The medical journal The Lancet recently published results from the Laser in Glaucoma and ocular HyperTension (LiGHT) study, which may impact how ophthalmologists treat new glaucoma diagnoses. The three-year trial found selective laser trabeculoplasty (SLT) may control intraocular pressure more effectively and at a lower cost than pharmacological drops, the current initial standard of care. The authors of the paper suggested SLT be offered as a first-line treatment for glaucoma, which would be a significant shift for clinical practice.
The Impressive Results of the LiGHT Study for SLT Treatment
The study was an observer-masked, randomized controlled trial involving 718 patients and 1,235 eyes at Moorfields Eye Hospital and five other centers in the United Kingdom. All participants had newly diagnosed and untreated open-angle glaucoma or ocular hypertension and were randomly assigned to SLT or medical therapy. Pressure targets were established individually based on disease severity and baseline pressures. These numbers also influenced set monitoring intervals and overall treatment intensity. Medical therapy consisted of prostaglandin analogs as first-line treatment.
At the end of three years, more than 78 percent of the eyes in the SLT group had achieved target pressures without the use of medications. Of these, three out of four needed only a single laser treatment to reach this goal. Furthermore, none needed trabeculectomy due to uncontrolled intraocular pressure, which occurred in 11 of the eyes treated only medically. In addition, 25 eyes receiving drops developed cataracts compared to only 13 on the SLT group, which could affirm the already-suggested possibility that drops speed cataract formation. From a cost perspective, the authors found a 97 percent probability that SLT as a first-line treatment would be more cost effective than pharmacologic therapy.
A Closer Look at SLT Treatment
SLT may provide certain benefits for patients, especially those who may have difficulty administering drops regularly. The procedure can be done directly in the clinic as an outpatient treatment. A trained practitioner uses a laser applied with a special contact lens to improve the drainage system of the eye. The laser causes biochemical changes to encourage greater outflow to reduce pressure within the eye. The treatment has an excellent safety profile and has been in regular use since 1995. Generally, SLT lowers eye pressure by about 20 percent to 30 percent and has an 80 percent success rate overall. The treatment can be repeated when effects begin to fade, which usually occurs in three to five years.
The side effects of SLT are rather rare and typically both mild and short-lived. However, some serious side effects such as inflammation and pressure spikes can occur, although these issues can be managed with medications. Overall, SLT has a better risk profile than the treatments that preceded it, such as argon laser trabeculoplasty, which involved the use or much higher energy resulting in possible structural damage and complication rates were fairly high. While SLT does not carry this same level of risk, it is likely the predecessor treatment’s adverse effects prevented it from being considered a first-line therapy. In the argon-laser era, eye drops made more sense. Perhaps this situation has now changed.
Pros and Cons of SLT as First-Line Therapy
Eye drops also have a fair share of side effects, the most concerning of which is dry eye. This issue likely relates to preservatives in the drops and tends to affect older individuals the most. While dry eyes can increase the risk of ocular pathology, it also simply makes the treatment uncomfortable for patients, which can lower compliance. If individuals do not use the drops regularly, they continue to face the serious risks of untreated glaucoma, including blindness. SLT does not have the same adherence issue and ensures that patients are not putting themselves at increased risk.
At the same time, it is important to recognize that SLT does not work for every patient. While it is true that patients who do not respond to this therapy can still turn to pharmacological options, there may also be a psychological effect on patients. These individuals may end up losing hope or simply losing faith in the competency of the provider. Thus, ophthalmologists may be motivated to continue relying on drops, which do not have the same limited rates of success. The other drawback to SLT is the fact that it is a surgical procedure. Not all patients may embrace the idea of a laser in their eye and so treatment could prove a hard sell to some patients.
The Bottom Line
While it remains to be seen whether the LiGHT study will change treatment recommendations when it comes to lowering intraocular pressure in patients with newly diagnosed glaucoma, it could influence individual practice. In the end, providers should discuss both options with their patients, including the benefits and drawbacks of each, before making a decision. Moving forward, the best option for a given patient may be driven largely by personal preference. However, the results of the new study should be an important part of the discussion between patient and provider.