Modifications and Clinical Use of Sub-Tenon's Anesthesia in Canine Ophthalmic Surgery: A Case Report

Abstract

This case report details the successful application of a specifically adapted sub-Tenon's block (STB) technique in a four-year-old male Shih Tzu undergoing dermoid cyst excision with concurrent left eye discomfort. While sub-Tenon's anaesthesia is a well-established and advantageous regional anaesthetic technique in human ophthalmology, known for its efficacy in providing both anesthesia and analgesia while minimizing potential complications, its clinical application in veterinary medicine, particularly in dogs, remains relatively unexplored, with limited published data available. In this instance, the STB, in conjunction with systemic analgesics, effectively managed post-operative pain and provided adequate intraoperative akinesia, thereby negating the need for systemic neuromuscular blockade. This outcome is significant, as systemic neuromuscular blockade often necessitates mechanical ventilation and intensive monitoring, potentially increasing the complexity and risks associated with the procedure. The successful application of STB in this case underscores its potential as a valuable alternative for regional anaesthesia in canine ophthalmic procedures. This approach mirrors the reduced complication rates, such as globe perforation and retrobulbar hemorrhage, and the efficacy observed in human patients, suggesting a potential for improved safety and outcomes in veterinary patients as well. This preliminary report advocates for further investigation into the broader applicability and safety profile of sub-Tenon's anaesthesia in veterinary ophthalmology. Future studies should aim to evaluate the technique across a larger sample size, encompassing various canine breeds and different types of ophthalmic surgeries, to establish standardized protocols and optimal drug dosages.