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Abstract #5677 Published in IGR 2-1
A comparative study of betaxolol and dorzolamide effect on ocular circulation in normal-tension glaucoma patients
Harris A; Arend O; Hak Sung Chung; Kagemann L; Cantor L; Martin BOphthalmology 2000; 107: 430-434
OBJECTIVE: To determine whether dosages of a selective beta-locking agent (betaxolol) and a topical carbonic anhydrase inhibitor (dorzolamide), sufficient to significantly lower intraocular pressure (IOP), have similar or disparate impact on the retinal and retrobulbar circulation. DESIGN: Counterbalanced crossover, with open-label use of medications. PARTICIPANTS: Nine persons with normal-tension glaucoma (NTG). INTERVENTION: After a three-week drug washout, NTG patients were studied after one month of treatment with either dorzolamide or betaxolol, with determinations of IOP and retinal and retrobulbar hemodynamics. MAIN OUTCOME MEASURES: At baseline and after treatment with each drug, retinal arteriovenous passage time was determined by scanning laser ophthalmoscopy after fluorescein dye injection, and flow velocities in the central retinal and ophthalmic arteries were measured with color Doppler ultrasonography imaging. RESULTS: Betaxolol and dorzolamide each lowered IOP significantly, with these changes apparent and maximal after two weeks (each p<0.05). In contrast, dorzolamide (but not betaxolol) accelerated arteriovenous passage of fluorescein dye in the inferior temporal quadrant of the retina (p<0.05). Neither drug affected arteriovenous passage in the superotemporal retina or any aspect of central retinal or ophthalmic artery flow velocity after either two or four weeks. CONCLUSIONS: Although both dorzolamide and betaxolol are effective ocular hypotensive agents and their topical instillation leaves retrobulbar hemodynamics unaltered, dorzolamide alone accelerates inferotemporal retinal dye transit.
Dr. A. Harris, Rotary 134, Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN 46202-5175, USA
Classification:
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)
9.2.4 Normal pressure glaucoma (Part of: 9 Clinical forms of glaucomas > 9.2 Primary open angle glaucomas)
11.3.4 Betablocker (Part of: 11 Medical treatment > 11.3 Adrenergic drugs)
11.5.2 Topical (Part of: 11 Medical treatment > 11.5 Carbonic anhydrase inhibitors)
