Comparison of Ahmed Glaucoma Implant (AGI) against trabeculectomy with mitomycin C in patients with uncontrolled open angle glaucoma

The objective of the Asia Primary Tube versus Trab (TVT) study is to compare the efficacy and safety of placement of an Ahmed Glaucoma Implant (AGI) (New World Medical Inc., Rancho Cucamonga, CA, USA) against trabeculectomy with mitomycin C in patients with uncontrolled glaucoma, who may or may not have had previous clear corneal cataract surgery with intraocular lens implantation, over 5 years. Outcome discrimination between the two treatment groups will be made using following parameters:

1. Intraocular pressure
2. Need for supplemental medical therapy
3. Incidence of short and long term surgical complications and need for re-operation.
4. Visual function (Visual acuity and Visual field)

Hypothesis: Glaucoma drainage implants have better surgical outcomes in terms of IOP lowering efficacy compared to trabeculectomy with mitomycin-C over 5 years in Asian patients with medically uncontrolled glaucoma.

Inclusion Criteria:

1. Open angle glaucoma including primary open angle glaucoma, pseudoexfoliative or pigmentary glaucoma.
2. IOP > 18 mm Hg on 2 or more medications on at least 2 visits
3. Informed consent given and consent form signed.

Exclusion Criteria:

1. Unwilling or unable to give consent, unwilling to accept randomisation, or unable to return for scheduled protocol visits.
2. Pregnant or nursing women
3. No light perception vision
4. Previous incisional intraocular surgery, other than uncomplicated clear corneal cataract surgery
5. Previous ocular laser in study eye (keratorefractive surgery and cyclodestructive procedure), except for laser trabeculoplasty procedures (Argon Laser and Selective Laser Trabeculoplasty)
6. Iris neovascularisation or proliferative retinopathy
7. Primary angle closure or primary angle closure glaucoma
8. Iridocorneal endothelial syndrome or anterior segment dysgenesis
9. Epithelial or fibrous downgrowth
10. Aphakia
11. Chronic or recurrent uveitis
12. Severe posterior blepharitis
13. Unwilling to discontinue contact lens use after surgery
14. Glaucoma secondary to penetrating keratoplasty, trauma, steroids, retinal disease/surgery or neovascular disease
15. Conjunctival scarring from prior ocular surgery, trauma or cicatrizing disease precluding a superior trabeculectomy
16. Need for glaucoma surgery combined with other ocular procedures (i.e. cataract surgery, penetrating keratoplasty, or retinal surgery) or anticipated need for urgent additional ocular surgery
17. Advanced glaucoma with MD <-20dB