A Comparative Study Between Single Medial Canthus Injection Using 13 x 0.45 mm Needle and Posterior Sub-Tenon Injection as Local Anesthesia Techniques for Strabismus Surgery in Adults

Abstract

Background: The quality of ophthalmic anesthesia is an important component of the surgical procedure. There is no absolutely well-tolerated local eye anesthetic technique. However, it is important to choose a technique with high efficacy and safety. Objective: This study aimed to compare the efficacy and safety of peribulbar block using medial canthus single injection and posterior sub-tenon injection techniques. Methods: This prospective observational study was carried out at the Research Institute of Ophthalmology, Cairo, Egypt during the period from March to December 2018. Consecutive 60 patients of both sexes, aged >18 years-old, scheduled for bilateral strabismus surgery were enrolled in this study. In one eye of the sixty patients, medial canthus single injection peribulbar anesthesia was used (Group A), whereas posterior sub-tenon technique was applied in the other eye (Group B). Results: The median total ocular akinesia score was significantly higher in group A than in group B when assessed at 1, 3, and 5 min (p < 0.001). Each of the intraoperative (at 5 min) and postoperative pain scores showed no significant differences between the two groups (p > 0.05). However, the median scores of surgeon and patient satisfaction were significantly higher in group A compared with group B (3 vs. 2 each, p < 0.05). No patient developed occulocardiac reflex or postoperative nausea and vomiting. Conclusion: Peribulbar anesthesia by medial canthus single injection showed better akinesia of the globe than sub-tenon injection technique. Otherwise, both techniques were equally effective and safe.