Effects of 0.024% latanoprostene bunod on intraocular pressure and pupil diameter in normal cats and cats with congenital glaucoma.

Objective: To evaluate the effects of latanoprostene bunod on intraocular pressure (IOP) and pupil diameter (PD) in normal cats and cats with feline congenital glaucoma (FCG).

Animals studied: Five normal and 5 FCG cats.

Procedures: This masked, controlled crossover study comprised a 1-day Pre-treatment phase followed by two 10-day Treatment phases, each followed by a 10-day Recovery phase. During treatment, all cats received twice daily 0.005% latanoprost (LAT) or 0.024% latanoprostene bunod (LBN) in a randomized eye. Following Recovery, the same eye was treated with the opposite drug. Contralateral eyes served as saline-treated controls. Intraocular pressure and PD measurements were performed three times daily during all study phases. Data were analyzed via constrained longitudinal data analysis models.

Results: Neither drug significantly reduced IOP in normal cats. In FCG cats, statistically significant reductions in mean (95% CI) IOP were observed relative to controls 4 h after LAT and LBN treatment (-5.5 mmHg [-8.4, -2.5], p < .001, -7.2 mmHg [-10.2, -4.3], p < .001, respectively). These differences represented 28.4% and 37.9% IOP reductions, respectively. Mean IOP reduction after 4 h was significantly greater with LBN treatment compared to LAT (-1.8 mmHg [-3.2, -0.4], p = .012). However, these IOP reductions were not considered clinically significant. Both drugs similarly reduced PD in normal and FCG cats.

Conclusions: Transient IOP reduction was observed after topical administration of LAT and LBN in FCG cats; and mean IOP difference was statistically significantly greater in LBN-treated eyes. However, the apparent enhanced hypotensive effect of LBN is not clinically significant.