Topical CAI was approved for ophthalmic clinical use in 1994. One of them is commercially available Dorzolamide 2% eye drops. This group of drugs act by inhibiting the action of the enzyme CAI in the ciliary processes, thereby slowing the formation of bicarbonate ions, subsequently reducing the sodium and fluid transport. This decreases the aqueous formation and therefore reduces IOP. In our study with regular checkup of 3 months, patients on antiglaucomatous drugs showed mean IOP reduction to be always higher in topical dorzolamide group with least side effect, when compared with drugs like Brimonidine Tartarate.