From the Guidelines
Selective Laser Trabeculoplasty (SLT) is generally successful in treating glaucoma, with high-certainty evidence showing it to be as effective as medical treatment as a first-line therapy in controlling intraocular pressure (IOP) in open-angle glaucoma, as noted in studies such as 1 and 1. The treatment typically lowers IOP by 20-30% from baseline, with effects lasting between 1-5 years in most patients. SLT works by using a Q-switched, frequency-doubled Nd:YAG laser (532 nm) to selectively target pigmented trabecular meshwork cells without causing widespread thermal damage, stimulating cellular changes that increase aqueous outflow. The procedure is performed in an office setting under topical anesthesia, with patients receiving approximately 50-100 non-overlapping laser spots applied to the trabecular meshwork over 180-360 degrees. Post-procedure, patients typically use anti-inflammatory drops like prednisolone acetate 1% four times daily for 4-7 days. SLT can be repeated when effects diminish, though subsequent treatments may be less effective than the initial one. The procedure's advantages include being non-incisional, preserving conjunctival tissue for future surgeries, having minimal side effects (temporary inflammation, mild pain, or IOP spikes), and serving as either first-line therapy or as an adjunct to medication. Some key points to consider include:
- The success rate of SLT in terms of IOP reduction is significant, with approximately 70-80% of patients experiencing a reduction, as seen in studies like 1.
- The effects of SLT can last for several years, but the procedure can be repeated if necessary, as noted in 1.
- SLT is a relatively safe procedure with minimal side effects, making it a viable option for patients with glaucoma, as discussed in 1.
- Patients should be informed that they may still need some medications after SLT and should continue regular follow-up appointments to monitor their glaucoma status, as emphasized in 1. Overall, SLT is a valuable treatment option for patients with glaucoma, offering a non-invasive and effective way to manage IOP and prevent disease progression.
From the Research
Success Rate of Selective Laser Trabeculoplasty (SLT) for Glaucoma
- The success rate of SLT for glaucoma varies across studies, with reported success rates ranging from 18% to 88% 2.
- A study on SLT as a replacement therapy for medically controlled glaucoma patients found that 77% of eyes no longer needed any medication after SLT at 18 months, with more than 20% IOP lowering achieved in 95% of eyes and more than 30% IOP lowering achieved in 86% of eyes 3.
- The LiGHT trial demonstrated good efficacy of SLT, with 75% of eyes achieving their target pressure without drops and 58% after a single SLT 2.
- A multicentre cohort study on the efficacy and safety of first-line or second-line SLT for normal-tension glaucoma found that the success rate at 1 year was higher in the first-line compared to the second-line group, with a success rate defined as an IOP reduction of ≥20% or an outflow pressure improvement rate of ≥20% 4.
- SLT has been shown to be effective in reducing IOP in various types of glaucoma, including pseudoexfoliation glaucoma, with a case report demonstrating the effectiveness of SLT in a patient allergic to all anti-glaucoma drops 5.
Factors Affecting Success Rate
- Higher pre-SLT IOP and thinner central corneal thickness have been associated with greater IOP reduction 4.
- Lower pretreatment IOP and the use of IOP-lowering medication before SLT have been associated with treatment failure 4.
- The success rate of SLT may be influenced by the specific type of glaucoma being treated, with varying success rates reported for different types of glaucoma 6, 4, 3, 5, 2.