Sub-Tenon anesthesia for segmental scleral buckling and assessment of postoperative pain

Background: To evaluate the safety and efficacy of sub-Tenon anesthesia for segmental scleral buckling. Methods: Thirty-two patients diagnosed with rhegmatogenous retinal detachment were treated with segmental scleral buckling under sub-Tenon anesthesia. After topical anesthesia, a buttonhole was made through the conjuntiva and Tenon's capsule 4 mm posterior to the limbus. Four milliliters of anesthetic solution was then delivered into the posterior sub-Tenon space using a blunt cannula. The buckling procedure was done immediately after the completion of anesthesia. We evaluated akinesia and recorded the pain with a visual analogue scale after surgery. Results: There were no anesthesia related complications. Twenty-two patients (69%) reported no pain during surgery. Nine patients (28%) felt pain during surgery. However, the pain was tolerable and the surgeries were finished smoothly with or without a supplemental anesthetic solution. One patient (3%) experienced uncomfortable pain and needed an additional retrobulbar block. Five patients (16%) retained complete eye movement 5 min after anesthesia, and only 4 patients (13%) experienced total akinesia. At the end of the surgery, 16 patients (50%) had total akinesia and 2 patients (6%) retained complete eye movement. Conclusions: Sub-Tenon anesthesia is efficient and safe in segmental scleral buckling. It can prevent the complications of peribulbar or retrobulbar anesthesia and is a good alternative to both methods of anesthesia, especially in highly myopic eyes.