Bull's eye maculopathy associated with hereditary hemochromatosis

Purpose: To report a case of bull's eye maculopathy, a novel finding in a patient with iron overload secondary to hereditary hemochromatosis with a homozygous mutation of the HFE gene. Observations: A 39-year-old man with recently diagnosed hereditary hemochromatosis undergoing treatment by serial phlebotomy presented with bilateral progressive blurry vision and recent onset of photopsias and headaches. Fundus examination revealed a symmetric bull's eye maculopathy with photoreceptor loss and retinal pigment epithelium transmission defects in the area of speckled hyper- and hypo-pigmentation by multimodal imaging. Full field and multifocal electroretinograms demonstrated generalized rod and cone dysfunction with some central preservation of waveforms. Further systemic work-up revealed low ceruloplasmin, mildly decreased serum copper and zinc levels, and low urinary copper. The patient underwent testing for inherited retinal dystrophies, but was not found to have any known pathogenic gene mutations. His ferritin levels normalized with serial phlebotomy and his retinopathy did not appear to progress over 6 months with normalization of his iron levels. Conclusions and Importance: We report a case of bull's eye maculopathy in a patient with hereditary hemochromatosis with no previous exposure to iron chelators and no known inherited retinal dystrophy. Ocular involvement in hereditary hemochromatosis is relatively rare. In this case, the patient's low serum ceruloplasmin is thought to have increased the amount of redox-active ferrous iron and potentiated retinal iron toxicity resulting in the observed retinopathy. To the authors' knowledge, this is a potentially novel ocular manifestation of hereditary hemochromatosis.