A prospective, multicenter, open-label, safety and preliminary efficacy study of the surgical implantation of OPKO's glaucoma drainage device (AquashuntTM) in patients with refractory chronic forms of open angle glaucoma (OAG). The primary objective of this study is to evaluate the surgical implantation, safety and preliminary efficacy of the AquashuntTM after implantation in patients with refractory chronic forms of OAG

Inclusion Criteria:

Patients of either sex will be eligible for the study if all of the following criteria are met:

1. Patients must be aged 18 years or more.
2. Patients must have a diagnosis of chronic forms of open angle glaucoma in the study eye, which is uncontrolled on maximum tolerated medical treatment with ocular hypotensive medications and has failed glaucoma surgery or is not considered a reasonable candidate for traditional surgery.
3. The patient's documented IOP must be considered by the treating physician to be too high for their glaucoma status.
4. Patients must have BCVA of between 20/400 and Light Perception, or no light perception with pain, in the study eye.
5. Patients must have a BCVA in the fellow eye, which is better than that of the study eye.
6. Patients must be mentally competent and willing to provide informed consent.
7. Patients must be willing to return for all study visits and assessments for at least 3 years after surgery.

Exclusion Criteria

Patients will not be eligible for the study if any of the following criteria are present:

1. Patients with a diagnosis of glaucoma other than open angle glaucoma including active uveitic, active neovascular or recent traumatic glaucoma.
2. Patients with clinically significant corneal disease including corneal dystrophy.
3. Patients with iridocorneal endothelial syndrome.
4. Any previous ocular surgery other than trabeculectomy, trabeculoplasty or cataract surgery and any surgery (including laser) within previous 3 months.
5. Patients with an Anterior Chamber configuration that puts the patient at high risk for the development of angle closure glaucoma.
6. Patients with any recent (within previous 30 days), or current, ocular/periocular inflammation or infection.
7. Patients with a history of extensive keloid formation.
8. Patients who will need ancillary procedures in the study eye at the time of implantation or during the initial one year study period.
9. Patients who have any known intolerance or hypersensitivity to topical anesthetics, mydriatics or components of the device.
10. Patients who are unable to interrupt their anti-coagulant, anti-platelet or NSAID (including aspirin) therapy for at least 3 weeks prior to surgery.
11. Patients who have within the previous 3 months, are currently, or intend to participate in a study with any investigational agent (drug or device).