in a 4-year , double-masked , parallel , multicenter study comparing the efficacy and safety of levobunolol and timolol , 391 patients with open-angle glaucoma or ocular hypertension were randomly assigned to receive masked 0.5 % or 1 % levobunolol , or 0.5 % timolol , twice daily .
C0017612
open-angle glaucoma
C0040233
timolol