VISUAL-ACUITY AND PUPILLARY REACTIONS AFTER PERIBULBAR ANESTHESIA

The effect of peribulbar anaesthesia on optic nerve function in 20 pat ients, before and after cataract surgery, was measured. All the patien ts had decreased visual acuity. Five (25%) had no perception of light. Seventeen (85%) developed a relative afferent pupil defect (RAPD). No patients saw the operating instruments. Seven (35%) had improved visu al acuity immediately postoperatively. Patients should be warned that they may lose vision completely on being given a peribulbar anaestheti c; however their vision will improve, but not necessarily immediately, postoperatively. Examination for an RAPD is a good method of providin g reassurance that the operating instruments will not be seen.