The ophthalmologist views the retina with an indirect
ophthalmoscope to determine the presence of tumors. A lid speculum
or metal clip is placed between the eyelids to help keep the child's
eye open. During the examination, the ophthalmologist uses a Q-tip
or a metal scleral indenter (which looks like a pen with a flattened
tip) to press on the scleral surface of the eye to push the most
forward portions of the retina into view. Because the child is under
anesthesia and his or her eye is numbed, they experience little
or no discomfort from this process.
A sketch, or fundus drawing, is made of the tumor(s)
of the eye. Sometimes photographs of the view through the indirect
ophthalmoscope, fundus photos, are also taken of the tumor(s). Both
the fundus drawing and the fundus photos serve as "maps"
for the tumor(s) in the eye. Future examinations will be based on
these original drawings and photographs; new drawings and photographs
may be sketched and taken at each follow-up visit.
Ultrasound examination, which uses sound
waves to penetrate and outline structures in the eye, confirms that
retinoblastoma tumors are present and determines their thickness
or height. Black and white polaroids of the ultrasound images may
be taken initially and during the follow-up visits.
An X-ray test called a CAT-scan (computed
axial tomography) is also performed to determine if there is any
tumor outside the eye or in the brain. An MRI (magnetic resonance
imaging), which uses magnetic waves to image the eyes, the orbits,
and the brain, may also be performed.
Children who are diagnosed with retinoblastoma
are also seen by a pediatric oncologist (children's cancer physician).
The pediatric oncologist determines whether there is cancer anywhere
else in the child's body. A physical examination and sometimes blood
tests, a spinal tap (to see if there are cancer cells in the central
nervous system), and a bone marrow biopsy (a sample of the blood
cells taken from the bone) are performed by a pediatric oncologist.