Anterior Ischaemic Optic Neuropathy (AION) Associated with Post Dialysis Hypotension

Abstract

Three patients on haemodialysis presented with acute painless visual loss. From each, a comprehensive medical and ophthalmic history was taken and each underwent a complete ophthalmic examination. Visual evaluation was carried out by recording Snellen visual acuities, Ishihara colour test scores, the presence of a relative afferent pupillary defect (RAPD) and visual fields with either Goldmann or Humphrey perimetry. Review of renal case notes was performed and appropriate laboratory investigations including imaging were carried out to investigate the cause of disc swelling in all cases. All cases presented with acute painless visual loss, a RAPD, disc swelling, impaired colour vision and a visual field defect. All cases had a history of post-dialysis hypotension. In 2 cases, post-dialysis hypotension was documented just prior to the development of anterior ischaemic optic neuropathy (AION) suggesting a causal relationship. Falls in mean arterial pressure (MAP) of 31 and 22 mmHg were recorded. None of the cases had other well documented risk factors for AION such as diabetes or hypercholesterolaemia. One case had crowded discs. Two cases had bilateral involvement. Two cases were treated with corticosteroids and 1 with aspirin. Visual improvement was noted in 1 case coincident with corticosteroid treatment. Common risk factors in all 3 cases were anaemia and post-dialysis hypotension. In conclusion, patients undergoing haemodialysis may be at risk of AION particularly if they are anaemic and develop post-dialysis hypotension. They should be informed of a small and unpredictable risk of visual loss.

Keywords:

• haemodialysis
• post-dialysis hypotension
• anterior ischaemic optic neuropathy (AION)