Optimal Treatment Protocol for Selective Laser Trabeculoplasty (OSLT)

March 6, 2023 updated by: Vastra Gotaland Region
A randomized controlled trial to evaluate which treatment protocol in selective laser trabeculoplasty that is most optimal in terms of efficacy and safety.

Study Overview

Status

Active, not recruiting

Intervention / Treatment

Detailed Description

A randomized controlled trial in which individuals scheduled for SLT are randomized to one of four treatment protocols, which represent the most common variants of the treatment in clinical use.

Treatment is performed either at 360 degrees or 180 degrees and with a laser energy level either 0,1 millijoules (mJ) below the microbubble formation limit ("low" energy) or at a level that gives microbubbles at 50-75% of laser effects ("high" energy). This gives four treatment arms: 180/low, 180/high, 360/low and 360/high. Group allocation is masked for the patient and is coded in the records.

The results for short and long term treatment effects are compared between the groups, as well as the complication rate and postoperative discomfort.

Study Type

Interventional

Enrollment (Anticipated)

400

Phase

  • Not Applicable

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

    • Vastra Gotaland
      • Boras, Vastra Gotaland, Sweden, 50182
        • Ogonkliniken, Sodra Alvsborgs Sjukhus
      • Molndal, Vastra Gotaland, Sweden, 43130
        • Ogonkliniken, Sahlgrenska Universitetssjukhuset
      • Skovde, Vastra Gotaland, Sweden, 54142
        • Ogonkliniken, Skaraborgs Sjukhus
      • Uddevalla, Vastra Gotaland, Sweden, 45153
        • Ogonkliniken NU-sjukvarden

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • diagnosis primary open-angle glaucoma, pseudo-exfoliative glaucoma or ocular hypertension.
  • intra-ocular pressure (IOP) at least 18 mmHg treatment day.
  • treatment is performed by an experienced laser surgeon.
  • SLT treatment and follow-up are expected to be possible to perform in an adequate way, considering anatomical factors, age and the general health of the patient.

Exclusion Criteria:

  • change of IOP-lowering medication during the last three months.
  • planned change of intra-ocular-pressure-lowering medication.
  • previous glaucoma surgery (other than SLT and ALT)
  • previous intra-ocular surgery during the last three months.
  • previous intra-ocular inflammatory disease during the last year.
  • planned intra-ocular surgery.
  • hyper-pigmented anterior chamber angle.

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: 180/low
SLT treatment in the lower half of the trabecular meshwork (180 degrees) consisting of 50+/-5 adjacent laser effects. The energy is adjusted 0,1 mJ below the threshold of formation of micro bubbles.
A drop of Pilocarpine 4% is administered to the eye 20 minutes before SLT. Immediately before SLT a drop of Tetracaine hydrochloride 1% is administered. Selective laser trabeculoplasty is conducted through a Latina lens, in a fashion determined by randomization to a study arm (see description).
Experimental: 180/high
SLT treatment in the lower half of the trabecular meshwork (180 degrees) consisting of 50+/-5 adjacent laser effects. The energy is adjusted to achieve the formation of micro bubbles at 50-75% of laser effects.
A drop of Pilocarpine 4% is administered to the eye 20 minutes before SLT. Immediately before SLT a drop of Tetracaine hydrochloride 1% is administered. Selective laser trabeculoplasty is conducted through a Latina lens, in a fashion determined by randomization to a study arm (see description).
Experimental: 360/low
SLT treatment in the full circumference of the trabecular meshwork (360 degrees) consisting of 100+/-10 adjacent laser effects. The energy is adjusted 0,1 mJ below the threshold of formation of micro bubbles.
A drop of Pilocarpine 4% is administered to the eye 20 minutes before SLT. Immediately before SLT a drop of Tetracaine hydrochloride 1% is administered. Selective laser trabeculoplasty is conducted through a Latina lens, in a fashion determined by randomization to a study arm (see description).
Experimental: 360/high
SLT treatment in the full circumference of the trabecular meshwork (360 degrees) consisting of 100+/-10 adjacent laser effects. The energy is adjusted to achieve the formation of micro bubbles at 50-75% of laser effects.
A drop of Pilocarpine 4% is administered to the eye 20 minutes before SLT. Immediately before SLT a drop of Tetracaine hydrochloride 1% is administered. Selective laser trabeculoplasty is conducted through a Latina lens, in a fashion determined by randomization to a study arm (see description).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in intraocular pressure (IOP)
Time Frame: Before SLT and thereafter regularly for 3 years

The IOP is measured with a Goldmann Applanation Tonometer (GAT) three times before SLT and then at regular intervals after the procedure. The reduction is registered and analyzed in absolute (mmHg) and relative (percent of the IOP before SLT) measures.

