Treatment of canine postoperative ocular hypertension with combined latanoprost 0.005% and atropine 1% ophthalmic solutions

Objective To compare the effects of topical 0.005% latanoprost (L) vs combined 0.005% latanoprost and 1% atropine (LA) on control of postoperative ocular hypertension (POH), development of posterior synechiae formation, pupil size, and blindness after phacoemulsification surgery in dogs. Animal studied Dogs with postoperative ocular hypertension were included in the study: L-group, latanoprost (eight dogs, 14 eyes) and LA-group, latanoprost and atropine (nine dogs, 15 eyes). Procedures Complete ophthalmic examinations including tonometry were performed at 1, 7, and 21 days following phacoemulsification. Results No significant differences were found between the measured intraocular pressure (IOP) at days 1 and 7 postphacoemulsification surgery in the L-group and the LA-group (P = 0.26 [14.12 +/- 1.76 mmHg vs 16.96 +/- 1.68 mmHg] and P = 0.71 [15.45 +/- 1.43 mmHg vs 16.20 +/- 1.36 mmHg], respectively). No significant differences were found between pupil sizes at day 7 for the two groups (P = 0.25 [13.83% vs 24.77%]). No significant differences were found between odds of posterior synechiae formation at day 21 (P = 0.92) with a probability +/- SE for L-group vs LA-group at 0.27 +/- 0.14 vs 0.25 +/- 0.13. No significant differences were found in odds of postoperative blindness between groups (P = 0.58) with a probability +/- SE of 0.21 +/- 0.11 vs 0.13 +/- 0.09, respectively for L and LA. Conclusions Combined topical latanoprost and atropine in dogs maintains normal postoperative IOPs but does not seem to cause increased mydriasis compared to latanoprost alone.