Ocular toxocariasis presenting as leukocoria in a patient with low ELISA titer to Toxocara canis.

A 4-year-old white female presented with leukocoria of the right eye. White punctate lesions were observed posterior to the retrolental membrane, which suggested retinoblastoma of some examiners. A full history, physical examination, ultrasonography, and CT scan failed to rule the diagnosis of retinoblastoma in or out. A serum ELISA titer was 1:4, which was considered nondiagnostic. Examination of the enucleated eye revealed a midsegment of the second stage larva of Toxocara canis. The strengths and weaknesses of various diagnostic modalities used to differentiate leukocoria caused by retinoblastoma and T canis are discussed.