Efficacy of perioperative 2% dorzolamide ophthalmic solution for reduction of postoperative ocular hypertension in dogs following routine phacoemulsification surgery: A prospective clinical trial.

Abstract

OBJECTIVE: To evaluate the efficacy of 2% dorzolamide ophthalmic solution for reduction of postoperative ocular hypertension (POH) following routine phacoemulsification surgery in dogs. ANIMALS STUDIED: Thirty one dogs (53 eyes) with naturally occurring cataracts undergoing routine phacoemulsification surgery. PROCEDURE(S): A prospective, double-masked, randomized, placebo-controlled study design was utilized. Dogs received 2% dorzolamide ophthalmic solution or saline 1&#x2009;h prior to surgery then three times daily for 21&#x2009;days postoperatively in the operated eye(s). Intraocular pressure (IOP) was recorded 1&#x2009;h prior to surgery and 3&#x2009;h, 7&#x2009;h, 22&#x2009;h, 1&#x2009;week and 3&#x2009;weeks postoperatively. Statistical analyses were performed using chi-squared and Mann-Whitney U test with a significance level of p&#x2009;<&#x2009;.05. RESULTS: Postoperative ocular hypertension (IOP&#x2009;&#x2265;25&#x2009;mmHg, <24&#x2009;h after surgery) occurred in 28/53 (52.8%) eyes. There was significant reduction in the incidence of POH for eyes receiving dorzolamide (10/26 (38.4%) eyes) versus eyes receiving placebo (18/27 (66.7%) eyes) (p&#x2009;=&#x2009;.0384). Animals were followed for a median of 163&#x2009;days after surgery. Thirty-seven (37/53 (69.8%)) eyes were visual at final examination and 3/53 (5.7%) globes were enucleated postoperatively. At last follow-up, there was no difference in visual status (p&#x2009;=&#x2009;.9280), need for topical IOP lowering medication (p&#x2009;=&#x2009;.8319) or incidence of glaucoma (p&#x2009;=&#x2009;.5880) based on treatment group. CONCLUSIONS: Perioperative administration of topical 2% dorzolamide reduced the incidence of POH after phacoemulsification in the dogs studied. However, this was not associated with differences in visual outcome, incidence of glaucoma or need for IOP-lowering medications.