Combined Phacoemulsification With iStent Inject W Versus Hydrus for Mild to Moderate Open Angle Glaucoma

Inclusion Criteria: * \>60 years or older * Visually significant cataract * Mild to moderate primary open angle glaucoma controlled on medications * undergoing cataract surgery with lens implantation and concurrent microstent placement * IOP ≥ 21 mmHg and ≤ 36 mmHg after washout of ocular hypotensive medication(s) * CCT 480 to 620μm * No prior ocular surgery including corneal refractive surgery * No SLT within 6 months of baseline visit, no history of intracameral glaucoma drug eluting implants * Visual field mean deviation ≤ -12 dB * Optic nerve abnormalities consistent with glaucoma, C/D ratio less than ≤0.8 Exclusion Criteria: * Prior intraocular surgery * Visual field MD ≥ -12 dB * secondary glaucoma including uveitis, traumatic, malignant, neovascular, and congenital glaucoma. * Glaucoma related to elevated episcleral venous pressure including Sturge-Weber syndrome, thyroid eye disease, orbital tumor, and etc. * Uncontrolled intraocular pressure on maximum tolerated medical therapy; * Unable to perform wash-out IOP * Anatomic exclusion of narrow anterior chamber angle (Shaffer grade I-II), other angle abnormalities including angle closure glaucoma * Corneal disease or dystrophy * Pathological myopia with degeneration that affects diagnostic imaging * Clinically significant ocular pathology or degenerative diseases that affect vision, visual field, or optical coherence tomography of optic nerve. * Inability to perform reliable Visual Field and optical coherence tomography.