A Trial to Compare the Laser Treatment (SLT vs. ALT) in Glaucoma Patients (SLTRepeat)

March 5, 2018 updated by: William Hodge, Lawson Health Research Institute

A Randomized Clinical Trial of Selective Laser Trabeculoplasty (SLT) in Open Angle Glaucoma Who Had Been Previously Treated With Complete SLT

Lasers are important therapy in glaucoma. They are a pivotal point in treatment between medical and surgical care. Over the last 10 years a new laser has emerged as the usual laser treatment: Selective laser trabeculoplasty (SLT). SLT works as well as the older laser used: argon laser trabeculoplasty (ALT). However SLT has many theoretical benefits over ALT including causing less damage to the tissue it affects. One of the potential patient centered benefits of this laser is that it may be repeatable. It is even possible that the old laser ALT may be useable after an SLT treatment. This study aims to uncover whether repeat laser is possible after SLT and if so which laser is more effective (ALT vs SLT). The potential of repeating laser therapies may delay surgical treatment and its complications. Also understanding which laser to use will help eye doctors know how to treat their patients at this point of the disease.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Unknown

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
139

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

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

  • Canada
    • Alberta
      • Calgary, Alberta, Canada, T3E 7M8
        • Rockyview General Hospital, University of Calgary
      • Edmonton, Alberta, Canada, T5H 3V9
        • Royal Alexandra Hospital, University of Alberta
    • Nova Scotia
      • Halifax, Nova Scotia, Canada, B3H2R1
        • Eye Care Centre, Dalhousie University
    • Ontario
      • Hamilton, Ontario, Canada, L8G 5E4
        • McMaser University, St. Joseph's Healthcare Hamilton, CAHS Regional Eye Institute
      • London, Ontario, Canada, N6A 4V2
        • Ivey Eye Institute, St. Joseph's Hospital, Western University
      • Toronto, Ontario, Canada, M4N 3M5
        • Sunnybrook Health Sciences Centre, University of Toronto
    • Quebec
      • Montreal, Quebec, Canada, H3A 1A1
        • McGill University, Dept. of Ophthalmology, Royal Victoria Hospital,

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Over age of 18 yo.
  • OAG including pigmentary dispersion syndrome and pseudoexfoliation
  • OAG has been treated with 360 degrees of SLT
  • two sighted eyes,
  • willing to participate after being informed of and reading the patient information material.

Exclusion Criteria:

  • Narrow angle glaucoma
  • Previous glaucoma surgery
  • Eye surgery expected in the next 12 months
  • Severe corneal disease
  • On or anticipated steroid in 6 months
  • Pregnant or breast feeding

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: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Argon laser trabeculoplasty
Up to the year 2005, the vast majority of ophthalmologists used Argon laser trabeculoplasty (ALT) as the mode of laser therapy. ALT is effective but its most significant problem is that its effectiveness decreases with re-treatment since the tissue it targets (the trabecular meshwork) is changed by the laser rendering repeat treatments less effective.
Procedure: Argon laser trabeculoplasty
With Argon laser trabeculoplasty (ALT), thermal energy is used directed towards the Trabecular Meshwork (the site of aqueous drainage from the eye),which causes focal scarring of trabecular meshwork, thus enable fluid drainage more effectively. However, this procedure may not be repeatable since it causes too much damage to the trabecular meshwork.
Procedure: Selective laser trabeculoplasty
Selective laser trabeculoplasty is a relatively newer technology that uses a Nd:YAG laser to target specific cells within the trabecular meshwork. SLT does not cause coagulative damage to the trabecular meshwork, and thus has the advantage of being repeatable.
Active Comparator: selective laser trabeculoplasty
Post 2005, a newer mode of laser therapy, selective laser trabeculoplasty (SLT) has emerged as the standard of care laser. There are many potential advantages to SLT but to date these advantages are only theoretical. The most important potential clinical advantage of SLT is that it causes less damage to the tissue it targets.
Procedure: Argon laser trabeculoplasty
With Argon laser trabeculoplasty (ALT), thermal energy is used directed towards the Trabecular Meshwork (the site of aqueous drainage from the eye),which causes focal scarring of trabecular meshwork, thus enable fluid drainage more effectively. However, this procedure may not be repeatable since it causes too much damage to the trabecular meshwork.
Procedure: Selective laser trabeculoplasty
Selective laser trabeculoplasty is a relatively newer technology that uses a Nd:YAG laser to target specific cells within the trabecular meshwork. SLT does not cause coagulative damage to the trabecular meshwork, and thus has the advantage of being repeatable.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Intraocular Pressure
Time Frame: 12 months post operatively
IOP difference between baseline and 12 month post-laser.
12 months post operatively

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
To compare the IOP lowering effect between the groups at other postoperative visits
Time Frame: 12 months
IOP difference between baseline, 1hr, 1 wk, and 1, 3, 6 and 12 mon post-laser.
12 months
To compare the visual acuity between the groups at all visits.
Time Frame: 12 months
VA difference between baseline, 1hr, 1 wk, and 1, 3, 6 and 12 mon post-laser.
12 months
To compare the trabecular meshwork pigmentation between the groups at all visits.
Time Frame: 12 months
12 months
To compare any adverse events between the two groups at all visits.
Time Frame: 12 months
12 months
SLT repeatability of long term follow up in glaucoma patients
Time Frame: 36 months after initial enrollment of the primary study
The follow up time has been extended two more years. Patients will be followed up Q6 months.
36 months after initial enrollment of the primary study

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Lawson Health Research Institute

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: William G Hodge, MD, PhD, Lawson Research Institute, Univ. of Western Ontario

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

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2012

Primary Completion (Anticipated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 1, 2018

Study Completion (Anticipated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 1, 2018

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 11, 2012

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 18, 2012

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 19, 2012

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 6, 2018

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 5, 2018

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2018

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • CIHR granted glaucoma RCT

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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