Angle-closure GlaucomaNCT06492538
Biometric Changes After Intervention of Anterior Chamber Angle : an Observational Study
An observational study of Angle-closure Glaucoma and Minimally Invasive Glaucoma Surgery, run by Zhongshan Ophthalmic Center, Sun Yat-sen University at 1 site in China.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 30 to 85 years
- Conditions the study is for
- Angle-closure Glaucoma, Minimally Invasive Glaucoma Surgery, Goniosynechialysis
- What is being tested?
- various types of angle interventions
- Type of treatment
- Surgery or procedure
- How many people
- 300 participants
- Where
- 1 siteChina
- Study dates
- 1 Dec 2023to 30 Dec 2025
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 30 to 85 years
- All sexes
- Adult, Older adult
Study population: 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;
Who may be able to join
- Glaucoma patients eligible for standalone or combined angle intervention surgeries, such as LPI, LPIP, goniosynechialysis, trabeculotomy alone or combined with surgical iridectomy or phacoemulsification and intraocular lens implantation;
- Patients capable of undergoing preoperative examinations including CASIA2-OCT (anterior segment OCT), UBM, slit-lamp gonioscopy, IOL Master (or other optical biometry);
- Patients willing to participate in this study, signing informed consent, and agreeing to follow-up according to the study protocol.
Who cannot join
- Patients with severe ocular conditions such as corneal infection, ulcer, trauma, ocular tumors, retinal vascular occlusion, and retinal detachment;
- Those with various types of eye diseases that affect ocular parameter acquisition or interfere with visual field examination;
- Long-term local or systemic use of glucocorticoids;
- Patients with severe systemic diseases;
- Pregnant or lactating women;
- Unable to complete 12-month postoperative follow-up.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
China1 site, 1 recruiting
- Recruiting
Zhongshan ophthalmic center
Guangzhou, Guangdong, 51006dddddd0
Xinbo Gao, MD, +8618319579657, gaoxb@mail.sysu.edu.cn
About this study
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.
Read the detailed description
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.
- Conditions
- Angle-closure Glaucoma, Minimally Invasive Glaucoma Surgery, Goniosynechialysis, Goniotomy, Glaucoma
- Being tested
- various types of angle interventions
- Medical subject headings
- Glaucoma, Angle-Closure, Glaucoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
various types of angle interventionsProcedure or surgery
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.
| Study group | Role | What they receive |
|---|---|---|
| laser peripheral iridotomy/iridoplasty group | based on angle closure mechanism, procedures were chosen LPI alone or combined with ALPIp.
LPI: laser peripheral iridotomy; ALPIp: argon laser peripheral iridoplasty. Receives: Procedure: various types of angle interventions | |
| peripheral iridectomy based surgery combo | SPI combined with GSL or GSL+GT SPI: surgical peripheral iridectomy GSL:goniosynechialysis GT: goniotomy GSL and GT are both guided by surgical goniolens Receives: Procedure: various types of angle interventions | |
| phacoemulsification and intraocular lens implantation based surgery combo | PEI: phacoemulsification and intraocular lens implantation surgery combo includes GSL alone or GSL+GT. Receives: Procedure: various types of angle interventions | |
| ab interno goniotomy | 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° Receives: Procedure: various types of angle interventions | |
| Schlemm canaloplasty | 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° Receives: Procedure: various types of angle interventions |
What is being measured
The primary outcome is the main question the study is designed to answer.
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
Measured: 12 months
Secondary outcomes (1)
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.
Measured: 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jul 2024
- Study start1 Dec 2023
- Primary completion30 Dec 2025 (estimated)
- Study completion30 Dec 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Angle-closure GlaucomaStudies of the same condition, open and under way.
- More trials run by Zhongshan Ophthalmic Center, Sun Yat-sen UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Xinbo Gao, Zhongshan Ophthalmic Center, Sun Yat-sen University
- Investigators
- Xinbo Gao, MD, Principal investigator, State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06492538
- Sponsor's protocol ID
- 2023KYPJ304
- Status last verified
- Oct 2025
- First submitted
- 1 Jul 2024
- Last updated
- 12 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 12 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Biometric Changes After Intervention of Anterior Chamber Angle : an Observational Study
- ClinicalTrials.gov ID
- NCT06492538
- Acronym / sponsor ID
- 2023KYPJ304
- Conditions
- Angle-closure Glaucoma, Minimally Invasive Glaucoma Surgery, Goniosynechialysis, Goniotomy, Glaucoma
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- Zhongshan Ophthalmic Center, Sun Yat-sen UniversityUniversity, hospital or other
- Study start
- 1 Dec 2023 (actual)
- Primary completion
- 30 Dec 2025 (estimated)
- Study completion
- 30 Dec 2025 (estimated)
- First posted
- 9 Jul 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| laser peripheral iridotomy/iridoplasty group | – | Procedure: various types of angle interventionsbased on angle closure mechanism, procedures were chosen LPI alone or combined with ALPIp. LPI: laser peripheral iridotomy; ALPIp: argon laser peripheral iridoplasty. |
| peripheral iridectomy based surgery combo | – | Procedure: various types of angle interventionsSPI combined with GSL or GSL+GT SPI: surgical peripheral iridectomy GSL:goniosynechialysis GT: goniotomy GSL and GT are both guided by surgical goniolens |
| phacoemulsification and intraocular lens implantation based surgery combo | – | Procedure: various types of angle interventionsPEI: phacoemulsification and intraocular lens implantation surgery combo includes GSL alone or GSL+GT. |
| ab interno goniotomy | – | Procedure: various types of angle interventionsGT 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° |
| Schlemm canaloplasty | – | Procedure: various types of angle interventionsperformed 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° |
Who may qualify
- Ages
- 30 to 85 years
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- 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;
Key inclusion criteria (3 listed)
- Glaucoma patients eligible for standalone or combined angle intervention surgeries, such as LPI, LPIP, goniosynechialysis, trabeculotomy alone or combined with surgical iridectomy or phacoemulsification and intraocular lens implantation;
- Patients capable of undergoing preoperative examinations including CASIA2-OCT (anterior segment OCT), UBM, slit-lamp gonioscopy, IOL Master (or other optical biometry);
- Patients willing to participate in this study, signing informed consent, and agreeing to follow-up according to the study protocol.
Key exclusion criteria (6 listed)
- Patients with severe ocular conditions such as corneal infection, ulcer, trauma, ocular tumors, retinal vascular occlusion, and retinal detachment;
- Those with various types of eye diseases that affect ocular parameter acquisition or interfere with visual field examination;
- Long-term local or systemic use of glucocorticoids;
- Patients with severe systemic diseases;
- Pregnant or lactating women;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| various types of angle interventionsprocedures 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. | Procedure or surgery | Schlemm canaloplasty, ab interno goniotomy, laser peripheral iridotomy/iridoplasty group, peripheral iridectomy based surgery combo, phacoemulsification and intraocular lens implantation based surgery combo |
Primary outcome
Changes in biological parameters of the anterior chamber angle
Time frame: 12 months
Biological parameter changes in the anterior chamber following angle intervention surgery will be measured using Casia2-OCT
1 secondary outcome
success rate of angle intervention surgeries
Time frame: 12 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 12 Dec 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Xinbo Gao, MD principal investigator
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Angle-closure Glaucoma and Minimally Invasive Glaucoma Surgery, run by Zhongshan Ophthalmic Center, Sun Yat-sen University at 1 site in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 12 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Xinbo Gao, MD (+8618319579657, gaoxb@mail.sysu.edu.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in biological parameters of the anterior chamber angle (time frame: 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Dec 2025.