Previous study showed that when aqueous comes into contact with conjunctiva and Tenon's capsule,an inflammatory reaction occurs.Factors such as prostaglandins, eicosanoids, tissue growth factor beta (TGF β)has been shown to occur in glaucomatous aqueous. These mediators induce an inflammatory reaction, and if excessive, will result in fibrosis and poor functioning of the bleb. High pressure within the bleb also results in the secretion of TGF β by the bleb lining. It may result in inflammation of the bleb wall and subsequent fibrosis and poor bleb function. The investigators supposed that with early use of aqueous suppressant medication after AGV implantation, the concentration of inflammatory mediators decreased in subconjunctival space and may lead to better IOP control after shunt surgery.