Comparison of the inhibitional effects of MK 507 and Timolol on the aqueous humor production by returning time to baseline intrliocular pressure

ABSTRACT

There has been need of carbonic anhydrase inhibitor eyedrops which has no systemic side effects, but it has problem in transcorneal coefficiency. Recently developed MK 507 has modified the lipid permeability. We researched on the efficiencies of MK 507 and Timolol by measuring the returning time to baseline intraocular pressure using Honan balloon. Forty-five healthy volunteers were divided into 3 groups. Group 1 was administered placebo. Group 2 was administered 0.25% timolol, and group 3 was administered 2% MK 507. The IOP was measured with Goldmann applanation tonometer at 2 hours before Honan balloon pressure (30mmHg, 30 minutes) and every 5 minutes after the pressure was released until IOP returned to baseline IOP. The returing time to baseline IOP was 19.17 +/- 2.31 minutes in group 1, 37.17 +/- 5.03 minutes in group 2, 31.67 +/- 2.40 minutes in group 3 (P- value 0.0001) (AVOVA). The result of this study suggests that measuring the returing time to baseline IOP using Honan balloon may be useful in determining the effects of MK 507 and Timolol, adrenergic beta-blocker.