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

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 44,568 cardiac surgery patients who underwent CPB between January 1, 1995, and January 5, 2017, using the Society of Thoracic Surgeons database and cross-matching it with International Classification of Diseases codes for visual changes.


INTERVENTIONS
None; this was a retrospective chart review.


MEASUREMENTS AND MAIN RESULTS
Six patients initially were identified as experiencing visual changes. Only 1 patient from 44,568 cardiac surgeries with CPB between January 1, 1995, and January 5, 2017, experienced ION, for an incidence 0.22 per 10,000. Because only 1 patient experienced ION, the authors were unable to determine risk factors for this complication; however, the nadir perioperative hemoglobin in the affected patient was 7.3 g/dL (postoperative).


CONCLUSION
The incidence of ION decreased from 6 per 10,000 in the authors' previous study from 1976-1994 to 0.22 per 10,000 in the present study. Because of the low incidence of this dreaded complication, the authors were not able to identify risk factors for ION. Practice improvements (eg, transition to membrane oxygenators, blood transfusion guidelines, less- invasive surgical options for high-risk patients) during the time between the authors' studies likely affected the incidence reduction.