GlaucomaNCT04495491
Predicting the Effect of Laser Peripheral Iridotomy
An observational study of Glaucoma, run by Zhongshan Ophthalmic Center, Sun Yat-sen University at 1 site in China.
Trial summary
This study will compare the angle parameters of patients with PACS before and after LPI. The investigators will analyze the results of patients with different angle closure mechanisms before and after LPI, and participants hope to find the structural parameters for predicting the effect of LPI. Read more about this study
- Who is it for?
- Ages 20 years and older
- Conditions the study is for
- Glaucoma
- What is being tested?
- pupillary block group, plateau iris group and mixing mechanism group
- How many people
- 200 participants
- Where
- 1 siteChina
- Study dates
- 1 Jul 2020to 31 Mar 2021
- How long will I take part?
- 4 Weeks
- Phase
- Observational
- Are there results?
- None posted in the registry
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 20 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Chinese Patient was diagnosed of primary angle closure angle suspect
Who may be able to join
- Patient was diagnosed of primary angle closure angle suspect;
- received ultrasound Biomicroscopy before and after laser peripheral iridotomy;
- Voluntary participation in this study;
- Have enough language comprehension ability;
- Patient or his legal representative has sign the informed consent.
Who cannot join
- severe health problems resulting in a life expectancy of less than 1 year;
- previous intraocular surgery or penetrating eye injury;
- media opacity preventing laser peripheral iridotomy;
- Researchers think not suitable to participate in this clinical trial subjects;
- Refused to sign the informed consent.;
- There are important viscera function failure or other serious disease, including clinical related coronary artery disease, cardiovascular disease or myocardial infarction into the group of the first six months; serious neurological or psychiatric illness; serious infections; coagulant function abnormality; general active infectious diseases; malignant tumor; serious immune diseases.
Trial locations and contacts
1 site in 1 country.
China1 site, 1 recruiting
- Recruiting
Zhongshan Ophthalmic Center, Sun Yat-San Univerdity
Guangzhou, Guangdong
Yuying Zhou, Master, 15270988097, 2053552500@qq.com
About this study
Official title: Prediction of the Degree of Angle Opening Distance in Patients With Primary Angle Closure Suspect After Laser Peripheral Iridotomy
This study will compare the angle parameters of patients with PACS before and after LPI. The investigators will analyze the results of patients with different angle closure mechanisms before and after LPI, and participants hope to find the structural parameters for predicting the effect of LPI.
Read the detailed description
Primary angle-closure glaucoma is the leading cause of blindness worldwide. It is associated with increased intraocular pressure, which causes optic nerve damage and field defects if untreated. The aqueous humor leaves the anterior chamber through the trabecular meshwork and flows into the aqueous vein and the superior scleral vein through the collector channels and Schlemm's canal. If the trabecular meshwork is not blocked, a wide angle allows enough aqueous humor to drain out. The iris corneal translocation may lead to angle-closure glaucoma.
Laser peripheral iridectomy is recognized as the best surgical method to relieve pupil block. Previous studies have shown increased anterior chamber depth (ACD), area (ACA), and volume (ACV), and increased Angle open distance (AOD) after LPI surgery.
However, postoperative outcomes of LPI were not the same for patients with different angle closure mechanisms.
Postoperative outcomes for LPI were best for patients with pupillary block type, but were moderate for patients with plateau iris group and mixed group.
The purpose of this study, conducted in Chinese subjects, aims to use UBM to evaluate changes in the anterior segment parameters of LPI, and to propose methods to predict postoperative outcomes of LPI.
- Conditions
- Glaucoma
- Being tested
- pupillary block group, plateau iris group, mixing mechanism group
- Keywords
- laser peripheral iridotomy, primary angle closure suspect, angle closure mechanism
- Medical subject headings
- Glaucoma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
pupillary block groupOther
According to the configurations of angle closure, the pupillary block group is defined as the iris bombe.
plateau iris groupOther
According to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris.
mixing mechanism groupOther
According to the configurations of angle closure, the mixing mechanism group is defined as the iris bombe plus thickening of the peripheral iris.
| Study group | Role | What they receive |
|---|---|---|
| Pupillary block group | According to the configurations of angle closure, the pupillary block group is defined as the iris bombe. Receives: Other: pupillary block group | |
| plateau iris group | According to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris. Receives: Other: plateau iris group | |
| mixed mechanism group | According to the configurations of angle closure, the mixing mechanism group is defined as the iris bombe plus thickening of the peripheral iris. Receives: Other: mixing mechanism group |
What is being measured
The primary outcome is the main question the study is designed to answer.
