Fentanyl versus magnesium sulphate as adjuvant to peribulbar anesthesia in cataract surgery

Addition of fentanyl (2 μg/ml) or magnesium sulphate (50 mg) to peribulbar block in patients undergoing cataract surgery equally prolongs the duration of postoperative analgesia. In addition to this effect, fentanyl fastens the onset lid and globe akinesia and provides better akinesia score.