Non-arteritic ischaemic optic neuropathy after first return to haemodialysis.

The authors present an interesting case of non-arteritic anterior ischaemic optic neuropathy (NAION) after 2 h of haemodialysis, in a 42-year-old Caucasian woman with anaemia (haemoglobin 7.1 g/dl) uraemia (56.3 mmol/l), spurious hypotension (42/26 mm Hg) and previous history of anterior ischaemic optic neuropathy (AION) in the other eye. Thirteen cases of haemodialysis related NAION in adults have been reported to date. NAION is produced when oxygen delivery to the optic nerve is compromised resulting in hypoxic swelling, nerve compression in the optic canal and ischaemia of the optic nerve head. It typically presents as a sudden, unilateral and painless inferior visual field defect with a fixed unreactive pupil after a period of relative hypotension. Clinicians should be aware of this unusual complication when considering and explaining dialysis options, particularly in patients with other risk factors such as hypotension, anaemia, significant uraemia and previous history of AION.