The purpose of this study is to evaluate the ocular hypotensive effect of the Hydrus Aqueous Implant (Standard and Low-Profile), as determined by the change in IOP from baseline (preoperative) and change in the number of glaucoma medications from baseline.

This is a prospective, multi-center study that will examine subjects with documented mild to advanced primary open angle glaucoma (POAG), who may or may not have a cataract requiring removal and placement of an intraocular lens.

Study subjects will be grouped by the severity of their disease (either mild/moderate or advanced). If all inclusion and exclusion criteria are met subjects in all four groups will be implanted with the Hydrus Aqueous Implant. Subjects in whom a cataract is present will undergo standard cataract removal and IOL implantation concurrent with implantation of the Hydrus.

Postoperatively, subjects will undergo a complete ophthalmic evaluation at regularly scheduled intervals.

Inclusion Criteria:

• Elevated intraocular pressure (IOP)
• Diagnosis of mild to advanced open-angle glaucoma
• Shaffer Grade III
• Mental capacity to cooperate when undergoing operative and postoperative examination
• 18 years of age or older
• Provide written informed consent
• Willing and able to return to scheduled follow-up examinations for 24-months

Exclusion Criteria:

• Closed-angle and narrow-angle forms of glaucoma
• Secondary glaucomas
• Congenital or developmental glaucoma