Comparing XEN®-63 Gel Stent and PRESERFLO® MicroShunt
MINI-BATTLE
Minimally Invasive Bleb-Forming Surgical Approaches for Treating Primary Open-Angle Glaucoma: A Randomized Controlled Trial Comparing XEN®-63 Gel Stent and PRESERFLO® MicroShunt
1 other identifier
interventional
166
3 countries
3
Brief Summary
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.  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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for not_applicable
Started Jan 2026
Typical duration for not_applicable
3 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
January 1, 2026
CompletedFirst Submitted
Initial submission to the registry
January 12, 2026
CompletedFirst Posted
Study publicly available on registry
January 22, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
January 1, 2027
ExpectedStudy Completion
Last participant's last visit for all outcomes
January 1, 2028
April 29, 2026
January 1, 2026
1 year
January 12, 2026
April 28, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Intraocular pressure
1 year
Secondary Outcomes (7)
Number of medications
2 year
adverse events
2 years
secundary pressure-lowering surgery
2 years
Mean Deviation changes on the visual field
2 years
Retinal Nerve Fibre Layer Thickness changes on Optical Coherence Tomography
2 years
- +2 more secondary outcomes
Study Arms (2)
PRESERFLO MicroShunt
EXPERIMENTALThe PFMS is a SIBS-polymer microshunt.
XEN 63 Gelstent
ACTIVE COMPARATORThe XEN 63 Gelstent is a hydrophilic gel implant made of cross-linked, purified collagen (gelatin).
Interventions
The XEN®-63 Gel Stent is a hydrophilic gel implant made of cross-linked, purified collagen (gelatin). This devices bypasses the trabecular meshwork and lower eye pressure via a subconjunctival filtering bleb, aided by intra-operative mitomycin C to reduce scarring. It has already been approved for the European market and therefore bear the CE mark.
The PRESERFLO™ MicroShunt is a SIBS-polymer microshunt. This devices bypasses the trabecular meshwork and lower eye pressure via a subconjunctival filtering bleb, aided by intra-operative mitomycin C to reduce scarring. It has already been approved for the European market and therefore bear the CE mark.
Eligibility Criteria
You may qualify if:
- \>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
You may not qualify if:
- 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
- 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.
- Presence of intraocular silicone oil
- No light perception vision
- Current corticosteroid use (ocular or oral)
- Conjunctival pathologies (e.g., pterygium)
- Active inflammation (e.g., blepharitis, conjunctivitis, keratitis, uveitis)
- Vitreous present in the anterior chamber
- Active iris neovascularization or neovascularization of the iris within 6 months of the surgical date
- Unwillingness or inability to give consent, accept randomization or return for and participate in scheduled protocol visits
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Universitaire Ziekenhuizen KU Leuvenlead
- University Hospital, Bonncollaborator
- Hospital de Santa Maria, Lisboncollaborator
Study Sites (3)
University Hospitals UZ Leuven
Leuven, Vlaams-brabant, 3000, Belgium
Universitätsklinikum Bonn
Bonn, North Rhine-Westphalia, D-53127, Germany
ULS Santa Maria
Lisbon, Lisbon District, 1649-028, Portugal
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- SINGLE
- Who Masked
- OUTCOMES ASSESSOR
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
January 12, 2026
First Posted
January 22, 2026
Study Start
January 1, 2026
Primary Completion (Estimated)
January 1, 2027
Study Completion (Estimated)
January 1, 2028
Last Updated
April 29, 2026
Record last verified: 2026-01