Retinoblastoma

Definition | Symptoms |  Treatment |  Clinic Information

Definition
Retinoblastoma is a malignant (cancerous) tumor of the retina. The retina is the thin nerve tissue that lines the back of the eye that senses light and forms images.

Although retinoblastoma may occur at any age, it most often occurs in younger children, usually before the age of five years. Retinablastoma affects one in every 18,000 births, with an estimated 250-500 cases diagnosed in the United States each year. The tumor may be in one eye only or in both eyes. Retinoblastoma is usually confined to the eye but, if left untreated, will spread to nearby tissues and other parts of the body.

Retinoblastoma may be hereditary (runs in families) or nonhereditary. The hereditary form may be in one or both eyes. Most retinoblastoma occurring in only one eye is not hereditary; when the disease occurs in both eyes, it is always hereditary. Because of the hereditary factor, brothers and sisters of children with retinoblastoma warrant examination to find out if they may develop the disease.

If your child has retinoblastoma, particularly the hereditary type, there is an increased chance that he or she may develop a second cancer in later years. Parents should continue taking their child for medical check-ups even after the cancer has been treated.

Your child's prognosis (chance of recovery and of retaining sight) and choice of treatment depend on the extent of the disease within and outside of the eye. Once retinoblastoma is found, more tests will be done to determine the size of the tumor and whether it has spread to surrounding tissue or to other parts of the body. This is called staging.

Stages of Retinoblastoma
To plan treatment, your child's doctor needs to know the stage of disease. Although there are several staging systems currently available for retinoblastoma, for the purposes of treatment retinoblastoma is categorized into intraocular and extraocular disease.

• Intraocular retinoblastoma.
  Cancer is found in one or in both eyes but does not extend beyond the eye into the tissues around the eye or to other parts of the body.
• Extraocular retinoblastoma.
  The cancer has extended beyond the eye. It may be confined to the tissues around the eye, or it may have spread to other parts of the body.
• Recurrent retinoblastoma.
  Recurrent disease means that the cancer has come back (recurred) or progressed (continued to grow) after it has been treated. It may recur in the eye or elsewhere in the body.

Symptoms

• Leukocoria (cat's eye reflex or white pupil). This may be first noticed by the lack of a "red reflex" on photographs.
• Crossed eyes (Strabismus)
• Blurred vision

The symptoms described above may not necessarily mean that your child has retinoblastoma. However, if you notice one or more of these symptoms, contact your eye doctor for a complete exam.

Treatment
There are treatments for all children with retinoblastoma, and most children can be cured. The type of treatment given depends on the extent of the disease within the eye, whether the disease is in one or both eyes, and whether the disease has spread beyond the eye. Treatment options consider both cure and preservation of sight, and include the following:

• Enucleation.
  Surgery to remove the eye.
• Cryotherapy.
  The use of extreme cold to destroy cancer cells.
• Photocoagulation.
  The use of laser light to destroy blood vessels that feed the tumor.
• Internal or external-beam radiation therapy.
  Radiation therapy uses high-energy radiation from x-rays and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy) or may be administered by placing radioactive material into or very near the tumor (internal radiation therapy or brachytherapy).
• Chemotherapy.
  Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells throughout the body. Chemotherapy drugs may be taken by mouth or injected into a vein (intravenous) or a muscle. In children with retinoblastoma, chemotherapy drugs may be injected directly into the fluid that surrounds the brain and spinal cord (intrathecal chemotherapy).

Clinic Information
For more information, see the Pediatric Ophthalmology & Adult Strabismus Clinic and the complete Clinic Services listing of the U-M Kellogg Eye Center.