Ophthalmol Ther DOI 10.1007/s40123-017-0082-x REVIEW A Review of Selective Laser Trabeculoplasty: Recent Findings and Current Perspectives Yujia Zhou . Ahmad A. Aref Received: January 17, 2017 Ó The Author(s) 2017. This article is published with open access at Springerlink.com ABSTRACT explored, revealing that minor modifications may lead to a more favorable or safer clinical Selective laser trabeculoplasty (SLT) has been outcome. The utilization of postoperative widely used in the clinical management of medications remains controversial based on the glaucoma, both as primary and adjunctive current evidence. A short-term IOP increase treatment. As new evidence continues to arise, may complicate SLT and can also persist in we review the current literature in terms of certain cases such as in exfoliation glaucoma. indications and efficacy, surgical technique, The efficacy and safety of repeat SLT are shown postoperative care, repeatability, and compli- in multiple studies, and the timing of repeat cations of this therapy. SLT has been shown to procedures may affect the success rate. be effective in various glaucomas, including primary open-angle glaucoma (POAG), nor- mal-tension glaucoma (NTG), steroid-induced Keywords: Glaucoma; Intraocular pressure; glaucoma, pseudoexfoliation glaucoma (PXFG), Laser; Selective laser trabeculoplasty and primary angle-closure glaucoma (PACG), as well as other glaucoma subtypes. Relatively high preoperative intraocular pressure (IOP) INTRODUCTION may predict surgical success, while other parameters that have been studied do not seem Intraocular pressure (IOP) reduction is the to affect the outcome. Different techniques for mainstay of therapy for glaucomatous optic performing the procedure have recently been neuropathy. Selective laser trabeculoplasty (SLT) has been widely employed for this pur- Enhanced content To view enhanced content for this pose over the past several years as both a pri- article go to http://www.medengine.com/Redeem/ mary and adjunctive treatment [1]. B097F0605AB49042. In recent years, there has been a surge in literature regarding the utilization of SLT in Y. Zhou patients with glaucoma. The procedure may Chicago Medical School, Rosalind Franklin address issues with topical medication compli- University, Chicago, IL, USA ance and side effects [1], and it is considered a A. A. Aref (&) cost-effective treatment [2]. Although the effect University of Illinois Eye and Ear Infirmary, of SLT wanes over time, repeating the procedure University of Illinois at Chicago College of may lead to clinical success comparable to that Medicine, Chicago, IL, USA e-mail: [email protected] achieved with the initial treatment [3–5]. Ophthalmol Ther In a study by Bovell and colleagues compar- Primary Open-Angle Glaucoma ing SLT to argon laser trabeculoplasty (ALT), SLT and Ocular Hypertension lowered IOP by over 6.5 mmHg at 3 years of follow-up [6]. Efficacy results were similar to The efficacy of SLT in patients with POAG or those achieved with ALT, with waning efficacy OHT has been demonstrated in numerous and a 50% failure rate after 2 years. The poten- studies. It has great therapeutic potential when tial repeatability of SLT is thought to be one of used as a primary or adjunctive treatment its advantages over ALT [5], which was shown to modality. Kadasi et al. have suggested that the have a success rate of only 14% after re-treat- efficacy of SLT is at least comparable to that of ment [7]. topical medications, and SLT may be preferred Globally, SLT also plays an important role as when considering the potential adverse sys- adjunctive or primary therapy for open-angle temic and local adverse effects as well as com- glaucoma. Realini demonstrated a prompt and pliance issues associated with long-term sustained reduction in IOP after SLT therapy in medication use [1]. patients from St. Lucia that were washed out A recent study investigated the use of SLT in from all medical therapy. Mean IOP reductions early and advanced open-angle glaucoma ranged from 7.3 to 8.3 mmHg (34.1–38.9%) (OAG), where the glaucoma staging was based through 12 months of follow-up [8]. on the vertical cup-to-disc ratio. SLT was shown Although SLT is considered a relatively safe to be successful in reducing IOP by more than procedure, risks of complications remain [9]. 