Dorzolamide/timolol combination versus concomitant administration of brimonidine and timolol: six-month comparison of efficacy and tolerability.

Purpose: To compare the efficacy and tolerability of the 2% dorzolamide/0.5% timolol combination ophthalmic solution twice daily to the concomitant administration of 0.2% brimonidine ophthalmic solution twice daily and 0.