Trabeculopuncture as Predictive Test for the Success of Ab Interno Trabeculectomy

Inclusion Criteria: * individuals ≥ 18 years of age * clinical diagnosis of: primary open angle glaucoma, pigmentary glaucoma, or pseudoexfoliation glaucoma * uncontrolled intraocular pressure (IOP) with maximally tolerated medical therapy * progressive thinning of retinal nerve fiber layer assessed by Spectral domain optical coherence tomography (p \< 0.05) * progression of visual field defects * visually significant cataract and indication to reduce IOP or glaucoma medication burden Exclusion Criteria: * clinical diagnosis of neovascular glaucoma, angle-closure glaucoma, uveitic glaucoma, neovascular glaucoma * prior glaucoma surgery * preexisting conditions affecting the episcleral venous pressure including Grave's ophthalmopathy, Sturge-Weber syndrome, Arteriovenous fistulas (carotid-cavernous fistula)