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 trabeculectomy 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 trabeculectomy? How do these two surgeries compare over 12 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 trabeculectomy or the PRESERFLO™ MicroShunt during a single glaucoma surgery.

Attend scheduled follow-up visits over 12 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.

Inclusion Criteria:

->21 years of age

• An established diagnosis of: Primary open angle glaucoma, Normal tension glaucoma, Pigment dispersion glaucoma (PDG) or Pseudoexfoliative glaucoma (PEXG)
• Inadequately controlled on maximum tolerated medical therapy
• Mean Deviation (MD) \