• Eighteen patients with glaucoma with a mean intraocular pressure (IOP) ± SD of 28.7 ± 5.5 mm Hg who were receiving maximum-tolerated antiglaucoma therapy were given 0.5% timolol maleate or a placebo twice daily to one eye in a double-masked cross-over fashion in addition to their usual antiglaucoma drugs. After one week of timolol therapy, the mean IOP was significantly lower (23.1 ± 4.1 mm Hg) than after one week of placebo administration (26.4 ± 7.8 mm Hg; P < .025, paired t test). Five patients had decreases in IOP >4 mm Hg, while six patients reached IOPs < 21 mm Hg while receiving timolol therapy. No adverse reactions to timolol were noted. Timolol had an additional IOP-lowering effect in some patients receiving maximum-tolerated medical therapy.
Zimmerman TJ, Gillespie JE, Kass MA, Yablonski ME, Becker B. Timolol Plus Maximum-Tolerated Antiglaucoma Therapy. Arch Ophthalmol. 1979;97(2):278-279. doi:10.1001/archopht.1979.01020010130005