Primary Selective Laser Trabeculoplasty for Open Angle Glaucoma and Ocular Hypertension: Clinical Outcomes, Predictors of Success and Safety from the Laser in Glaucoma and Ocular Hypertension (LiGHT) Trial

ABSTRACT Purpose To report clinical efficacy, predictors of success and safety of primary selective laser trabeculoplasty (SLT) used in treatment-naive open-angle glaucoma (OAG) or ocular hypertension (OHT) patients. Design Post-hoc analysis of a multicentre prospective randomized-controlled-trial. Participants Treatment-naive OAG or OHT patients. Methods Patients randomized to SLT or topical medication and treated to pre-defined target IOPs requiring ≥20% IOP reduction from baseline for all disease severity levels. Outcome Measures Initial (“early”) absolute IOP-lowering at 2-months. Achievement of “drop-free disease-control”: meeting target IOP without disease progression or need for additional topical medication over 36-months following SLT. Predictors of early absolute IOP-lowering and drop-free “disease-control” after single initial SLT. Frequency of laser-related complications. Results 611 eyes (195 OHT & 416 OAG) of 355 patients received SLT and 622 eyes (185 OHT & 437 OAG) of 362 patients received topical medication at baseline. Early absolute IOP-lowering following SLT was no different between OHT and OAG eyes (adjusted mean difference = -0.05mmHg; 95% confidence interval (CI) -0.6 to 0.5mmHg; p=0.85). No difference was noted in early absolute IOP-lowering between topical medication and primary SLT (adjusted mean difference = -0.1mmHg; 95% CI, -0.6 to 0.4mmHg; p=0.67). Early absolute IOP-lowering with primary SLT was positively associated with baseline IOP (Coefficient 0.59; 95% CI, 0.54 to 0.64; p 5mmHg from pre-treatment IOP) with 1 eye requiring treatment. Conclusion Primary SLT achieved comparable early absolute IOP-lowering in OHT vs OAG eyes. Drop-free “disease-control” was achieved in ∼75% eyes at 36-months following 1 or 2 SLTs; the majority of these following single SLT. These analyses are exploratory, but support primary SLT to be effective and safe in treatment-naive OAG and OHT eyes.