Randomized controlled trial to evaluate intraocular pressure following sub-Tenon's local anesthesia for cataract...

To evaluate effect on intraocular pressure (IOP) during sub-Tenon's local anesthesia (LA) during cataract surgery with 4 ml of anesthetic injected without and with addition of hyluronidase to anesthetic solution.

This randomized controlled study included 65 eyes of 65 patients undergoing phacoemulsification and lens implant for cataract. The patients were randomized to a standardized procedure of administration of 4 ml of sub-Tenon's LA without and with addition of 15 IU/ml hylaluronidase to 2% lidocaine (control group and intervention group respectively). IOP measurements were carried out immediately prior to and at 2, 5, and 10 and 15 min after sub-Tenon's injection using a hand held tonometer (Tonopen).

All patients achieved satisfactory akinesia and complete analgesia during surgery. The mean age of patients in control group was 59.56 ± 14.3 years, and 61.77 ± 11.91 years in intervention group (P = 0.507). The mean preinjection and 15 min IOP was 19.16 ± 4.39 and 20.21 ± 5.49 mm Hg, respectively in control group (P = 0.220); and 19.81 ± 3.8 and 19.68 ± 5.19 mmHg respectively in intervention group (P = 0.911). No statistical difference from baseline was detected between preinjection and at 2, 5, 10, and 15 min after injection in control (P = 0.124, 0.310, 0.804, 0.220, respectively) and intervention group (P = 0.367, 0.879, 0.765, 0.911 respectively).

No significant rise in IOP occurs following injection of sub-Tenon's LA, when up to 4 ml of anesthetic is injected. The addition of hyaluronidase to 2% lignocaine has no beneficial lowering effect on IOP in sub-Tenon's LA. Hence, the practice of addition of this agent may not be necessary during cataract surgery.