Intraoperative Visual Evoked Potential Responses to Preserve Vision in Operation with Sellar and Parasellar Lesions

ABSTRACT

Damage to the visual system is an unfortunate complication of surgery in the area of the optic nerve and chiasm. It is now possible to monitor the functional status of the visual system intraoperatively at regular intervals. We studied the patients during parasellar surgery to determine if this technique could be used to indicate potential danger to the visual system. Our objective was to determine if the visual evoked response was sensitive and dynamic enough to detect premoibid changes in the function of the visual system. This is accomplished by recording the Visual Evoked Potential Response to flash of light from light-emitting diodes goggle. 1) We studied two patients during sellar and parasellar surgery to determine if this technique could be used to indicate potential danger to the visual system. 2) It was benefit to determine if the intraoperative VEP was sensitive and dynamic enough to detect premorbid changes in the function of the visual system. 3) The VEP showed conduction was blocked when the optic nerve was manipulated and restored when the optic nerve was decompressed. 4) After the optic nerves were decompressed, VEP of nearly normal latency, amplitude and form was recorded. 5) Changes in the VEP pararell improvement of function after surgical removal of sellar and parasellar tumors. 6) Determination of improved nerve conduction permitted the prediciton of visual recovery during surgery.