Transient blindness associated with transurethral resection of the prostate.

Visual impairment or even transient blindness can result from transurethral resection of the prostate when glycine is used as the irrigating fluid. Electroretinograms were obtained from patients in the anesthetic preparation area and in the recovery room immediately after surgery. Four patients reported visual aberrations ranging from a "gray darkening" to "light perception only" coincident with elevated serum levels of glycine. Electroretinograms consistently demonstrated a loss of oscillatory potentials only in those patients with visual impairment. Thirty-hertz "flicker-following" was also attenuated. The excessive serum levels of glycine may contribute to visual impairment and may account for the dropout of oscillatory potentials generated by the retina due to glycine's role in the retina as an inhibitory transmitter.