Use of clonidine as a component of the peribulbar block in patients undergoing cataract surgery

Background and Objectives. This study was designed to determine whether adm inistration of clonidine as a component of a peribulbar block enhanced anal gesia increased sedation, improved akinesia, or decreased intraocular press ure. Methods. A randomized, double-blinded study was undertaken at a Univer sity-affiliated tertiary care hospital. Forty outpatients undergoing unilat eral cataract surgery by a single surgeon (J.P.) under peribulbar blockade were evaluated. Patients received either 100 mu g (1 mL) clonidine or 1 mL preservative-free normal saline mixed with the local anesthetic (7 mL 1% pr eservative-free lidocaine). A Honan adapter was applied for 10 minutes afte r block placement. The outcome measures included sedation scores, intraocul ar pressure (IOP) before and after peribulbar block, need for supplemental block, 24-hour analgesic requirement, and patient satisfaction. Results. Th ere were no differences between groups with respect to pain, sedation, or s atisfaction scores, There was no difference with respect to onset of akines ia. This Study revealed no significant difference in baseline IOP and postp eribulbar IOP. Conclusions. Clonidine did not alter, in any appreciable way , the perioperative course for patients undergoing cataract operations. We do not recommend clonidine as a component of a peribulbar block in patients undergoing cataract extraction operations.