Updated June 08, 2015.

Retinoblastoma is a rare eye cancer that occurs in children. It is a malignant congenital intraocular tumor that develops from the neural tissue in the retina, the light sensitive tissue layer in the back of the eye. Although rare, retinoblastoma is the most common malignant intraocular tumor in children. It usually begins to develop inside the womb.

In some cases, the tumor can extend out from the retina into the cavity of the eye, sometimes occupying most of the space inside the eyeball itself.

In 75% of patients with retinoblastoma, the cancer affects only one eye; 25% have it in both eyes. This rare eye cancer is almost always diagnosed before the age of four, with an average age of 18 months. There are approximately 350 new cases per year in the United States. If left untreated, retinoblastoma can be fatal.

Signs and Symptoms of Retinoblastoma:

Children with retinoblastoma may have one pupil that appears to have white spots. These white spots appearing in the pupil are called leukocoria, and are sometimes referred to as "cat’s eye reflex." When photographs are taken of a child with retinoblastoma, the affected eye will not have the normal red reflex. Other times, the pupil may appear normal but the child may have an eye that is turned in or crossed (esotropia) or turned out (exotropia). The tumor blocks light from reaching the back of the eye, causing the vision to develop improperly. In rare cases, children can have pain, redness, poor vision and inflammation of the surrounding tissue.

Causes of Retinoblastoma:

The primary cause of retinoblastoma is a mutation in a cell of the growing retina.

This mutation causes the cell to grow out of control and become cancerous. Seventy-five percent of patients develop this mutation after conception while in the womb, whereas 25% inherit it from one of their parents.

Risk Factors of Retinoblastoma:

It is thought that retinoblastoma may have a hereditary pattern, though it can occur without prior family history. Inherited retinoblastoma accounts for 40% of all cases. However, about 5% of these patients may also carry a mutated retinoblastoma gene with the risk of passing the trait on to their children.

Diagnosing Retinoblastoma:

In many cases, a parent is the first to notice something wrong with their child’s eye. An immediate referral to an eye doctor is usually made after a physical examination by the pediatrician. A complete eye examination is performed, including dilation of the eyes so the entire retina can be seen. After an examination by an optometrist or ophthalmologist, the patient is usually referred to a high-level specialist with experience in treating this type of tumor. CT (Computed Tomography) and MRI (Magnetic Resonance Imaging) are also ordered. Blood tests and genetic testing may also take place. Additional testing may be ordered to rule out the possible spreading of the cancer to the rest of the body.

Treating Retinoblastoma:

Early detection is absolutely crucial in the treatment of retinoblastoma. Treatment is based on the size and location of the tumor and condition of the other eye. Often, the eye is removed (enucleated) to prevent possible spreading of the cancer to the rest of the body. If the physician feels that it may be treated without enucleation, other methods are used such as radiation, photocoagulation (laser treatment), cryotherapy (freezing treatment) or chemotherapy.

What You Need to Know About Retinoblastoma:

• More than 95% or more of patients treated in the U.S. for retinoblastoma are cured.
• More than 90% of patients retain at least one eye.
• More than 80% of patients keep 20/20 vision.
• Total blindness in successfully treated children is unusual.

<sub>Source:

Alexander, Larry J. Primary Care of the Posterior Segment, Second Edition. Pp 213-215. Copyright 1994 by Appleton & Lange, ISBN 0-8385-7970-1.</sub>