Central retinal vein occlusion complicating iron deficiency anaemia.

Abstract

Sudden blindness as a consequence of severe blood loss was well known at the turn of the century, when a common cause of blindness in young people was anaemia due to blood loss from the gastrointestinal tract or to abortion (Gowers, I904). The retinal changes described include pallor of the disc, sometimes with disc oedema, and small numbers of retinal haemorrhages and exudates. Such retinal abnormalities usually develop within 48 hours of haemorrhages and occur typically in patients rendered anaemic by repeated episodes of blood loss rather than a single major haemorrhage. Transient impairment of retinal blood flow during episodes of hypotension was considered to be the most likely cause of the ocular changes in such cases by Pears and Pickering ( I960). Though retinal haemorrhages and exudates often occur in severe chronic iron deficiency anaemia (Holt and Gordon-Smith, I969), the retinal abnormalities are not usually severe and consist, in the main, of "cotton wool" exudates. Profound retinal damage suggesting central retinal vein occlusion would appear to be a most unusual complication of iron deficiency anaemia; such a case is reported here and the pathogenesis of the retinal changes is dis- cussed.