To evaluate safety, effectiveness, and the surgical performance of CADENCE in patients with refractory glaucoma.

CADENCE a single use implantable glaucoma drainage device used for the surgical treatment of refractory glaucoma. The device is implanted in the eye using an ab-externo approach

Inclusion Criteria:

• 22-80 years of age.
• moderate to severe refractory glaucoma
• Able to consent

Exclusion Criteria:

• Women of child-bearing potential

• Intraocular surgery or laser within the last 3 months

• Ocular infection or inflammation within the last 6 months or currently active

• Current use of anti-coagulant therapy

• History of bleeding disorder or coagulopathies

• Subject plans to undergo any ocular surgery (including cataract surgery) during the study period

• History of corneal transplantation

• History of ICE Syndrome or epithelial ingrowth/downgrowth

• History of congenital glaucoma

• Elevated episcleral venous pressure

  -. Persistent angle closure-

• Previous glaucoma filtration surgery- -Presence of conjunctival scarring -

• neovascular glaucoma

• AC lens or scleral sutured IOL

• Aphakia

• inability to DC contact lenses

• Presence of intraocular silicone oil

• Vitreous in AC