Purchase this article with an account.
Corbin Telford, Brian C Gilger, Jacklyn H Salmon; Synergistic Effect of Once Daily Topical 0.03% Bimatoprost and 0.5% Timolol Maleate on Intraocular Pressure Reduction in Normal Beagles. Invest. Ophthalmol. Vis. Sci. 2014;55(13):544.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Glaucoma is a common cause of vision loss in humans and dogs. Medical therapy is the mainstay of treatment, however, optimization of therapeutic regimens is needed. The purpose of this study was to compare the efficacy of topical 0.03% bimatoprost and 0.5% timolol as monotherapies and in combination to lower intraocular pressure (IOP) in normal dogs.
Untreated control IOPs were measured (via Tonovet® tonometer) in nine normotensive, adult, male laboratory beagles at 0, 2, 4, 8 and 24-hours post-administration daily for three days (short term; n=5) and once daily on days 3, 7, 10, and 14 of the treatment period (long term; n=4). The IOP schedule was repeated after a single daily dose (short term) or twice daily dose (long term) of 0.5% timolol, and a single daily dose of 0.03% bimatoprost or both medications (BT - separated by 5 mins.) for three days (short term) or fourteen days (long term), consecutively.
In the short-term study, IOP of eyes treated with timolol was not significantly lower than baseline at any time point. In eyes treated with bimatoprost only, IOP was significantly reduced compared to baseline by 4 hours on day 2 (P=0.0404), while eyes treated with BT had significantly lower IOP than baseline by 8 hours on day 1 (P=0.0161). In the long-term study, the mean IOP of eyes treated with bimatoprost (14.0 ± 1.77 mmHg) was significantly lower than the untreated control (18.75 ± 2.85 mmHg; P=.0006). However, eyes treated with BT had mean IOP (11.56 ± 1.83 mmHg) that was significantly lower than untreated eyes (P<.0001) and eyes treated twice daily with timolol (P=.0069).
Once-daily bimatoprost-timolol combination therapy resulted in a more rapid reduction of IOP compared to bimatoprost monotherapy. Additionally, overall mean IOP of eyes treated with BT was significantly lower than IOP in eyes treated with timolol in normotensive beagles. This synergistic IOP-lowering effect of timolol and bimatoprost supports further clinical evaluation of this combination in glaucomatous patients.
This PDF is available to Subscribers Only