The most common surgical technique for controlling the intraocular pressure in glaucoma patients is trabeculectomy.In this surgery, internal cavity of the eye is connected by a fistula like openings to subconjunctival space. The main cause of failure in trabeculectomy is excessive postoperative conjunctival scarring at the site of fistula, which is related to severity of conjunctival vascularization, tortuousity of vessel, and fibroblast migration and proliferation. At the time of surgery most surgeons use mitomycin C, which is an antimitotic and antifibrotic agent, to improve the results of the procedure. Although this agent is very effective, but is not without complication. The most significant and sight threatening complications are low intraocular pressure and endophthalmitis. Therefore investigations are going on to find a much safer and effective agents. Bevacizumab is a monoclonal antibody against vascular endothelial factor (VEGF). VEGF is an important vasculogenic and fibrogenic factor with a prominent role in wound healing.Bevacizumab is widely used in ophthalmology and has a promising effect in treatment of neovascularization in conjunctiva, cornea and retina. There are limited animal and human case series regarding the effect of this agent in trabeculectomy. In this study the investigators are trying, in addition to evaluating the efficacy and safety of this agent in result of trabeculectomy, compare this agent with mitomycin C.
