Unilateral Blindness Occurring During Anesthesia for Neurosurgical Operations

SUDDEN unilateral blindness can appear during general anesthesia. In the eight cases reported in this paper the blindness followed neurosurgical procedures. These clinical cases and a series of experiments on monkeys corroborate the theories promulgated by previous authors on the etiology of this occurrence, that it is due to inadvertent application of pressure to the orbital contents. All the patients in this series underwent operation at the Mayo Clinic during a 12-year period, from 1940 to February, 1952. No cases have occurred other than those reported, and none have appeared during other types of surgery. Each patient had a lesion which required a suboccipital or posterior cervical approach. The patient either sat or lay prone with the face cushioned on a wellpadded headrest. Intratracheal nitrous oxide and ether anesthesia was employed in every case. In spite of prolonged surgical procedures (two to six hours), the brachial blood pressure fell below