Both brimonidine and timolol are effective treatments in slowing visual field deterioration and may also improve mean deviation slopes in open-angle glaucoma patients, a study in the Journal of Glaucoma reports.

Japanese researchers compared the results of 0.1% brimonidine and 0.5% timolol on the progression of visual field defects in 56 glaucoma patients who were treated with at least one prostaglandin analog.

The patients’ baseline mean deviation slopes were less than -0.5dB/year based on at least five visual field tests within three years. Eligible eyes were randomly assigned to the brimonidine group (26 eyes) or the timolol group (30 eyes), and treatments were administered without a wash-out period. Clinical exams were performed every four months for two years.

The study reported the dropout rates of the brimonidine and timolol treatment groups were 27.8% and 6.3%, respectively.

Researchers found no significant differences in baseline intraocular pressure (IOP) or mean deviation slopes between the brimonidine and timolol groups (12.7mm Hg and 12.9mm Hg, and -1.22dB/y and -1.08dB/y, respectively). Researchers also reported IOP decreased significantly in the brimonidine group at four, eight, 12 and 16 months, and in the timolol group at four months—without significant differences between the drugs.

Also of note: mean deviation slopes significantly improved in both groups (brimonidine: -0.38dB/y; timolol: -0.52dB/y), and investigators reported no significant difference between the groups’ primary endpoint.