The effectiveness of sub-Tenon's infiltration of local anaesthesia for cataract surgery

Purpose: To determine if adequate anaesthesia and akinesia could be obtained using an inferonasal quadrant sub-Tenons anaesthesia for cataract surgery.
Methods: The sub-Tenons method of local anaesthesia was used in 50 patients undergoing extracapsular cataract extraction and lens implantation. The technique followed was that described by JD Stevens in his study of 50 patients. Posterior sub-Tenons space was approached through a conjunctival incision in the inferonasal quadrant and the anaesthetic solution delivered by an irrigating cannula. The patients were assessed for residual ocular movements just before surgery. Effectiveness of anaesthesia was assessed during surgery using a verbal pain rating score. Scoring was based on the concept of a visual analogue pain score chart.
Results: Total akinesia was obtained in 20% patients and total anaesthesia in 24% patients. The remainder of the patients had adequate akinesia and anaesthesia to proceed with and complete the surgery.
Conclusion: This method provides satisfactory anaesthesia for cataract surgery.