Predicting the Effect of Laser Peripheral Iridotomy

July 28, 2020 updated by: Mingkai Lin, Zhongshan Ophthalmic Center, Sun Yat-sen University

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.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

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 Type

Observational

Enrollment (Anticipated)

200

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
    • Guangdong
      • Guangzhou, Guangdong, China
        • Recruiting
        • Zhongshan Ophthalmic Center, Sun Yat-San Univerdity
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

20 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Chinese Patient was diagnosed of primary angle closure angle suspect

Description

Inclusion Criteria:

  1. Patient was diagnosed of primary angle closure angle suspect;
  2. received ultrasound Biomicroscopy before and after laser peripheral iridotomy;
  3. Voluntary participation in this study;
  4. Have enough language comprehension ability;
  5. Patient or his legal representative has sign the informed consent.

Exclusion Criteria:

  1. severe health problems resulting in a life expectancy of less than 1 year;
  2. previous intraocular surgery or penetrating eye injury;
  3. media opacity preventing laser peripheral iridotomy;
  4. Researchers think not suitable to participate in this clinical trial subjects;
  5. Refused to sign the informed consent.;
  6. 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.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Other
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Pupillary block group
According to the configurations of angle closure, the pupillary block group is defined as the iris bombe.
Other: pupillary block group
According to the configurations of angle closure, the pupillary block group is defined as the iris bombe.
plateau iris group
According to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris.
Other: plateau iris group
According to the configurations of angle closure, the plateau iris group is defined as the thickness of the peripheral iris.
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.
Other: mixing 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
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
between the baseline and 1 hour before discharge

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Zhongshan Ophthalmic Center, Sun Yat-sen University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 1, 2020

Primary Completion (Anticipated)

December 31, 2020

Study Completion (Anticipated)

March 31, 2021

Study Registration Dates

First Submitted

July 22, 2020

First Submitted That Met QC Criteria

July 28, 2020

First Posted (Actual)

July 31, 2020

Study Record Updates

Last Update Posted (Actual)

July 31, 2020

Last Update Submitted That Met QC Criteria

July 28, 2020

Last Verified

July 1, 2020

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2019KYPJ182

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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