the changes in anterior opening distance before and after LPI
To compare the difference of anterior opening distance after LPI and baseline parameters before LPI. Anterior opening distance, measured on a line perpendicular to the plane of the trabecular surface 500 μm anterior to the scleral spur and extended to meet the surface of the iris
Measured: between the baseline and 1 hour before discharge
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Jul 2020
- Study start1 Jul 2020
- Primary completion31 Dec 2020 (estimated)
- Study completion31 Mar 2021 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for 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
- Other
- Time perspective
- Prospective
- Enrolment
- 200 participants (estimated)
- Target duration
- 4 Weeks
Sponsor and investigators
- Lead sponsor
- Zhongshan Ophthalmic Center, Sun Yat-sen University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mingkai Lin, Zhongshan Ophthalmic Center, Sun Yat-sen University
- Investigators
- Mingkai Lin, MD, Study chair, Zhongshan Ophthalmic Center, Sun Yat-San University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04495491
- Sponsor's protocol ID
- 2019KYPJ182
- Status last verified
- Jul 2020
- First submitted
- 22 Jul 2020
- Last updated
- 31 Jul 2020
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
He M, Jiang Y, Huang S, Chang DS, Munoz B, Aung T, Foster PJ, Friedman DS. Laser peripheral iridotomy for the prevention of angle closure: a single-centre, randomised controlled trial. Lancet. 2019 Apr 20;393(10181):1609-1618. doi: 10.1016/S0140-6736(18)32607-2. Epub 2019 Mar 14.
PubMed 30878226He M, Friedman DS, Ge J, Huang W, Jin C, Lee PS, Khaw PT, Foster PJ. Laser peripheral iridotomy in primary angle-closure suspects: biometric and gonioscopic outcomes: the Liwan Eye Study. Ophthalmology. 2007 Mar;114(3):494-500. doi: 10.1016/j.ophtha.2006.06.053. Epub 2006 Nov 21.
PubMed 17123610He M, Foster PJ, Ge J, Huang W, Zheng Y, Friedman DS, Lee PS, Khaw PT. Prevalence and clinical characteristics of glaucoma in adult Chinese: a population-based study in Liwan District, Guangzhou. Invest Ophthalmol Vis Sci. 2006 Jul;47(7):2782-8. doi: 10.1167/iovs.06-0051.
PubMed 16799014
Study at a glance
From the registry record, last updated by the sponsor on 31 Jul 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Prediction of the Degree of Angle Opening Distance in Patients With Primary Angle Closure Suspect After Laser Peripheral Iridotomy
- ClinicalTrials.gov ID
- NCT04495491
- Acronym / sponsor ID
- 2019KYPJ182
- Conditions
- Glaucoma
- Keywords
- laser peripheral iridotomy, primary angle closure suspect, angle closure mechanism
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Zhongshan Ophthalmic Center, Sun Yat-sen UniversityUniversity, hospital or other
- Study start
- 1 Jul 2020 (actual)
- Primary completion
- 31 Dec 2020 (estimated)
- Study completion
- 31 Mar 2021 (estimated)
- First posted
- 31 Jul 2020 (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 will compare the angle parameters of patients with PACS before and after LPI. The investigators will analyze the results of patients with different angle closure mechanisms before and after LPI, and participants hope to find the structural parameters for predicting the effect of LPI.
Detailed description
Primary angle-closure glaucoma is the leading cause of blindness worldwide. It is associated with increased intraocular pressure, which causes optic nerve damage and field defects if untreated. The aqueous humor leaves the anterior chamber through the trabecular meshwork and flows into the aqueous vein and the superior scleral vein through the collector channels and Schlemm's canal. If the trabecular meshwork is not blocked, a wide angle allows enough aqueous humor to drain out. The iris corneal translocation may lead to angle-closure glaucoma.
Laser peripheral iridectomy is recognized as the best surgical method to relieve pupil block. Previous studies have shown increased anterior chamber depth (ACD), area (ACA), and volume (ACV), and increased Angle open distance (AOD) after LPI surgery.
However, postoperative outcomes of LPI were not the same for patients with different angle closure mechanisms.
Postoperative outcomes for LPI were best for patients with pupillary block type, but were moderate for patients with plateau iris group and mixed group.
The purpose of this study, conducted in Chinese subjects, aims to use UBM to evaluate changes in the anterior segment parameters of LPI, and to propose methods to predict postoperative outcomes of LPI.
