Visual disturbances, serum glycine levels and transurethral resection of the prostate

Transient visual disturbances have been noted in patients undergoing transurethral resection of the prostate. It has been suggested recently that these visual aberrations were secondary to high serum concentrations of glycine from the intravasation of irrigant solutions used during the procedure. We prospectively studied visual acuity, serum electrolytes, glucose, ammonia and glycine concentrations in 18 patients undergoing transurethral resection of the prostate. Of our patient population 22% experienced significant decreases in visual acuity. We found that all patients had significantly elevated serum glycine concentrations but that there was no correlation of visual symptomatology with serum electrolyte or glucose concentrations. Our data further suggest that impeded metabolism of glycine may be more important than the absolute serum concentration in symptomatic patients.