Comparison of 4% Articaine and 0.5%Levobupivacaine/ 2% Lidocaine Mixture for Sub-Tenon’s Anaesthesia in Phacoemulsification Cataract Surgery

Abstract

Purpose:: To compare the efficacy and safety of 4% articaine with a mixture containing equal volumes of 2% lidocaine and 0.5% levobupivacaine without hyaluronidase for subtenons anesthesia in phacoemulsification cataract surgery.

Methods:: A prospective, randomised double masked clinical trial of 59 patients allocated to receive either 4% articaine or a mixture containing equal parts of 2% lidocaine and 0.5% levobupivacaine. All patients had pre and postoperative Hess charting to document ocular motility dysfunction. Ocular and eyelid movements were scored at two minute intervals from 2 -10 minutes after injection of the anaesthetic agent, and at the end of surgery. Complications related to injection including pain, chemosis and subconjunctival haemorrhage were recorded. Patients rated pain (none/mild/moderate/severe) during surgery. The operating surgeon masked to the anaesthetic agent assessed proptosis/ chemosis at the start of the operation and the degree of ocular akinesia and analgesia at the end of surgery.

Results:: The articaine group demonstrated a rapid onset of ocular akinesia with a mean time to readiness for surgery (achieving a score of ≤5) of 3.9 minutes compared to 8.4 minutes for the lidocaine/levobupivacaine mixture (P=0.001) The density of block was significantly greater in the articaine group at all points (P<0.01). Surgeons rated ocular akinesia to be superior in the articaine group (P<0.001). Patients and surgeons rated the analgesic effect as comparable in either group. Eyelid scores, and subconjunctival haemorrhage were comparable in either group though chemosis was slightly more in the articaine group. Hess chart was performed on all patients pre and post operatively. There was no clinically significant motility disturbance in the articaine group, whereas one patient in the 2% lidocaine/ 0.5%levobupivacaine group developed diplopia with abnormal ocular motility on the Hess chart.

Conclusions:: 4% articaine is a safe and a superior anaesthetic agent than a mixture of 2% lidocaine and 0.5% levobupicaine in achieving ocular akinesia for subtenons block in phacoemulsification cataract surgery.

Clinical Trial:: www.ISRCTN.org ISRCTN40732847

Keywords: cataract • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • injection