Tegaderm and Visual Evoked Potentials

The purpose of this study is to determine if a clear barrier placed over the eyes has any effect on goggle monitoring. When a patient has general anesthesia they lose the ability to blink and their eyes may dry. They may also lose the ability to keep their eyes fully closed. The anesthesiologist takes several steps to prevent injury to the eyes. First the eyes will be lubricated with ointment and the eyelids will be held in a closed position by the use of a clear barrier. During pituitary surgery it is the routine practice to perform many types of monitoring. One type of monitoring is to stimulate your eyes with a light. This helps your surgeon protect the nerve supply to your eyes. The light is supplied by a pair of goggles placed over your eyes during surgery. To help achieve our objective, the investigators are asking patients who are undergoing pituitary surgery to give us permission to record two sets of numbers form the monitoring device once prior to the application of the clear barrier and the second after the barrier is applied. This will be done when the patient is already asleep and will not be aware this is happening.