Ultrasound Imaging of No-Needle 1-Quadrant Sub-Tenon Local Anaesthesia for Cataract Surgery

Objective: To show that direct inferior-nasal 1-quadrant infiltration of local anaesthetic directly to the sub-Tenon space provides anaesthesia for cataract extraction and to assess the distribution of solution. Results: Ultrasound imaging of sub-Tenon delivery to the inferiornasal quadrant reveals rapid movement of solution from this quadrant to the temporal side and posteriorly out of Tenon's space to the anterior intra-conal region. Conclusions: This distribution of solution posteriorly out of Tenon's space is evidence that initial sub-Tenon irrigation can become anterior intra-conal anaesthesia.