Retinoblastoma

Retinoblastoma is a cancer that begins in the retina of the eye, and is the most common type of eye cancer in children. The retina is the inner layer of cells in the back of the eye – when light signals reach the retina, they are sent through the optic nerve to the brain and are translated as images, allowing us to see.

What are the Symptoms of Retinoblastoma?

Symptoms of retinoblastoma are rare as the disease most often affects infants or small children.

Some possible signs are:

  • A white color in the pupil when light is shone through the eye
  • Eyes that appear to look in different directions
  • Eye redness and/or swelling

What Causes Retinoblastoma?

The eyes of a child develop very early on while in the womb. The eyes have cells called retinoblasts which divide into new cells to populate the retina. The retinoblasts eventually stop dividing and mature into mature retinal cells. Retinoblastoma is formed when those retinoblasts do not stop dividing and grow out of control

What exactly causes the events that create retinoblastoma is still relatively unknown, cases almost always start because of a mutation in a gene called the retinoblastoma (RB1) gene. A normal RB1 gene prevents retinoblasts from growing out of control, but a mutation in the gene stops it from doing so.

It is possible to inherit the retinoblastoma gene from parents. The gene is passed in an autosomal dominant pattern, which means that only one parent needs a copy of the mutated gene to pass it on. However, just possessing the gene does not mean a child will develop retinoblastoma, it is only an increased risk.

How is Retinoblastoma Diagnosed?

Retinoblastomas are typically found when a child is brought in because of specific signs or symptoms. For most cancers, a biopsy (sample from the tumor to be inspected) is required to make a diagnosis. However, retinoblastoma cases are the exception as taking a biopsy from the eye is very difficult to do without harming the eye or potentially spreading the cancer. Retinoblastoma is also unlikely to be confused with other eye diseases in children.

If your child possesses any signs or symptoms of retinoblastoma, medical history and any family history of retinoblastoma will be requested. If the disease is suspected, your doctor will refer you to an ophthalmologist (a doctor who is a specialist in eye diseases) to inspect the case further. If diagnosis seems likely, imaging tests will be done for further confirmation and to see the progress of the disease.

What is the Survival Rate for Retinoblastoma?

If the tumor does not spread and is contained within the eye(s), the long-term survival rate is 95%. For children with retinoblastoma in both eyes, about 70 to 80 percent of the eyes can be saved.

How is Retinoblastoma Treated?

Treatments depend on size and location of the tumor, whether the cancer has spread, and your child’s state of health. Treatments should work to prevent loss of vision if possible.

Chemotherapy (taken either through pills or through blood vessels) can be used to kill cancer cells and to shrink tumors so that other treatments, such as radiation therapy, may work better on the remaining cancer cells. Other methods such as laser therapy, cryotherapy, or thermotherapy may be used to kill cancer cells.

When the tumor has grown too large to be treated by the above methods, it may have to be surgically removed. Removing the tumor may help prevent the spread of the cancer to other parts of the body. Surgery may include removing the affected eye and fitting a prosthetic eye. Removing an eye will affect vision, but children normally adapt to the loss of the eye.