Retinoblastoma

What Is Retinoblastoma?

Retinoblastoma is a type of eye cancer that affects the retina, the inner layer of the eye. Nerve cells in the retina sense light and send images to the brain and allow us to see.

Retinoblastoma causes tumors (clumps of cells) to grow in the retina. This happens when the nerve cells grow out of control. This means the eye can't communicate with the brain as it should.

Retinoblastoma can happen at any age, but most cases are in children younger than 2 years. Tumors can be in one eye or both eyes. They rarely spread to other parts of the body.

Retinoblastoma can be treated.

What Are the Signs & Symptoms of Retinoblastoma?

The most common early sign of retinoblastoma is leukocoria (a cloudy white pupil). In bright light, the pupil can look silvery or yellow.

Other signs include:

• eyes that are not lined up as they should be
• crossed eyes
• a pupil that is bigger than normal
• a cloudy iris (the colored part of the eye)
• poor vision

What Causes Retinoblastoma?

Most cases of retinoblastoma are caused by a genetic mutation (a change in a gene).

Heritable retinoblastoma can happen:

• when a child inherits a mutation (change in a gene) from a parent. Often, the baby will be born with retinoblastoma.
• spontaneously in a fetus during pregnancy. Most of these children will develop retinoblastoma before they are 1 year old.

This form of retinoblastoma usually affects both eyes and can cause more than one tumor in each eye.

Sporadic retinoblastoma happens when a gene mutation happens in early childhood, usually after 1 year of age and affecting just one eye. Doctors don't know why this happens.

How Is Retinoblastoma Diagnosed?

A pediatric ophthalmologist (an eye doctor for children) will carefully check the retina by dilating (enlarging) the pupil with eye drops. Sometimes, mostly in younger children, the doctor may give a medicine to make the child sleep during the exam.

The doctor might also order tests, like an ultrasound of the eye, magnetic resonance imaging (MRI), blood tests, and genetic testing.

If retinoblastoma is found, a pediatric oncologist (a children's cancer doctor) may do tests to see if the cancer also is anywhere else in the child's body.

• Retinoblastoma that is in the eye only is called intraocular.
• Retinoblastoma that has spread from the eye to tissues around the eye or other parts of the body is called extraocular. This type of cancer is rare, but can affect the brain, spinal cord, bone marrow, or lymph nodes. It may need many different types of treatment, such as radiation, chemotherapy, and a bone marrow transplant.

If the retinoblastoma is extraocular, the doctor will order more blood tests, a spinal tap (lumbar puncture), and a bone marrow biopsy , taking a sample of cells from the hip bone.

How Is Retinoblastoma Treated?

The ophthalmologist and oncologist work together with a team of other experts to treat a child with retinoblastoma. The team will make a care plan based on the size of the tumor, whether it is in one or both eyes, and whether it has spread beyond the eye.

When they treat a child with retinoblastoma, doctors try to:

• get rid of the cancer
• save the eye when possible
• help the child see as well as possible

There are many treatments for retinoblastoma, and all are aimed at killing cancer cells. These treatments, or a combination of them, may be recommended:

• Systemic chemotherapy: Tumor-killing medicines are given by mouth, through an injection (a shot), or intravenously (into a vein).
• Intra-arterial chemotherapy: Chemotherapy medicines are injected into a small artery (a blood vessel that goes to the eye). This helps the medicine go straight to the tumor.
• Intra-vitreous chemotherapy: Chemotherapy is injected into the eye to treat small tumors that float in the vitreous (the jelly-like substance that fills the eyeball).
• Cryotherapy: Liquid nitrogen or argon gases are used to freeze and destroy cancerous tissue.
• Laser therapy: Laser energy is delivered to blood vessels around the tumor, causing small blood clots and depriving the cancer cells of nutrients they need.
• Radioactive plaques: Radioactive material (little rods or pellets) is placed straight into the tumor to deliver beams of radiation to specific areas. This form of treatment lessens the damage to surrounding healthy tissue.
• External beam radiation (EBRT): Beams of radiation are carefully focused onto the tumor to kill cancer cells. This therapy is sometimes used to treat aggressive tumors.
• Enucleation (eye removal): In severe cases of retinoblastoma, the whole eye is removed to stop the spread of cancerous cells to other parts of the body.

A child will need regular eye exams (usually while under anesthesia) to make sure the treatment is working.

What Happens After Treatment?

Retinoblastoma treatment can cause side effects in some kids.

• Chemotherapy can leave kids feeling nauseated, weak, dizzy, or feverish.
• Radiation therapy might make kids feel more tired. Their skin can get red or dry in the area being treated.

During this time, the doctor may order pain relievers for your child.

When treatment is over, kids can get back to normal activities if they feel well enough and if the doctor says it's OK. Recovery time can vary from one child to another.

Children who have an eye removed get a prosthetic eye in its place. Prosthetic eyes are of such good quality that most people can't tell which eye is natural and which is prosthetic.

Most children treated for retinoblastoma go on to lead normal lives.

What Else Should I Know?

If a baby's parent or sibling has had retinoblastoma, the baby should have an eye exam shortly after birth to see if there is a tumor in the eye. If a tumor is found early, the child may need less treatment and doctors might have a better chance of saving the baby's eyesight.

Kids with hereditable retinoblastoma in one eye could get it later in the other eye. So they should have regular checkups of the healthy eye as recommended by the ophthalmologist. After treatment, they should have checkups for as long as directed by the treatment team.

Looking Ahead

Learning that a child has cancer is upsetting, and cancer treatment can be stressful for any family.

But remember, you're not alone. To find support, talk to your doctor or a hospital social worker. Many resources are available to help you get through this difficult time, including online sites such as:

• The Eye Cancer Foundation
• Oncolink