Retinoblastoma (eye cancer in children)

Retinoblastoma is a malignant tumour of the retina, the light-sensitive layer at the back of the eye. It is rare and occurs almost exclusively in small children: most cases are found before the age of three and only a handful after five. It is the commonest eye tumour of childhood and one of those conditions in which almost everything turns on how soon someone is seen.

If you have opened this page because one of your child's pupils came out white in a photograph, read the next section and book an appointment with an ophthalmologist. The rest will keep.

The white glow in the pupil

The main sign of retinoblastoma is a white or yellowish reflection in the pupil, where you would normally see black or red. The tumour grows inside the eye and throws the light back instead of the retina. Parents usually notice it not in a clinic but at home: in a photograph taken with flash one eye has come out the usual red and the other white, milky or rather like a cat's.

It also shows up well in dim light, when a single lamp is on in the room, the light falls on the child from one side and the child is not looking straight at it. In bright daylight the glow is generally lost.

A few practical points. Look with an ordinary flash and switch the camera's red-eye reduction off: that setting removes exactly the difference between the two eyes you are trying to see. A phone that processes the shot automatically may "correct" the pupils too. Go back through old photographs: a white pupil is often visible in pictures taken months before anyone thought about it.

A white glow does not always mean a tumour. Congenital cataract and several other retinal conditions look the same, and sometimes it is simply an unlucky angle of the flash. But they can only be told apart by examining the back of the eye through a dilated pupil, not from a photograph and not with a phone app. So the conclusion is always the same: take the child to an ophthalmologist.

Other signs that must not be "kept an eye on"

The second commonest reason children are brought in is a squint that has newly appeared. The eye starts to drift because it has stopped seeing, and the brain no longer pulls the two pictures together. Some squints in babies are harmless, but any persistent or newly appearing turn of the eye calls for a look at the back of the eye, not for waiting to see whether the child grows out of it.

Other things that should raise concern:

• a change in the colour of the iris — one eye a different shade, or a new patch on the iris;
• a red eye with no cold, no snuffles and no injury, especially if it does not settle within a few days and drops do nothing;
• an eye that looks bigger than the other, bulges forward, or a swollen eyelid;
• a pupil that no longer closes down in bright light, or is wider than the pupil of the other eye;
• involuntary wobbling movements of the eyes;
• the child stops noticing things on one side, walks into corners, or holds toys right up to the face;
• pain in the eye — the child rubs it, is unsettled, sleeps badly.

The great trap is that in every other respect the child is well: eating, playing, growing, no temperature. A tumour inside the eye does not hurt until it is large, and general health gives nothing away. That is exactly why it is so often found late — by a visible sign rather than by illness.

Why this is not counted in weeks

While the tumour stays inside the eye, the outlook is good: where care is available almost all children are cured, and in many cases both the eye and useful vision are saved. It becomes difficult once the tumour leaves the eye, along the optic nerve, into the orbit and beyond. Treatment then becomes incomparably harder and the outcome far less predictable.

The only thing that separates the two situations is time. So a white pupil, a new squint or an unexplained red eye means an ophthalmologist within days. Not "we'll look at it at the next check", not a two-week wait for a slot, not "let's try drops first". When you book, say that you have seen a white reflection in the pupil: it changes how urgently you are seen.

What is needed is specifically an examination of the back of the eye with the pupil dilated. Measuring visual acuity, testing for glasses or looking at the eye from outside will not show the tumour. And if a doctor could not get a proper view in a wriggling child, that is not "all clear" — it is a reason to examine the eye under anaesthetic.

The inherited form and the whole family

In roughly four cases in ten, retinoblastoma is linked to a gene change present in every cell of the child's body. That form behaves differently: there are usually several tumours, often in both eyes, and they appear earlier, frequently in the first year of life. Almost all cases affecting both eyes are inherited. With one eye affected it is less common, but it cannot be excluded without a test.

The word "inherited" does not mean that anyone in the family has had it. Most often the change arises for the first time in this child, with healthy parents. From there, though, it can pass to that child's own children later on, and for that reason alone it is worth finding.

