Trabeculectomy Versus Peripheral Iridectomy Plus Goniotomy in Advanced PACG

Effectiveness and Safety of Trabeculectomy and Peripheral Iridectomy Plus Goniotomy in Advanced Primary Angle-closure Glaucoma: a Multicenter Non-inferiority Randomized Controlled Trial

A multicenter, parallel, open, non-inferior randomized controlled trial is conducted to compare the effectiveness and safety of trabeculectomy and peripheral iridectomy plus goniotomy (TVG) in the treatment of advanced primary angle closure glaucoma with no or mild cataracts.

Primary angle-closure glaucoma (PACG) has a high prevalence and blinding rate in China. The routine first-line treatment of advanced PACG is trabeculectomy, especially in those without cataract. However, due to surgery complications and exhausting post-surgery caring, traditional trabeculectomy is not an ideal choice in clinical practice, particularly in patients with high risk of complications such as younger age and shorter axial length. Peripheral iridectomy (SPI) plus intraocular pressure (IOP)-lowering medications is an alternative.

Minimally invasive glaucoma surgery (MIGS) has recently showed its safety and effectiveness in the treatment of PACG, usually combined with cataract surgery, goniosynechialysis (GSL) and goniotomy(GT). The safety and effectiveness of phacoemulsification and intraocular lens implantation (PEI)+GSL+GT in advanced PACG with cataract has been conducted (clinical trials.gov, NCT04878458). It is valuable to explore the safety and efficacy of SPI+GSL+GT in these PACG patients with no or mild cataracts.

Therefore, this study intends to conduct a multicenter, non-inferior randomized controlled clinical trial to compare the effectiveness and safety of trabeculectomy versus SPI+GSL+GT in advanced PACG with no or mild cataracts.

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:

   1. PAS: ≥180° range, including nasal and inferior quadrants;
   2. IOP >21 mmHg with or without anti-glaucoma medications (the medications include the maximally tolerated medications), taken with the Goldmann applanation tonometer;
   3. 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 vertical diameters of the optic disc);
   4. Glaucomatous visual field defects (nasal step, arcuate scotoma, and paracentral scotoma on a reliable Humphrey analyzer and a mean deviation of ≤-12 dB).

3. No or mild cataracts and uncorrected visual acuity of ≥0.63 (Early Treatment Diabetic Retinopathy Study chart);

4. 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 of glaucoma, including open-angle glaucoma, secondary angle-closure glaucoma, steroidal glaucoma, angle recession glaucoma, neovascular glaucoma, nanophthalmos, and pseudoexfoliation 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 or anticoagulant 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 nerve will be included.