Table 1.

Patient Eligibility Criteria in the Tube Versus Trabeculectomy (TVT) Study

Inclusion criteria	Age 18 to 85 years
	Inadequately controlled glaucoma with IOP > 18 mm Hg and < 40 mm Hg on maximum tolerated medical therapy
	Previous cataract extraction with intraocular lens implantation, trabeculectomy, or both
Exclusion criteria	Unwilling or unable to give consent, unwilling to accept randomization, or unable to return for scheduled protocol visits
	Pregnant or nursing women
	No light perception vision
	Active iris neovascularization or active proliferative retinopathy
	Iridocorneal endothelial syndrome
	Epithelial of fibrous downgrowth
	Aphakia
	Vitreous in the anterior chamber for which a vitrectomy is anticipated
	Chronic or recurrent uveitis
	Severe posterior blepharitis
	Unwilling to discontinue contact lens use after surgery
	Previous cyclodestructive procedure, scleral buckling procedure, or silicone oil present
	Conjunctival scarring precluding a trabeculectomy superiorly
	Need for glaucoma surgery combined with other ocular procedures (i.e. cataract surgery, penetrating keratoplasty, or retinal surgery) or anticipated need for additional ocular surgery