Let There Be (Laser) Light

From 2019 to 2020, I co-chaired the European Glaucoma Society (EGS) Guidelines Committee with Carlo Traverso. The 5th Edition of the EGS guidelines was published in October 2020, after a superb team effort among a large number of colleagues (1). We aimed to promote evidence-based clinical practice and, to that end, followed GRADE methodology, including identification of key questions, critical evaluation of published literature, and formulation of recommendations. A key issue was the recommendation for an initial treatment for open angle glaucoma and the role of the laser as primary therapy.

The impact of the LiGHT trial
Laser trabeculoplasty has been a valuable option for treating open angle glaucoma and ocular hypertension for several decades. The Argon Laser Trabeculoplasty Trial was a landmark trial in the US (2) that compared beta-blockers – the best medical treatment at the time – with argon laser trabeculoplasty (ALT). Despite the evidence favoring ALT, medications remained the first and foremost choice in glaucoma treatment. This result might have been due to a number of factors, including the technical expertise required to deliver ALT, difficulties in changing established practice, and financial considerations (such as different reimbursement processes offered by healthcare providers and insurance companies). Whatever the reasons, ALT was not and has not been considered a first-line glaucoma treatment. Even to this day, patients with newly-diagnosed glaucoma usually start on medications. But the LiGHT trial may be changing this.

There have been a number of trials over the years highlighting evidence of the effectiveness of selective laser trabeculoplasty (SLT), but there has never been a landmark, decisive, high-quality trial until recently. Though smaller trials have value, there is always the concern of the potential risk of generalizability and bias, which may explain why – despite evidence showing that laser is just as effective – medications have remained the primary therapy for glaucoma patients.

The LiGHT trial found that SLT was both more effective (including IOP control, disease progression, and the reduced need for glaucoma surgery) and also more cost-effective than eye drops (3). Among the patients receiving SLT treatment, 74 percent did not require any eye drops at the end of the three-year follow-up. The trial, led by an international leader (Gus Gazzard of Moorfields Eye Hospital in London, UK) was very well designed and conducted, with a 700+ patient population and minimal attrition. These factors have significantly influenced the trial’s well-received reputation. Its distinct impact is clear; after publishing the trial, the UK National Institute for Health and Care Excellence (NICE) decided to update their guidelines to suggest that lasers should be considered a first-line treatment (4). Thanks to the trial, surgeons are considering SLT now more than ever.

Lasers as first-line treatment

There have always been significant issues with patient compliance when it comes to medications. In my opinion, an increase in the proportion of patients with glaucoma and ocular hypertension who receive laser treatments will be associated with better patient outcomes. An exciting and novel laser technology by BELKIN Laser Ltd., direct selective laser trabeculoplasty (DSLT), has the potential to revolutionize glaucoma care. The technology really is ground-breaking; delivering the treatment requires little expertise, and involves simply pressing a key and delivering the laser in seconds. Importantly, general ophthalmologists who may not feel that they are experienced enough in delivering ALT or SLT will be able to offer laser trabeculoplasty. A large multi-centre trial designed to compare SLT and DSLT is currently ongoing and will be completed this year (5).

Moreover, DSLT’s non-contact delivery makes it patient-friendly and removes the risk of infection – a significant factor to consider in a post-pandemic climate.

But that’s not to say medications will no longer play an important role in glaucoma treatment. After all, medications are also changing, and there are now more effective preservative-free eye drops that reduce adverse events and tolerability issues that were typical.

Other new considerations in the 2020 EGS Guidelines
One vital, qualitative aspect we wanted to deliver with the new guidelines was the patient’s voice. In the previous (2016) edition of the EGS guidelines, we focused on the important questions to ask patients as well as patients’ potential concerns, but this information was based on clinical opinion. For the new guidelines, we directly asked patients and patient representatives from a large glaucoma charity (Glaucoma UK) to tell us about their most important concerns, their most common anxieties, and aspects vital to patients, such as the best ways for surgeons to break the difficult news that a patient has glaucoma. Though this section is only a couple of pages long, bringing the patient’s voice to these guidelines was incredibly important.

Another aspect that differs from previous versions of the guidelines is the evidence-based approach and quality-control process. We reached out to other glaucoma societies and were lucky enough to receive comments from the American Glaucoma Society, the World Glaucoma Association, and the Latin American Glaucoma Society. They all provided fantastic feedback, which also influenced some of the content of the recommendations. This international team effort is a big departure from previous guidelines, and it strengthens their validity.

The future
So far, the reaction to the guidelines has been overwhelmingly positive. However, only time will tell what the impact of the guidelines will be, as it takes time for people to take the recommendations into account and change their working practices. Though there is no such thing as a “perfect” set of guidelines, we are very confident in the strength of the methodology used!

We are all now in an exciting time in glaucoma management, with new options arriving frequently and better treatments following hot on their heels. Yes, there are still unmet needs in glaucoma treatment, but there is significant potential for improvement in the future.