Retinoblastoma

Overview

Retinoblastoma (Rb) is a rapidly develping cancer which develops in the cells of the retina, the light sensitive cells fo the eye. In the developed wrld, Rb has one of the best cure rates of all childhood cancers (95-98%), with mroe than nine out of every ten sufferers surviving int adulthood. Retinoblastma is a very treatable cancer. There are two froms of the disease; a genetic heritable from and a non-genetic non-inheritable form. Approximately 55% of children with Rb have the non-genetic form. If there is n history of the disease within the family, the disease is labelled "spradic", but this des not necessarily indicate that it is the non-genetic form. In about two thirds of cases, [1] only one eye is affected (unilateral retinblastma); in the ther third, tumours develop in both eyes (bilateral retinoblastma). The number and size of tumours on each eye may vary. The position, size and quantity of tumours are cnsidered when chosing the type of treatment for the disease.

Symptoms

One or both eyes may be affected.

They pupil may appear white or have white spots. A white glow in the eye is often seen in photographs taken with a flash. Instead of the typical "red eye" from the flash, the pupil may appear white or distorted.

Other symptoms can include:

  • Crossed eyes
  • Double vision
  • Eyes that do not align
  • Eye pain and redness
  • Poor vision
  • Differing iris colors in each eye
  • If the cancer has spread, bone pain and other symptoms may occur.

Causes

Retinoblastoma is caused by a mutation in a gene controlling cell division, causing cells to grow out of control and become cancerous.

In a little over half of the cases, this mutation develops in a child whose family has never had eye cancer.

Other times the mutation is present in several family members. If the mutation runs in the family, there is a 50% chance that an affected person's children will also have the mutation. They will therefore have a high risk of developing retinoblastoma themselves.

The cancer generally affects children under the age of 6. It is most commonly diagnosed in children aged 1 - 2 years.

 

Prevention

Genetic counseling can help families understand the risk of retinoblastoma. It is especially important when more than one family member has had the disease, or if the retinoblastoma occurs in both eyes.

Diagnosis

The health care provider will perform a complete physical exam, including an eye exam. The following tests may be done:

  • Bone marrow biopsy and cerebrospinal fluid examination in the case of more aggressive tumors
  • CT scan or MRI of the head
  • Eye exam with dilation of the pupil
  • Ultrasound of the eye (head and eye echoencephalogram)

Prognosis

If the cancer has not spread beyond the eye, almost all patients can be cured. A cure, however, may require aggressive treatment and even removal of the eye in order to be successful.

If the cancer has spread beyond the eye, the likelihood of a cure is lower and depends on how the tumor has spread.

Treatment

  • Treatment options depend on the size and location of the tumor.

  • Small tumors may be treated by laser surgery or cryotherapy.
  • Radiation is used for both local tumor and for larger tumors.
  • Chemotherapy may be needed if the tumor has spread beyond the eye.

The eye may need to be removed (a procedure called enucleation) if the tumor does not respond to other treatments. In some cases, it may be the first treatment.