Medial Canthus (Caruncle) Single Injection Periocular Anesthesia

Abstract

We studied 151 consecutive patients scheduled for elective short-duration ophthalmic procedures to assess the efficacy of an alternative approach to periocular anesthesia. Single injection at the medial canthus was performed with a 25-gauge needle. The studied variables were: injected volume, onset time of the block, akinesia (scored on a 12-point scale), adequate surgical anesthesia (scored on a 5-point scale), and need for reinjection. The injected volume of local anesthetic solution was 8.6 +/- 1.7 mL. The onset time of anesthesia was 6.9 +/- 3.0 min, with an akinesia score of 11.6 +/- 1.1 (maximum 12). Additional reinjections were necessary in 14 cases (9.2%). There was a learning curve for the technique, with 8 of the additional injections being performed in the first 30 patients (26.6%), and 6 in the last 121 (4.9%). The surgical score recorded after surgery was 4.8 +/- 0.6 (maximum 5). There were no complications, including injury to the globe, optic nerve, or retina or orbital hematoma. Medial canthus single injection periocular anesthesia appears to be a promising alternative to the usual double injection peribulbar block. (Anesth Analg 1996;83:1234-8)