Primary Angle-Closure GlaucomaNCT07523139
Vitreous Zonule in Primary Angle-Closure Glaucoma
An observational study of Primary Angle-Closure Glaucoma, run by Peking University People's Hospital at 1 site in China.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 30 to 79 yearsHealthy volunteers can take part
- Conditions the study is for
- Primary Angle-Closure Glaucoma
- How many people
- 440 participants
- Where
- 1 siteChina
- Study dates
- 1 Jan 2025to Jun 2027
- 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 79 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: The study population will be recruited from the Department of Ophthalmology at Peking University People's Hospital, a tertiary referral center in Beijing, China. Participants will include patients diagnosed with primary angle-closure disease (PACS, PAC, and PACG) and healthy controls with open angles. Patients will be identified from outpatient clinics and through routine ophthalmic examinations. Healthy controls will be recruited from volunteers undergoing routine eye examinations, as well as from hospital staff and community members. All participants will be recruited prospectively and consecutively to minimize selection bias.
Who may be able to join
- 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.
Who cannot join
- 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.
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
Peking University People's Hospital
Beijing, 100044
Kun Lv, M.D., 13681213130, lvkun0327@163.com
About this study
Official title: A Cross-Sectional, Prospective Observational Study on the Role of the Vitreous Zonule in the Pathogenesis of Primary Angle-Closure Glaucoma
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.
- Conditions
- Primary Angle-Closure Glaucoma
- Keywords
- Ultrasound Biomicroscopy, Vitreous Zonule, Three-dimensional Imaging
- Medical subject headings
- Glaucoma, Angle-Closure
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Group 1 Healthy Controls | Not described | |
| Group 2 Primary Angle-Closure Suspects (PACS） | Not described | |
| Group 3 Primary Angle Closure | Not described | |
| Group 4 Primary Angle Closure Glaucoma | Not described |
What is being measured
The primary outcome is the main question the study is designed to answer.
Vitreous Zonule Visibility on Ultrasound Biomicroscopy
Presence and quadrant count of the VZ assessed by ultrasound biomicroscopy (UBM). VZ is defined as fibrous bands extending from the pars plana to the posterior lens equator or ciliary processes. Presence is defined as VZ visible in at least one quadrant; quadrant count ranges from 0 to 4.
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Apr 2026
- Study start1 Jan 2025
- Primary completionJun 2027 (estimated)
- Study completionJun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Primary Angle-Closure GlaucomaStudies of the same condition, open and under way.
- 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
- 440 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Peking University People's Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Wu Huijuan, Peking University People's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07523139
- Sponsor's protocol ID
- PekingUPHOphthalmology003
- Status last verified
- Apr 2026
- First submitted
- 5 Apr 2026
- Last updated
- 13 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Cross-Sectional, Prospective Observational Study on the Role of the Vitreous Zonule in the Pathogenesis of Primary Angle-Closure Glaucoma
- ClinicalTrials.gov ID
- NCT07523139
- Acronym / sponsor ID
- PekingUPHOphthalmology003
- Conditions
- Primary Angle-Closure Glaucoma
- Keywords
- Ultrasound Biomicroscopy, Vitreous Zonule, Three-dimensional Imaging
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 440 participants (estimated)
- Lead sponsor
- Peking University People's HospitalUniversity, hospital or other
- Study start
- 1 Jan 2025 (actual)
- Primary completion
- Jun 2027 (estimated)
- Study completion
- Jun 2027 (estimated)
- First posted
- 13 Apr 2026 (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.
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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Group 1 Healthy Controls | – | – |
| Group 2 Primary Angle-Closure Suspects (PACS） | – | – |
| Group 3 Primary Angle Closure | – | – |
| Group 4 Primary Angle Closure Glaucoma | – | – |
Who may qualify
- Ages
- 30 to 79 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- The study population will be recruited from the Department of Ophthalmology at Peking University People's Hospital, a tertiary referral center in Beijing, China. Participants will include patients diagnosed with primary angle-closure disease (PACS, PAC, and PACG) and healthy controls with open angles. Patients will be identified from outpatient clinics and through routine ophthalmic examinations. Healthy controls will be recruited from volunteers undergoing routine eye examinations, as well as from hospital staff and community members. All participants will be recruited prospectively and consecutively to minimize selection bias.
Key inclusion criteria (1 listed)
- 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.
Key exclusion criteria (1 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Vitreous Zonule Visibility on Ultrasound Biomicroscopy
Time frame: Baseline
Presence and quadrant count of the VZ assessed by ultrasound biomicroscopy (UBM). VZ is defined as fibrous bands extending from the pars plana to the posterior lens equator or ciliary processes. Presence is defined as VZ visible in at least one quadrant; quadrant count ranges from 0 to 4.
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 13 Apr 2026.
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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.
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 Primary Angle-Closure Glaucoma, run by Peking University People's Hospital 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 1 inclusion and 1 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 13 Apr 2026. 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 Kun Lv, M.D. (13681213130, lvkun0327@163.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Vitreous Zonule Visibility on Ultrasound Biomicroscopy (time frame: Baseline). 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 13 Apr 2026.