Postoperative Visual Loss: Risk Factors
Advanced, Organ-Based and Clinical Sciences
Postoperative visual loss after non-ocular procedures is a rare but devastating complication after general anesthesia. Visual loss may or may not be permanent and can be unilateral or bilateral. Risk factors vary depending on the etiology of post-operative visual loss.
Posterior ION (PION): prone position, especially if Wilson frame is used, surgery duration(particularly if >6hrs), age > 50yrs, male gender(estrogen is thought to be protective), anemia(particularly if blood loss is >1 L), hypotension(MAPs <70mmHg), and excessive fluid resuscitation(colloid is thought to be less likely to cause edema than crystalloid but data is unclear). Obesity is increasingly recognized as a risk factor as increased intraabdominal pressure can lead to increased central venous pressure and compression of optic nerves. Use of vasopressors is also considered to be a risk factor, particularly if they are used in lieu of blood transfusion for hypotension and hypovolemia.2
Central retinal artery occlusion (CRAO): cardiac surgery where atherosclerotic plaque can be dislodged by catheters into retinal circulation, Giant Cell Arteritis, prior transient ischemic attacks, carotid artery stenosis, embolic stroke and hypercoagulable states.4