Retinoblastoma is a malignant tumor on the retina, the
light-sensing part of the eye that is located in the back of the
eye. This type of cancer can be present in one or both eyes.
What causes retinoblastoma?
Our eyes begin to
develop very early in the womb. Rapidly growing cells in the eye,
called retinoblasts, will eventually mature and form the retina.
Sometimes, these specialized cells do not stop reproducing and form
a tumor on the retina. These tumors might continue to grow, filling
almost the entire vitreous humor (the jelly-like substances that
fills the eyeball), but also break off and spread to other parts of
the eye, and eventually outside to lymph nodes and other
organs.
Who gets retinoblastoma?
Retinoblastoma occurs most
often in children 5 years and under. It rarely occurs in adults.
Between 200 and 300 children are diagnosed with retinoblastoma each
year, affecting one in every 20,000. About 40 percent of all cases
of retinoblastoma are inherited, meaning the cancer is passed on
from parent to child. Retinoblastoma occurs about 75 percent of the
time in one eye, and 25 percent of the time in both eyes.
What are the symptoms of Retinoblastoma?
Symptoms
of retinoblastoma include:
- A pupil that appears white when light is shone into it, called
leucocoria, might mean that a retinal tumor is present. Blood
vessels in the back of the eye will normally reflect red.
- The eyes might not move or focus in the same direction.
- There might be eye pain.
- The pupil is constantly dilated.
- The eye(s) might be red.
How is retinoblastoma diagnosed?
An eye exam and
imaging test given by an ophthalmologist (an eye doctor) can
diagnose the condition.
If retinoblastoma is suspected, an ophthalmologist will need to
examine the eye using special equipment to see the retina. Other
tests might be conducted to determine the stage of the
retinoblastoma, or how far it has spread. These tests include
ultrasound, MRI scans, CT scans, bone scans, spinal tap, and bone
marrow tests.
What are the stages of retinoblastoma?
Stages of
retinoblastoma include:
- Intraocular retinoblastoma -- This is the earliest
stage of retinoblastoma, found in one or both eyes. It has not yet
spread to tissue outside of the eye.
- Extraocular retinoblastoma -- This type of cancer
has either spread outside of the eye or to other parts of the
body.
- Recurrent retinoblastoma -- The cancer has come
back or spread in the eye or to other parts of the body after being
treated.