An observational study in Angle-closure Glaucoma, Minimally Invasive Glaucoma Surgery and Goniosynechialysis, sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University. Recruiting at 1 site in China. Open to participants aged 30 Years to 85 Years. Per ClinicalTrials.gov, last updated 2025-12-12.
Sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University · Observational
The drainage angle in the anterior chamber of the eye mediates the outflow of aqueous humor, and pathological changes here can lead to high intraocular pressure and glaucoma. Minimally invasive glaucoma surgery, particularly angle surgery, has advanced recently, allowing clear visualization of angle structures like the trabecular meshwork and Schlemm's canal using surgical goniolens. Techniques for angle intervention include widening the angle, reopening closed angles, and rebuilding outflow pathways using methods such as laser peripheral iridotomy, Argon laser peripheral iridoplasty, and mechanical separation of adhered tissues. Our research team plans to conduct imaging studies to track the healing of angle tissues post-surgery, aiming to support innovation and standardization of minimally invasive angle surgery.
Pathological elevated intraocular pressure is one of the most important disease characteristics of glaucoma. Blockage of aqueous humor outflow within the eye is the primary cause of high intraocular pressure. The drainage angle in the anterior chamber of the eye mediates the outflow of aqueous humor. Pathological changes in this area can lead to the development of high intraocular pressure and glaucoma, such as primary angle closure glaucoma (PACG) caused by angle closure. Minimally invasive glaucoma surgery has rapidly developed in recent years, with angle surgery being a major branch. With the use of surgical goniolens, structures within the angle, such as trabecular meshwork and Schlemm's canal, can be visualized clearly during surgery. Methods for angle intervention include but not limit ed to widening the peripheral anterior chamber angle, reopening adhered or appositionally closed angles, and rebuilt outflow pathways by incising diseased areas to increase aqueous humor outflow. Techniques include laser peripheral iridotomy (LPI) to relieve pupillary block and deepen the peripheral anterior chamber, Argon laser peripheral iridoplasty (ALPIP) to stimulate iris contraction and widen the angle, and mechanical separation of adhered angle tissues using instruments like goniosynechialysis hooks or iris repositors. Surgical incision using instruments such as Microhook, trabeculectomy hooks, or cannulas can be performed to remove the diseased inner wall of Schlemm's canal and the diseased trabecular meshwork either partially or circumferentially. However, the healing and outcomes of angle tissues following invasive angle interventions, and their impact on surgical outcomes, remain unclear. Therefore, our research team proposes to conduct imaging observation studies to track, observe, and quantify the status of the angle, exploring the healing process of angle tissues. This aims to provide theoretical support for the innovation and standardization of minimally invasive angle surgery.
91 studies on the registry are indexed under Glaucoma, Angle-Closure; 17 are open to participants now.
This study's planned enrollment of 300 is above the median of 225 across 32 observational studies indexed under Glaucoma, Angle-Closure.
Browse Glaucoma, Angle-Closure studies →Zhongshan Ophthalmic Center, Sun Yat-sen University is the lead sponsor of 164 studies on the registry; 80 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Patients diagnosed with glaucoma typically present with: IOP > 21 mmHg with or without the use of ocular hypotensive medications; (3) with obvious glaucomatous optic neuropathy [cup-to-disc (C/D) ratio ≥ 0.7, C/D ratio asymmetry > 0.2, or rim width at the superotemporal and inferotemporal \< 0.1 vertical diameter of the optic disc], and glaucomatous visual field defects, such as nasal step, arcuate scotoma, and paracentral scotoma;
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
based on angle closure mechanism, procedures were chosen LPI alone or combined with ALPIp. LPI: laser peripheral iridotomy; ALPIp: argon laser peripheral iridoplasty.
Procedure: various types of angle interventions
SPI combined with GSL or GSL+GT SPI: surgical peripheral iridectomy GSL:goniosynechialysis GT: goniotomy GSL and GT are both guided by surgical goniolens
Procedure: various types of angle interventions
PEI: phacoemulsification and intraocular lens implantation surgery combo includes GSL alone or GSL+GT.
Procedure: various types of angle interventions
GT was performed in the nasal-inferior quadrant or nasal quadrant because the collector channels were mainly concentrated in the nasal quadrant, by inserting the tip of a microblade (TMH; Tanito Microhook, Inami \& Co., Ltd., Tokyo, Japan) into Schlemm's canal, and then the inner wall of Schlemm's canal and trabecular meshwork was incised over 120°
Procedure: various types of angle interventions
performed in the nasal quadrant by the collector channels were mainly concentrated in the nasal quadrant, by inserting the tip of a microblade (TMH; Tanito Microhook, Inami \& Co., Ltd., Tokyo, Japan) into Schlemm's canal, and then the inner wall of Schlemm's canal and trabecular meshwork was incised over 120°
Procedure: various types of angle interventions
procedures include laser peripheral iridotomy (LPI) to relieve pupillary tissue and deepen peripheral anterior chamber depth, Argon laser peripheral iridoplasty (ALPIp) to stimulate iris contraction and widen the angle, and mechanical separation of adhered angle tissues using instruments like goniosynechialysis hooks or iris repositor. Ab interno goniotomy using instruments like retina hooks, trabeculectomy hooks, or cannulas are used to incise trabecular meshwork and Schlemm's canal walls to enhance aqueous humor outflow.
Changes in biological parameters of the anterior chamber angle
Biological parameter changes in the anterior chamber following angle intervention surgery will be measured using Casia2-OCT
Time frame: 12 months
success rate of angle intervention surgeries
complete success was defined as postoperative IOP within the range of 6-18 mmHg, and a reduction of 20% from baseline without loss of light perception, additional ocular hypotensive medication, and reoperation. The definition of qualified success was similar to that of complete success, except for the need for ocular hypotensive medications. Postoperative ocular hypotensive medications were adjusted according to the IOP at each visit.
Time frame: 12 months
safety of angle intervention surgeries
The main observation includes recording intraoperative and postoperative complications, including hyphema, choroidal detachment, cyclodialysis, persistent hypotony, corneal decompensation, and intraocular inflammation.
Time frame: 1 months
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Zhongshan Ophthalmic Center, Sun Yat-sen University →