Comparing two eye implants for lowering eye pressure in open-angle glaucoma
Compares two small eye implants in adults with open-angle glaucoma needing surgery.
Key facts
- Who runs it
- Universitaire Ziekenhuizen KU Leuven
- Where
- Lisbon, PortugalSee the siteAlso in 2 other countries, 2 sites
- Trial code
- Registry title
- Comparing XEN®-63 Gel Stent and PRESERFLO® MicroShunt
- Status
- Recruiting
- People taking part
- 166 people, planned
- Started
- 1 Jan 2026
- Expected to end
- Jan 2028
- Type of study
- Interventional, 2 groupsOne group gets an existing treatment, for comparison.
- Treatments tested
- XEN®-63 Gel Stent
- PRESERFLO™ MicroShunt
- Record updated
- 29 April 2026
Who can take part
AI summary
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults over 40 with open-angle glaucoma whose eye pressure is not controlled by medicines. They would have glaucoma surgery with one of two small implants.
- Age
- Over 40 years
- Sex
- All sexes
- Disease stage
- Primary open angle glaucoma, normal tension glaucoma, pigment dispersion glaucoma or pseudoexfoliative glaucoma. Mean Deviation of -3 or lower.
- Earlier treatment
- Not well controlled on the highest medicine treatment the person can tolerate. No earlier glaucoma shunt, valve, surgery or cyclodestructive procedure.
- Biomarker or test result
- Eye pressure of 14-28 mmHg. Endothelial cell count of at least 1000 cells/mm2.
Main reasons for not taking part
- Closed-angle glaucoma or secondary open-angle glaucoma (other than pigment dispersion or pseudoexfoliative)
- Current corticosteroid use, eye drops or tablets
- Active eye inflammation or conjunctival problems such as pterygium
- Aphakic eye or anterior chamber intraocular lens
- No light perception vision
The registry criteria, word for word
Show all 17 criteriaShow less
Who can take part
- >40 years of age
- An established diagnosis of: Primary open angle glaucoma, Normal tension glaucoma, Pigment dispersion glaucoma (PDG) or Pseudoexfoliative glaucoma (PEX)
- Inadequately controlled on maximum tolerated medical therapy
- Mean Deviation (MD) </= -3
- Intraocular pressure of 14-28 mmHg
- Endothelial Cell Count ≥1000 cells/mm2
Who cannot take part
- Previous procedures: Glaucoma shunt/valve/ surgery or cyclodestructive procedure, Selective laser trabeculoplasty within the past 3 months, Incisional ophthalmic surgery involving the conjunctiva within the past 3 months, Clear corneal cataract or trabecular meshwork surgery conducted within the past 6 months
- Current corticosteroid use (ocular or oral)
- Active iris neovascularization or neovascularization of the iris within 6 months of the surgical date
- An established diagnosis of: Closed-angle glaucoma or Secondary open-angle glaucoma (besides PDG and PEX)
- Lens status: Aphakic patients or Anterior chamber intraocular lens
- Presence of intraocular silicone oil
- No light perception vision
- Conjunctival pathologies (e.g., pterygium)
- Active inflammation (e.g., blepharitis, conjunctivitis, keratitis, uveitis)
- Vitreous present in the anterior chamber
- Unwillingness or inability to give consent, accept randomization or return for and participate in scheduled protocol visits
Where in Portugal
Also in 2 other countries, 2 sites
- ULS Santa MariaLisbon, PortugalContact: Luis Pinto, Prof. Dr.Not yet recruiting
About the trial
What the trial wants to find out
The goal of this randomized controlled clinical trial is to learn whether two minimally invasive bleb-forming glaucoma implants can effectively treat adult patients with open-angle glaucoma who require surgical lowering of intraocular pressure (IOP). Specifically, the study evaluates whether the PRESERFLO™ MicroShunt is at least as effective as the XEN®-63 Gel Stent in reducing IOP after surgery. 
Read full original descriptionShow less
The main questions it aims to answer are:
* Does the PRESERFLO™ MicroShunt provide IOP reduction at 12 months that is non-inferior to the XEN®-63 Gel Stent? * How do the two devices compare over 24 months with respect to medication reduction, need for additional glaucoma procedures, complications, and preservation of visual function and ocular structures?
Participants will:
* Be randomly assigned (1:1) to receive either the XEN®-63 Gel Stent or the PRESERFLO™ MicroShunt during a single glaucoma surgery. * Attend scheduled follow-up visits over 24 months for eye-pressure measurements, vision testing, visual-field testing, OCT imaging, endothelial-cell counts, and safety assessments. * Receive standard postoperative care and report any complications or additional treatments during the study period.
The 2 groups in the trial
- PRESERFLO MicroShuntTreatment being tested
The PFMS is a SIBS-polymer microshunt.
- XEN 63 GelstentExisting treatment, for comparison
The XEN 63 Gelstent is a hydrophilic gel implant made of cross-linked, purified collagen (gelatin).
Treatment: XEN®-63 Gel Stent
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Contact the study team: see the registry record → Contacts and Locations
Print a page for my doctorData and sources
- Registry record
- Listed on ClinicalTrials.gov.
- Official title
- Minimally Invasive Bleb-Forming Surgical Approaches for Treating Primary Open-Angle Glaucoma: A Randomized Controlled Trial Comparing XEN®-63 Gel Stent and PRESERFLO® MicroShunt
- Plain-language title
- Comparing two eye implants for lowering eye pressure in open-angle glaucomaGenerated from the registry record. The registry title is the official one.
- AI summary
- From the trial's eligibility criteria. Read by machine on 13 November 2026.
- Record updated
- 29 April 2026