Retinoblastoma, the most common type of eye tumor seen in children, occurs most often in young children before the age of five and affects boys and girls in equal numbers. The tumor may be in one eye (referred to as unilateral retinoblastoma), or in both eyes (bilateral retinoblastoma).
Retinoblastoma tumors originate in the retina, the light-sensitive layer of the eye that enables sight. About 75 percent of retinoblastoma cases are unilateral, and 90 percent of retinoblastoma patients have no family history of the disease.
Retinoblastoma occurs most often before the age of five. There are approximately 350 new diagnosed cases per year in the United States, making it the seventh most common pediatric cancer.
Most retinoblastoma patients have a white pupil reflex or leukocoria instead of a normal black pupil or red reflex. This abnormal white pupillary reflex is sometimes referred to as a cat’s eye reflex. Many times the parent is the first one to notice the cat’s eye reflex. This white pupillary reflex may also be indicative of another disorder and does not always indicate retinoblastoma. An ophthalmologist can determine the correct diagnosis.
A crossed eye or strabismus is the second most common symptom of retinoblastoma. The child’s eye may turn towards the ear (exotropia) or towards the nose (esotropia).
Children with retinoblastoma may also have the following symptoms:
- a painful red eye
- poor vision
- inflammation of tissue surrounding the eye
- an enlarged or dilated pupil
- different colored irises (a condition known as heterochromia)
- failure to thrive (trouble eating or drinking)
- extra fingers or toes (a condition known as hexadactylism)
- malformed ears
- delayed development or retardation
More than 95 percent of children treated for retinoblastoma in the US are cured. In addition, more than 90 percent of patients retain at least one eye and more than 80 percent of children treated keep 20/20 vision.