xen-45 gel stent versus trabeculectomy in glaucoma: gold-standard pathway study (gps)

Conditions: Glaucoma

Summary: the purpose of this study is to compare the safety and efficacy of xen-45 to trabeculectomy in participants with open angle glaucoma refractory to topical medical therapy.

this is a multi-center, randomized, parallel group, prospective, open-label clinical trial to evaluate the ability of xen-45 to reduce intraocular pressure (iop) and reduce the amount of topical iop-lowering medications in participants poorly controlled on topical therapy. the planned study duration is 12 months. participants were to be screened for enrollment and eligible candidates were to be approached to ascertain interest in study participation. eligible participants were to be randomized 2:1; resulting in approximately 95 eyes implanted with xen-45 and 44 eyes received trabeculetomy by study end.

Eligibility criteria:
inclusion criteria: * open-angle glaucoma where the intraocular pressure (iop) is not controlled when using topical iop-lowering glaucoma medication * best-corrected baseline snellen visual acuity of 20/100 or better * visual field mean deviation no worse than -18.0 decibels (db) * medicated iop ≥15 millimeter of mercury (mm hg) and ≤44 mm hg * participants not anticipated to require any ocular surgery (e.g., cataract surgery) in either eye up to 3 months from the time of inclusion * area of healthy, free, and mobile conjunctiva in the target area (superior bulbar conjunctiva) * trabecular meshwork must be visible (with shaffer angle grade ≥2 in the target quadrant) * failed ab-interno canal or suprachoroidal micro invasive glaucoma surgery (migs) procedures (such as i-stent, gonioscopy-assisted transluminal trabeculotomy \[gatt\], ab-interno canaloplasty \[abic\], kahook dual blade goniotomy, etc.) are allowed ≥3 months before enrollment. cypass® micro-stents were not allowed. exclusion criteria: * participant has active neovascular, uveitic or angle recession glaucoma or any glaucoma associated with vascular disorders * participant has had prior ab externo incisional glaucoma surgery (such as trabeculectomy, viscocanalostomy, canaloplasty, tube shunts of any type, collagen implants, etc.), conjunctival filtering surgery, transscleral cycloablative procedures (such as cyclophotocoagulation, micro pulse cyclophotocoagulation, cryotherapy, ultrasound circular cyclocoagulation \[uc3\], etc.) or prior major conjunctival surgery (i.e., scleral buckle) * clinically significant inflammation or infection within 30 days before the preoperative visit (e.g., blepharitis, conjunctivitis, severe ocular surface disease, keratitis, uveitis, herpes simplex infection) * presence of conjunctival scarring or prior conjunctival surgery or other conjunctival pathologies (e.g., pterygium) in the target area * history of corneal surgery, corneal opacities, or corneal disease * central corneal thickness ≤490 micrometer (μm) or ≥620μm * vitreous present in the anterior chamber * aphakic * participant has had prior intraocular surgery in either eye within ≤3 months before the preoperative visit (including phacoemulsification) * history of complicated cataract surgery (e.g. with visual impairment, e.g. vitreous loss, anterior chamber intraocular lens \[aciol\], perhaps sutured intraocular lens \[iol\] or scleral fixated iol, prior cystoid macular edema \[cme\], etc.) * presence of intraocular silicone oil * active diabetic retinopathy, proliferative retinopathy, choroidal neovascularization, branch retinal vein occlusion, central retinal vein occlusion, geographic atrophy, or other ophthalmic disease or disorder that could confound study results or impaired episcleral venous drainage (e.g., sturge-weber or nanophthalmos, axenfeld-reiger, iridocorneal endothelial syndrome \[ice\], etc.) * known or suspected allergy or sensitivity to drugs required for the protocol (including anesthesia), or any of the device components (e.g., bovine or porcine products, or glutaraldehyde) * pregnant or nursing women and those planning a pregnancy during the study period. * participation in another drug or device clinical trial concluding within 30 days before the preoperative visit