Primary Angle-Closure GlaucomaPCB-RiskNCT07549438
Predicting the Risk of Partial Ciliary Block After Cataract and Goniosynechialysis Surgery in Primary Angle-Closure Disease
An observational study of Primary Angle-Closure Glaucoma, run by Peking University People's Hospital.
Trial summary
Primary angle-closure disease (PACD) is a major cause of vision loss, often treated with a combined surgery that removes the eye's natural lens (cataract surgery) and physically opens the eye's drainage system (goniosynechialysis). Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Primary Angle-Closure Glaucoma
- How many people
- 1,150 participants
- Where
- No sites listed yet
- Study dates
- 20 Apr 2026to 19 Apr 2031
- 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 Any age
- All sexes
- Child, Adult, Older adult
Study population: Patients with Primary Angle-Closure Disease (PACD)-spanning PACS, PAC, and PACG-who require surgical intervention with phacoemulsification combined with goniosynechialysis. Participants will be enrolled from the routine clinical care settings across multiple participating tertiary ophthalmic centers.
Who may be able to join
- Diagnosis of Primary Angle-Closure Disease (PACD), including Primary Angle-Closure Suspect (PACS), Primary Angle-Closure (PAC), or Primary Angle-Closure Glaucoma (PACG).
- Clinical indication for phacoemulsification combined with intraocular lens implantation and goniosynechialysis (Phaco+GSL), due to poorly controlled intraocular pressure, extensive peripheral anterior synechiae (PAS), or the presence of a clinically significant cataract.
- Ability to cooperate with required preoperative imaging examinations, including Ultrasound Biomicroscopy (UBM), IOLMaster, and Anterior Segment Optical Coherence Tomography (AS-OCT).
Who cannot join
- Secondary angle closure (e.g., neovascular glaucoma, uveitic glaucoma, iridocorneal endothelial [ICE] syndrome, or intraocular tumors/cysts).
- Specific lens abnormalities that confound anatomical assessment, including lens subluxation, hypermature intumescent cataract, or traumatic cataract.
- Previous intraocular surgery, including glaucoma filtering surgeries (e.g., trabeculectomy, tube shunts) or vitreoretinal surgeries (Note: Previous laser peripheral iridotomy is permitted).
- Use of systemic or topical medications known to affect ciliary body morphology or pupillary function (e.g., topiramate, cholinergic agonists) during the time of imaging.
- Poor quality or uninterpretable preoperative UBM or OCT images due to corneal opacity, edema, or other media opacities.
- Axial length shorter than 19mm.
About this study
Official title: Risk Prediction of Partial Ciliary Block After Phacoemulsification Combined With Goniosynechialysis in Primary Angle-Closure Disease: A Prospective Multicenter Study
Primary angle-closure disease (PACD) is a major cause of vision loss, often treated with a combined surgery that removes the eye's natural lens (cataract surgery) and physically opens the eye's drainage system (goniosynechialysis). While effective, this surgery carries a small risk of a severe complication called ciliary block (or aqueous misdirection), where fluid builds up in the wrong part of the eye, pushing structures forward and causing high eye pressure. Recently, doctors have also noticed a "partial" form of this block, which can slowly cause the eye's drainage angle to close again without immediate severe symptoms.
The purpose of this prospective, observational study is to identify which patients are at the highest risk for developing classic or partial ciliary block after this combined surgery. Researchers will use standard, non-invasive eye imaging tools-such as ultrasound biomicroscopy (UBM) and optical coherence tomography (OCT)-to take highly detailed measurements of the front of the eye before surgery. They will specifically look at factors like the width of the anterior chamber, the thickness of the lens, and the eye's overall length. To ensure accuracy, patients with a very short eye length (less than 19mm) will not be included in the study.
Read more
Because this is an observational study, participation will not change a patient's standard surgical plan. Patients will undergo their scheduled surgery and be monitored for 12 months during routine follow-up visits to track their eye pressure, vision, and any structural changes in the eye.
By confirming which pre-surgery measurements predict ciliary block, researchers hope to validate a risk-warning model. This will help eye surgeons take preventive steps-such as administering specific medications like mannitol before surgery-to make the procedure safer and improve long-term outcomes for patients with PACD.
- Conditions
- Primary Angle-Closure Glaucoma
- 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 |
|---|---|---|
| CB Group | Patients who develop classic or partial ciliary block (CB) during the 12-month follow-up period after phacoemulsification combined with goniosynechialysis. | |
| Non-CB Group | Patients who do not develop any form of ciliary block during the 12-month follow-up period after the surgery. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of Ciliary Block (Classic and Partial)
The primary outcome is the occurrence rate of classic or partial ciliary block (CB) following phacoemulsification combined with goniosynechialysis. Classic CB is diagnosed by a shallow or flat anterior chamber with elevated intraocular pressure, excluding pupillary block or choroidal effusion. Partial (subclinical) CB is defined by meeting at least two of the following criteria: an unexpected shallow anterior chamber (e.g., less than the expected 3mm or significantly smaller than the contralateral eye), a significant myopic shift (≥ -1.50D) indicating IOL-iris diaphragm anterior shift, UBM/OCT evidence of ciliary body anterior rotation, or significant deepening of the anterior chamber after cycloplegic administration. Intraoperative aqueous misdirection is also recorded as a primary endpoint event.
Measured: Up to 12 months postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Apr 2026
- Study start20 Apr 2026 (estimated)
- Primary completion19 Apr 2030 (estimated)
- Study completion19 Apr 2031 (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.
