The objective of this early feasibility clinical study is to evaluate the safety and effectiveness of several different GORE Glaucoma Drainage Implant configurations in subjects with primary open-angle glaucoma that is uncontrolled by hypotensive medications or for which conventional incisional glaucoma surgery would be more likely to fail due to scarring.

Inclusion Criteria:

• Males and females, age 18 to 85 years, inclusive at screening visit
• A diagnosis of primary open-angle glaucoma (Shaffer angle ≥ 3 as seen on gonioscopy) at screening visit
• Medicated intraocular pressure at screening visit and the mean medicated diurnal IOP at baseline visit ≥ 18 mmHg and ≤ 40 mmHg by Goldmann Applanation Tonometry

Exclusion Criteria:

• Expected inability to implant the study device in the superotemporal quadrant (e.g., a lack of freely mobile conjunctiva to cover the entire implanted device in the superotemporal quadrant)
• Diagnosis of any active ocular disease or disorder (other than glaucoma) that requires treatment, where the disease or treatment could be reasonably expected to affect the vision or IOP during the duration of the study
• Prior corneal transplant surgery (full or partial thickness transplants) or clinically significant corneal dystrophy, e.g., Fuchs' dystrophy (> 12 confluent guttae) in the study eye
• Concurrent cataract surgery or anticipated need for cataract surgery (i.e., clinically significant cataract) in the study eye during the 12 months following implantation
• BCDVA worse than 20/200 in the fellow (non-study) eye at the screening visit and BCDVA of the fellow eye cannot be worse than that of the study eye.