Phaco-ECP vs Phaco Alone in Primary Angle Closure

Inclusion Criteria: 1. Age is above 40 years old. 2. A diagnosis of either PAC or PACG. PAC will be defined as the presence of irido-trabecular contact on gonioscopy, either appositional or in the presence of peripheral anterior synechiae (PAS), without indentation (or prior documentation before a LPI has been performed) without any evidence of glaucomatous optic neuropathy. PACG will be defined as PAC along with an evidence of glaucomatous optic neuropathy. An optic neuropathy secondary to glaucoma will be defined as evidence of structural and functional damage suggestive of glaucoma as demonstrated by clinical examination, optical coherence tomography, and visual field testing. 3. IOP measurement that is more than 21 mmHg (not exceeding 35 mmHg) without the use of glaucoma medications or less than 21 mmHg with medications. 4. Patient is able to give an informed consent and tolerate a period of medication washout. Exclusion Criteria: 1. Previous intraocular surgery (including CPC). Glaucoma laser procedures are allowed (e.g. LPI, iridoplasty, and laser trabeculoplasty). 2. Previous ocular trauma. 3. A central corneal thickness that does not lie between 500 and 600 microns. 4. A diagnosis of nanophthalmos (defined as an axial length that is less than 20 mm). 5. Presence of pseudoexfoliation. 6. Presence of secondary causes of angle closure such as neovascular glaucoma and uveitic glaucoma. 7. Presence of diabetic retinopathy (active PDR or active DME) or agerelated macular degeneration. PHEPHA Protocol Version 2 September 3, 2020 8. Advanced glaucoma as defined by the Glaucoma Severity Staging System12 (mean deviation worse than -12.01 dB and at least one of the following: 1. On pattern deviation plot, greater than or equal to 50% but fewer than 75% of points depressed below the 5% level and greater than or equal to 25% but fewer than 50% of points depressed below 1% level 2. Any point within central 5 degrees with sensitivity \< 0db 3. Both hemifields containing a point(s) with sensitivity \< 15 dB within 5 degrees of fixation). 9. Any ocular or systemic condition that is presumed to prevent reliable clinical examination and/or visual field testing. 10. Pregnancy. 11. Inability to attend postoperative follow ups for a period of 12 months after surgery.