Effect of dexmedetomidine on intraocular pressure as an additive in peribulbar block during glaucoma surgery

Purpose: The purpose of this study is to assess the effect of dexmedetomidine on intraocular pressure (IOP) as an additive in peribulbar injections in glaucoma surgeries. Methods: A prospective, randomized, double-blind, parallel assignment interventional study was conducted for patients undergoing glaucoma surgeries at a tertiary eye care hospital in North India. Patients were randomized to two groups, Dexmed group and Placebo group. In the Dexmed group, dexmedetomidine (0.4 μg/kg body weight) was given as an additive along with peribulbar block. The primary outcome was change in IOP pre- and postperibulbar injections (IOP before the block, and after 5 and 15 min of the block). Secondary outcome measures were onset of block, adverse effects (bradycardia, hypotension, respiratory depression, and level 4 sedation), and surgeon satisfaction. Results: A total of 104 patients were randomized, 52 each in the Dexmed group and Placebo group. The percentage decrease in IOP was significantly more in the Dexmed group than in the Placebo group both at 5 and 15 min' post block (P < 0.05). At 5 min, the mean percent decrease in IOP in Dexmed group was -10.48, whereas it was 2.85 in the Placebo group. At 15 min, the mean percent decrease in IOP was -22.59 and -9.42 in the Dexmed and Placebo group, respectively. There was no significant difference between the two groups in the onset of block and adverse effects. Surgeon satisfaction was significantly greater in the Dexmed group than the Placebo group (P < 0.05). Conclusion: Dexmedetomidine lowers IOP significantly in patients undergoing glaucoma surgeries with safe hemodynamic changes and sedative effect.