Retinoblastoma is an uncommon type of eye cancer in children. It commonly effects children under the age of five but can occur at any age.
There are two types of Retinoblastoma:
1. A heritable form – this is genetic or inherited. There are often tumours in both eyes (bilateral) or sometimes only in one eye.
2. A non-heritable form – this is not passed on in the family. There’s one tumour in only one eye (unilateral).
The retina is the light sensitive lining of the eye. The tumour or tumours grow inside the retina. About 80 cases of Retinoblastoma are diagnosed each year.
What are the symptoms of Retinoblastoma?
In circumstances where there is an existing family history of the condition then Retinoblastoma will be picked up during the screening process.
If there’s no family history of retinoblastoma, the first sign of the condition is often a white pupil that does not reflect light (leucocoria).
This may be picked up on when a picture of your child is taken using flash photography. The pupil of the affected eye may look white in the photograph.
Some children may have a squint or, if the tumour is large, they may have a painful red eye.
What are the causes of Retinoblastoma?
The heritable form of retinoblastoma, which accounts for about two in every five cases, is caused by a genetic abnormality. This means that an abnormal gene allows the tumour to develop. This abnormal gene may either be inherited from a parent or happen for the first time at an early stage of development in the womb.
Genetic counselling and support is available for families in which a member has retinoblastoma. Not all children of a parent with retinoblastoma will inherit this gene, but children born into families with a history of retinoblastoma are offered blood testing. They are also usually checked (screened) soon after birth for signs of retinoblastoma. This means that treatment can be started early if a tumour does develop.
Screening usually starts shortly after birth and is repeated every few months for five years. An eye specialist examines the eye, while shining a light into it with an opthalmoscope.
The causes of none-heritable retinoblastoma are unknown.