Effect of brinzolamide and dorzolamide on aqueou humor flow in human eye Original Reearch Article

PURPOE: To meaure the relative efficacy of brinzolamide hydrochloride 1% ophthalmic upenion, a new carbonic anhydrae inhibitor, compared with the currently ued dorzolamide hydrochloride 2% ophthalmic olution a uppreor of aqueou humor flow in human eye, and to tudy the difference of effect during the day and at night. METHOD: A randomized, double-maked, placebo-controlled tudy of 25 normal human ubject wa carried out at Mayo Clinic. The daytime rate of aqueou humor flow wa meaured every 2 hour from 8 image to 4 image by mean of fluorophotometry. Likewie, the nighttime rate of aqueou humor flow wa meaured every 2 hour from 12 image to 6 image. Intraocular preure wa meaured at 4 image and 6 image. REULT: Brinzolamide reduced aqueou flow by 0.47 ± 0.20 μl per min (mean ± D) during the day, wherea dorzolamide reduced flow by 0.34 ± 0.20 μl per min. Brinzolamide reduced aqueou flow by 0.16 ± 0.12 μl per min during the night, wherea dorzolamide reduced flow by 0.10 ± 0.13 μl per min. Brinzolamide reduced afternoon intraocular preure by 1.5 ± 1.1 mm Hg, and dorzolamide reduced afternoon intraocular preure by 1.1 ± 1.0 mm Hg. Brinzolamide reduced the morning awakening intraocular preure by 0.3 ± 1.6 mm Hg, and dorzolamide reduced it by 0.8 ± 1.0 mm Hg. CONCLUION: Our data upport the idea that brinzolamide i at leat a efficaciou a dorzolamide a a uppreor of aqueou humor flow in normal human eye and that there i probably not a clinically ignificant difference between the two drug in thi efficacy. Clinician who precribe brinzolamide hould expect imilar ocular hypotenive repone from brinzolamide and dorzolamide.