Vitreous Zonule in Primary Angle-Closure Glaucoma

Recruiting now

Conditions studied: Primary Angle-Closure Glaucoma

In brief

This study aims to investigate the role of the vitreous zonule (VZ) in the pathogenesis of primary angle-closure glaucoma (PACG) and to explore the feasibility of three-dimensional ultrasound biomicroscopy (3D-UBM) for imaging the circumferential VZ. This prospective, observational study will enroll patients with primary angle-closure disease (PACD), including primary angle-closure suspect (PACS), primary angle-closure (PAC), and PACG, as well as healthy controls. All participants will undergo comprehensive ophthalmic examinations, including gonioscopy, biometric measurements using IOLMaster, and UBM imaging. The study consists of three main components: (1) analysis of VZ morphology, location, number of visible quadrants, and anterior segment parameters across different age groups and axial length groups in healthy individuals, with comparisons to age-matched PACD patients; (2) development and validation of a 3D-UBM imaging system using a rotational scanning approach to reconstruct the spatial structure of the VZ; and (3) characterization of VZ features, including density and morphology, in normal eyes versus PACD eyes using 3D-UBM. The primary outcomes include the presence, quadrant count, and morphological characteristics (vitreous zonule-pars plana angle and maximum distance) of the VZ, as well as anterior segment parameters such as lens vault, anterior chamber depth, trabecular-iris angle, and angle opening distance. By elucidating age-related and axial length-related changes in the VZ and establishing 3D-UBM as a novel imaging modality for the posterior zonular apparatus, this study seeks to provide new evidence for the mechanistic role of the VZ in angle-closure glaucoma and to identify potential imaging biomarkers for early diagnosis and risk stratification.

Key facts

Study ID: NCT07523139
Run by: Peking University People's Hospital
People needed: 440
Starts: 2025-01-01
Expected to finish: 2027-06-01
Last updated by the study team: 2026-04-13

Who can join

Age: 30 and older, up to 79. Sex: any. Healthy volunteers: accepted.

You may qualify if…

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.

You may not qualify if…

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 it is running

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

Full record on ClinicalTrials.gov

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