20% in both early and advanced OAG. Fur- Furthermore, follow-up visits are required to thermore, functional and/or structural progres- monitor for adverse events, and additional sion was not detected in treated patients for up treatment with medications or incisional pro- to 12 months post-operation. The success rates cedures ultimately may be required [10, 11]. were 63% and 59.1% for early and advanced There is an increasing need for better OAG, respectively. Results from this study allow understanding of SLT and how it fits within the clinicians to consider SLT as an alternative to picture of treating glaucoma. In this article, we higher-risk incisional therapies in advanced will review recent findings pertaining to SLT, stages of OAG [13]. including its indications and efficacy, surgical Kerr et al. used the water-drinking test technique, postoperative care, and (WDT) to demonstrate that SLT is effective in complications. reducing both peak IOP and IOP fluctuation in This article is based on previously conducted patients with OAG or ocular hypertension. studies, and does not involve any new studies of Following SLT, there was a significant reduction human or animal subjects performed by any of in both baseline and peak IOP, and the per- the authors. centage rise from baseline after the WDT was significantly lower as well. Since WDT provides an accurate prediction of diurnal IOP spikes, INDICATIONS AND EFFICACY SLT would be expected to minimize IOP fluc- tuations outside of the clinic when IOP mea- Various glaucoma subtypes may be amenable to surement is not attainable [14]. treatment with SLT in order to reduce baseline IOP and/or medication burden. A recently published review investigating SLT outcomes in Primary Angle-Closure Glaucoma the Hong Kong Chinese population reports that expected efficacy may depend on the underly- Traditionally, clinicians have not considered ing glaucoma subtype [12]. Most studies define SLT in angle-closure glaucomas, as the proce- successful SLT treatment as a reduction in IOP dure requires visualization and treatment of the [20% from baseline levels. Recent data per- trabecular meshwork. However, recent studies taining to SLT efficacy are summarized in have investigated the efficacy and safety of SLT Table 1. Table 1 Summary of indications and efficacy of SLT Ophthalmol Ther Paper Design Diagnosis Number Postoperative Definition Success rate Average IOP Additional of eyes (n) follow-up of success reduction outcomes or medication reduction Schlote et al. Retrospective Early stage of OAG n = 27 12 months Eyes with elevated IOP 63% N/A Re-treatment in 7.4% of [13] chart review (vCDR \ 0.8 and prior to SLT: eyes GSS 0–1) reduction in IOP \ 21 mmHg and [20% of the initial IOP Or Eyes with discomfort to anti-glaucoma medication but controlled IOP: reduction in the number of medications C1 and an IOP \ 21 mmHg Advanced stage of n = 44 Definition 1: Reduction Definition 1: 59.1% N/A Additional glaucoma \ OAG in IOP 21 mmHg Definition 2: surgery in 18.2% of C [ (vCDR 0.9, and 20% of the 65.9% eyes GSS 2 C 3, or baseline IOP vCDR 0.6–0.8 Definition 3: 50% Definition 2: IOP and GSS2 C 2) reduction \18 mmHg and no additional glaucoma medication at all time points after SLT Definition 3: IOP reduction \18 mmHg and [30% of the baseline IOP Kerr et al. [14] Retrospective OAG or OHT n = 20 At least 6 weeks Significant reduction in N/A Reduction in mean Peak IOP decreased cohort study baseline IOP, peak baseline IOP from from 21.9 ± 3.7 to IOP, and % rise in 16.9 ± 2.4 to 16.9 ± 3.1 mmHg IOP from baseline 14.2 ± 2.3 mmHg (P \ 0.001) and rise induced by the water (P \ 0.001) in IOP from baseline drinking test reduced from 5.0 ± 2.5 to 2.6 ± 1.8 mmHg (P \ 0.002) Table 1 continued Paper Design Diagnosis Number Postoperative Definition Success rate Average IOP Additional of eyes (n) follow-up of success reduction outcomes or medication reduction Ali Aljasim et al. Retrospective PAC/PACG, n = 96 (SLT), PAC/PACG: IOP reduction C20% PAC or PACG: IOP reduction in N/A [15] case–control POAG n = 99 6–20 months without further 84.7%, POAG: patients with study (PGA) POAG: medical or surgical 79.6% uncontrolled IOP: intervention or a (P = 0.47) 38% (PAC/PACG) 6–17 months reduction in the vs. 32.7% (POAG), number of glaucoma P = 0.08 C medications by 1 Number of while maintaining the medications target IOP reduction in patients with controlled IOP: 1.6 (PAC/PACG) vs. 1.5 (POAG), P = 0.4 Narayanaswamy Randomized PAC/PACG n = 20, 6 months Complete success: IOP Complete success: IOP reduction: 16.9% No patient required et al. [16] clinical trial (PXFG), \21 mmHg and 60% (SLT) vs. (SLT) vs. 18.5% glaucoma surgery = = n 28 without any 84% (PGA), (PGA), P 0.52 Additional medication: = (POAG) additional P 0.008 22% (SLT) vs. 8% IOP-lowering Qualified success: (PGA), P = 0.05 medications 18% (SLT) vs. Qualified success: IOP 6% (PGA), \21 mmHg who P = 0.06 required IOP lowering medication Miraftabi et al. Prospective PXFG, POAG n = 94 12 months IOP reduction C20% At 6 months, 75% Significant IOP N/A [17] non-randomized (PXFG), from baseline without (POAG) vs. reduction up to comparative n = 250 additional 94.1% (PXFG), 6 months study (non-PXFG) IOP-lowering P = 0.08 post-operation medications At 12 months, 29.1% (POAG), 25% (PXFG), P = 0.9 Ophthalmol Ther Ophthalmol Ther Table 1 continued Paper Design Diagnosis Number Postoperative Definition Success rate Average IOP Additional of eyes (n) follow-up of success reduction outcomes or medication reduction Lindegger et al.