Incidence of Ischemic Optic Neuropathy Following Cardiopulmonary Bypass: 20-Year Experience

Abstract Objective: This study evaluated the incidence and risk factors for ischemic optic neuropathy (ION) as a complication of cardiac surgery requiring cardiopulmonary bypass (CPB). Design: Retrospective chart review of prospectively collected data at a tertiary care center Setting: Single tertiary academic referral center Participants: This study comprised of 44,568 cardiac surgery patients with CPB between January 1, 1995 and January 5, 2017 using the Society of Thoracic Surgeons’ (STS) database and cross-matched with International Classification of Diseases (ICD) codes for visual changes. Interventions: None – this is a retrospective chart review. Measurements and Main Results: Six patients were initially identified as having visual changes. There was only 1 patient from 44,568 cardiac surgeries following CPB between January 1, 1995 and January 5, 2017 that experienced ION, incidence 0.22 per 10,000. With only one patient we were unable to determine risk factors for ION; however, the nadir perioperative hemoglobin in the affected patient was 7.3 g/dL (postoperative). Conclusion: The incidence of ischemic optic neuropathy decreased from 6 per 10,000 in our previous study, 1976 and 1994, to 0.22 per 10,000 in our current study. Due to the low incidence of this dreaded complication, we were not able to identify risk factors for ION. Practice improvements (e.g. transition to membrane oxygenators, blood transfusion guidelines, less invasive surgical options for high risk patients) during this time likely impacted the incidence reduction.