Okuläre Nebenwirkung der Deferoxamin-Therapie bei aplastischer Anämie mit transfusionsbedingter Hämochromatose

BACKGROUND: Deferoxamine, an iron chelating agent, has been used for the treatment of hemochromatosis for more than 30 years. Ocular toxicity has begun to be reported only in the last few years. In most cases differentiation 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 deferoxamine for transfusional hemochromatosis. HISTORY AND SIGNS: An 8-year-old boy was routinely evaluated in the eye clinic before initiation of treatment with deferoxamine. Over the last three years the boy had developed a transfusional hemochromatosis after multiple blood transfusions for his aplastic anemia. Ophthalmologic examination displayed normal anterior segments with the exception of a unilateral small opacification of the posterior lens cortex, bilateral tortuous vessels, and mottling of the retinal pigment epithelium. After four months the patient developed a decrease in visual acuity, distortion of color vision, visual 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 patient displayed a normalization of visual acuity and visual fields. The changes of the retinal pigment epithelium and electrophysiological parameters showed further deterioration and did not return to normal. The patient subsequently was restarted on an adequate treatment dose of deferoxamine and maintained an essentially uneventful course with close ophthalmologic followup. CONCLUSION: Deferoxamine can cause severe ocular toxicity with incomplete recovery. Measurement of dark adaptation was especially valuable for follow-up examination.