The purpose of this study is to evaluate the safety and efficacy of the iStent medical device that is implanted into the eye and designed to reduce eye pressure in patients with your condition.

Inclusion Criteria:

• Diagnosed with primary open-angle glaucoma (POAG)
• Subject on two topical hypotensive medications

Exclusion Criteria:

• Traumatic, uveitic, neovascular, or angle closure glaucoma
• Fellow eye already enrolled