Retinoblastoma can either affect one or both eyes. If it affects both eyes, it's usually diagnosed before a child is one year old. If it affects one eye, it tends to be diagnosed later (between the ages of two and three).
Signs and symptoms of retinoblastoma
Signs and symptoms of retinoblastoma include:
- an unusual white reflection in the pupil – this may be seen 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 one eye or sometimes only in one area of the eye
- a red or inflamed eye – though your child won't 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 that they can't see as well as they used to
These symptoms may be caused by something other than retinoblastoma. You should get them checked by your GP as soon as possible.
It's unusual for retinoblastoma to progress unnoticed beyond the age of five. 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. In rare cases, one or more cells continue to grow and form a cancer called retinoblastoma.
In about 4 out of 10 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 per cent of retinoblastoma cases. In these cases, there's no faulty gene and only one eye is affected (unilateral).
Around 50 to 60 children are diagnosed with retinoblastoma in the UK each year.
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 to an eye specialist for further investigation.
After these investigations, if the eye specialist thinks your child has retinoblastoma they'll refer them to a specialist retinoblastoma treatment centre.
If your child needs chemotherapy, it will usually be carried out at a local children's cancer centre and overseen by the retinoblastoma team at a specialist hospital.
The treatment will depend on the stage of the tumour which can either be:
- intraocular – where the cancer is completely within the eye
- extraocular – where the cancer spreads beyond the eye to the surrounding tissue, or to another part of the body (this is rarely seen in the UK)
The health professionals looking after your child’s care will discuss the treatment options with you.
Most cases of retinoblastoma (9 out 10) are detected early and successfully treated before the cancer spreads outside the eyeball.
If the cancer has spread beyond the eye it will be more difficult to treat. This is rare as the condition is usually identified well before it reaches this stage.
Your child's treatment team will discuss any possible side effects of treatment with you. Different treatments have different side effects.
Retinoblastoma requires a long period of follow-up tests, which will, at first, be carried out at one of the specialist retinoblastoma centres. After a period of treatment, the tests will usually take place at your local eye department.
Screening for retinoblastoma
If you're expecting a baby and you had retinoblastoma yourself 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 tests can be arranged when your baby is born.
The aim of screening is to identify tumours as early as possible so that treatment can be started straight away. Children under five years of age are usually screened by having their eyes examined while under general anaesthetic.
Your child will need to be screened often up until they're five years old.