Equine glaucoma: Where are we now?

Effects of 0.0015% preservative-free tafluprost on the equine eye

OBJECTIVE

The purpose of this study was to determine the effects and potential side effects of topical preservative-free (PF) tafluprost 0.0015% in ophthalmologically normal horses.

ANIMALS

Five adult grade horses.

PROCEDURES

One of the eyes of each horse was randomly chosen as the "treatment" eye, and consequently, the contralateral eye served as the "control." A single dose of PF tafluprost 0.0015% (0.2 mL) was instilled in the treated eye of each horse. Intraocular pressure (IOP), Schirmer's tear test (STT) levels of each eye, and an ophthalmic examination were performed at T0 (baseline), T30, T120, T24 h, and T48 h.

RESULTS

The mean IOP values of the treated eyes at baseline (T0), T30, T120, T24 h, and T48 h were 25.4 ± 4.8 mmHg, 21.2 ± 1.92 mmHg, 15.20 ± 2.48 mmHg, 18.40 ± 1.51 mmHg, and 24.60 ± 1.94 mmHg, respectively. Significant differences were observed between the mean baseline IOP level and the T120 and T24 h time points (p = .001 and p = .009). The mean STT levels at each time point showed insignificant fluctuations during the study (p = .140). Adverse effects such as chemosis and episcleral injection were observed 30 min after the instillation of tafluprost 0.0015% (T30). Blepharospasm and conjunctival hyperemia were observed 120 min (T120) after the administration of the medication.

CONCLUSION AND CLINICAL RELEVANCE

Tafluprost 0.0015% showed potential in reducing IOP, but due to its local side effects, it is not a good candidate for management of glaucoma in horses. Tafluprost did not notably affect STT.

Ophthalmologic Disorders in Aged Horses

Ocular abnormalities are a common finding in aged horses. Although these seldom cause overt visual deficits detected by their owners, they can be a source of chronic or acute discomfort so early detection, and treatment when available, is essential. Some of these abnormalities are specific to old horses, whereas others are a result of ongoing disease or inflammation that started earlier in life but that becomes more evident when the damage sustained to the eye is advanced. If vision is significantly affected, consideration of human safety and animal welfare is paramount.