During early stages of fetal development, fast-growing, immature cells called retinoblasts form. Later, these cells become retinal cells. In retinoblastoma, some of these cells quickly grow out of control. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue called a tumor grows. The cancer may grow along the optic nerve and reach the brain, or it may travel to other parts of the body.

Retinoblastoma is caused by defects in the retinoblastoma gene.

Risk Factors

Retinoblastoma is more common in children under 5 years old. Other factors that may increase your child's chance of retinoblastoma are family members with retinoblastoma.



Retinoblastoma usually forms only in one eye, but both eyes may have tumors. Symptoms are usually noticed by the parent or caregiver and may include, but are not limited to:

  • Eyes do not look normal, often described as a glazed look or a “cat’s eye.”
  • When a light is directed at the eye, the pupil looks white rather than red. This is often noticed on a photograph.
  • Eyes may appear to be crossed or looking in different directions.
  • Less common symptoms may include:
    • Eye may grow in size
    • Eye pain
    • Redness in the white part of the eye
    • Excessive tearing
    • Pupil may not respond to light
    • Iris (colored part of the eye) changes color
    • Double vision
Normal Anatomy of the Eye
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You will be asked about your symptoms and family medical history. A physical exam will be done. Many retinoblastomas are found during routine physical exams. If a tumor is suspected, your child will usually be referred to a specialist for a more complete eye exam. In children with a family history of the disease, eye exams often begin within 1-2 days of birth. Additional eye exams are scheduled at regular intervals thereafter.

Tests may include:

  • Dilated eye exam—To examine the inside of the eye with a lighted instrument.
  • Imaging test to evaluate the eye and surrounding tissue may include:
    • Ultrasound
    • MRI scan
    • CT scan
  • Microscopic evaluation of the tumor
    • Routine biopsy is not usually done
    • Biopsies from surrounding area or bone marrow will be done if the tumor might have spread
    • Spinal fluid is examined if spread to the central nervous system is suspected

The physical exam combined with all of the test results, will help to determine the stage of cancer. Staging is used to guide your child's treatment plan. Like other cancers, retinoblastoma is staged from I-IV. Stage I is a very localized cancer, while stage IV indicates a spread to other parts of the body.



Treatment depends on the stage of the cancer. Treatment aims to cure the cancer and preserve sight.

Therapies may be used alone or in combination, and may include:


This involves surgical removal of the entire eye and as much of the optic nerve as possible. The optic nerve is the nerve leading from the eye to the brain that is responsible for vision. Surgery may be used for a large tumor in one eye.

Radiation Therapy

This treatment involves the use of radiation to kill cancer cells and shrink tumors. Radiation may be:

  • External—radiation directed at the tumor from a source outside the body
  • Internal—radioactive materials placed into the body near the cancer cells


Cryotherapy is the use of cold to freeze and destroy small tumors.


This treatment uses heat to kill cancer cells.


Lasers are used to destroy a small tumor.


Chemotherapy is the use of drugs to kill cancer cells. This treatment may be given in many forms including pill, injection, and through a catheter. The drugs enter the bloodstream and travel through the body killing mostly cancer cells, but also some healthy cells.


Prevention and early detection techniques include:

  • Screening—Children born into families with a history of retinoblastoma should have regular eye exams to screen for development of the tumor. All children should have regular eye screening by their doctor.
  • Genetic counseling—This may help determine a person’s risk of developing retinoblastoma. If you have retinoblastoma or have a family history of the disorder, you can talk to a genetic counselor when deciding to have children.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.