Studies have pointed out racial differences in the outcome of conventional filtration surgery. Glaucoma drainage implants have been found to do well in Asian eyes but no randomized controlled trial is available to support this claim. Objectives: It is the aim of this study to compare the effectiveness and safety of combined phacoemulsification, posterior chamber intraocular lens implantation , trabeculectomy (phacotrabeculectomy) versus phacoemulsification, intraocular lens implantation and glaucoma drainage device(phacotube) in the early and intermediate control of intraocular pressure(IOP) in patients with primary open angle and angle closure glaucoma. The secondary objective is to look into the post-operative complications encountered in phacotrabeculectomy and phacotube including the additional interventions (laser suture lysis, bleb needling, antimetabolite injections, etc.) applied in both procedures being studied Study Design. Randomized controlled trial. Methods. A total of 50 Asian subjects, 21 years old and above diagnosed with primary open/angle closure glaucoma, inadequately controlled by laser and medical treatment, with significant cataract and no previous eye surgery will be randomized to two types of combined procedures, phacotrabeculectomy and phacotube. Primary outcome measure is intraocular pressure and secondary outcome measures will be visual acuity, anterior chamber depth, visual field stability or progression, glaucoma medication requirement, operative and post-operative complications and additional, secondary interventions(e.g. laser suture lysis, bleb needling, 5-FU injections, anterior chamber reformation). All subjects will be followed up for a period of 1 year.This trial may define the role of GDI as a primary surgical option for Asian patients and the first randomized clinical trial in Asia to compare two combined procedures for glaucoma and cataract namely phacotrabeculectomy and phaco-glaucoma drainage implant surgery.﷡