Deferoxamine-related ocular toxicity - Incidence and outcome in a pediatric population

Purpose: Deferoxamine (DFO) is a chelating agent used widely for the treatment of transfusional hemochromatosis. DFO-related ocular toxicity has been previously reported several times, and many institutions have adopted an ophthalmic screening protocol for patients treated with DFO despite little information regarding the rate of ocular toxicity. Our study aimed to determine the incidence of DFO toxicity at a major pediatric hospital that uses regular ophthalmic screening for all DFO-treated patients. Methods: A retrospective case series of all patients treated with DFO for transfusional hemochromatosis at The Hospital for Sick Children (Toronto, Ontario, Canada) between 1995 and 2005 inclusive. Results: A total of 84 patients received regular DFO treatment for transfusional hemochromatosis related to long-term hypertransfusion. A total of 421 ophthalmic screening examinations were performed (average, 5.0 examinations per patient). DFO-related ocular toxicity was found only in one patient (1.2%). This patient had central blurriness and retinal pigmentary changes shown by examination and decreased central responses shown by electroretinography, but these changes were all found to be completely reversible after a change from intravenous to subcutaneous therapy at a reduced dose. Conclusions: In this large pediatric center, DFO-related ocular toxicity has been a rare and mild finding. Regular ophthalmic screening should be carried out for patients receiving high-dose subcutaneous or intravenous therapy, because early detection of retinal toxicity may lead to optimization of the DFO dose and thus prevention of long-term visual sequelae.