Retinoblastoma is a malignant (cancerous) tumor that occurs in the eye. It appears in the part of the eye known as the retina, which is located along the back wall of the inside of the eye.

Retinoblastoma is relatively rare, occurring in 1 in 15,000-16,000 births. It is often diagnosed in children who are less than 2 years of age. It more commonly occurs in only one eye. There are two forms of retinoblastoma: sporadic and heritable. About 60% of retinoblastoma cases are sporadic.

When retinoblastoma occurs in both eyes, there is usually a hereditary factor. When a person has both eyes affected (called bilateral retinoblastoma), their children have about a 45% chance of developing retinoblastoma.

Signs and Symptoms of Retinoblastoma

Retinoblastoma is hard to diagnose early because the symptoms are not obvious. You may have been the first to notice a white reflection in your child's pupil called the cat's eye reflex. This is when you can actually see the tumor as the eye moves and light reflects off the tumor. Sometimes pictures are useful in picking up this abnormal light reflex.

Your child may have been squinting or having a hard time focusing both eyes on the same object. This is called strabismus. It usually occurs if the tumor is in or very near the most sensitive part of the eye. Symptoms occurring in later stages of the disease include a painful red eye and loss or decrease of vision in the affected eye.

Retinoblastoma Diagnosis

Retinoblastoma is easily confused with other less severe eye conditions. A careful exam is needed for accurate diagnosis. The exam will be done in the operating room so that the entire retina can be seen. An ophthalmologist (eye doctor) may help with this exam. This procedure is done under general anesthesia where medication is given so that your child is not awake and will not feel any pain.

Retinoblastoma Treatment

If the exam shows a large amount of disease in one eye, treatment may include removal of that eye. If both eyes are involved, current treatment approaches make every effort to try to save at least one eye. Removal of your child's eye is done only when the disease has progressed beyond hope of saving useful vision.

Treatment depends on the size and location of the tumor and whether the tumor has spread. Rarely, retinoblastoma can spread to places outside of the eye as well. The most common places are the bone marrow, the central nervous system and the bones. After diagnosis, a number of tests will be done to see if the tumor cells have spread. These tests may include a bone marrow aspirate and biopsy, spinal tap, CT scan, MRI and bone scan. Several types of treatment are available. These include surgery, chemotherapy, cryotherapy and laser therapy, and radiation. Surgery and chemotherapy are the most common treatments for retinoblastoma. Cryotherapy and laser therapy are used for small tumors, less than 6mm in size.

Complications of radiation therapy can include slight damage to the blood vessels, which should not reduce vision. Radiation can eventually lead to glaucoma, increased pressure in the eye. Radiation of the lens of the eye can result in cataracts, clouding of the lens of the eye. Radiation also has cosmetic consequences due to effects on orbital bone growth. In advanced cases, surgery to remove the affected eye is the usual treatment. Cryotherapy, or freezing of the tumor, with or without chemotherapy, may be used to treat small, localized tumors.

When surgery is finished, your child may be given chemotherapy to destroy any remaining traces of disease. Some of the chemotherapy medicines may be Carboplatin, Etoposide, Vincristine, Cyclophosphamide, Ifosfamide, doxorubicin and Topotecan. These drugs have all been found to be somewhat effective against retinoblastoma. They may be used alone or in combination for a course of chemotherapy.

Local chemotherapy is used for large tumors. Chemotherapy can be delivered to the tumor by a more direct route through the arteries within the eye. Chemotherapy that is commonly used in this way includes Melphalan, Carboplatin and Topotecan. Side effects of this chemotherapy include swelling of the eyelid, bleeding into the eye, eye muscle dysfunction, drooping of the upper eyelid, or harm to the artery.

After the treatment is completed, your child will have regular check-ups, including eye exams under anesthesia and follow up with an oncologist (cancer doctor). If needed, your child can be fitted with a prosthesis or glass eye.

Retinoblastoma Prognosis

Success in treating retinoblastoma can be measured either by survival or preservation of vision. For disease confined within the eye itself, nearly 95% of children survive. Changes in the patient’s vision largely depend on the extent of tumor involvement. The prognosis when the tumor has metastasized is not as favorable.

Treatment may be more successful due to early screening of children who have a family history of the disease.