Objective To evaluate effects of Coherin™ on intraocular pressure (IOP), pupil size (PS), and heart rate (HR) in glaucomatous Beagles in single-dose studies in a pilot study.
Materials and methods Intraocular pressure, PS, and HR were measured in eight glaucomatous Beagles. One randomly chosen eye received single 50 μL doses of differing concentrations of Coherin™ (treated eye) or vehicle (placebo-treated eye), and the fellow eye served as the untreated control. After the first measurements, a single dose of either Coherin™ or sterile water vehicle was instilled in the drug and placebo eyes, respectively.
Results The mean ± SEM diurnal changes in IOP after 0.005%, 0.01%, 0.2%, 0.284%, 1%, 2%, and 4% topical Coherin™ once daily were 7.6 ± 3.2 mmHg, 15.5 ± 5.3 mmHg, 11.2 ± 4.4 mmHg, 11.8 ± 4.4 mmHg, 19.1 ± 3.8 mmHg, 5.0 ± 1.8 mmHg, and 8.8 ± 2.8 mmHg, respectively. The declines in IOP were significantly different (P < 0.05) from the untreated control eyes with the 0.2% and 0.284% Coherin™-treated eyes and suggestive for 1% Coherin™ concentrations. No signs of irritation, significant PS, and HR changes were detected in the Coherin™-treated eyes.
Conclusion Of seven different concentrations, 2% and 0.248% Coherin™ produced significant declines in IOP in the glaucomatous beagle in single-dose studies when compared to both untreated control and placebo-treated eyes. One percent Coherin™ solution produced significant IOP decreases compared with the placebo-treated eye but not the untreated control eyes. No local ocular irritation, PS and HR changes were observed in Coherin™-treated eyes. This pilot study suggests that topical Coherin™ has potential as an ocular hypotensive agent.