Effects of topical 0.5% levobunolol alone or in association with 2% dorzolamide compared with a fixed combination of 0.5% timolol and 2% dorzolamide on intraocular pressure and heart rate in dogs without glaucoma.

The goal of glaucoma management is to reduce intraocular pressure (IOP) and maintain it at a level compatible with the health of the optic nerve. New therapies are constantly being sought. Topical instillation of levobunolol 0.5%, alone or with dorzolamide 2%, has a hypotensive effect on the IOP in healthy dogs, and levobunolol combined with dorzolamide produces a stronger hypotensive effect than the combination of timolol and dorzolamide. All animals tolerate these topical medications well with no signs of discomfort, and no ocular side effects have been observed. Levobunolol, alone or in combination with dorzolamide, induces bradycardia, as does timolol with dorzolamide.