Clarifying the Optimal Application of SLT Therapy Trial

Study Overview
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Brief Summary
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The goal of this study is to understand if SLT performed at low energy is as effective as SLT performed at standard energy, and also to see if repeating SLT at low energy once a year will prevent or delay the need for daily eye drop medications better than waiting for SLT to wear off before repeating it.

Official Title
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Clarifying the Optimal Application of SLT Therapy Trial

Conditions
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Glaucoma and Ocular Hypertension

Intervention / Treatment
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* Procedure: Low Energy SLT
* Procedure: Standard Energy SLT


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1. In good health, newly diagnosed and treatment naïve (no prior IOP-lowering treatments), with decision to treat made by an ophthalmologist on the basis of risk profile, patient preference, or both 3. Age 18 years or older 4. Each eye with BCVA at least 20/200 (UK 6/60) 5. Each eye with one of the following qualifying diagnoses (diagnoses may differ between eyes): High-risk ocular hypertension (OHT): IOP > 21 mmHg without glaucomatous optic neuropathy (excavation, diffuse or focal thinning or notching of the neuroretinal rim, visible nerve fiber layer defects, or asymmetry of the vertical cup-to-disc ratio of >0.2 between eyes) [enrollment of trial participants with High-risk OHT will be capped at 25% of total enrollment] Mild primary open-angle glaucoma: glaucomatous optic neuropathy, visual field mean deviation >-6.0 dB with no points in the central 5° <15 dB Moderate primary open-angle glaucoma: glaucomatous optic neuropathy, visual field mean deviation -6.0 dB to >-12 dB and no more than 1 central 5° point <15 dB Exclusion Criteria: Advanced POAG in either eye Glaucoma other than POAG (including pigmentary and pseudoexfoliation glaucoma) in either eye Mean IOP > 35 mmHg at either the screening or baseline visit in either eye Narrow or closed angle (Shaffer Grade 0, 1, or 2) in either eye Contraindications to SLT, brimonidine, or any other study intervention Any corneal pathology that would preclude accurate assessment of IOP by Goldmann tonometry in either eye Any intraocular surgical procedure within the past 6 months in either eye Inability to attend all scheduled study visits

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Subjects are randomized twice: the first, at study entry, to low energy or standard SLT; and the second, at Month 12, to annual or as-needed repeat SLT. There are 2 arms in the first 12 months of the study and 2 different arms in Months 13-48.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: First Randomization: Low Energy SLT<br>Low energy SLT will consist of 100 treatment spots delivered at 0.4mJ per spot throughout the full 360° treatment, with the exception that energy can be reduced to 0.3mJ if bubbles are seen with 5 consecutive spots and can be increased back to a maximum of 0.4mJ is no bubbles are seen with 5 consecutive spots. Regardless of energy level randomization, energy may be adjusted downward in 0.1mJ increments throughout the procedure in response to factors such as heavy focal pigmentation or patient discomfort. | Procedure: Low Energy SLT<br>* SLT performed at low energy<br>|
| Active Comparator: First Randomization: Standard Energy SLT<br>Standard SLT will be performed as follows: beginning at 0.8 mJ, energy will be titrated up or down within the first 5-10 spots until champagne bubbles are visualized with every 2nd or 3rd spot. Energy can be titrated throughout the procedure, in response to variations in pigmentation, to ensure the appearance of champagne bubbles with every 2nd or 3rd spot throughout the full 360° treatment. Energy should be increased if no bubbles are seen with 5 consecutive spots and decreased if bubbles are seen with 5 consecutive spots. Regardless of energy level randomization, energy may be adjusted downward in 0.1mJ increments throughout the procedure in response to factors such as heavy focal pigmentation or patient discomfort. | Procedure: Standard Energy SLT<br>* SLT performed at standard energy<br>|
| Experimental: Second Randomization: Annual Low Energy Repeat SLT<br>At month 12, subjects remaining medication-free will be re-randomized to undergo repeat SLT either annually at low energy or as needed at initially assigned energy (from first randomization). The method of SLT delivery is as described in the sections above. | Procedure: Low Energy SLT<br>* SLT performed at low energy<br>|
| Active Comparator: Second Randomization: As-Needed Repeat SLT at Initial Energy<br>At month 12, subjects remaining medication-free will be re-randomized to undergo repeat SLT either annually at low energy or as needed at initially assigned energy (from first randomization). The method of SLT delivery is as described in the sections above. | Procedure: Low Energy SLT<br>* SLT performed at low energy<br>Procedure: Standard Energy SLT<br>* SLT performed at standard energy<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 12-month survival | Survival of first SLT through Month 12 | 12 months | 
| 48-month medication-free survival | At Month 12, subjects are re-randomized to repeat SLT either annually at low energy or PRN at initially-assigned energy. The proportion surviving medication-free at Month 48 will be compared between groups | 48 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean IOP | Mean IOP at month 12 | 12 months | 
| Long-term mean IOP | Mean IOP at each study visit | 12, 24, 36, and 48 months | 
| Incidence of IOP spikes | IOP spikes > 5 mmHg on day of SLT | 0, 12, 24, 35, and 48 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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glaucoma, selective laser trabeculoplasty, clinical trial