Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
Visual loss is a relatively rare but devastating and unpredictable complication of open heart surgery
with cardiopulmonary bypass. The most common cause of postoperative visual loss following cardiac
surgery is ischemic optic neuropathy (ION), which is generally categorized as anterior ischemic optic
neuropathy (AION) and posterior ischemic optic neuropathy (PION). PION is clinically differentiated
from AION with a normal-appearing optic nerve head. PION is relatively more common in cases of
spinal surgery and radical neck dissection, while AION appears to be more common than PION after
cardiac surgery. We report a very rare case of transient bilateral visual loss due to PION in a 44-yearold man undergoing mitral valve replacement and coronary artery bypass graft surgery.