Effectiveness of Selective Laser Trabeculoplasty Applied to 360° vs. 180° of the Angle

PURPOSE: To compare the effectiveness and safety of 360° and 180° of Selective Laser Trabeculoplasty (SLT) for the treatment of elevated intraocular pressure (IOP). METHODS: Retrospective cohort study. The main outcome measure was the Kaplan–Meier analysis comparing the cumulative probabilities of survival between the 360° and 180° SLT groups in terms of IOP reduction. Success was defined as ≥20% IOP reduction from baseline with an IOP between 5–18 mmHg and ≤1 glaucoma medication added postoperatively. Additional outcome measures included changes in average IOP, number of glaucoma medications, and the incidence of postoperative IOP spikes. Measurements were obtained at 6 weeks, 1 year, and 2 years postoperatively. RESULTS: Two hundred and fifty-eight eyes of 258 patients were included in the 360° group, and 196 eyes of 196 patients were included in the 180° group. The mean IOP reductions at 2 years were 2.21 ± 2.02 mmHg and 2.43 ± 1.81 mmHg (p=0.33) in the 180° and 360° groups, respectively. There were no significant differences in the incidence of postoperative IOP spikes between the two groups. There was a significant difference in the survival curves of the two groups (p=0.035). The Cox proportional-hazard model indicated that 360° of SLT application was a significant predictor of long-term success (p=0.030). CONCLUSIONS: 360° of SLT application seems to provide for greater long-term IOP control than 180° of application without putting patients at an elevated risk for postoperative IOP spikes.