Trabeculectomy Versus Peripheral Iridectomy Plus Goniotomy in Advanced PACG

Inclusion Criteria:

1. Age 45-80 years.
2. Eyes diagnosed with advanced PACG who meet following criteria a, b, and c; or a, b,and d:
3. PAS: ≥180° range, including nasal and inferior quadrants;
4. IOP >21 mmHg with or without anti-glaucoma medications (the medications includethe maximally tolerated medications), taken with the Goldmann applanationtonometer;
5. Glaucomatous optic neuropathy (cup-to-disc [C/D] ratio ≥0.7, C/D asymmetry >0.2,or rim width at the superior and inferior temporal areas <0.1 of the verticaldiameters of the optic disc);
6. Glaucomatous visual field defects (nasal step, arcuate scotoma, and paracentralscotoma on a reliable Humphrey analyzer and a mean deviation of ≤-12 dB).
7. No or mild cataracts and uncorrected visual acuity of ≥0.63 (Early Treatment DiabeticRetinopathy Study chart);
8. Axial length of ≥20 mm.

Exclusion Criteria:

1. History of ocular surgery or trauma.
2. Retinal disease that influences the collection of ocular parameters or other types ofglaucoma, including open-angle glaucoma, secondary angle-closure glaucoma, steroidalglaucoma, angle recession glaucoma, neovascular glaucoma, nanophthalmos, andpseudoexfoliation syndrome.
3. Monophthalmia (best-corrected visual acuity of <0.01 in the non-study eye).
4. An International Standardized Ratio of >3.0, for patients receiving warfarin oranticoagulant therapy before surgery.
5. Patients with serious systemic diseases.
6. Pregnant or lactating women. If both eyes are eligible for the study, the eye with the worse visual field or optic nervewill be included.