A Comparison of 1% Ropivacaine and 1% Ropivacaine with Clonidine for Retrobulbar Block

Abstract

Background and Objectives: To compare the efficacy of 1% ropivacaine as a sole agent and ropivacaine with additional clonidine for retrobulbar (intraconal) anesthesia in cataract surgery. Methods: Sixty patients undergoing retrobulbar anesthesia for elective cataract phacoemulsification were prospectively studied and randomly assigned to 1 of 2 groups according to the local anesthetic used. Patients were randomized to receive 1% ropivacaine (ropivacaine group) or 1% ropivacaine with additional clonidine 1 μg/kg (ropivacaine plus clonidine group). Retrobulbar anesthesia was always accomplished by the same physician who was blind to the anesthetic used. Evaluation included assessment of pain on local anesthetic injection, ocular and eyelid akinesia, intraocular pressure (IOP), the duration of anesthesia, hemodynamic parameters, and incidence of perioperative complications. Results: No difference between the groups was found regarding the ocular movement. There was no difference between the groups in terms of IOP. Retrobulbar injection caused a significant drop of IOP in both of the groups (p 0.05). Lid injection was less painful in the ropivacaine plus clonidine group (p<0.05). Lid injection was more painful than the retrobulbar injection for both of the groups (p<0.05). Mean arterial pressure (MAP) was not significantly different between the study groups. Heart rate (HR) was significantly lower in the ropivacaine plus clonidine group (p<0.05). Conclusion: 1% ropivacaine is effective as a sole agent for retrobulbar anesthesia with a long recovery time. Additional clonidine to 1% ropivacaine for retrobulbar injection had no clinically significant benefit.