Anesthesiology 2001; 95:575–7 © 2001 American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins, Inc. Postoperative Visual Loss Still No Answers—Yet POSTOPERATIVE visual loss (PVL) is a devastating and poorly understood injury. Although rare, there are cer- tain operative procedures, especially spinal surgery, in which the incidence seems to be significantly higher. Ischemic optic neuropathy (ION), which affects the an- terior or posterior portions of the optic nerve, is the most common cause of PVL. 1 Visual loss may also be caused by retinal arterial occlusion and cortical blind- ness. Awakening with visual impairment may be one of the most frightening and catastrophic postanesthetic complications that a patient could sustain. It is also an enormous medical–legal liability problem. PVL has evoked controversy. Is it a preventable injury? If so, is it possible or even desirable to change our practice in an attempt to prevent it? Should we routinely inform pa- tients of this risk? 1,2 Lee and Lam 3 report in this issue of ANESTHESIOLOGY yet another case of postoperative blind- ness after spinal surgery. Although the report does not contain new information, it is disturbing as one more vivid reminder of how PVL can follow a seemingly un- complicated anesthetic administration without the com- monly cited risk factors, which include hypotension, anemia, and external compression of the eye. 1,4 There have been many other cases reported that lack these risk factors as well. 4 We need to look beyond a simple ap- proach to PVL and consider how we might try to prevent this adverse event by taking a systems approach. Be- cause of the impression that the incidence of PVL is increasing, it is essential that we learn more about its causes. To achieve our goals of consistently good outcomes, an environment fostering a rich reporting culture must be created and supported to capture accurate data with details of clinical care. 5 However, many obstacles pre- vent adequate reporting of rare but serious events of this type. Disincentives to reporting include extra work, skepticism, lack of trust, fear of reprisal, no effective means to report, and an “organizational culture” that discourages reporting. 6,7 The majority of our knowledge about PVL derives from case reports by ophthalmologists and surgeons, and it is only in the past 5 yr that cases have begun to be reported in the anesthesia litera- ture. 8 –10 The incidence of PVL in a general surgical population is 1 in 61,000. 9 This low incidence renders a prospective study difficult if not impossible. In a recent study of nearly 225,000 anesthetics over a 15-yr period at our institution, the incidence of PVL after spinal surgery was 1 in 1,100 (3 patients of 3,351), a 50-fold higher rate compared with all other procedures. The result after spinal surgery is in accordance with estimates derived from survey studies. 11–13 Open heart surgery, head and neck surgery, and sinus surgery are also believed to be associated with a higher risk of PVL. 4 The medical–legal implications, underreporting, and the absence of an an- imal model have hampered achievement of an adequate understanding of the mechanisms of PVL. Anesthesiologists may not be responsible for this in- jury in many instances, but we are in the best position to gather data to begin to understand this complication. There are a number of means to capture adverse event data reliably as demonstrated, e.g., by the Australian Incident Monitoring System. 14 The American Society of Anesthesiologists (ASA) Closed Claims Project has estab- lished a Post-Operative Visual Loss Registry.* Since June 1999, 35 cases have been submitted anonymously to the Registry. Preliminary results were reported at the last ASA annual meeting 15 and in the ASA Newsletter. 16 The goal is to accumulate data from 100 patients with PVL. When completed, this project will provide by far the largest and most detailed characterization of patients that have sustained PVL. This is an important step to- ward beginning to achieve an understanding of PVL. To submit cases, the patient’s medical record must be avail- able, and data must be entered on standardized forms available from the Registry. Although the Registry has its limitations, e.g., it cannot definitively establish the mech- anisms of PVL, it is currently the only organized data gathering tool for PVL. With anonymity assured, anesthe- siologists should not be reluctant to submit cases. Ano- nymity will help to ensure trust and confidentiality while incident reporting systems continue to evolve. Another possibility would be to conduct a large, mul- ticenter case control study to compare patients with case-matched controls. This type of study at our hospital did not show any differences in intraoperative factors, such as blood loss, blood pressure, hematocrit, or the quantities of fluid administered intraoperatively, but our results were limited by the small sample size of visual loss patients (four patients at a single institution). A larger study encompassing at least 15–20 affected pa- tients undergoing the same surgical procedure might This Editorial View accompanies the following article: Lee LA, Lam AM: Unilateral blindness after prone lumbar spine sur- gery. ANESTHESIOLOGY 2001; 95:793–5.  Accepted for publication May 22, 2001. Supported by grant No. EY10343 from the National Institutes of Health, Bethesda, Maryland, and the Glaucoma Research Foundation, San Francisco, California. The authors are not supported by, nor main- tain any financial interest in, any commercial activity that may be associated with the topic of this article. * Available at: http://depts.washington.edu/asaccp/eye/index.shtml. Accessed July 2001 Anesthesiology, V 95, No 3, Sep 2001 575 Downloaded from http://pubs.asahq.org/anesthesiology/article-pdf/95/3/575/403588/7i0901000575.pdf by guest on 20 November 2021