Original articleEffect of dorzolamide timolol combination versus timolol 0.5% on ocular bloodflow in patients with primary open-angle glaucoma☆
Section snippets
Methods
Fifteen patients with primary open-angle glaucoma were studied in a randomized, cross-over, double-masked design that included initial washout of medications other than timolol, maintenance treatment on timolol, and then study with either timolol or the combination of timolol and dorzolamide (Cosopt®; Merck, Inc, Whitehouse Station, New Jersey). All procedures were reviewed and approved by an institutional review board at Indiana University School of Medicine, and subjects signed informed
Results
The mean deviation of the visual field testing was unchanged by participation in the study (Table 1); the corrected pattern standard deviation was unaltered as well (Table 1). Neither timolol (control) nor timolol plus dorzolamide treatment affected visual acuity (Table 1), or altered contrast sensitivity at 3, 6, 12, or 18 cycles per degree (Table 1).
Intraocular pressure was significantly reduced by dorzolamide-timolol combination as compared with timolol alone (P < .05, Table 1). Intraocular
Discussion
Reduction of intraocular pressure remains the primary goal of glaucoma therapy. Although the β-adrenergic blockers have served as standard ocular hypotensive agents for many years, these medicines can provoke cardiovascular, pulmonary, central nervous system, and endocrine side effects.7 Dorzolamide is a safe, effective, and easily tolerated topical carbonic anhydrase inhibitor that retains the ocular hypotensive actions of systemic carbonic anhydrase inhibition without the accompanying side
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This work was supported in part by Grant EY10801 (AH) from the National Institutes of Health, Bethesda, Maryland, an unrestricted grant from Research to Prevent Blindness, New York, New York, and an unrestricted grant from Merck, Inc. Study medications were provided by Merck, Inc. A.H. is a recipient of the William and Mary Greve Award from Research to Prevent Blindness.