Retinoblastoma is a rare ocular (eye) tumor that occurs almost exclusively in children under the age of five, most often under the age of three. The tumor arises from the retina, which is a layer at the back of the eye responsible for sight. The tumor grows into the middle of the eye. If left untreated, it can eventually spread to the optic nerve, the brain, or even into the bones. Retinoblastoma is treatable and often curable if caught early.

Pediatricians begin looking for retinoblastoma in the newborn nursery. To do so, they use a light called an ophthalmoscope and, with the lights dimmed, look through it into the newborn’s eyes. If the light is reflected back properly from the retina, this comes through as a “positive red reflex” and looks just like the red eye you see when you take a picture with a flash. This exam is repeated at each well-child exam throughout the first year of life and well into the first five years of childhood.

An eye that contains a tumor will reflect light back in a white color. Often called a “cat’s eye appearance,” the technical term for this is leukocoria. This may be noticed by the doctor, or a parent may pick it up as a white spot or shadow they see through their child’s pupil. Retinoblastoma can also cause strabismus (an eye turning either in or out), poor vision, or pain.

Retinoblastoma can occur in one or both eyes and is caused by a genetic mutation called RB1. The mutation can be hereditary meaning it is passed from parent to child or spontaneous and all children with retinoblastoma will have a genetic evaluation to find out which type of gene they possess. Retinoblastoma treatment depends on if one or both eyes are affected as well as if there has been any tumor spread into the adjacent structures of the eye or beyond. Treatment options include removal of the affected eye, called enucleation, chemotherapy and radiation.

Reviewed by Dr. Sara Connolly, February 2019

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  1. Genetics Home Reference. Retinoblastoma.
  2. St. Jude Children’s Research Hospital. Retinoblastoma.


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