Kahook Dual Blade Goniotomy in Chronic Primary Angle-Closure Glaucoma

Inclusion Criteria: * (1) age ≥ 40 years; (2) a confirmed diagnosis of CPACG, defined as the presence of peripheral anterior synechiae (PAS) extending ≥ 180° on indentation gonioscopy, accompanied by glaucomatous optic neuropathy and corresponding visual field defects; (3) a visually significant cataract that impaired daily activities and necessitated phacoemulsification; and (4) inadequately controlled intraocular pressure (IOP), defined as an IOP \> 21 mmHg despite maximally tolerated anti-glaucoma medications, or an IOP ≤ 21 mmHg dependent on the continuous use of two or more topical medications. Exclusion Criteria: * (1) any form of secondary angle-closure glaucoma (e.g., neovascular, uveitic, or lens-induced glaucoma); (2) a history of prior intraocular surgery or incisional glaucoma procedures, although eyes with a previous uncomplicated laser peripheral iridotomy (LPI) were permitted; (3) concurrent severe ocular pathologies that could profoundly limit visual prognosis or confound functional assessments (e.g., severe diabetic retinopathy, advanced age-related macular degeneration, or optic atrophy of non-glaucomatous origin); (4) a central corneal endothelial cell density of \< 1500 cells/mm² to ensure the safety of the planned anterior chamber interventions; and (5) any severe systemic conditions precluding surgical tolerance or adherence to the 1-year follow-up protocol.