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Target follow-up
- 4 Weeks
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Pupillary block group | – | Other: pupillary block groupAccording to the configurations of angle closure, the pupillary block group is defined as the iris bombe. |
| plateau iris group | – | Other: plateau iris groupAccording to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris. |
| mixed mechanism group | – | Other: mixing mechanism groupAccording to the configurations of angle closure, the mixing mechanism group is defined as the iris bombe plus thickening of the peripheral iris. |
Who may qualify
- Ages
- 20 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Chinese Patient was diagnosed of primary angle closure angle suspect
Key inclusion criteria (5 listed)
- Patient was diagnosed of primary angle closure angle suspect;
- received ultrasound Biomicroscopy before and after laser peripheral iridotomy;
- Voluntary participation in this study;
- Have enough language comprehension ability;
- Patient or his legal representative has sign the informed consent.
Key exclusion criteria (6 listed)
- severe health problems resulting in a life expectancy of less than 1 year;
- previous intraocular surgery or penetrating eye injury;
- media opacity preventing laser peripheral iridotomy;
- Researchers think not suitable to participate in this clinical trial subjects;
- Refused to sign the informed consent.;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| pupillary block groupAccording to the configurations of angle closure, the pupillary block group is defined as the iris bombe. | Other | Pupillary block group |
| plateau iris groupAccording to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris. | Other | plateau iris group |
| mixing mechanism groupAccording to the configurations of angle closure, the mixing mechanism group is defined as the iris bombe plus thickening of the peripheral iris. | Other | mixed mechanism group |
Primary outcome
the changes in anterior opening distance before and after LPI
Time frame: between the baseline and 1 hour before discharge
To compare the difference of anterior opening distance after LPI and baseline parameters before LPI. Anterior opening distance, measured on a line perpendicular to the plane of the trabecular surface 500 μm anterior to the scleral spur and extended to meet the surface of the iris
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 31 Jul 2020.
- Background: PubMed 30878226He M, Jiang Y, Huang S, Chang DS, Munoz B, Aung T, Foster PJ, Friedman DS. Laser peripheral iridotomy for the prevention of angle closure: a single-centre, randomised controlled trial. Lancet. 2019 Apr 20;393(10181):1609-1618. doi: 10.1016/S0140-6736(18)32607-2. Epub 2019 Mar 14.
- Background: PubMed 17123610He M, Friedman DS, Ge J, Huang W, Jin C, Lee PS, Khaw PT, Foster PJ. Laser peripheral iridotomy in primary angle-closure suspects: biometric and gonioscopic outcomes: the Liwan Eye Study. Ophthalmology. 2007 Mar;114(3):494-500. doi: 10.1016/j.ophtha.2006.06.053. Epub 2006 Nov 21.
- Background: PubMed 16799014He M, Foster PJ, Ge J, Huang W, Zheng Y, Friedman DS, Lee PS, Khaw PT. Prevalence and clinical characteristics of glaucoma in adult Chinese: a population-based study in Liwan District, Guangzhou. Invest Ophthalmol Vis Sci. 2006 Jul;47(7):2782-8. doi: 10.1167/iovs.06-0051.
Related trials for Glaucoma
Recruiting
The Acute Effect of Exercise Type And Timing on Ambulatory Blood Pressure and Intra-Ocular Pressure in Individuals With Glaucoma (The ACHIEVE-project).
Glaucoma Open-Angle Primary, Hypertension
RecruitingObservational study
Anterior Segment Anatomy Assessed by Swept-Source OCT in Ocular Surgery Patients
Cataract, Primary Angle-Closure Glaucoma
RecruitingObservational study
PRESERFLO™ MicroShunt XI Observational PMCF Study With no Control Group
Primary Open Angle Glaucoma
RecruitingPhase 4
Adaptive Optics OCT Evaluation of Rhopressa's Effects on the Retinal Ganglion Cells in Glaucoma Patients
Open Angle Glaucoma (OAG), Glaucoma
Active, not recruitingObservational study
Impact of Glaucoma and Visual Field Loss on Life Space
Primary Open-angle Glaucoma
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. This study is not recruiting at the moment.
Mingkai Lin, MD study chair
Zhongshan Ophthalmic Center, Sun Yat-San University
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 Glaucoma, run by Zhongshan Ophthalmic Center, Sun Yat-sen University 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 5 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: status not confirmed, as of the sponsor's last update on 31 Jul 2020. 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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Yuying Zhou, Master (8615270988097, 2053552500@qq.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
the changes in anterior opening distance before and after LPI (time frame: between the baseline and 1 hour before discharge). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04495491, which also lists 3 linked publications.
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 31 Jul 2020; AzTrials last refreshed its copy on 30 Oct 2026.