PRESERFLO™ MicroShunt XI Observational PMCF Study With no Control Group

Inclusion Criteria: 1. Male or female, age 18 to 85 years, inclusive 2. Patient diagnosed with primary open glaucoma where the IOP is not adequately controlled on maximum tolerated medical therapy and has intraocular pressure ≥18 mmHg and ≤35 mmHg while on glaucoma medications 3. Patient willing to comply with study requirements 4. Patient who has signed an approved informed consent form Exclusion Criteria: 1. Angle closure glaucoma 2. Presence of conjunctival scarring, previous incisional ophthalmic surgery involving the conjunctiva or conjunctival pathologies (e.g., thin conjunctiva, pterygium) 3. Active iris neovascularization 4. Active inflammation (e.g., blepharitis, conjunctivitis, scleritis, keratitis, uveitis) 5. Vitreous in the anterior chamber 6. Presence of an anterior chamber intraocular lens (ACIOL) 7. Intraocular silicone oil 8. Need for glaucoma surgery combined with other ocular procedures (e.g., cataract surgery with IOL implantation) or anticipated need for additional ocular surgery during the investigational period 9. Central corneal thickness that is less than 450 microns or greater than 620 microns 10. Previous cilioablative procedure 11. Neovascular glaucoma 12. Uveitic Glaucoma 13. Pseudoexfoliative or pigmentary glaucoma 14. Chronic inflammation 15. Previous incisional ophthalmic surgery within 6 months prior to study 16. Enrolled in this or another study (only one eye can participate in this study) or completed their participation in another study within 30 calendar days of the screening exam 17. Ocular pathology or medical condition for which, in the investigator's judgment, the following factors would either place the patient at increased risk of complications or contraindicate device implantation or interfere with compliance to elements of the Protocol