your child's pupils, allowing a clear view of the retina at the back of the eye.

An ultrasound scan is also sometimes used to help diagnose retinoblastoma.

This is a painless procedure where gel is rubbed on the outside of the eyelid and a small ultrasound probe is placed on the eyelid, which scans the eye.

After these investigations, if the eye specialist thinks your child has retinoblastoma they'll refer them to a specialist retinoblastoma treatment centre, either at The Royal London Hospital or Birmingham Children's Hospital.

Your child's appointment should be within a week of being seen at your local eye clinic.

At the specialist centre, your child will need to have a general anaesthetic so their eyes can be thoroughly examined and a diagnosis of retinoblastoma can be confirmed or ruled out.

Treating retinoblastoma

Your child will be treated by a specialist retinoblastoma team at either The Royal London Hospital or Birmingham Children's Hospital.

But if your child needs chemotherapy, this will usually be carried out at a local children's cancer centre and overseen by the retinoblastoma team at one of the specialist hospitals.

The recommended treatment for retinoblastoma will depend on the stage of the tumour, which can either be:

• intraocular – where the cancer is completely within the eye, or
• extraocular – where the cancer spreads beyond the eye to the surrounding tissue, or to another part of the body (this is rare in the UK) 

Most cases of retinoblastoma (9 out of 10) are detected early and successfully treated before the cancer spreads outside the eyeball.

If the cancer has spread beyond the eye, it'll be more difficult to treat. But this is rare as the condition is usually identified well before it reaches this stage.

Depending on the size and position of the tumour, your child's specialist will be able to accurately stage the cancer into one of a number of categories (A to E).

The American Cancer Society has more information about how retinoblastoma is staged.

Treating small tumours

There are 2 possible treatment options for treating small tumours contained within the eye:

• laser treatment to the eye (photocoagulation or thermotherapy)
• freezing the tumour (cryotherapy)

The aim of these treatments is to destroy the tumour. They're carried out under general anaesthetic, so your child will be unconscious and will not feel any pain or discomfort during the procedure.

In some cases, chemotherapy may be needed before or after these treatments.

Treating larger tumours

Larger tumours will be treated with one or a combination of the following treatments:

• brachytherapy – if the tumour is not too large, small radioactive plates called plaques are stitched over the tumour and left in place for a few days to destroy it, before being removed; radiotherapy to the whole eye may be recommended for larger tumours that have not responded to other treatment methods
• chemotherapy – may be used to shrink the tumour at the start of treatment, or it may be recommended if there's a chance of the cancer spreading; in some cases, chemotherapy medication can be delivered directly to the eye
• surgery to remove the eye – is often necessary for very large tumours where there's no sight from the eye; if your child needs to have their eye removed, they'll have an artificial eye fitted in its place

You can find out more about artificial eyes from the National Artificial Eye Service.

Side effects of treatment

Your child's treatment team will discuss any possible side effects of treatment with you. Different treatments have different side effects.

Sight loss is one of the biggest worries for parents. Your child's treatment team will do everything they can to avoid your child losing their sight.

If your child needs to have one of their eyes removed, the sight in their other eye will not be affected as long as there are no tumours in the important areas for seeing in that eye.

Children who lose sight in 1 eye are usually able to adapt very quickly to using their other eye, without it affecting their home and school life.

If both eyes are affected by retinoblastoma, your child will probably have some degree of sight loss and may need support either within a mainstream or specialist school.

The UK-based retinoblastoma charity, the Childhood Eye Cancer Trust (CHECT), has more information about the side effects of treatment for retinoblastoma.

Follow-up

Retinoblastoma requires a long period of follow-up tests, which will initially be carried out at one of the specialist retinoblastoma centres.

After a period of treatment and observation, the tests will usually take place at your local eye department.

Screening for retinoblastoma

If you're pregnant and you had retinoblastoma as a child, or you have a family history of retinoblastoma, it's important to tell your GP or midwife.

This is because in some cases retinoblastoma is an inherited condition and babies considered at increased risk of developing it may be offered screening after the birth.

Your GP will be able to refer you to a specialist centre so the appropriate tests can be carried out when your baby is born.

Your children's risk will depend on the type of retinoblastoma you or your relative had.

Screening aims to identify tumours as early as possible so treatment can be started straight away.

Children under 5 years of age are usually screened by having their eyes examined while under general anaesthetic.

This will be carried out at one of the UK's 2 specialist retinoblastoma centres: The Royal London Hospital or Birmingham Children's Hospital.

Your child will need to be screened frequently up until they're 5 years old.

Does my child need screening?

Your child may need to be screened if:

• you or your partner has had retinoblastoma and you're expecting a baby or you have recently had a baby
• you or your partner has had retinoblastoma and you have a child under 5 who has not been checked
• you have a child who's been diagnosed with retinoblastoma and you're expecting a baby, or you have other children under 5 who have not been checked
• your parent (or brother or sister) had retinoblastoma and you have a child under 5 who has not been checked

Help and support

The specialist teams at the retinoblastoma centres at The Royal London Hospital and Birmingham Children's Hospital have a wealth of knowledge about retinoblastoma.

You can discuss any worries or concerns you have with them.

They'll also be able to put you in touch with the parents of children who have recently been diagnosed with and treated for retinoblastoma.

The Childhood Eye Cancer Trust (CHECT) can give you further information about retinoblastoma.

It also provides help and support to parents and carers of children affected by retinoblastoma, as well as adults who were affected during childhood. 

You can contact them on 020 7377 5578 (Monday to Friday, 9am to 5pm) or by email: support@chect.org.uk.

You can also call the Cancer Research UK helpline to speak to a cancer nurse, who'll be able to provide you with information and support. The number is 0808 800 4040 (Monday to Friday, 9am to 5pm).

Macmillan operate a similar helpline on 0808 808 00 00 (Monday to Friday, 9am to 8pm).