The effects of single-dose administration of two topical antiglaucoma medications, 0.005% latanoprost and 0.125% demecarium bromide, on intraocular pressure and iridocorneal angle parameters in nonglaucomatous companion rabbits

Abstract

Glaucoma is a blinding, painful disease in mammals, including rabbits. This study aimed to determine effects on intraocular pressure (IOP) and iridocorneal angle (ICA) morphology of two antiglaucoma therapies, 0.005% latanoprost (latanoprost) and 0.125% demecarium bromide (demecarium) in companion rabbits. Twenty healthy rabbits of varying breeds and ages were used. All animals received a complete ophthalmic examination including rebound tonometry and gonioscopy, and ICA imaging using spectral domain optical coherence tomography (SD-OCT), high-resolution ultrasound, and Scheimpflug imaging (Pentacam® HR). Angle opening distance (AOD) and angle recess area (ARA) were measured. Demecarium was applied to one eye and latanoprost to the contralateral eye. Each eye was re-evaluated 1 hour later with tonometry, imaging, and gonioscopy. Pre- and post-treatment groups were compared with a Wilcoxon signed-ranked test for IOP, ARA, AOD, and gonioscopy score. Estimates of treatment effects were performed to identify clinically significant differences of demecarium and latanoprost on ICA parameters. Latanoprost caused a significant increase in gonioscopy score, ARA, and AOD when measured via SD-OCT whereas demecarium caused a significant decrease in gonioscopy score, ARA, and AOD when measured via SD-OCT and Pentacam® HR. Demecarium significantly increased IOP whereas latanoprost had no effect on IOP. Based on the increased ICA parameters in normal companion rabbits, latanoprost can be considered as a glaucoma medication in rabbits. Demecarium increased IOP and decreased ICA parameters; therefore, its use in rabbits is not recommended.