title: Perioperative optic neuropathy in patients undergoing off-pump coronary artery bypass graft surgery.
abstract: OBJECTIVE
  Perioperative optic neuropathy (PON) is a rare, but devastating complication following coronary artery bypass graft surgery (CABG). We performed a retrospective study of PON associated with off-pump CABG (OPCABG) to identify possible risk factors.
  
  
  METHODS
  1442 patients underwent OPCABG over a 10-month period from October 2008 to August 2009; PON was identified in four (0.28%) patients. A retrospective review of the charts was done to identify the patient characteristics, pre-operative status, intra-operative details, and ophthalmic examination details. Friedman test was used to compare the hematocrit (Hct) and the mean arterial pressure (MAP) values across the three time periods: Pre-, intra- and post-operative periods.
  
  
  RESULTS
  All four patients were male, diabetic, and in the age range 51-69 years. All patients noted unilateral or bilateral severe visual loss in the immediate post-operative period, which was permanent. All the four patients had statistically significant decrease in the Hct (P < 0.039) and mean arterial blood pressure (P < 0.018) in the intraoperative and post-operative period when compared to pre-operative value.
  
  
  CONCLUSIONS
  PON is a rare but definite possibility in patients undergoing OPCABG. Diabetes mellitus may be a risk factor. Perioperative hemodynamic abnormalities like decrease in MAP and anemia may play a role in the development of PON in OPCABG.
authors.affiliation: Department of Vitreoretina, Narayana Nethralaya, Institute of Medical Sciences, Bengaluru, Karnataka, India.
authors.forename: Rajani
authors.initials: R
authors.lastname: Battu
authors.forename: Apoorva
authors.initials: A
authors.lastname: Prasad
authors.forename: Muralidhar
authors.initials: M
authors.lastname: Kanchi
mesh_terms: D000368:Aged; D000768:Anesthesia, General; D062186:Arterial Pressure; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects*; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009901:Optic Nerve Diseases / Q000209:etiology*; D059035:Perioperative Period