Thursday, October 23, 2014
What are the risks of blindness after being administered anesthesia during a "face down" neck surgery? A friend of mine recently had a "face down" neck surgery, and he said when he entered the O.R., the doctor informed him that seeing as he was going to be face down for 4 hours, under anesthesia, there was a risk he may be blind after surgery. Others in the room immediately said "No", that he was not at risk. I am having a posterior neck surgery soon and will most likely be face down. I was wondering if blindness was a possibility, and what makes a person, "at risk" for this complication. Thank You in advance for any help you may be able to give me.
What you've described is I would say a textbook example of how not to inform patients of the risks of surgery and anesthesia.
Perioperative visual loss (POVL) is the term now used to describe a rare but devastating complication that can occur with surgery. (Surgery on the eye itself is excluded here).
Of all surgical procedures, those of most concern are prolonged spinal surgeries done in the prone (face down position). The chances of POVL occurring are very small but not known exactly in any individual case. The incidence of visual loss associated with spinal fusion - a major spine operation - was found in one study to be around 1 case in every 3,300 cases. For less major spinal surgery, such as laminectomy, the incidence was about 1 in 10,000 cases.
The recognition of POVL as a rare but important complication led the American Society of Anesthesiology in 1999 to establish a special registry of cases in order to study the problem and try to establish the cause and means of prevention. See the Postoperative Visual Loss Registry for more information.
The visual loss is often temporary but can be permanent, and severe.
This type of complication can occur even when the surgery and the anesthesia appear to have gone well, and in otherwise healthy patients. There does not appear to be any clear link between unintended direct pressure on the eyeball which at one time was thought be a major cause of POVL. Anesthesiologists nevertheless do take great care when positioning unconscious patients to avoid pressure on sensitive and delicate body parts such as the eyes.
There may be some link with low blood pressure, low blood count, amount and type of intravenous fluid given during the case, and duration of surgery. There aren't any other kinds of illnesses unrelated to the surgery that appear to clearly influence the chances of a patient developing POVL.
Unfortunately, because of the uncertainty around causation there isn't a clear way to prevent POVL.
Neck surgeries while not "minor" operations are probably in the lower risk category. These procedure usually have less blood loss and less dramatic fluctuations in blood pressure than spinal fusions.
The web site referred to above has additional information for patients including the handout Blindness After Surgery: A Guide for Patients.
Gareth S Kantor, MD
Assistant Professor of Anesthesiology
School of Medicine
Case Western Reserve University