OCULAR TOXICITY OF DEFEROXAMINE IN A PATI ENT WITH APLASTIC-ANEMIA AND TRANSFUSIONAL HEMOCHROMATOSIS

Background Deferoxamine, an iron chelating agent, has been used for th e treatment of hemochromatosis for more than 30 years. Ocular toxicity has begun to be reported only in the last few years. In most cases di fferentiation of the true etiology, i.e. the underlying disease versus the toxicity of the substance, is not clear. We report a patient with development of severe ocular toxicity during treatment with deferoxam ine for transfusional hemochromatosis. History and signs An 8-year-old boy was routinely evaluated in the eye clinic before initiation of tr eatment with deferoxamine. Over the last three pears the boy had devel oped a transfusional hemochromatosis after multiple blood trans fusion s for his aplastic anemia. Ophthalmologic examination displayed normal anterior segments with the exception of a unilateral small opacificat ion of the posterior lens cortex, bi lateral tortuous vessels, and mot tling of the retinal pigment epithelium. After four months the patient developed a decrease in visual acuity, distortion of color vision, vi sual field defects, alteration of electrophysiological parameters. and severe changes of the retinal pigment epithelium. Therapy and outcome The deferoxamine was discontinued. Over a period of 3 months the pati ent displayed a normalization of visual acuity and visual fields. The changes of the retinal pigment epithelium and electrophysiological par ameters showed further deterioration and did not return to normal. The patient subsequently was restarted on an adequate treatment dose of d eferoxamine and maintained an essentially uneventful course with close ophthalmologic follow-up. Conclusion Deferoxamine can cause severe oc ular toxicity with incomplete recovery. Measurement of dark adaptation was especially valuable for follow-up examination.