Comparative clinical trial of topical anesthetic agents in cataract surgery: Lidocaine 2% gel, bupivacaine 0.5% drops, and benoxinate 0.4% drops

Abstract

Purpose: To assess the efficacy of lidocaine gel, bupivacaine drops, and benoxinate drops as topical anesthetic agents in cataract surgery. Setting: Kasr El-Aini Hospital, Cairo University, Cairo, Egypt. Methods: This prospective randomized study comprised 90 patients scheduled for routine cataract extraction. Patients were randomized into 3 groups of 30 each based on which anesthetic agent they received: lidocaine 2% gel, bupivacaine 0.5% drops, or benoxinate 0.4% drops. Subjective pain at application of the agent and intraoperatively was quantified by the patients using a verbal pain score (VPS) scale from 0 to 10. The duration of discomfort at application, duration of surgery, rate of supplemental sub-Tenon's anesthesia, and complications were recorded. Results: The mean VPS at application was 2.97, 1.53, and 1.03 in the lidocaine, bupivacaine, and benoxinate groups, respectively; the VPS in the lidocaine group was statistically significantly higher than in the other 2 groups ( P<.001). The mean duration of pain at application was 25 seconds, 14 seconds, and 6 seconds in the lidocaine, bupivacaine, and benoxinate groups, respectively, and was statistically significantly higher in the lidocaine group ( P<.001). The mean VPS during surgery was 1.6, 4.1, and 7.1 in the lidocaine, bupivacaine, and benoxinate groups; the lidocaine group had a statistically significantly lower mean VPS than the other 2 groups ( P<.001). The incidence of supplemental sub-Tenon's injection was 3.3%, 10.0%, and 73.3%, respectively, and was statistically significantly lower in the lidocaine and bupivacaine groups than in the benoxinate group ( P<.001). The patients' overall satisfaction was statistically significantly higher in the lidocaine and bupivacaine groups than in the benoxinate group (93.3%, 83.3%, and 33.3%, respectively) ( P<.001). Three patients in the lidocaine group had corneal haze at the time of surgery, which was not statistically significant ( P>.1). Conclusions: Lidocaine gel was a better topical anesthetic agent than bupivacaine and benoxinate drops. Bupivacaine drops were effective in providing deep topical anesthesia.