Ya-Ru Dong1,2, Shi-Wei Huang1, Ji-Zhe Cui1, Takeshi Yoshitomi2. 1. Department of Ophthalmology, the Second Hospital of Jilin University, Changchun 130041, Jilin Province, China. 2. Department of Ophthalmology, Akita University School of Medicine, Akita 010-8543, Japan.
Abstract
AIM: To investigate if significant improvement of optic disc blood flow (ODBF) occurs after instillation of brinzolamide onto rabbit eyes. METHODS: Testing of bilateral intraocular pressure (IOP) and left ODBF in 10 male rabbits took place every 3h over a 24h period. Brinzolamide (1% ophthalmic solution, two drops at 9:00 and 21:00) was administered to the left eye. ODBF, assessed using laser speckle flowgraphy, was determined as the mean blur rate (MBR). Furthermore, the effect of brinzolamide on isolated rabbit ciliary arteries using isometric tension recording system was performed. RESULTS: After brinzolamide instillation, IOP was significantly decreased in the left eye. MBR-vessel was greater at 18:00 and 21:00 (P<0.05) than in the controls. MBR-tissue and MBR-average were greater at 18:00 (P<0.05) than in the controls. For isolated arteries pre-contracted with a high-K solution, brinzolamide induced concentration-dependent relaxation, reaching 46.1%±9% (n=21) at 1 mmol/L. In Ca2+-free solutions, incubation with brinzolamide suppressed 1 µmol/L histamine-induced contractions (P<0.05). CONCLUSION: Brinzolamide decreases IOP and increases ocular blood flow. The direct vasodilatory effect of brizolamide is mediated by suppression of Ca2+ release from intracellular calcium stores.
AIM: To investigate if significant improvement of optic disc blood flow (ODBF) occurs after instillation of brinzolamide onto rabbit eyes. METHODS: Testing of bilateral intraocular pressure (IOP) and left ODBF in 10 male rabbits took place every 3h over a 24h period. Brinzolamide (1% ophthalmic solution, two drops at 9:00 and 21:00) was administered to the left eye. ODBF, assessed using laser speckle flowgraphy, was determined as the mean blur rate (MBR). Furthermore, the effect of brinzolamide on isolated rabbit ciliary arteries using isometric tension recording system was performed. RESULTS: After brinzolamide instillation, IOP was significantly decreased in the left eye. MBR-vessel was greater at 18:00 and 21:00 (P<0.05) than in the controls. MBR-tissue and MBR-average were greater at 18:00 (P<0.05) than in the controls. For isolated arteries pre-contracted with a high-K solution, brinzolamide induced concentration-dependent relaxation, reaching 46.1%±9% (n=21) at 1 mmol/L. In Ca2+-free solutions, incubation with brinzolamide suppressed 1 µmol/L histamine-induced contractions (P<0.05). CONCLUSION:Brinzolamide decreases IOP and increases ocular blood flow. The direct vasodilatory effect of brizolamide is mediated by suppression of Ca2+ release from intracellular calcium stores.
Authors: Klaudia Karola Huber-van der Velden; Anja Lux; Katja Severing; Matthias Karl Josef Klamann; Sibylle Winterhalter; Andreas Remky Journal: Curr Eye Res Date: 2012-05-29 Impact factor: 2.424
Authors: Brent Siesky; Alon Harris; Joseph Carr; Alice Verticchio Vercellin; Rehan M Hussain; Priyanka Parekh Hembree; Scott Wentz; Michael Isaacs; George Eckert; Nicholas A Moore Journal: J Glaucoma Date: 2016-09 Impact factor: 2.503
Authors: Nikolaus Luft; Piotr A Wozniak; Gerold C Aschinger; Klemens Fondi; Ahmed M Bata; René M Werkmeister; Doreen Schmidl; Katarzyna J Witkowska; Matthias Bolz; Gerhard Garhöfer; Leopold Schmetterer Journal: PLoS One Date: 2016-12-13 Impact factor: 3.240