EyeWorld Asia-Pacific March 2021 Issue

GLAUCOMA 50 EWAP MAR C H 2021 The LiGHT trial An observer-masked, randomized, controlled trial of 718 treatment-naive patients with open-angle glaucoma or ocular hypertension and no other ocular comorbidities received either first-line SLT treatment (n=356) or eye drops (n=362). 1 The primary outcome was health-related quality of life at 3 years, followed by secondary outcomes of cost, cost- effectiveness, disease specific health-related quality of life, clinical effectiveness, and safety. The researchers found more SLT eyes within their target IOP at more visits (93%) compared to those that received eye drops (91%). No patients in the SLT group in this timeframe required glaucoma surgery while 11 required surgery in the eye drop group. SLT was also determined to be more cost-effective than drops. The authors concluded that SLT “should be offered as a first-line treatment for open- angle glaucoma and ocular hypertension, supporting a SLT studies change in clinical practice.” The authors wrote later that the results “support a change in clinical practice by providing evidence that primary SLT should be offered to treatment- naive patients with OAG and OHT.” Predictive factors for SLT outcomes In this study, Hirabayashi et al. evaluated the baseline characteristics and 2- and 6-month effect of SLT on 252 eyes from 198 patients with open-angle glaucoma. 2 Success of SLT was defined as a 20% or more reduction in IOP or reduction of 1 or more medications without an IOP-lowering procedure. Age, type, and severity of glaucoma, trabecular meshwork pigment, total laser energy delivered, and baseline IOP were evaluated with success of the procedure. At 2 months, 33.6% of eyes were considered successful with SLT; 38.5% were successful at 6 months. A baseline IOP of more than 18 mm Hg was significantly associated with success of the procedure at both timepoints, with a mean IOP reduction of 5.4±5.3 mm Hg. Those with a lower baseline actually saw a mean increase in IOP (−0.7±4.6 mm Hg) at 6 months. Other characteristics such as age, glaucoma type, severity, TM pigmentation, etc., did not have an association with success of the procedure or IOP spikes. MicroPulse laser trabeculoplasty vs. SLT Hirabayashi et al. compared MicroPulse (Iridex) laser trabeculoplasty (MLT) with SLT in 100 eyes (50 eyes in each group) of patients who had open-angle glaucoma. 3 Success of the procedure was defined as a 20% or more IOP reduction or reduction of one or more medications through 6 months of follow-up. Success of MLT and SLT was 44% and 40%, respectively. The researchers reported older age being a predictor of success for SLT but not MLT. Both procedures had greater IOP lowering in patients with a baseline IOP of more than 18 mm Hg. There was a significant association between SLT success with baseline IOP, and success with MLT was associated with number of laser shots. There was a higher rate of IOP spikes in the SLT group (none occurred in the MLT group). Overall, the investigators concluded that “older age and higher baseline IOP predicted success with SLT while MLT was equally efficacious regardless of these factors.” With no IOP spikes in the MLT group (10% in the SLT group), the authors also concluded that “MLT may be a safer alternative to SLT that is effective in lowering IOP and need for medications for a wider variety of patients with open-angle glaucoma.” References 1. Gazzard G, et al. Selective laser trabeculoplasty versus eye drops for first-line treatment of ocular hypertension and glaucoma (LiGHT): a multicentre randomised controlled trial. Lancet. 2019;393:1505–1516. 2. Hirabayashi M, et al. Predictive factors for outcomes of selective laser trabeculoplasty. Sci Rep. 2020;10;9428. 3. Hirabayashi M, et al. Comparison of successful outcome predictors for MicroPulse laser trabeculoplasty and selective laser trabeculoplasty at 6 months. Clin Ophthalmol. 2019;13:1001–1009.