title: Bilateral ischaemic optic neuropathy following laparoscopic proctocolectomy: a case report.
abstract: BACKGROUND
  Perioperative visual loss occurring during non-ocular surgery is a devastating event. Ischaemic optic neuropathy (ION) is a complication described following many procedures. We report the first case of ION occurring during laparoscopic proctocolectomy and discuss the aetiological factors.
  
  
  METHODS
  A 58-year-old male presented with rectal bleeding and was diagnosed with an adenocarcinoma of the sigmoid colon. A very difficult laparoscopic sigmoidectomy and a low anterior resection of the rectum with an end colostomy were carried out. The technical difficulties were due to body habitus and the size and position of the tumour. The operation lasted over six hours. On the first day postoperatively, the patient complained of blurred vision. Examination showed that he had suffered bilateral ION.
  
  
  CONCLUSIONS
  Despite the growing numbers of laparoscopic operations, ION has rarely been described. The cases that were published involved laparoscopic prostatectomy and a prolonged steep Trendelenburg position. We postulate that the patient presented here had suffered both from a relative hypotension and from an acute rise in the intraorbital pressure due to patient position, both factors combining to cause a disruption to ocular perfusion resulting in ION with severe permanent visual damage.
authors.affiliation: Department of Colorectal Surgery, Darent Valley Hospital, Dartford, UK. hagarmizrahi@gmail.com
authors.forename: H
authors.initials: H
authors.lastname: Mizrahi
authors.forename: C E
authors.initials: CE
authors.lastname: Hugkulstone
authors.forename: P
authors.initials: P
authors.lastname: Vyakarnam
authors.forename: M C
authors.initials: MC
authors.lastname: Parker
mesh_terms: D000230:Adenocarcinoma / Q000601:surgery; D006801:Humans; D007022:Hypotension / Q000209:etiology; D007431:Intraoperative Complications / Q000209:etiology; D008297:Male; D008875:Middle Aged; D018917:Optic Neuropathy, Ischemic / Q000209:etiology*; D009916:Orbital Diseases / Q000209:etiology; D011183:Postoperative Complications / Q000209:etiology; D011312:Pressure; D016737:Proctocolectomy, Restorative / Q000009:adverse effects*; D012811:Sigmoid Neoplasms / Q000601:surgery; D012812:Sigmoidoscopy / Q000009:adverse effects*; D014786:Vision Disorders / Q000209:etiology