Glaucoma Laser Assessment of Stability and Sustainability

The GLASS Study (Glaucoma Laser Assessment of Sequential Sessions) is a prospective, interventional, paired-eye, single-site, investigator-initiated clinical trial designed to evaluate the safety and effectiveness of repeated applications of Direct Selective Laser Trabeculoplasty (DSLT) in treatment-naive patients with ocular hypertension (OHT), glaucoma suspect, or mild to moderate primary open-angle glaucoma (POAG). DSLT is a non-contact, automated laser procedure that delivers 120 laser pulses evenly around the limbus to stimulate aqueous outflow by targeting the trabecular meshwork. The procedure is performed with the patient in an upright seated position using the Voyager DSLT device (Alcon). Unlike conventional SLT, this method does not require gonioscopy, coupling gel, or a contact lens. All enrolled subjects must be treatment-naive, meaning they have not previously been on any ocular hypotensive medications. Eligible subjects will first complete a screening visit to verify inclusion and exclusion criteria. If criteria are met, they will be enrolled and proceed to the Baseline visit, where both eyes will undergo DSLT. At the 3-month visit, one randomly selected eye (the "dual-treatment eye") will undergo a second DSLT session. The fellow eye (the "single-treatment eye") will receive no further laser treatment and serve as a control. Subjects will continue follow-up visits at 4 months (1 month after the second treatment), 6 months, 9 months, and 12 months from the baseline treatment. Each study visit will include assessments such as best-corrected visual acuity (BCVA), intraocular pressure (IOP) via Goldmann applanation tonometry, slit-lamp examination, adverse event monitoring, ocular medication review (if applicable), and specular microscopy to assess corneal endothelial cell density. The primary endpoint is the difference in mean IOP between the dual-treatment and single-treatment eyes at 12 months. Secondary endpoints include change in IOP from baseline at each follow-up timepoint, time to re-initiation of ocular hypotensive medications, and any difference in safety or complication rates between the two eyes. The hypothesis is that a second treatment at the 3-month mark will provide enhanced and more durable IOP reduction, possibly reducing or delaying the need for medication. While DSLT has been studied previously in single-treatment applications, this is the first prospective trial evaluating repeat bilateral DSLT in a paired-eye design using one eye as its own internal control. All procedures will be conducted at Twin Cities Eye Consultants in Minnesota. The study is sponsored and monitored internally by Twin Cities Eye Consultants' Research Committee, who will oversee compliance, data integrity, and protocol adherence.