PURPOSE: The LiGHT trial has shown selective laser trabeculoplasty (SLT) to be clinically and cost-effective as a primary treatment of open-angle glaucoma (OAG) and ocular hypertension (OHT) at 3 years. This paper reports health-related quality of life (HRQL) and clinical effectiveness of initial treatment with SLT compared to intra-ocular pressure (IOP) lowering eye drops, after 6 years of treatment. DESIGN: Prospective multicentre randomized controlled trial. PARTICIPANTS: Treatment-naïve eyes with OAG or OHT, initially treated with SLT or IOP-lowering drops. METHODS: Patients were randomly allocated to initial SLT or eye drops. Eye specific target IOP and monitoring intervals were based on international guidelines. After the initial 3 years of the trial, patients in the SLT arm were permitted a 3rd SLT if necessary; patients in the drops arm were allowed SLT as a treatment switch or escalation. Analysis was by intention to treat. This study is registered at controlled-trials.com (ISRCTN32038223). MAIN OUTCOME MEASURES: The primary outcome was HRQL at 6 years; secondary outcomes were clinical effectiveness and safety. RESULTS: Of the 692 patients completing 3 years in the LiGHT trial, 633 (91.5%) entered the extension and 524 patients completed 6 years in the trial (82.8% of those entering the extension phase, 73% of those initially randomised). At 6 years, there were no significant differences in HRQL for EQ-5D, GUI and GQL-15 (all p>0.05). The SLT arm had better GSS scores than the drops arm (83.6 (SD 18.1) vs 81.3 (SD 17.3), respectively). 69.8% of eyes in the SLT arm remained at or below target IOP without the need for medical or surgical treatment. More eyes in the drops arm exhibited disease progression (26.8% vs 19.6%, respectively, p=0.006). Trabeculectomy was required in 32 eyes in the drops arm compared to 13 eyes in the SLT arm (p<0.001); there were more cataract surgeries in the drops arm (95 compared to 57 eyes, p=0.03). There were no serious laser-related adverse events. CONCLUSIONS: SLT is a safe treatment for OAG and OHT, providing better long-term disease control than initial drop therapy, with reduced need for incisional glaucoma and cataract surgery over 6 years
