Commentary on: Role of selective laser trabeculoplasty in India

Glaucoma is one of the leading causes of irreversible blindness, and in India, around 12 million people suffer from this disease.[1] To date, topical glaucoma medications are the first line of choice for lowering intraocular pressure (IOP). However, there are significant concerns related to the side effects of medical therapy limiting its adherence. Additionally, there are select groups such as pregnant women and patients with systemic comorbidities in whom the drug class limits adequate IOP control with medical management and who may not be fit to undergo surgery immediately. Selective laser trabeculoplasty (SLT), a minimally invasive laser procedure, can reduce IOP with fewer side effects than traditional treatments. It is a simple outpatient procedure that can be performed by all ophthalmologists trained in gonioscopy, taking about 5–10 minutes. Using a frequency-doubled Q-switched Nd:YAG laser, SLT targets specific cells in the trabecular meshwork, enhancing aqueous humor outflow with minimal collateral damage to surrounding tissues. It requires 80–100 very low-energy shots (0.3–1.2 mJ) delivered directly to the angle by using a goniolens and is amenable to repeat treatments. The LIGHT trial showed that SLT provides drop-free IOP control for 70% of primary open-angle glaucoma (POAG) and ocular hypertension (OHT) patients at the end of 6 years.[2,3] Being cost-effective and safe, it is now recommended as first-line therapy for POAG and OHT by the UKNICE.[4] Narayanaswamy et al.,[4] in their review of SLT, documented multiple peer-reviewed reports along with seven meta-analyses establishing the procedure’s efficacy for POAG treatment. Its efficacy is similar for OHT, pseudoexfoliation glaucoma, and pigmentary glaucoma, and slightly lower for normal tension glaucoma. There is minimal literature on SLT in open-angle glaucomas from India, and they have reported adequate IOP reduction in 50% of treated patients.[4-7] It has been found that failure is most common after 3 years, and investigators have done retreatment in 60% of the cases at the end of 10 years.[4] It has a very good safety profile, with adverse effects being minimal inflammation in very few patients, easily controlled by topical NSAIDs.[5] This non-invasive technique is gaining popularity as a first-line treatment for glaucoma due to its effectiveness, safety profile, and patient acceptance. Glaucoma treatment poses a significant financial burden on patients and their families. A survey conducted among glaucoma patients in India reported that the patients find it challenging to use topical glaucoma medications due to reasons apart from cost, such as difficulty in remembering the timing of medications, inconvenient dosage timing, difficulty in opening the bottle or placing the drop into the eye, and local ocular side effects such as redness/itching or watering.[8] This is particularly true when multiple drugs are prescribed. There are no studies comparing the cost-effectiveness of SLT vis-à-vis medical therapy from India. However, besides cost considerations, adherence to therapy also remains a major barrier to glaucoma treatment in our country. In this context, offering the SLT as a first-line treatment in open-angle glaucomas may serve to bridge the problems of dealing with cost and adherence to medical management. Additionally, Indian manufacturers are offering lower-cost SLT equipment (Twinstar YAG and SLT combo 507, Appasamy Associates, India), which may allow for its wider use in India. The future direction of SLT includes trials to optimize its outcomes, given the excellent results of the LIGHT trial. The results of the Clarify the Optimal Application of SLT (COAST) trials will help us know if annually repeated low-energy SLT is useful in reducing or delaying other glaucoma interventions and improving the quality of life.[9] A novel method of “Direct SLT,” which directly delivers the energy to the trabecular meshwork (peri-limbal ocular area) without the need for a goniolens, is also undergoing a large trial: the GLAUrious study.[10] Therefore, the prospects of improving the treatment of open-angle glaucomas by using SLT are very appealing. In India, SLT may be tried as an alternate first line of treatment due to its clinical efficacy and its role in reducing the challenges of using glaucoma medications for these patients.