XEN‑63 Gel Stent versus PRESERFLO MicroShunt for lowering eye pressure in open‑angle glaucoma.

Minimally Invasive Bleb-Forming Surgical Approaches for Treating Primary Open-Angle Glaucoma: A Randomized Controlled Trial Comparing XEN®-63 Gel Stent and PRESERFLO® MicroShunt

Not applicable Interventional Universitaire Ziekenhuizen KU Leuven · NCT07359547

This trial tests whether the PRESERFLO MicroShunt is at least as good as the XEN‑63 Gel Stent at lowering eye pressure over 12 months in adults with open‑angle glaucoma who need surgery.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment166 (estimated)
Ages40 Years and up
SexAll
SponsorUniversitaire Ziekenhuizen KU Leuven Academic / other
Locations3 sites (Leuven, Vlaams-brabant and 2 other locations)
Trial IDNCT07359547 on ClinicalTrials.gov

What this trial studies

Adults with open‑angle glaucoma who need surgical lowering of intraocular pressure are randomly assigned 1:1 to receive either the XEN‑63 Gel Stent or the PRESERFLO MicroShunt during a single glaucoma operation. The primary goal is to show non‑inferior IOP reduction at 12 months, with additional follow‑up to 24 months to compare medication use, need for further glaucoma procedures, complications, and preservation of vision and ocular structures. Follow‑up visits include eye‑pressure measurements and clinical exams at scheduled intervals. The trial is conducted at major academic centers in Belgium, Germany, and Portugal.

Who should consider this trial

Good fit: Adults over 40 with primary open‑angle, normal tension, pigment dispersion, or pseudoexfoliative glaucoma who have inadequate pressure control on maximal tolerated medical therapy, mean deviation ≤ −3, IOP 14–28 mmHg, and endothelial cell count ≥1000 cells/mm² are the intended candidates.

Not a fit: Patients with closed‑angle glaucoma, secondary open‑angle glaucoma (other than PDG/PEX), prior glaucoma shunt or recent conjunctival/incisional ophthalmic surgery, aphakia or anterior chamber intraocular lens, no light perception, current corticosteroid use, or intraocular silicone oil are unlikely to be eligible or benefit from participation.

Why it matters

Potential benefit: If successful, the comparison could identify a surgical option that provides similar or better long‑term eye‑pressure control and reduces the need for glaucoma medications or further procedures.

How similar studies have performed: Other clinical work with both XEN and PRESERFLO devices has shown they can lower intraocular pressure, but randomized head‑to‑head comparisons over 24 months are limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* \>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

Exclusion Criteria:

* 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

Where this trial is running

Leuven, Vlaams-brabant and 2 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions GLAUCOMA 1, OPEN ANGLE, DGlaucomaMIBSMinimally Invasive Bleb-Forming SurgeryBleb-Forming Devices Without a PlateSurgeryPRESERFLOMicroShunt
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.