The primary objective of this study is to evaluate the safety, efficacy, and performance of the Suprachoroidal Dissection Instrument in creating a fistula between Schlemm's canal and the suprachoroidal space in refractory, open angle glaucoma subjects.

The Suprachoroidal Dissection Instrument (SDI) is a manually operated surgical instrument designed for use within Schlemm's canal. The instrument can access Schlemm's canal through a small ab-externo dissection, allowing use in eyes with scarring due to previous surgery or trauma.

Inclusion Criteria:

• Available for up to 3 years follow-up.
• Diagnosed with primary open-angle, pseudoexfoliative, or pigmentary glaucoma or more than one glaucoma diagnosis of these types.
• Subject scheduled to undergo glaucoma surgery with the Suprachoroidal Dissection Instrument involving creation of fistula between Schlemm's canal and the suprachoroidal space without combined cataract surgery.
• Subject has failed at least one incisional glaucoma surgery (trabeculectomy, tube shunt, deep sclerectomy, viscocanalostomy, canaloplasty) or angle surgery (Trabectome) OR Is not a candidate for conventional glaucoma surgery due to reasons such as the presence of scleral buckle or compromised conjunctiva.
• Subject has IOP ≥ 16 mm Hg on maximally tolerated medications within the six week (-42 days) period prior to surgery.
• Visual field defect defined as mean deviation (MD) score worse than or equal to -10 dB on the Swedish Interactive Threshold Algorithm [SITA] Standard 24-2 Humphrey Analysis during the 6 month period prior to surgery. OR Subject has vertical cup-to-disk ratio ≥ 0.75 during the 6 month period prior to surgery.

Exclusion Criteria:

• Significant lens opacities or patient is candidate for cataract surgery during the duration of the study.
• The patient had developmental glaucoma or a secondary glaucoma including steroid-induced, uveitic, or neovascular glaucoma (with the exception of pigmentary and pseudoexfoliative glaucoma).
• The patient has narrow angle component possibly associated with glaucoma in the operative eye.
• The subject has angle recession in the operative eye.
• Significant ocular disease other than glaucoma affecting the assessment of visual function.