The retina is part of the eye, which is the organ that lets you see. The retina is the inner layer of cells in the back part of the eyeball. It is made up of special nerve cells that are sensitive to light.
When the eyes are developing, they have cells called retinoblasts. These cells divide into new cells and fill the part of the eye that will become the retina. Sometimes there is a change, or mutation, in a gene in a retinoblast called the retinoblastoma (RB1) gene. This mutated gene causes the retinoblast to change and grow out of control. The abnormal cells caused by this mutation form a tumour called retinoblastoma. Retinoblastoma is the most common type of eye cancer in children. It is usually found in children under the age of 2 years.
Other types of cells in the eye can sometimes change and cause non-cancerous, or benign, conditions or tumours that have some of the same symptoms as retinoblastoma. These include congenital cataract, pseudoretinoblastoma, retinopathy of prematurity (ROP) and retinocytoma.
Because retinoblastoma mostly affects infants and small children, symptoms are rare. Signs you may notice include:
A white color in the center circle of the eye (pupil) when light is shone in the eye, such as when taking a flash photograph
Eyes that appear to be looking in different directions
When to see a doctor
Make an appointment with your child's doctor if you notice any changes to your child's eyes that concern you. Retinoblastoma is a rare cancer, so your child's doctor may explore other more common eye conditions first.
If you have a family history of retinoblastoma, ask your pediatrician when your child should begin regular eye exams to screen for retinoblastoma.
Children treated for retinoblastoma have a risk of cancer returning in and around the treated eye. For this reason, your child's doctor will schedule follow-up exams to check for recurrent retinoblastoma. The doctor may design a personalized follow-up exam schedule for your child. In most cases, this will likely involve eye exams every few months for the first few years after retinoblastoma treatment ends.
Additionally, children with the inherited form of retinoblastoma have an increased risk of developing other types of cancers in any part of the body in the years after treatment. For this reason, children with inherited retinoblastoma may have regular exams to screen for other cancers.
How is retinoblastoma treated?
What treatments are best for retinoblastoma depends on the size and location of the tumour, whether cancer has spread to areas other than the eye and the child’s overall health. Radiation can be used to kill the cancer cells. Internal radiation is achieved by placing a small radioactive disk that is stitched in place near the tumour and left there for several days. This localizes the treatment and avoids damage to other healthy parts of the eye. External radiation is much more invasive and is often reserved for tumours that are non-responsive to other treatments. Laser therapy, cold therapy (cryotherapy) and heat therapy (thermo therapy) can also be used. If the tumour is unresponsive to other treatments or is too large, surgical removal of the tumour, or in some cases the entire eye, may be the only option.