Biometric Changes After Intervention of Anterior Chamber Angle : an Observational Study

NCT ID: NCT06492538

Last Updated: 2025-12-12

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 300 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2023-12-01
• Study Completion Date: 2025-12-30

Brief 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 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.

Conditions

Angle-closure Glaucoma; Minimally Invasive Glaucoma Surgery; Goniosynechialysis; Goniotomy; Glaucoma

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

phacoemulsification and intraocular lens implantation based surgery combo

PEI: phacoemulsification and intraocular lens implantation surgery combo includes GSL alone or GSL+GT.

various types of angle interventions

Intervention Type: PROCEDURE

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.

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.

various types of angle interventions

Intervention Type: PROCEDURE

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.

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

various types of angle interventions

Intervention Type: PROCEDURE

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.

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°

various types of angle interventions

Intervention Type: PROCEDURE

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.

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°

various types of angle interventions

Intervention Type: PROCEDURE

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.

Interventions

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.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• 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.

Exclusion Criteria

• 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.

• Minimum Eligible Age: 30 Years
• Maximum Eligible Age: 85 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Zhongshan Ophthalmic Center, Sun Yat-sen University

OTHER

Sponsor Role: lead

Responsible Party

Xinbo Gao

associate professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Xinbo Gao, MD

Role: PRINCIPAL_INVESTIGATOR

State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University

Locations

Zhongshan ophthalmic center

Guangzhou, Guangdong, China

Site Status: RECRUITING

Countries

China

Central Contacts

Xinbo Gao, MD

Role: CONTACT

gaoxb@mail.sysu.edu.cn

+8618319579657

Facility Contacts

Xinbo Gao, MD

Role: primary

gaoxb@mail.sysu.edu.cn

+8618319579657

Other Identifiers

2023KYPJ304

Identifier Type: -

Identifier Source: org_study_id