Laser Offers a Reliable Alternative to Eye Drops to Treat Glaucoma or Ocular Hypertension: The Results of the LiGHT Study
Glaucoma is a chronic eye condition that necessitates lifelong monitoring and management. For many patients, controlling intraocular pressure (IOP) through medication, particularly eye drops, can help manage the disease. However, this approach is not without its challenges. Complications, side effects, and adherence to treatment regimens can significantly impact effectiveness. Additionally, some patients may not respond to medications, experience reduced effectiveness over time (tachyphylaxis), or find the financial burden too high.
Why Consider SLT?
Adherence to prescribed medication among glaucoma patients is a notable concern, with studies indicating that between 20% to 66% of patients do not use their medication as directed. Laser treatments, such as selective laser trabeculoplasty (SLT), offer an alternative with a perfect compliance rate. SLT employs low-energy nanosecond pulses in a highly localized and controlled manner, targeting the trabecular meshwork (TM) to improve aqueous outflow and lower IOP.
Compared to other laser treatments, SLT utilizes larger spot sizes and lower power density, resulting in minimal thermal damage to surrounding tissues. For instance, standard argon laser trabeculoplasty (ALT) involves significantly higher energy and irradiance than SLT, which uses only about 1 mJ per pulse. This careful application of energy confines the heat within a small area, reducing the risk of collateral damage and allowing for repeated treatments if necessary.
The Importance of the LiGHT Study
The LiGHT (Laser in Glaucoma and Ocular Hypertension) study has been pivotal in reshaping glaucoma treatment paradigms. This multicenter, randomized controlled trial assessed the quality of life, IOP control, disease management, and the necessity for surgery in patients treated with either SLT or medications.
Three-Year Results
The study, which ran from 2012 to 2014, enrolled 718 patients with mild to moderate glaucoma. Half received SLT first, while the other half began with medication. The primary outcome was health-related quality of life, with other measures including IOP control and the need for surgery. Notably, 78% of eyes treated with primary SLT remained drop- and surgery-free at the three-year mark. Most patients required only one SLT treatment, although the IOP control effect gradually diminished over time. Repeat treatments proved equally effective, suggesting that SLT is a viable long-term strategy for managing glaucoma.
Six-Year Extension
An extension of the study included 88% of the original participants. Those initially treated with SLT could receive up to three treatments, while those on medication could switch to SLT. The results were compelling: 70% of the SLT-first group maintained target IOP without medications. Moreover, disease progression was slower, and the time to surgical intervention was longer in the SLT group compared to the medication-first group.
Conclusion
SLT has demonstrated its ability to control IOP effectively and safely in patients with mild to moderate open-angle glaucoma. The LiGHT study’s findings support SLT as a primary intervention, potentially reducing the need for ongoing medication and delaying or preventing the need for surgery. While questions about the optimal frequency of SLT treatments and post-laser drug regimens remain, SLT should be a strong consideration for newly diagnosed patients or those in the early stages of the disease. By integrating SLT into glaucoma management, patients can benefit from a more straightforward, compliance-friendly treatment that offers sustained IOP control and improves long-term outcomes.
