<prompt> Drug used in refractory glaucoma ?Systemic glucocoicoidACE inhibitorAlpha agonistBeta blocker  <response>: Ans. is c i.e., Alpha agonist Drug of choice for initial treatment of open angle glaucoma is either an topical b-blocker or topical PG analogue latanoprost It target IOT is not attained either change over to alternative drug or use both concurrently. In refractory cases who are not responding to 3-blockers and PG analogues, topical a-agonist Brimozidine or topical carbonic anhydrase inhibitor dorazolamide is added. It target IOT is still not attained, laser trabeculoplasty is considered. 