Child presenting with unilateral vision loss

A previously healthy 3-year-old girl child presented to the emergency department for progressive ataxia and left iris discoloration (Figure 1A). Examination revealed a dilated, non-reactive left pupil, leukocoria, and decreased visual acuity. A dilated fundus examination revealed a large inferior white tumor, exudative retinal detachment, and vitreous seeding consistent with Group E retinoblastoma. Magnetic resonance imaging confirmed a left retinal mass with hemorrhagic retinal detachment. Due to localized disease, the patient was a candidate for intra-arterial chemotherapy (IAC). Triple drug IAC was initiated. With her third cycle of IAC, she had improvement in pupillary dilatation, reactivity, and resolving heterochromia iridium (Figure 1B).

Heterochromia iridium is often benign and congenital; however, new onset heterochromia should raise suspicion for a sinister underlying process. Retinoblastoma, the most common intraocular malignancy of childhood, typically presents with leukocoria or strabismus, while heterochromia iridium is observed in less than 2% of cases. Potential mechanisms causing heterochromia iridium include siderosis secondary to hemorrhagic retinal detachment as was present in this case.

The authors declare no conflicts of interest.