Vitreous zonule and its role in primary angle-closure glaucoma.

A Cross-Sectional, Prospective Observational Study on the Role of the Vitreous Zonule in the Pathogenesis of Primary Angle-Closure Glaucoma

This project will try 3D ultrasound imaging to see if the vitreous zonule contributes to angle-closure glaucoma in adults with or at risk for primary angle-closure disease and in healthy people.

Quick facts

• Study type: Observational
• Enrollment: 440 (estimated)
• Ages: 30 Years to 79 Years
• Sex: All
• Sponsor: Peking University People's Hospital (other)
• Locations: 1 site (Beijing)
• Trial ID: NCT07523139 on ClinicalTrials.gov

What this trial studies

This prospective observational study will enroll adults with primary angle-closure disease (PACS, PAC, PACG) and age-matched healthy controls to undergo detailed eye exams, gonioscopy, biometry with IOLMaster, and ultrasound biomicroscopy (UBM). Investigators will analyze vitreous zonule (VZ) morphology, location, visible quadrants, and anterior segment parameters across age and axial-length groups and compare findings between healthy eyes and PACD eyes. The team will also develop and validate a rotational-scanning three-dimensional UBM (3D-UBM) method to reconstruct the circumferential VZ. No therapeutic interventions are given; the focus is imaging, measurement, and method development.

Who should consider this trial

Good fit: Adults aged 30–80 with a diagnosis of PACS, PAC, or PACG, or healthy controls with open angles, lens opacity below grade 2 (LOCS III), and ability to give informed consent are eligible.

Not a fit: Patients with prior intraocular surgery or laser, other significant anterior or posterior segment eye diseases, or systemic conditions that affect ocular measurements, as well as those outside the 30–80 age range, are unlikely to benefit from this observational imaging study.

Why it matters

Potential benefit: If successful, improved 3D imaging and understanding of the vitreous zonule could help identify patients at risk and guide more targeted diagnosis or management of angle-closure glaucoma.

How similar studies have performed: Prior work using standard UBM has suggested a role for the vitreous zonule in angle closure, but circumferential 3D reconstruction with rotational 3D-UBM is largely novel and not yet widely validated.

Eligibility criteria

Inclusion Criteria:

1\. Age between 30 and 80 years, inclusive. 2. Diagnosis of primary angle-closure disease (PACS, PAC, or PACG) according to standardized gonioscopic criteria; or healthy controls with open angles. 3. Lens opacity graded \< 2 for cortical and nuclear opacities according to the Lens Opacities Classification System III (LOCS III). 4. Ability and willingness to provide written informed consent.

Exclusion Criteria:

1\. Any intraocular disease affecting the anterior or posterior segment, including but not limited to corneal disease, iris abnormalities, lens disorders other than age-related cataract, vitreous disorders, uveoretinal diseases, or optic neuropathies. 2. Prior intraocular surgery or laser treatment, including cataract surgery, trabeculectomy, laser trabeculoplasty, laser peripheral iridotomy, laser iridoplasty, or vitreoretinal surgery. 3. Systemic diseases that may affect ocular examination or confound measurements, such as end-stage cardiac disease, renal disease, pulmonary disease, or advanced malignancy. 4. Inability to undergo ultrasound biomicroscopy (UBM) examination due to inability to maintain supine position or other contraindications. 5. Pregnancy or lactation. 6. Any condition that, in the opinion of the investigator, would compromise the participant's ability to comply with study procedures or affect the validity of the study results.

Where this trial is running

Beijing

• Peking University People's Hospital — Beijing, China (RECRUITING)

Study contacts

• Study coordinator: Kun Lv, M.D.

Conditions: Primary Angle-Closure Glaucoma, Ultrasound Biomicroscopy, Vitreous Zonule, Three-dimensional Imaging