Abstract: Objective To evaluate the analgesic effects and clinical application values of sub-Tenon's anesthesia for posterior scleral reinforcement in patients with pathologic myopia. Design Prospective cases series. Participants Forty cases (40 eyes) underwent posterior scleral reinforcement from December 2008 to October 2010 in Beijing Tongren Hospital. Methods Anesthetic drug was 0.375% ropivacaine-2% lidocaine 1:1 mixture. Patients were randomly divided into 2 groups, sub-Tenon's anesthesia group (20 eyes, 0.5~1.0 ml anesthetic was injected into sub-Tenons' space) and retrobulbar anesthesia group (20 eyes, 3.0~4.0 ml anesthetic was injected to retrobulbar space). Anesthesia and surgery were performed by the same doctor. The number of eyes were counted according to the different levels of intraoperative pain and tissue edema, and the surgery duration, intraoperative complications and postoperative symptoms were recorded as well. The effects of two different anesthesia methods were observed. Main Outcome Measures Intraoperative pain, tissue edema, surgery duration, intraoperative complications and postoperative symptoms. Results In the sub-Tenon's anesthesia group, mild pain in 17 eyes (85%), moderate in 3 eyes (15%) and severe in 0 eyes; and in the retrobulbar anesthesia group, mild pain in 16 eyes (80%), moderate in 4 eyes (20%) and severe in 0 eyes. There was no statistically significant difference (P=0.681) in intraoperative pain between sub-Tenon's anesthesia group and retrobulbar anesthesia group. In the sub-Tenon's anesthesia group, mild edema of tissue in 16 eyes (80%), moderate in 4 eyes (20%) and severe in 0 eyes; and in the retrobulbar anesthesia group, mild  edema of tissue in 10 eyes (50%), moderate in 7 eyes (35%) and severe in 3 eyes(15%). Tissue edema of the sub-Tenon's anesthesia group was less significant than that of the retrobulbar anesthesia group (P=0.033). Operative duration of the sub-Tenon's anesthesia group (34.70±2.70 minutes) was shorter than that of the retrobulbar anesthesia group (39.60±3.52 minutes) (t=-4.946；P=0.000). Intraoperative complications and postoperative symptoms of the sub-Tenon's anesthesia group were less than those of the retrobulbar anesthesia group. Conclusions Sub-Tenon's anesthesia can contribute to the success of posterior scleral reinforcement surgery. It is safe and simple to operate with few intraoperative complications. It should be an alternative anesthesia for posterior scleral reinforcement surgery. (Ophthalmol CHN, 2012, 21: 102-105)

Key words: sub-Tenon's anesthesia, retrobulbar nerve block anesthesia, posterior scleral reinforcement, pathologic myopia/surgery