Comparative effects of latanoprost and latanoprostene bunod on intraocular pressure and pupil size in ophthalmologically normal Beagle dogs.

Abstract

To compare effects of latanoprost, a topical prostaglandin analogue (PGA) commonly used to treat glaucoma and lens instability in dogs, and latanoprostene bunod, a novel PGA with a nitric oxide-donating moiety, on intraocular pressure (IOP) and pupil diameter (PD). Ten ophthalmologically normal Beagle dogs. Dogs were treated twice a day for 5days in a randomly selected eye with either latanoprost or latanoprostene bunod. After a 6-week washout period, dogs were treated with the opposite drug. IOP and PD were measured at treatment times, at midday on days 1 and 5, and for 6days post-treatment. Both drugs significantly decreased IOP and PD. At midday on day 5 of treatment, mean IOP in eyes treated with latanoprost was 4.5mmHg lower than the fellow eye and 3.0mmHg lower than the same eye at baseline, while mean IOP in eyes treated with latanoprostene bunod was 5.5mmHg lower than the fellow eye and 3.6mmHg lower than baseline. Mean PD was 0.94mm in eyes treated with latanoprost and 0.76mmHg in eyes treated with latanoprostene bunod. There was no significant difference between the two drugs for either parameter at that time point (p=.372 and .619, respectively, for IOP relative to control and to baseline; p=.076 for PD) or when analyzed longitudinally. Significant diurnal variation in PD was noted and may have implications for treatment of lens' instability. Latanoprost and latanoprostene bunod produce similar IOP reduction and miosis in normal canine eyes.