Patient and surgeon comfort in vitreoretinal surgery performed with Sub-Tenon's Anaesthesia

Background. Since Stevens first introduced Sub-Tenon's anaesthesia into cataract surgery it has shown itself to be a safe, simple, and efficient technique. The advantages of this type of block are comparable to those of sharp needle anaesthesia and complications are minimal. Several studies have found that the anaesthesia provided by Sub-Tenon's capsule injection is as good as or better for cataract surgery than that achieved by retrobulbar injection, but the efficacy of Sub-Tenon's block in vitreoretinal surgery is less well established. Methods. We performed 50 vitreoretinal procedures; 50 eyes received a Sub-Tenon's injection of a 5 ml mixture (50:50) of lidocaine and ropivacaine, plus 15 IU mL-1 of Hyaluronidase. Results. In 45 cases, only one injection was needed to achieve sufficient anaesthesia and akinesia; in 5 cases a second injection was performed five minutes after the first. Mean surgical time was 45.7 minutes. After surgery, each patient was asked to indicate his value on the VAS pain scale. Mean VAS degree was 2.4. In 7 cases, VAS was > 3 and the pain was successfully managed with the administration of paracetamol in the postoperative period. No light perception was detected at the end of surgery in 33 patients. All cases with 2 injections had no light perception at the end of surgery. Anaesthesia lasted throughout the surgery in all cases. The surgeon performed all surgery comfortably and with no difficulty. Conclusions. According to our experience and to a growing body of evidence, Sub-Tenon's anaesthesia appears to be a safe, simple, versatile, and effective technique and should be considered as a real alternative method of anaesthesia in vitreoretinal surgery.