Effects of brimonidine timolol fixed combination therapy on anterior ocular segment configuration

Purpose To assess the effects of brimonidine and of brimonidine and timolol fixed combination (BTFC) therapy on the pupil and angle structures in both normal subjects and in open angle glaucoma patients. Methods For the first study, 60 healthy normal subjects were divided into 2 groups. In group 1, brimonidine was administered to the right eye and timolol to the left eye. In group 2, a BTFC was administered to the right eye and pilocarpine 2% to the left eye. All subjects had a full phthalmic examination including IOL master, ORB II scan and three times of Visante OCT both before and after instillation of the eyedrops. After testing, we analyzed thepupil size, anterior chamber depth and anterior chamber angle parameters including angle opening distance, rabecular-iris space area, angle recess area and trabeculariris ngle. In the second study, we evaluated the effects of BTFC therapy on the anterior chamber over time through eviewing ORB scan data of glaucoma patients who had instilled BTFC for at least 6 months (n = 126). esults Brimonidine and BTFC therapy caused miosis and widening of most of the anterior chamber angle parameters without changing the anterior chamber depth. he effects of BTFC on the angle were likely to be greater than those resulting from the use of pilocarpine. The miotic effects remained during instillation of BTFC. Conclusion Brimonidine and BTFC cause passive miosis with angle widening; these results could be applied in the treatment of various types of glaucoma.