Effect of clonidine added to lidocaine for sub-Tenon’s (episcleral) anesthesia in cataract surgery

Purpose We aimed to evaluate the duration of anesthesia, analgesia and ocular akinesia of clonidine added to lidocaine in sub-Tenon’s anesthesia in patients undergoing cataract surgery. Methods Forty patients were prospectively enrolled. They were randomized to two sub-Tenon’s anesthesia groups: group L (6 ml of lidocaine 2 %, 1 ml of 0.9 % saline and 25 UI/ml of hyaluronidase), and group C (6 ml lidocaine 2 %, clonidine 1 μg/kg, 1 ml of 0.9 % saline and 25 UI/ml of hyaluronidase). Duration of sensory anesthesia, ocular akinesia in all directions, akinesia of the levator palpebrae superioris and orbicularis oculi muscles, the duration of analgesia (time to the first postoperative use of analgesics), the overall use of analgesics and the presence of adverse effects were recorded . Results The duration of sensory anesthesia and akinesia of the four rectus, levator palpebrae superioris, and orbicularis oculi muscles was significantly longer in group C ( p