Background: Seroprevalence studies in Spain have shown that a high number of the population has been in contact with Toxocara canis although no cases of ocular involvement by this helminth have been described. The clinical and age of presentation makes differential diagnosis with retinoblastoma necessary, which is at time difficult, although essential since the treatment and prognosis are very different.
Methods: One case of ocular toxocariosis and the diagnostic keys based on the following are described: ophthalmologic exploration, imaging techniques (ECHO, TC, NMR), aqueous humor cytology, LDH quotient of aqueous/serum humor, and determination of specific anti-Toxocara antibodies by ELISA in serum and aqueous humor.
Conclusions: Correct differential diagnosis between ocular toxocariosis and retinoblastoma is required.