title: The incidence of vision loss due to perioperative ischemic optic neuropathy associated with spine surgery: the Johns Hopkins Hospital Experience.
abstract: METHODS
  Twenty-year retrospective review of 14,102 spine surgeries.
  
  
  OBJECTIVE
  To determine the incidence of perioperative ischemic optic neuropathy (POION) in spine surgery at our institution.
  
  
  BACKGROUND
  In recent years, perioperative vision loss in patients undergoing spine surgery has become an issue of increasing concern to physicians, patients, and medicolegal experts. The incidence of POION in spine surgery has been addressed in two separate studies that found incidences of 0% and 0.12%.
  
  
  METHODS
  We performed a 20-year database search for all patients who underwent spine surgery and had a concurrent ICD-9 discharge diagnosis pertaining to vision loss. Patient charts were reviewed in detail to confirm the diagnosis of POION.
  
  
  RESULTS
  Of 14,102 cases of spine surgery during the study time frame, we identified 4 cases of POION, for an incidence of 0.028%. In 3 of the 4 cases, surgery was performed with the patient in the prone position; the fourth patient was placed in the lateral decubitus position. All affected patients had experienced intraoperative anemia, hypotension, or both. The average time of surgery was 420 minutes.
  
  
  CONCLUSIONS
  POION is a rare but potentially devastating and untreatable complication of spine surgery, particularly that performed with the patient in the prone position. Anemia, hypotension, long duration of surgery, and significant intraoperative hydration may all be risk factors for this condition. All patients undergoing spine surgery should be informed about the low but definite risk of this condition, and every attempt should be made during surgery to maintain stable hemoglobin and mean arterial pressure and to avoid overhydration.
authors.affiliation: Neuro-Ophthalmology Unit, Department of Ophthalmology, The Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Shu-Hong
authors.initials: SH
authors.lastname: Chang
authors.forename: Neil R
authors.initials: NR
authors.lastname: Miller
mesh_terms: D000046:Academic Medical Centers; D000293:Adolescent; D000328:Adult; D015142:Baltimore / Q000453:epidemiology; D016063:Blood Loss, Surgical; D016208:Databases, Factual; D006801:Humans; D015994:Incidence; D018917:Optic Neuropathy, Ischemic / Q000453:epidemiology / Q000209:etiology*; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects*; D015354:Vision, Low / Q000453:epidemiology / Q000209:etiology*