title: Postoperative vision loss after spine surgery: a single-institution case-control comparison.
abstract: BACKGROUND
  Postoperative vision loss (POVL) after spine surgery is a rare but devastating outcome. We present the first case-control study from a single institution for POVL with the diagnoses of ischemic optic neuropathy or central vision loss after complex spine surgery.
  
  
  METHODS
  POVL cases following spine surgeries between December 1995 and December 2010 at the Cleveland Clinic were identified retrospectively using administrative codes. Each instance of POVL was matched to 5 case-control patients based on age, gender, body mass index, systolic blood pressure, diastolic blood pressure, mean arterial pressure, and hematocrit. Duration of anesthesia, fluid volumes, and hemodynamic measurements were then compared between POVL cases and control cases using Wilcoxon rank sum test.
  
  
  RESULTS
  Six patients developed POVL. These patients had significantly greater blood loss (P=0.002, Wilcoxon test) and a significantly greater volume of red blood cells transfused (P=0.006) than the control patients. No other intraoperative measures differed significantly after Bonferroni correction for multiple outcomes.
  
  
  CONCLUSIONS
  We found that patients with POVL had significantly greater blood loss and significantly more red blood cell transfusions than their matched controls.
authors.affiliation: Department of General Anesthesiology, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH ; Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH.
authors.forename: Ehab
authors.initials: E
authors.lastname: Farag
authors.affiliation: Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: Alaa A
authors.initials: AA
authors.lastname: Abd-Elsayed
authors.affiliation: Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH ; Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH.
authors.forename: Jarrod E
authors.initials: JE
authors.lastname: Dalton
authors.affiliation: Department of Anesthesiology, University of Arkansas for Medical Sciences, Little Rock, AR.
authors.forename: Eman
authors.initials: E
authors.lastname: Nada
authors.affiliation: Department of General Anesthesiology, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Parker
keywords: Optic neuropathy–ischemic; spinal fusion; surgical procedures–operative; vision–ocular