An agent for the prophylaxis and treatment of glaucoma, which contains a compound having a Rho kinase inhibitory activity, particularly an agent for the prophylaxis and treatment of glaucoma, which contains a compound of the formula (I) wherein each symbol is as defined in the specification, as the compound having a Rho kinase inhibitory activity, is provided. The agent for the prophylaxis and treatment of glaucoma of the present invention is a novel agent for the prophylaxis and treatment of glaucoma and has intraocular pressure lowering action, optic disc blood flow improving action and aqueous humor outflow promoting action.
