Comparing XEN®-63 Gel Stent and PRESERFLO® MicroShunt

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