Comparison of subtenon anaesthesia with peribulbar anaesthesia for manual small incision cataract surgery

Purpose: To compare the safety and efficacy of subtenon anaesthesia with peribulbar anaesthesia in manual small incision cataract surgery using a randomised control clinical trial. Method: One hundred and sixty-eight patients were randomised to subtenon and peribulbar groups with preset criteria after informed consent. All surgeries were performed by four surgeons. Pain during administration of anaesthesia, during surgery and 4 h after surgery was graded on a visual analogue pain scale and compared for both the techniques. Sub-conjuntival haemorrhage, chemosis, akinesia after administration of anaesthesia and positive pressure during surgery were also compared. Patients were followed up for 6 weeks postoperatively. Results: About 146/168 (86.9%) patients completed the six-week follow-up. Thirty-one out of 88 (35.2%) patients of peribulbar group and 62/80(77.5%) of subtenon group experienced no pain during administration of anaesthesia. There was no significant difference in pain during and 4 h after surgery. Subtenon group had slightly more sub-conjunctival haemorrhage. About 57 (64.8%) patients of the peribulbar group had absolute akinesia during surgery as compared to none (0%) in sub-tenon group. There was no difference in intraoperative and postoperative complications and final visual acuity. Conclusion: Sub-tenon anaesthesia is safe and as effective as peribulbar anaesthesia and is more comfortable to the patient at the time of administration.