A Trial of Hydrus Microstent Versus Goniotomy

Inclusion Criteria:

* Visually significant cataract planned for surgery
* Mild to moderate open-angle glaucoma, including pigmentary glaucoma and pseudoexfoliation glaucoma
* Mild stage glaucoma includes glaucomatous optic neuropathy and visual field mean deviation better than -6.0 dB, with no points in the central 5 degrees \<15 dB
* Moderate stage glaucoma includes: 1) glaucomatous optic neuropathy and visual field mean deviation equal to or worse than -6.0 dB but no worse than -12.0 dB and no central 5 degree points \<15 dB or 2) mean deviation -12.0 dB or better with 1 central 5 degree point \<15 dB
* Medicated IOP between 10 to 31 mm Hg, inclusive, at time of decision for surgery
* Willing and able to understand and provide informed consent
* Willing and able to attend postoperative examinations per protocol schedule

Exclusion Criteria:

* Prior argon laser trabeculoplasty, laser peripheral iridotomy, incisional glaucoma surgery, or cyclophotocoagulation
* Selective laser trabeculoplasty within 90 days of study enrollment
* Iridotrabecular contact for 180 degrees or greater
* Peripheral anterior synechiae in nasal or inferior angle
* Best corrected visual acuity worse than 20/200
* Phacodonesis on pre-operative examination
* Vitreous in anterior chamber on pre-operative examination
* Nanophthalmos
* Anti-platelet and anticoagulant medications other than aspirin 81mg daily
* Active treatment for another ophthalmic condition in either eye (e.g., anti-VEGF injections, steroids for corneal transplant)
* Abnormality in study eye that could affect tonometry
* Glaucoma diagnosis other than the above
* Normal tension glaucoma
* Conditions that can cause elevated episcleral venous pressure (e.g., Sturge-Weber syndrome, Graves disease, retrobulbar tumor)
* History of uveitis in either eye
* Inability to complete gonioscopy examination
* Use of oral steroids within 90 days or anticipated use of oral steroids
* Oral medications that can affect IOP, including oral carbonic anhydrase inhibitors such as acetazolamide and methazolamide
* History of steroid-associated IOP elevation
* Medically unfit for attending planned study visits
* Involvement in another interventional research study