- More trials run by Peking University People's HospitalThe 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
- 1,150 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
- NCT07549438
- Sponsor's protocol ID
- PekingUPHOphthalmology004
- Acronym
- PCB-Risk
- Status last verified
- Apr 2026
- First submitted
- 18 Apr 2026
- Last updated
- 24 Apr 2026
- Results posted
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Risk Prediction of Partial Ciliary Block After Phacoemulsification Combined With Goniosynechialysis in Primary Angle-Closure Disease: A Prospective Multicenter Study
- ClinicalTrials.gov ID
- NCT07549438
- Acronym / sponsor ID
- PCB-Risk / PekingUPHOphthalmology004
- Conditions
- Primary Angle-Closure Glaucoma
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 1,150 participants (estimated)
- Lead sponsor
- Peking University People's HospitalUniversity, hospital or other
- Study start
- 20 Apr 2026 (estimated)
- Primary completion
- 19 Apr 2030 (estimated)
- Study completion
- 19 Apr 2031 (estimated)
- First posted
- 24 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.
Primary angle-closure disease (PACD) is a major cause of vision loss, often treated with a combined surgery that removes the eye's natural lens (cataract surgery) and physically opens the eye's drainage system (goniosynechialysis). While effective, this surgery carries a small risk of a severe complication called ciliary block (or aqueous misdirection), where fluid builds up in the wrong part of the eye, pushing structures forward and causing high eye pressure. Recently, doctors have also noticed a "partial" form of this block, which can slowly cause the eye's drainage angle to close again without immediate severe symptoms.
The purpose of this prospective, observational study is to identify which patients are at the highest risk for developing classic or partial ciliary block after this combined surgery. Researchers will use standard, non-invasive eye imaging tools-such as ultrasound biomicroscopy (UBM) and optical coherence tomography (OCT)-to take highly detailed measurements of the front of the eye before surgery. They will specifically look at factors like the width of the anterior chamber, the thickness of the lens, and the eye's overall length. To ensure accuracy, patients with a very short eye length (less than 19mm) will not be included in the study.
Because this is an observational study, participation will not change a patient's standard surgical plan. Patients will undergo their scheduled surgery and be monitored for 12 months during routine follow-up visits to track their eye pressure, vision, and any structural changes in the eye.
By confirming which pre-surgery measurements predict ciliary block, researchers hope to validate a risk-warning model. This will help eye surgeons take preventive steps-such as administering specific medications like mannitol before surgery-to make the procedure safer and improve long-term outcomes for patients with PACD.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| CB Group | – | –Patients who develop classic or partial ciliary block (CB) during the 12-month follow-up period after phacoemulsification combined with goniosynechialysis. |
| Non-CB Group | – | –Patients who do not develop any form of ciliary block during the 12-month follow-up period after the surgery. |
Who may qualify
- Sex
- All
- Age groups
- Child, Adult, Older adult
- Study population
- Patients with Primary Angle-Closure Disease (PACD)-spanning PACS, PAC, and PACG-who require surgical intervention with phacoemulsification combined with goniosynechialysis. Participants will be enrolled from the routine clinical care settings across multiple participating tertiary ophthalmic centers.
Key inclusion criteria (3 listed)
- Diagnosis of Primary Angle-Closure Disease (PACD), including Primary Angle-Closure Suspect (PACS), Primary Angle-Closure (PAC), or Primary Angle-Closure Glaucoma (PACG).
- Clinical indication for phacoemulsification combined with intraocular lens implantation and goniosynechialysis (Phaco+GSL), due to poorly controlled intraocular pressure, extensive peripheral anterior synechiae (PAS), or the presence of a clinically significant cataract.
- Ability to cooperate with required preoperative imaging examinations, including Ultrasound Biomicroscopy (UBM), IOLMaster, and Anterior Segment Optical Coherence Tomography (AS-OCT).
Key exclusion criteria (6 listed)
- Secondary angle closure (e.g., neovascular glaucoma, uveitic glaucoma, iridocorneal endothelial [ICE] syndrome, or intraocular tumors/cysts).
- Specific lens abnormalities that confound anatomical assessment, including lens subluxation, hypermature intumescent cataract, or traumatic cataract.
- Previous intraocular surgery, including glaucoma filtering surgeries (e.g., trabeculectomy, tube shunts) or vitreoretinal surgeries (Note: Previous laser peripheral iridotomy is permitted).
- Use of systemic or topical medications known to affect ciliary body morphology or pupillary function (e.g., topiramate, cholinergic agonists) during the time of imaging.
- Poor quality or uninterpretable preoperative UBM or OCT images due to corneal opacity, edema, or other media opacities.
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
Incidence of Ciliary Block (Classic and Partial)
Time frame: Up to 12 months postoperatively
The primary outcome is the occurrence rate of classic or partial ciliary block (CB) following phacoemulsification combined with goniosynechialysis. Classic CB is diagnosed by a shallow or flat anterior chamber with elevated intraocular pressure, excluding pupillary block or choroidal effusion. Partial (subclinical) CB is defined by meeting at least two of the following criteria: an unexpected shallow anterior chamber (e.g., less than the expected 3mm or significantly smaller than the contralateral eye), a significant myopic shift (≥ -1.50D) indicating IOL-iris diaphragm anterior shift, UBM/OCT evidence of ciliary body anterior rotation, or significant deepening of the anterior chamber after cycloplegic administration. Intraoperative aqueous misdirection is also recorded as a primary endpoint event.
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 24 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.
The record lists no contact. Use the official record to reach the sponsor.
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.
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: opening soon, as of the sponsor's last update on 24 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of Ciliary Block (Classic and Partial) (time frame: Up to 12 months postoperatively). 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 24 Apr 2026.