Abstract
PURPOSE: To compare metal posterior, flexible posterior, and flexible medium sub-Tenon cannulas for akinesia and anesthesia.
SETTING: King Khaled Specialist Eye Hospital, Riyadh, Saudi Arabia.
DESIGN: Prospective blind randomized comparison.
METHOD: Patients having cataract surgery under sub-Tenon block received a mixture of bupivacaine and lidocaine with hyaluronidase. The patients were divided into 3 groups based on whether a metal posterior sub-Tenon cannula, flexible posterior sub-Tenon cannula, or flexible medium sub-Tenon cannula was used. Pain during injection, akinesia, anesthesia, and complications were recorded.
RESULTS: The study enrolled 159 patients. The akinesia score, superior oblique muscle activity, lid movements, and pain during injection were significantly lower in the metal posterior cannula group 2 minutes after injection (P=.002, P=.008, P=.097, and P=.001, respectively); there was no significant difference at 4 minutes, 6 minutes, 8 minutes, and 10 minutes. The incidence of intra-operative pain was low in all groups (P=.607). Chemosis was significantly less in the flexible posterior cannula group (P=.003); however, there was no significant difference in the site of chemosis (P=.460). There was no significant difference in the incidence, site, or severity of subconjunctival hemorrhage (P=.087, P=.072, and P=.331, respectively). No serious complications occurred.
CONCLUSIONS: Rigid posterior, flexible posterior, and flexible medium cannulas produced effective and equivalent anesthesia. The flexible cannulas may be safer than the rigid cannulas.
Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. J Cataract Refract Surg 2012; 38:1398-1402 (C) 2012 ASCRS and ESCRS