Iron overload and iron chelating agent exposure in anemia-associated outer retinal degeneration: a case report and review of the literature

Abstract

Background Deferoxamine retinopathy is the informally designated term used to describe a characteristic pattern of outer retinal degeneration in iron-overloaded chronic anemia patients who are treated with deferoxamine. We hypothesize that insufficiently treated iron overloading and not only deferoxamine is the cause of the retinal degeneration. Our case report is based on exposure histories of two anemia patients and literature review. Case presentation Both anemia patients presented with bilateral visual loss secondary to photoreceptor and retinal pigment epithelium degeneration. Chart review showed that visual loss came after a year-long slow, and rather monotonous rise in plasma ferritin concentrations, with no obvious relation to iron chelator exposure. In one patient, the onset of symptomatic visual loss came after a bout of fever followed by two additional febrile episodes, all accompanied by plasma ferritin spikes. Adjustment of iron chelation therapy did not improve visual function. Experimental studies clearly show that both systemic and intraocular exposure to iron ions can induce retinal degeneration. Conclusion The available evidence indicates that retinal degeneration in chronic anemia patients treated by deferoxamine is cause by insufficient iron chelation, not by deferoxamine. The actual role of iron chelating agents may be to promote a long enough survival to allow the slow development of retinal siderosis.

Effects of medications on hypoxia‐inducible factor in the retina: A review

“…The ff‐ERG is currently used as a standard exam to track DFO toxicity, although its results may be normal and non‐specific 97 . Overall, the clinical presentation of DFO toxicity varies widely and there has been recent debate whether DFO truly causes retinal toxicity or if retinal toxicity is secondary to insufficiently treated iron overload 104,105 . While further study in needed to understand the pathophysiology and the pattern of ocular presentation of DFO toxicity, patients with long term DFO use require regular meticulous exams by an ophthalmologist including FAF, OCT, ERG, and EOG.…”