Angioid streaks and optic disc drusen in a patient with congenital dyserythropoietic anaemia.

A man in his 60s with dry eye symptoms was noted to have angioid streaks under the peripapillary retina. Congenital dyserythropoietic anaemia was the major health issue throughout his life, requiring venesection for iron overload, but no transfusions for many years. Close inspection of the eyes with optical coherence tomography also detected small subclinical optic disc drusen, which have not been reported in association with congenital dyserythropoietic anaemia. Together, optic disc drusen and angioid streaks represent an ectopic calcification phenotype in the eye and can be seen in the more common inherited condition of pseudoxanthoma elasticum or other inherited haemolytic anaemias such as sickle cell or thalassaemia. These associations highlight the role of pyrophosphate as a physiological inhibitor of calcification, and deficiencies of serum pyrophosphate lead to excessive and ectopic calcification. This raises intriguing hypotheses for the treatment of optic disc drusen, angioid streaks and other conditions of ectopic calcification.