Optimal Treatment Protocol for Selective Laser Trabeculoplasty - Repeat Trial (OSLT-R)

Glaucoma is a common eye disease that can lead to blindness. The only known way to reduce the rate of disease progression is by reducing the pressure in the eye (the intraocular pressure, IOP). Selective laser trabeculoplasty (SLT) is an ophthalmic laser intervention with the purpose of reducing the IOP.

SLT can be performed in different ways, with four of the treatment protocols being evaluated in the Optimal SLT (OSLT) trial.

SLT is a repeatable procedure, but scientific evidence is scarce regarding more than one repetition. In this trial, patients included in the OSLT trial will be invited to the extended trial (OSLT-R), for further follow-up and re-treatment with SLT, if needed.

Study Overview

• Status: Enrolling by invitation
• Conditions: Ocular Hypertension; Glaucoma, Open-Angle; Pseudoexfoliation Glaucoma
• Intervention / Treatment: Procedure: SLT

Detailed Description

Subjects already included in the OSLT trial (NCT03798223) will be invited to the extended trial (OSLT-R) when OSLT follow up is scheduled to terminate. Patients are re-treated as needed, according to the randomized group assignment performed in the OSLT inclusion process.

Each patient is followed until the last of:

• 3 years after OSLT inclusion
• 31 December 2024 or
• Six months after the last SLT was performed, during the above time period.

The OSLT-R trial is aiming to elucidate:

• If the SLT efficacy, in terms of relative IOP reduction (percent of baseline IOP), changes with additional SLT iterations.
• If the longevity of IOP reduction after SLT changes with additional SLT iterations.
• If repeated SLT is associated with a change in the frequency and severity of postoperative discomfort or adverse events.

All of the above will be analyzed within each of the four treatment groups (SLT protocols) in the trial. Further, analysis will also be conducted regarding differences between the treatment groups regarding the above.

Further, analysis will be performed regarding SLT efficacy depending of the total number of SLT:s an eye has received, including those performed before entering the OSLT and OSLT-R trials.

• Study Type: Interventional
• Enrollment (Estimated): 400
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Sweden
  • Vastra Gotaland
    • Skövde, Vastra Gotaland, Sweden, 54142
      • Department of Ophthalmology, Skaraborg Hospital
    • Uddevalla, Vastra Gotaland, Sweden, 45153
      • Department of Ophthalmology, NU Hospital Group

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Included in the OSLT trial
• Followed up without the need for other treatment escalation than repeat SLT

Exclusion Criteria:

• Unable to participate in follow up due to health conditions, strength or physical location.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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.	Procedure: SLT; 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.	Procedure: SLT; 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/low; SLT treatment in either 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.	Procedure: SLT; 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 either 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.	Procedure: SLT; 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
Relative IOP reduction for each SLT iteration	Relative IOP reduction for each SLT iteration is calculated as the percentage IOP reduction from baseline (the mean of 3 pre-SLT measurements) to result IOP (the mean of the IOP at follow-up 1, 3 and 6 months after SLT).	1-6 months after each SLT, as described above

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain perioperatively: on a scale	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	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
Survival (for each SLT iteration)	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, including repeat SLT.	From randomization to failure (IOP lowering intervention, except repeat SLT) or censoring (death, patients choice), assessed until the last of: 1. 3 years after randomization; 2. 31 Dec 2024 or; 3. Six months after the last SLT during that timespan.
Survival (repeat SLT allowed)	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, except repeat SLT.	From each SLT iteration to failure (IOP lowering intervention incl. repeat SLT) or censoring (death, patients choice), assessed until the last of: 1. 3 years after randomization; 2. 31 Dec 2024 or; 3. Six months after the last SLT during that timespan.
Achievement of 20% reduction in IOP	The proportion of eyes achieving and maintaining an IOP reduction of at least 20% compared to baseline.	From randomization until the last of: 1. 3 years after randomization; 2. 31 Dec 2024 or; 3. Six months after the last SLT during that timespan.
Absolute IOP reduction for each SLT iteration	Absolute IOP reduction for each SLT iteration is calculated as the IOP reduction, in mmHg, from baseline (the mean of 3 pre-SLT measurements) to result IOP (the mean of the IOP at follow-up 1, 3 and 6 months after SLT).	1-6 months after each SLT, as described above
Light sensitivity postoperatively: on a scale	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: on a scale	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: on a scale	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
Adverse events	The type and frequency of adverse events will be recorded and analyzed in each of the study arms.	From randomization until the last of: 1. 3 years after randomization; 2. 31 Dec 2024 or; 3. Six months after the last SLT during that timespan. However, generally adverse events are anticipated to emerge in the first post-operative days or weeks.

Collaborators and Investigators

• Sponsor: Vastra Gotaland Region
• Collaborators: Göteborg University
• Investigators: Principal Investigator: Tobias Dahlgren, MD, Vastra Gotaland Region; Study Chair: Marcelo Ayala, MD, PhD, Vastra Gotaland Region

Study record dates

Study Major Dates

• Study Start (Actual): January 10, 2022
• Primary Completion (Estimated): November 30, 2025
• Study Completion (Estimated): November 30, 2025

Study Registration Dates

• First Submitted: November 30, 2021
• First Submitted That Met QC Criteria: December 15, 2021
• First Posted (Actual): December 16, 2021

Study Record Updates

• Last Update Posted (Actual): August 30, 2023
• Last Update Submitted That Met QC Criteria: August 29, 2023
• Last Verified: August 1, 2023

More Information

Terms related to this study

• Keywords: Selective Laser Trabeculoplasty
• Additional Relevant MeSH Terms: Eye Diseases; Uveal Diseases; Iris Diseases; Glaucoma; Glaucoma, Open-Angle; Ocular Hypertension; Exfoliation Syndrome
• Other Study ID Numbers: OSLT-R; 277612 (Other Identifier: FoU i VGR ID number)

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