Clinical Study of LPI With Different Laser Wavelengths

September 11, 2016 updated by: Maosong Xie, First Affiliated Hospital of Fujian Medical University

Clinical Study of Laser Peripheral Iridoplasty With Different Laser Wavelengths

Glaucoma is the second cause of blindness worldwide. Laser peripheral iridoplasty (LPI) is a simple and effective treatment for angle closure glaucoma. LPI can widen or reopen an existing angle close or angle adhesion in order to reduce the risk of attack of the angle closure glaucoma. However, there are very little research on the laser site, laser wavelengths, laser energy and laser spot intervals. The purpose of this study is to determine the optimum laser wavelengths of LPI.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Glaucoma is the second cause of blindness worldwide. Laser peripheral iridoplasty (LPI) is a simple and effective treatment for angle closure glaucoma. LPI can widen or reopen an existing angle close or angle adhesion in order to reduce the risk of attack of the angle closure glaucoma. However, there are very little research on the laser site, laser wavelengths, laser energy and laser spot intervals.Conventional LPI uses wavelength 532nm laser. However, our preclinical studies have found that the laser penetration of the laser wavelength 561nm is stronger than that of the laser wavelength 532nm. It can produce a stronger contraction effect.

The purpose of this study is to determine the optimum laser wavelengths of LPI. Baseline and 7days, 1 month, 3 months after LPI, the structure of anterior chamber, including angle anterior chamber depth(ACD), angle of anterior chamber (AA), anterior chamber angle opening distance 750(AOD750) are measured with ultrasound biomicroscopy. Baseline and 7days, 1 month, 3 months after LPI, the outflow resistance of aqueous humor are evaluated with C value. Baseline and 1hour, 1days, 3day, 7days, 1 month, 3 months after LPI, intraocular pressure are measured with Goldmann tonometry. Baseline and 3 months after LPI, retinal nerve layer thickness and the optic disc cup disc ratio are measure with optical coherence tomography.

Study Type

Interventional

Enrollment (Anticipated)

30

Phase

  • Not Applicable

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

30 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients with primary angle closure suspect (PACS), primary angle closure (PAC) or primary angle closure glaucoma (PACG).
  • PACS is diagnosed in eyes with an occludable angle but no other abnormality.
  • PAC is diagnosed in eyes with an occludable angle, normal optic discs and visual fields and any of the following: raised IOP (>19 mm Hg), PAS, pigment smearing in the superior angle, or sequelae of acute angle closure (iris whirling or glaucomatous fleck).
  • PACG is diagnosed in eyes with an occludable angle and glaucomatous optic neuropathy. Evidence of glaucomatous optic neuropathy is defined as a cup: disc ratio (CDR) of >0.7 or >0.2 CDR asymmetry.
  • An occludable angle is defined as one in which three quarters of the posterior pigmented trabecular meshwork is not visible on viewing with a Goldmann two mirror lens in the primary position of gaze without indentation.

Exclusion Criteria:

  • Patients with previous ocular surgery, and those with secondary angle closure, such as lens intumescence or subluxation, iris neovascularisation and a history of uveitis.
  • Patients who have systemic contraindications to medical therapy (including renal impairment, sulfur allergy, asthma and heart failure), pre-existing corneal opacities obstructing laser access to more than one quadrant of the peripheral iris and single-eyed patients are also excluded.

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

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 532nm laser group
LPI with 532nm laser.
Procedure: 532nm laser group
LPI with 532nm laser.
Experimental: 561nm laser group
LPI with 561nm laser.
Procedure: 561nm laser group
LPI with 561nm laser.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change of anterior chamber angle(AA)
Time Frame: Baseline and 3 months after LPI.
Anterior chamber angle (AA) is measured with ultrasound biomicroscopy.
Baseline and 3 months after LPI.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change of anterior chamber depth(ACD)
Time Frame: Baseline and 3 months after LPI.
Anterior chamber depth(ACD) is measured with ultrasound biomicroscopy.
Baseline and 3 months after LPI.
Change of intraocular pressure (IOP)
Time Frame: Baseline and 1hour, 1days, 3day, 7days, 1 month, 3 months after LPI.
IOP is measured with Goldmann tonometry.
Baseline and 1hour, 1days, 3day, 7days, 1 month, 3 months after LPI.
Change of C value
Time Frame: Baseline and 7days, 1 month, 3 months after LPI.
IOP is measured with Schφtz tonometry.
Baseline and 7days, 1 month, 3 months after LPI.
Change of retinal nerve layer thickness
Time Frame: Baseline and 3 months after LPI.
Retinal nerve layer thickness is measured with optical coherence tomography.
Baseline and 3 months after LPI.
Change of optic disc cup disc ratio
Time Frame: Baseline and 3 months after LPI.
Optic disc cup disc ratio is measured with optical coherence tomography.
Baseline and 3 months after LPI.
Change of mean defect
Time Frame: Baseline and 3 months after LPI.
Mean defect is measured with computer perimetry.
Baseline and 3 months after LPI.
Change of mean sensitivity
Time Frame: Baseline and 3 months after LPI.
Mean sensitivity is measured with computer perimetry.
Baseline and 3 months after LPI.
Change of scotoma
Time Frame: Baseline and 3 months after LPI.
Scotoma is measured with computer perimetry.
Baseline and 3 months after LPI.
Change of anterior chamber angle opening distance 750(AOD750)
Time Frame: Baseline and 3 months after LPI.
Anterior chamber angle opening distance 750(AOD750) is measured with ultrasound biomicroscopy.
Baseline and 3 months after LPI.

Collaborators and Investigators

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

Sponsor

First Affiliated Hospital of Fujian Medical University

Investigators

  • Study Chair: Maosong Xie, doctor, Department of ophthalmology, First Affilited Hospital of Fujian Medical 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

September 1, 2016

Primary Completion (Anticipated)

December 1, 2017

Study Completion (Anticipated)

December 1, 2017

Study Registration Dates

First Submitted

September 11, 2016

First Submitted That Met QC Criteria

September 11, 2016

First Posted (Estimate)

September 15, 2016

Study Record Updates

Last Update Posted (Estimate)

September 15, 2016

Last Update Submitted That Met QC Criteria

September 11, 2016

Last Verified

September 1, 2016

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • [2016]102-2

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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