PURPOSE: To study the influence of the calcium channel blocker verapamil on the development of glaucoma in the adrenalin-induced experimental model of glaucoma. METHODS: In the experimental model, glaucoma was induced in albino rabbits by repeated injections of small doses of adrenalin. The criteria for experimental glaucoma were (1) increased IOP, (2) decreased outflow and (3) decreased blood supply to the eye. One group with advanced glaucoma served as a control. In the other 3 groups, instillations of 0.25% verapamil were applied at different stages of the glaucomatous process. RESULTS: Verapamil blocked the development of experimental glaucoma when applied concurrently with the adrenalin injections, and instillations at the initial or advanced stages of the disease stabilized the progression of glaucoma. CONCLUSION: We demonstrate that mechanisms involving adrenalin and calcium are involved in glaucoma and that the use of calcium channel blockers is most effective in the early stages of the glaucomatous process.