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  • Glaucoma

    A randomized controlled trial evaluated whether there were efficacy and safety differences between 180 and 360 degrees of selective laser trabeculoplasty (SLT) treatment, using contralateral eyes as both treatment arms to limit confounding factors.

    Study design

    Forty patients (80 eyes) with treatment-naïve open-angle glaucoma or glaucoma suspect with IOP >21 mm Hg in both eyes had one eye randomized to 360-degree selective laser trabeculoplasty (SLT) treatment and the fellow eye to 180 degrees of SLT treatment. Patients were followed for 1 year and assessed for change in visual acuity, Goldmann IOP, Humphrey visual fields, retinal nerve fiber layer thickness, OCT-derived cup–disc ratio, and any adverse events or requirements for additional medical interventions.


    At 1 year, IOP was reduced from 25.3 to 21.5 mm Hg In the 180-degrees group and from 25.5 to 19.9 mm Hg in the 360-degrees group. There were no statistically significant differences in the secondary endpoints between the 2 groups. No serious adverse events were reported.


    One year of follow-up is too short a length of time to answer the question of whether 360 degrees of treatment increases the longevity of the procedure. As only treatment-naïve eyes were included, these study results may not be applicable to eyes that are not treatment-naïve, which are the majority of eyes undergoing SLT treatment.

    Clinical significance

    In treatment-naïve eyes, 360-degree SLT treatment reduces IOP to a greater extent than 180-degree SLT treatment, with similar safety results. Clinicians who are routinely performing SLT 180 degrees at a time may consider switching to 360 degrees of treatment to aid in patient convenience, cost-effectiveness, and improved IOP lowering.

    Financial disclosures: Dr. Gillian Treadwell discloses no financial relationships.