When there is a family history of retinoblastoma, newborn babies should be examined in the nursery at birth by an ophthalmologist. When there is no family history, it is frequently the parents who notice leukocoria (a white pupil reflex instead of a normal black pupil or red reflex) or strabismus (a crossed eye), the discovery of which leads the parents to bringtheir child in for an examination.
Unlike other types of cancer, a biopsy is rarely, if ever, done in cases of retinoblastoma. Although biopsy can accurately aid in diagnosis, there is concern about the possibility of spreading the cancer with biopsy.
Worldwide, many eyes thought to have retinoblastoma are enucleated (surgically removed) and found to have some other, non-malignant disorder. It is therefore critical that the ophthalmic oncologist making the diagnosis be experienced in the diagnosis of retinoblastoma and the diagnosis of conditions that look like retinoblastoma. At Memorial Sloan Kettering, our ophthalmic oncologist has preformed more than 12,000 examinations for retinoblastoma.
The ophthalmic examination is best done under general anesthesia. Some very young and older patients can be examined without general anesthesia. If you have any questions about whether your child should have anesthesia, ask your ophthalmologist, anesthesiologist, or nurse.
The ophthalmologist views the retina with an indirect ophthalmoscope (a lighted instrument used to perform a magnified examination of the eye) to determine the presence of tumors. A metal clip known as a lid speculum 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 move the most forward portions of the retina (the sensory membrane located in the back of the eye) into view. Because the child is under anesthesia and his or her eye is numbed, they experience little or no discomfort from this process.
Fundus Drawings and Photographs
A drawing or photographs, called fundus (defined as the larger part of a hollow organ that is farthest away from the organ’s opening) drawings or photos, are made of the tumors. The fundus drawing and photos serve as maps. Future examinations will be based on these original drawings and photographs; new drawings and photographs may be made at each follow-up visit.
Ultrasound examination, which uses sound waves to penetrate and outline structures in the eye, can confirms if retinoblastoma tumors are present and can determine their thickness or height. Black and white Polaroid photographs of the ultrasound images may be taken.
Testing for Metastatic Retinoblastoma
An examination called MRI (Magnetic Resonance Imaging) — which uses magnetic waves to image the eyes, the orbits, and the brain — may be performed to determine if there is any tumor outside the eye or in the brain.
Children who are diagnosed with retinoblastoma are also seen by a pediatric oncologist. 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, and a bone marrow biopsy are performed.