To the Editor.
—The article comparing efficacy and side effects of betaxolol and timolol in lowering intraocular pressures by Berry et al1 in the January Archives raises several interesting points.The comparison between the two drugs was not conducted on a random sample of eyes with elevated IOP. The subjects tested were patients from glaucoma clinics, and almost all of them were already receiving timolol for elevated IOP (with or without glaucomatous disc or field changes). As the authors rightly point out, this represents a preselected population who were presumably β-blocker responders and who were not intolerant to timolol. Moreover, during the trial, a majority of the patients were receiving adjunctive therapy, mostly pilocarpine. Hence, conclusions about differences between response to betaxolol and timolol are difficult to draw. Without a placebo control, it is also difficult to determine efficacy in comparing the two β-blockers. It seems unsure that the methodology
Harrison R. Betaxolol and Timolol. Arch Ophthalmol. 1984;102(10):1424. doi:10.1001/archopht.1984.01040031154003