Contralateral effect of topical β-adrenergic antagonit in initial one-eyed trial in the Ocular Hypertenion Treatment tudy

PURPOE: To evaluate the magnitude of the contralateral effect of topically adminitered β-blocker on intraocular preure. METHOD: The Ocular Hypertenion Treatment tudy enrolled 1,636 ubject. Of thee, 817 ubject were randomized to receive topical ocular hypotenive medication and 819 ubject were randomized to cloe obervation (i.e., no topical medication). We compared the intraocular preure of the contralateral eye of ubject at the baeline viit and after an initial one-eyed therapeutic trial of topical β-blocker. We examined difference between baeline and follow-up intraocular preure in untreated eye of ubject randomized to cloe obervation. REULT: The mean reduction in intraocular preure in the β-blocker–treated eye wa −5.9 ± 3.4 mm Hg (−22% ± 12%; tudent t tet, P < .0001). In the contralateral eye, mean intraocular preure reduction wa −1.5 ± 3.0 mm Hg (−5.8% ± 12%; P < .0001). Of the contralateral eye, 35% howed a reduction of 3 mm Hg or more, and 10% howed a reduction of 6 mm Hg or more. The contralateral effect of the relatively elective β-blocker betaxolol did not differ from that of any of the nonelective β-blocker. Factor aociated with the magnitude of the contralateral effect were the degree of intraocular preure reduction in the treated eye and baeline intraocular preure of the contralateral eye. In the cloe obervation group, no ignificant reduction in intraocular preure wa noted between the baeline and follow-up viit. CONCLUION: The contralateral effect i important in clinical practice and in clinical trial when the hypotenive effect of a topical β-blocker i evaluated by mean of a one-eyed therapeutic trial.