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Abstract #6204 Published in IGR 2-2
Effect of calcium channel blockers alone and in combination with antiglaucoma medications on intraocular pressure in the primate eye
Siegner SW; Netland PA; Schroeder A; Erickson KAJournal of Glaucoma 2000; 9: 334-339
PURPOSE: To determine the effect of representative members from six classes of calcium channel blockers on intraocular pressure (IOP) in the primate eye. Other antiglaucoma medications were administered with verapamil to determine their combined effect on IOP. METHODS: Six healthy cynomolgus monkeys were anesthetized, and baseline IOP measured. Drug-containing solution (50 μl) was instilled in one eye and IOP measured in both eyes 90 minutes later. RESULTS: All classes of calcium channel blockers significantly lowered IOP in the treated eye. The percent reduction in IOP compared with the baseline pressure was 10% for verapamil (p < 0.002), 18% for nifedipine (p < 0.001), 15% for diltiazem (p < 0.001), 17% for flunarizine (p < 0.001), 19% for prenylamine (p < 0.001), and 6% for perhexiline (p < 0.01). In the fellow eye, a significant reduction in IOP was also seen with all calcium channel blockers, except perhexiline, which suggested a crossover effect. In contrast, neither vehicle-treated nor contralateral eyes showed a lowering of IOP when tested under the same conditions. In the treated eye, 0.5% timolol (p < 0.01) and 0.05% clonidine (p < 0.02) combined with 0.25% verapamil each appeared to produce an additive effect, with a significantly greater pressure-lowering effect than either agent alone. In addition, 0.005% pilocarpine (p < 0.001) and 0.00125% demecarium (p < 0.01) combined with 0.25% verapamil each appeared to produce a synergistic effect, with a significantly greater reduction in IOP than both agents combined. CONCLUSIONS: Topical calcium channel blockers and combinations of verapamil with antiglaucoma medications may provide a useful alternative for reducing IOP in patients with ocular hypertension or primary open-angle glaucoma.
Dr. K. Erickson, Department of Ophthalmology, Boston University School of Medicine, 715 Albany Street, L-914, Boston, MA 02118, USA
Classification:
11.7 Treatment of bloodflow (Part of: 11 Medical treatment)