What follows from this in practice:

• the child has a blood test for the gene change, and the result shapes the follow-up and much else besides;
• if the change is found, brothers and sisters are examined, and often the parents too. Newborns in such a family are examined from their first days, with checks repeated until school age;
• if the child does not carry the change, relatives are usually spared years of examinations, and that is a result in itself;
• with the inherited form the risk of other tumours lasts for life, so follow-up continues into adulthood and unnecessary radiation, including unnecessary CT scans, is avoided. Smoking is particularly inadvisable for these people.

If someone in the family has already had retinoblastoma, it is better to talk to a geneticist before a pregnancy than after the birth.

How the diagnosis is confirmed

The diagnosis is made by a children's ophthalmologist who specialises in eye tumours, and the main method is examination. In a small child it is done under general anaesthetic: only then can the retina be searched calmly right out to its edge, with every focus measured and photographed. The other eye is examined at the same time, even if it looks entirely normal.

Added to the examination are an ultrasound scan of the eye, retinal photographs and an MRI scan of the orbits and brain, which shows whether the tumour has left the eye and at the same time checks for a rare association with a tumour deep in the brain. CT scanning is avoided where possible because of the radiation. Blood is taken for genetic testing.

A biopsy is not done in retinoblastoma. Putting a needle into the eye can carry tumour cells outside it, and in the overwhelming majority of cases the diagnosis is made from the appearance of the retina and the scans. If you are offered "a small sample for analysis", that is a reason to seek a specialist centre.

What treatment looks like now

Treatment is tailored to the individual eye: the size and position of the tumour, whether there are seedings in the vitreous, whether one eye or both are affected, and the age of the child. The aims come in order: save the life first, then the eye, then the sight. In most cases today all three are achieved.

• Chemotherapy, given into a vein to shrink the tumour before local treatment, or delivered straight into the artery supplying the eye, which allows smaller doses to reach the rest of the body. Where there are seedings, medicine is also injected into the eye itself.
• Laser treatment and cryotherapy — destroying small tumours with heat or with cold; they often finish off the job after chemotherapy.
• Brachytherapy — a tiny plaque carrying radioactive material, stitched for a few days to the wall of the eye opposite the tumour and then removed.
• Removing the eye is still needed when the tumour is too large, when sight in that eye has already gone, or when other treatments have not worked. It is a hard decision, but it saves life and often avoids chemotherapy altogether. A few weeks later an artificial eye is fitted; it looks and moves much like the other one, and is replaced as the child grows.

Radiotherapy to the whole eye is now used rarely and is avoided in children with the inherited form, because of the risk of other tumours later. Treatment almost always runs in cycles, with the child re-examined under anaesthetic in between to see how the tumour is responding.

After treatment: follow-up and the other eye

Examinations under anaesthetic carry on regularly for several more years, for as long as new tumours could still appear, particularly in the inherited form. They must not be skipped even when everything has been fine for a long time: they are precisely what catches a recurrence while it is still tiny.

A separate and very practical matter is protecting the eye that still sees. If a child sees with one eye, that eye becomes irreplaceable. Glasses worn all the time with impact-resistant lenses, separate protective goggles for ball games and cycling, and care around scissors, sticks, fireworks and household chemicals all stop being parental fussing and become compulsory.

Children cope with one eye better than adults expect: what suffers most is judging distance, and the brain finds its way round that fairly quickly. Small things help — seating the child in class so the board is on the side of the seeing eye, and telling teachers and nursery staff so that clumsiness is not mistaken for inattention. And bear in mind that the anaesthetics, the hospital and the examinations are a hard stretch for the whole family; asking for psychological support for the parents and for older siblings is as reasonable here as treating the eye itself.

Online consultation

A remote appointment does not replace examining the back of the eye, but it deals well with everything around it: working out how urgently you need to be seen in person, and where exactly to go.

An online consultation is well suited to looking at your photographs and judging whether there really is a white reflection in the pupil; explaining which examination the child needs and what words to use when booking it; putting an existing report or genetic result into plain language; setting out a schedule of examinations for brothers and sisters if the form is inherited; preparing questions for the treating team; and discussing care of an artificial eye, protection of the other eye, and the child's return to nursery or school.

Have ready for the appointment: several photographs of the child taken with flash in dim light, from different angles and with red-eye reduction switched off; letters and examination reports; imaging and genetic results; whether anyone in the family has had an eye tumour; and a list of what you noticed and when you first noticed it. Find the date of the earliest photograph showing a white pupil beforehand — it is an important detail.

This material is for information only and does not replace medical advice.