Data from a 3-year extension of the LiGHT trial show that selective laser trabeculoplasty provides better long-term disease control than initial drop therapy.

Selective laser trabeculoplasty (SLT) has been approved to treat glaucoma since 2001, but data on its efficacy as primary therapy are limited. In 2019, the Laser in Glaucoma and Ocular Hypertension (LiGHT) trial showed that SLT was more cost-effective than initial treatment with eye drops after 3 years. Aiming to assess longer-term outcomes with SLT, Gus Gazzard, MD, MBBChir, MA, MD, FRCOphth, and colleagues extended monitoring in LiGHT another 3 years. Their findings, published in Ophthalmology, show that SLT provides better long-term disease control than initial drop therapy, with reduced need for incisional glaucoma and cataract surgery over 6 years.

“After 6 years of treatment, 70% of patients with mild to moderate glaucoma had eye pressure at target, with control of the disease (no worsening of optic nerve damage) without the need for medication and the use of only laser. Of them, 50% needed only one laser treatment,” says Dr. Gazzard. “If someone has open angle glaucoma and has not yet been offered SLT, there may be a good reason, but they should be asking why.”

The Extension Study

“Traditional medical treatment for glaucoma is the cause of huge rates of local and systemic side effects that often go unrecognized until too late,” says Dr. Gazzard. “Our aim was to determine whether initial treatment with SLT would control eye pressure and preserve vision as well as eye drops followed by surgery, when needed.”

The 692 patients in the LiGHT trial, all of whom were newly diagnosed with previously untreated open angle glaucoma (OAG) and ocular hypertension (OHT), were randomized to either primary therapy with eye drops or to SLT, followed by eye drops if needed. At 3 years, nearly 75% of participants who received SLT were free from eye drops.

The extension study enrolled 633 patients from the original trial. Those who had received SLT were permitted to undergo it again, if necessary; those in the eye drop arm could switch to SLT or receive it for escalation. At 6 years, no significant differences were found for the EuroQoL EQ-5D 5 Levels, Glaucoma Utility Index, and Glaucoma Quality of Life-15 (P>0.05 for all). Glaucoma Symptom Scale scores were worse in the eye drop arm and more of those eyes exhibited disease progression (P=0.006). Trabeculectomy was significantly less likely in eyes in the eye drop arm than in the SLT arm (P=0.03; Figure). No serious laser-related adverse events occurred.

Better Long-Term Disease Control With SLT

Assessing treatment effectiveness and visual function, the authors found that at 6 years, 94.2% of eyes initially treated with SLT were at target, compared with 94.7% of eyes initially treated with medication. Respective rates for achieving target intraocular pressure at office visits were 92.8% and 93.2%.

“Our study shows that 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,” says Dr. Gazzard. “We are now conducting a randomized trial comparing low-power SLT and ‘treat and repeat’ on an annual basis with the current ‘treat as required.’ Low-power SLT and a new Direct SLT that uses trans-limbal laser delivery without a contact lens promise a transformation of glaucoma laser delivery.”