A 14-month-old boy was referred by his pediatrician because a whitish reflex from his left pupil (Figure 16-1) was noticed by his parents in certain directions of gaze. It was also noted on a few recent photographs. His pediatrician had checked the pupillary light reflex and indeed noted a dimmer and tan-colored reflex from the left pupil as opposed to a brighter and more reddish reflex in the left eye. She referred the child for further evaluation and management. Dilated fundus examination revealed a single large tumor in the left eye, occupying more than 50 percent of the globe. Ultrasonography showed a pattern consistent with calcifications within the tumor, and suggestive of retinoblastoma. A magnetic resonance imaging (MRI) scan showed no evidence of optic nerve or intracranial involvement. There were no other tumors in either eye. There was no family history of retinoblastoma. A decision was made to enucleate the eye because of the size of the tumor.
Leukocoria in the left eye of this infant with retinoblastoma. The tumor can actually be visualized behind the clear lens. (Used with permission from Elias Traboulsi, MD.)
Leukocoria means a white (leuko) reflex from the pupil (coria). Leukocoria is a sign observed by the naked eye or with a scope, often detected incidentally on routine eye examination, or in photographs; it is not a diagnosis. The most feared cause of a white reflex in the pupil is retinoblastoma, the most common intraocular tumor of childhood. Other conditions can manifest themselves initially with leukocoria. Precise diagnosis ensures appropriate and early treatment to prevent irreversible blindness from primary pathology, secondary amblyopia, or life-threatening malignancies.
White pupillary reflex. White pupil.
Retinoblastoma is diagnosed in 47 percent of children who are referred with leukocoria to tertiary centers.1
The majority (32 to 73%) of children with retinoblastoma present with leukocoria.2,3
Retinoblastoma occurs as rarely as in 1:13,000 to 1:20,000 live births, with an annual incidence of 11.8 per million children between zero and four years of age in the US and similar statistics in Europe.4
Other causes of leukocoria are slightly more common but exact estimates of their incidence are not available.
Etiology and Pathophysiology
The direct cause underlying leukocoria that is common to the different conditions that cause it is an interference with the normal red reflex from opacities or abnormalities that occur strictly anywhere from the crystalline lens and posteriorly, hence excluding corneal opacities.
Leukocoria from retinoblastoma is caused by the whitish well-circumscribed retinal mass.
The tumor develops when a negative regulator of the cell cycle (pRB) is inactive or absent secondary to mutations in ...