What is Retinoblastoma?

Retinoblastoma is a tumour of early childhood arising in the cells of the light sensitive lining of the eye known as the retina. In about two-thirds of children only one eye is affected but in one-third, tumours may develop in both eyes. Retinoblastoma is caused by a gene that controls the growth of cells in the eye. This gene change may be inherited from a parent who also had retinoblastoma. Every child of an affected parent should be screened regularly from birth, however most children with retinoblastoma do not have any other family history of this disease.

Signs and symptoms

Retinoblastoma is usually noticed as a white appearance or glow of the pupil, which tends to reflect light, similar to a cat's eye. Other times, a squint or a crossed, or turned eye may develop. Children with very large tumours may have a painful, red eye or poor vision.

Diagnosis

The diagnosis is made by an ophthalmologist (an eye specialist) who examines the eye usually under a general anaesthetic. An ultrasound and MRI scan will also be done. A biopsy is not required to make the diagnosis. 

Treatment

The extent or spread of the tumour, together with the biology of the tumour and the age of the child will determine what chemotherapy (if any) will be required. Surgery can be difficult and may not be able to be performed safely until the tumour has been shrunk by chemotherapy. Treatment may vary from observation alone, to intensive chemotherapy, surgery, radiotherapy and immunotherapy which may last for ~18 months. The outcomes for neuroblastoma in children are vary variable and depend significantly on the results of the above tests. For example, many infants are cured with minimal therapy, but older children with metastatic disease have a poor prognosis even with intensive therapy. 

Follow-up care

The number, size and site within the eye or eyes determines the best treatment. Chemotherapy and focal therapy (heating or freezing) may be used together or on their own treat retinoblastoma. Chemotherapy may be given systemically (into the veins), intra-arterially (behind the eye) or directly into the eye itself. When the tumour is very large or cannot be controlled, or the vision in the eye has been lost, it may be necessary to remove the eye completely (enucleation). Radiotherapy is only required vary rarely. Outcomes for children with retinoblastoma are extremely favourable.