In these nonoperative cases, risk factors include atherosclerosis, hypertension, diabetes mellitus and nocturnal hypotension, among others. The etiology of postoperative ischemic optic neuropathy is unclear but may be associated with decreased oxygen delivery to the optic nerve. However, it is important to emphasize that cases of postoperative ischemic optic neuropathy have occurred in the absence of these factors. Many cases of postoperative ischemic optic neuropathy are reported from head and neck dissections and prone spine procedures where there is significant facial swelling and where venous hemodynamics may be altered. Patients who develop visual deficits within seven days after nonophthamologic surgery are eligible for inclusion in the registry, and data are collected on standardized forms from the registry Web site .
Information is collected anonymously, and reporting is voluntary.
Thus far, we have received and analyzed data on 23 patients. The other three cases were diagnosed as either central retinal artery obstruction, retinal ischemia or a questionable transient ischemic attack. Controlled hypotension was utilized in 42 percent of these cases. Bilateral lesions were present in 56 percent of the 23 patients. There was partial recovery of vision in 39 percent of patients in the database overall, consistent with a reported partial recovery rate of 30 percent to 43 percent.