[The influence of RS-Timolol in comparison with R-Timolol and S-Timolol on the intraocular pressure in water-loaded rabbits].

PURPOSE: It is assumed that S-timolol can produce more severe systemic adverse reactions than R-timolol. The aim of this study was to estimate the intraocular pressure-lowering effect of RS-timolol in comparison to R-timolol and S-timolol in water-loaded rabbits. MATERIAL AND METHODS: Ocular hypertension was provoked in rabbits by orogastric water loading. Topical administration of one of three timolol solutions: 0.85%, RS-timolol, or 3% R-timolol, or 0.5% S-timolol was performed to the right eyes 40 min before starting the water loading procedure. Left eyes served as a control group. Intraocular pressure was measured before and 30, 60, 90, 120 min after the water loading. RESULTS: Intraocular pressure-lowering effect of all three timolol solutions was comparable. CONCLUSION: RS-timolol can be effective for lowering intraocular pressure in rabbits.