This study compares two laser treatments for open-angle glaucoma: Selective Laser Trabeculoplasty (SLT) and Direct Selective Laser Trabeculoplasty (DSLT). SLT is a widely used procedure that requires a manual technique with a goniolens, while DSLT is a new, automated, non-contact method using the Eagle system. The study will evaluate whether DSLT is as effective as SLT in reducing intraocular pressure (IOP). Participants will be randomly assigned to receive either treatment and will be monitored over 12 months to assess changes in IOP, medication use, and safety outcomes. The goal is to determine if the simpler DSLT procedure can provide similar results to SLT, potentially improving patient comfort and access to glaucoma care.

Glaucoma management is fundamentally aimed at reducing intraocular pressure (IOP) to prevent optic nerve damage and preserve vision. Selective Laser Trabeculoplasty (SLT) has been a cornerstone in the treatment of open-angle glaucoma due to its efficacy and safety profile. However, SLT's manual delivery method using a goniolens can introduce variability, patient discomfort, and operator dependency.

Direct Selective Laser Trabeculoplasty (DSLT) represents an innovative advancement, offering a non-contact, automated laser treatment via the Eagle system. This technology is designed to simplify the procedure, enhance patient comfort, and minimize operator-induced variability. Early evidence suggests that DSLT may provide similar or improved IOP reduction compared to SLT, with a potentially better safety profile.

This study seeks to rigorously evaluate whether DSLT is non-inferior to SLT in reducing IOP, thus providing critical data on the efficacy and safety of this novel approach. Demonstrating non-inferiority would support broader adoption of DSLT, potentially improving patient outcomes and expanding access to effective glaucoma treatment.

Inclusion Criteria:

• Age ≥18 years.

• Diagnosed with OAG (including exfoliative/pigmentary glaucoma) or OHT.

• Gonioscopically visible scleral spur for 360 degrees.

• Ability to provide informed consent.

• In good health, without prior laser trabeculoplasty, with decision to treat made by an ophthalmologist on the basis of risk profile, patient preference, or both.

• 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 OAG (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, apraclonidine, 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
• Pregnancy or plan to become pregnant in the next 1 year
• Any prior laser trabeculoplasty, including ALT, MLT and SLT.