Selective Laser Trabeculoplasty Clinically Effective for Long-Term Glaucoma Management

Gus Gazzard, MD

Selective laser trabeculoplasty safely provided drop-free intraocular pressure (IOP) control in nearly 70% of eyes with ocular hypertension (OHT) and open-angle glaucoma (OAG), according to six-year results from the Laser in Glaucoma and Ocular Hypertension (LiGHT) trial.

This was reduced only slightly from the three-year results of the LiGHT trial (78%), suggesting a greater importance of this finding for the long-term management of glaucoma and OHT.

“Drop-free IOP control and safety of SLT as a first-line treatment for OHT and OAG are confirmed after 6 years of careful, protocolized monitoring and treatment,” wrote corresponding author Gus Gazzard, MD, FRCOphth, Director of the Glaucoma Service, Moorfields Eye Hospital and Chief Investigator of the LIGHT trial.

Since its endorsement by the US Food and Drug Administration for the treatment of glaucoma in 2001, SLT has been adopted as an alternative to IOP-lowering eye drops, but efficacy data as a sole treatment was limited. The current findings report health-related quality of life (HRQoL) and clinical effectiveness of initial treatment with SLT compared with initial IOP-lowering eye drops after 6 years of protocolized treatment.

The patient population in the LiGHT trial was assigned randomly to receive either primary therapy with IOP-lowering eye drops or SLT, followed by IOP-lowering eye drops if required. After the first 3 years of the trial, patients were permitted a third SLT treatment if necessary and the next escalation was medical treatment. Those initially randomized to receive IOP-lowering eye drops were not permitted SLT and failure to control IOP or OAG resulted in trabeculectomy, but they were allowed SLT as a treatment switch or escalation after the first 3 years.

The trial’s primary outcome measure was HRQoL measured using the EuroQol 5 Dimensions 5 Levels (EQ-5D) utility scores at the six-year mark. Secondary outcomes were clinical effectiveness measured by the Glaucoma Utility Index (GUI), Glaucoma Symptom Scale (GSS), and Glaucoma Quality of Life-15 (GQL-15), as well as the safety of the treatment arms.

A total of 692 patients completed three years in the LiGHT Trial and 633 patients (91.5%) entered the extension. At six years, 524 patients completed the extension (82.8% of those entering the extension phase).

The intention-to-treat analysis revealed no significant difference in HRQoL between the two treatments for the EQ-5D, GUI, and GQL-15 scores at 6 years (P >.05 for all).

The eye drop group showed worse GSS scores at 72 months, at 81.3 ± 17.3 compared with 83.6 ± 18.1 for the SLT group (adjusted mean difference, 3.3; 95% CI, -0.54 to 6.0). This was the only time point at which a notable difference was observed, according to investigators.

At 72 months, drop-free IOP control was obtained without incisional surgery in 69.8% of eyes initially treated with SLT, compared with 18.0% of eyes initially treated with IOP-lowering eye drops.

Of the eyes initially treated with SLT, 90% of eyes needed up to 2 SLT treatments in total. Of eyes initially treated with eye drops, 79.5% of eyes had switched to SLT and 20.5% underwent either cataract surgery alone or with SLT.

Fewer eyes initially treated with SLT demonstrated progression from OHT to OAG or deterioration of OAG compared with eyes initially treated with eye drops (19.6% vs. 26.8%, respectively; P = .006). Eyes initially treated with SLT additionally needed fewer trabeculectomies (13 eyes [2.4%] vs. 32 eyes [5.8%]; P <.001), while more cataract surgeries occurred in the drops arm (95 eyes vs. 57 eyes; P = .03).

There were no sight-threatening complications of SLT and no clinically identifiable corneal changes occurring throughout the trial, said the investigators.

“Selective laser trabeculoplasty has been shown to be a safe alternative to eye drops in areas where advanced glaucoma is more common and where treatment resources and access to these are limited,” Gazzard added. “The proven safety of SLT in such areas can transform glaucoma treatment rapidly and prevent sight loss.”

The study, “Six-Year Results of Primary Selective Laser Trabeculoplasty versus Eye Drops for the Treatment of Glaucoma and Ocular Hypertension,” was published in Ophthalmology.