title: [Optic nerve ischemia after spine surgery: case report].
abstract: OBJECTIVE
  Visual loss is an uncommon complication in the postoperative period of non-ocular procedures and its incidence may be confirmed by the increasing number of studies in the international literature. This report aimed at describing a case of anopsia after prone spinal procedure.
  
  
  METHODS
  Male patient, 58 years old, body mass index of 37.6 scheduled for spinal cord decompression associated to lumbar spine arthrodesis. Clinical history of smoking and untreated hypertension. Normal physical, lab and cardiologic exams. Patient was anesthetized with general anesthesia associated to epidural catheter. There were no intraoperative complications. The day after, patient presented with ocular proptosis, conjunctival edema and left visual loss.
  
  
  CONCLUSIONS
  This case evidences the possibility of visual loss after prone spine surgery. Ischemic optic neuropathy results from the unbalance between optic nerve oxygen supply and demand as a consequence of increased intraocular pressure (IOP) as compared to systemic blood pressure, determining poor nervous tissue perfusion. Although the cause of this complication is still not explained, risk factors may be advanced age, atherosclerosis, diabetes mellitus, hypertension, smoking, changes in vascular supply and procedure duration.
authors.affiliation: Hospital Vita, Universidade Federal do Paraná, Curitiba, PR, Brazil. tanaka@bsi.com.br
authors.forename: Clóvis Marcelo
authors.initials: CM
authors.lastname: Corso
authors.forename: Pedro Paulo
authors.initials: PP
authors.lastname: Tanaka
authors.forename: Karina
authors.initials: K
authors.lastname: Khon