Measurement of IOP is planned 1, 3, 6 and 12 months post SLT, and thereafter every six months for 3 years after SLT. The study is conducted in a regular clinical setting and the above mentioned times might be delayed. If target pressure is not achieved, measurements will be planned at shorter intervals, according to a specified algorithm, due to safety reasons.

Before SLT and thereafter regularly for 3 years
Achievement of 20% reduction in IOP
Time Frame: For 3 years
See Outcome 1. Analysis of differences between the study arms will also be conducted measuring the proportion of eyes achieving 20% reduction in IOP or more at different time points in each group.
For 3 years
Survival (no additional intervention)
Time Frame: For 3 years
Kaplan-Meier survival analysis will be conducted, measuring the proportion of eyes that stay in the study groups but do not receive any further IOP-lowering intervention (medical, surgical or laser).
For 3 years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Survival (SLT allowed)
Time Frame: For 3 years
See Outcome 3. Kaplan-Meier survival analysis is performed the same way, but additional SLT-treatment will not be judged as failure.
For 3 years
Pain perioperatively: on a scale
Time Frame: Immediately after treatment
The patient will grade perioperative pain on an arbitrary scale between 0 (no pain) and 4 (maximum pain) on a written protocol.
Immediately after treatment
Pain postoperatively: on a scale
Time Frame: During the first month
The patient will grade post-operative pain on an arbitrary scale between 0 (no pain) and 4 (maximum pain) on a written protocol, also stating the duration of pain.
During the first month
Light sensitivity postoperatively
Time Frame: During the first month
The patient will grade post-operative sensitivity to light on an arbitrary scale between 0 (no difference) and 4 (very intense sensitivity to light) on a written protocol, also stating the duration of light sensitivity.
During the first month
Impairment of vision postoperatively
Time Frame: During the first month
The patient will grade post-operative impairment of vision on an arbitrary scale between 0 (no difference) and 4 (cannot see ones own hand) on a written protocol, also stating the duration of vision impairment.
During the first month
Redness postoperatively
Time Frame: During the first month
The patient will grade post-operative redness of the eye on an arbitrary scale between 0 (no difference) and 4 (very intense redness) on a written protocol, also stating the duration of redness.
During the first month
Flare (inflammation measurement of the anterior chamber)
Time Frame: Pre-operatively and then one day, one week and one month post-operatively.
15 participants from each treatment arm (60 in total, randomized in a separate block after informed consent) will undergo measurement with a Laser Flare Meter.
Pre-operatively and then one day, one week and one month post-operatively.
Adverse events
Time Frame: 3 years (although adverse events, if any, are anticipated to emerge in the first post-operative days or weeks).
The type and frequency of adverse events will be recorded and analyzed in each of the study arms.
3 years (although adverse events, if any, are anticipated to emerge in the first post-operative days or weeks).

Collaborators and Investigators

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

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)

January 10, 2019

Primary Completion (Anticipated)

May 31, 2025

Study Completion (Anticipated)

May 31, 2025

Study Registration Dates

First Submitted

January 3, 2019

First Submitted That Met QC Criteria

January 8, 2019

First Posted (Actual)

January 9, 2019

Study Record Updates

Last Update Posted (Estimate)

March 7, 2023

Last Update Submitted That Met QC Criteria

March 6, 2023

Last Verified

January 1, 2023

More Information

Terms related to this study

Other Study ID Numbers

  • Optimal SLT
  • 254861 (Other Identifier: FoU i VGR ID nr)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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.

Clinical Trials on Ocular Hypertension

Clinical Trials on SLT

3
Subscribe