DE-111 ophthalmic solution will be evaluated for superiority in comparison with Tafluprost 0.0015% ophthalmic solution, or for non-inferiority in comparison with Tafluprost 0.0015% and Timolol ophthalmic solution 0.5% used concomitantly, in IOP(intraocular pressure) -lowering effect in primary open-angle glaucoma or ocular hypertension patients, in a multicenter, randomized, double-masked, parallel-group comparison study. Safety will be compared and evaluated as well.