Inclusion criteria  Aged 40-80 years;  Diagnosed with advanced PACG: meet with (1) (2) (3) or (1) (2) (4)  At least 180-degree PAS under gonioscopy and it should cover the nasal and inferior quadrants for surgical purposes; IOP >21 mmHg with or without anti-glaucoma medication; Obvious glaucomatous optic neuropathy (cup-to-disc [C/D] ratio≥0.7, or C/D asymmetry > 0.2, or the rim width at the superior and inferior temporal < 0.1 vertical diameters of optic disc); With glaucomatous visual field defects, such as nasal step, arcuate scotoma, and paracentral scotoma on a reliable Humphrey analyzer using SITA-Standard 24-2 or 30-2 algorithm; mean deviation ≤ -12dB; Clinically obvious cataract and uncorrected visual acuity (UCVA) <0.63 (Early Treatment Diabetic Retinopathy Study, [ETDRS] chart), or need lens extraction assessed by a clinician; Voluntarily participate in study and provide signed informed consent. Exclusion criteria a. History of ocular surgery (other than laser iridotomy or laser iriplasty) or trauma; b. With other types of glaucoma; (i.e. open angle glaucoma, secondary angle-closure glaucoma, steroidal glaucoma, angle regression glaucoma, neovascular glaucoma, nanophthalmos, pseudoexfoliation syndrome) c. The International Standardized Ratio > 3.0 for patients receiving warfarin or anticoagulant therapy before surgery; d. With retinal disease that affects the collection of ocular parameters; f. Monophthalmia (best-corrected visual acuity [BCVA] <0.01 in the non-study eye); g. With other serious systemic diseases; h. Pregnant or lactating women * If both eyes are eligible for the study, the eye with the worse UCVA will be recruited.