In the present invention, an efficacious therapy for glaucoma is discovered and provided as a medicine. A combination of the present invention, in particular a combination of 2-propanyl 4-{(3S, 5aR, 6R, 7R, 8aS)-6-[(1E, 3R)-4-(2, 5-difluoro-phenoxy)-3-hydroxy-1-butene-1-yl]-7-hydroxy-octahydro-2H-cyclopenta [b] oxepine-3-yl}butanoate and a β blocker is useful as a therapeutic agent for glaucoma since intraocular tension depressive action is increased and an effect of maintaining the intraocular tension depressive action is provided, compared to single-agent administration of each medical agent.
