The Efficacy and Safety of Radiation-Free Retrograde Intrarenal Surgery: A Prospective Multicenter-Based, Randomized, Controlled Trial.

PURPOSE: Fluoroscopy is usually required during retrograde intrarenal surgery (RIRS). Although fluoroscopy is considered necessary for effective and safe RIRS, there is growing awareness regarding radiation exposure risk to patients and surgeons. We conducted a multicenter-based, randomized, controlled trial to compare the safety and effectiveness of radiation-free (RF) RIRS with radiation-usage (RU) RIRS for kidney stone management. MATERIALS AND METHODS: From August 2020 to April 2022, patients with a unilateral kidney stone (≤20 mm) eligible for RIRS were prospectively enrolled in 5 tertiary medical centers after randomization and divided into the RF and RU groups. RIRS was performed using a flexible ureteroscope with a holmium:YAG laser. The primary end point of this study was the success rate, defined as complete stone-free or residual fragments with asymptomatic kidney stones ≤ 3 mm. The secondary end point of this study was ascertaining the safety of RF RIRS. The success rates were analyzed using a noninferiority test. RESULTS: Of the 140 consecutive randomized participants, 128 patients completed this study (RF: 63; RU: 65). The success rates (78% vs 80%, P = .8) were not significantly different between the groups. The rate of high-grade (grade 2-4) ureter injury was not significantly higher in the RF group compared to the RU group (RF = 3 [4.8%] vs RU = 2 [3.1%], P = .6). In RF RIRS, the success rate was noninferior compared to RU RIRS (the difference was 2.2% [95% CI, 0.16-0.12]). CONCLUSIONS: This study demonstrated that the surgical outcomes of RF RIRS were noninferior to RU RIRS.

Effectiveness and safety of the ablative fractional 2940-nm Er: YAG laser for the treatment of androgenetic alopecia.

Laser sources have established their potential effect in inducing hair regrowth. No large cohort study has evaluated the effect of ablative fractional 2940-nm erbium yttrium aluminum garnet (Er: YAG) laser in the treatment of androgenetic alopecia (AGA). To investigate the efficacy and safety of the ablative fractional 2940-nm Er: YAG laser in combination with medication therapy for the treatment of AGA. We performed a retrospective study between first July 2021 to 30th December 2021. All included patients received oral finasteride and topical minoxidil, or combined with six sessions of Er: YAG laser at 2-week intervals. Patients were divided into medication or combined therapy groups. The efficacy of the two therapies was evaluated by the investigator's Global Assessment (IGA) scores and the patient's Likert satisfaction scale at week 12 and week 24. Changes in total, terminal and villous hair count, total and terminal hair diameter, and AGA grade were also recorded. Adverse events were evaluated at each follow-up. A total of 192 male patients with AGA were included, including 67 receiving combination treatment, and 125 receiving medication treatment. At week 24, the combination treatment afforded superior outcomes in the IGA score, patient's global assessment, total and terminal hair counts, and diameters (all P<0.05). No severe adverse events were reported in both groups. The combined therapy of ablative fractional Er: YAG laser and medication was superior in treating male AGA than single medication therapy without serious adverse effects.

Effect of erbium, chromium-doped: yttrium, scandium, gallium, and garnet laser-assisted periodontal therapy using radial firing tip during early healing period: a randomized controlled split-mouth clinical trial.

BACKGROUND: This study aimed to demonstrate the efficacy of erbium, chromium-doped:yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser-assisted nonsurgical periodontal therapy in periodontitis patients during 8 weeks of healing. METHODS: A split-mouth, single-blinded, randomized controlled clinical trial was conducted on 12 patients diagnosed with stage III/IV periodontitis and had a minimum of two teeth with probing pocket depth (PPD) > 5 mm in at least two quadrants. Upon randomization, each quadrant was assigned for conventional scaling and root planing (SRP) procedure or laser-assisted therapy (SRP + laser) using radial firing tip (RFPT 5, Biolase). Clinical measurements and gingival crevicular fluid collection were performed for statistical analysis. RESULTS: In the initial statistical analysis on the whole subject teeth, modified gingival index (MGI) reduction was greater in test group at 1(P = 0.0153), 4 (P = 0.0318), and 8 weeks (P = 0.0047) compared to the control in the same period. PPD reduction at 4 weeks in test group was -1.67 ± 0.59 showing significant difference compared to the control (-1.37 ± 0.63, P = 0.0253). When teeth with mean PPD ≥5 mm were sorted, MGI decrease was significantly greater in test group at 1 (P=0.003) and 8 week (P=0.0102) follow-ups. PPD reduction was also significantly greater in test group at 4 week period (-1.98 ± 0.55 vs -1.58 ± 0.56, test vs control, P=0.0224). CONCLUSIONS: Er,Cr:YSGG-assisted periodontal therapy is beneficial in MGI and PPD reductions during early healing period.

Modified holmium laser enucleation for benign prostatic obstruction to preserve sexual and ejaculatory function.

INTRODUCTION: To report ejaculatory and urinary results in patients who underwent holmium laser enucleation of the prostate (HoLEP) with selective laser enucleation of the median lobe (MLHoLEP). METHODS: Patients with lower urinary tract symptoms (LUTS)/benign prostatic obstruction (BPO) who underwent MLHoLEP to preserve ejaculatory function in a single center were retrospectively identified. Urinary function was assessed using International Prostate Score Symptom (IPSS), IPSS-Quality of Life index (IPSS-QoL), peak urinary flow (Qmax) and postvoid residual (PVR). Erectile function was assessed using International Index of Erectile Function (IIEF-5). In patients with preoperative antegrade ejaculation, retrograde ejaculation was routinely screened at each follow-up visit. Sexual and urinary functions at 3 and 12 months were compared with baseline values. RESULTS: A total of 55 patients met our inclusion criteria. A significant improvement in the IPSS, IPSS-QoL, PVR and Qmax was found at 3 and 12 months, compared with baseline (all P<0.05). Eight patients (14.5%) required surgical reintervention due to persistant LUTS/BPO. No significant changes in the erectile function were found at 3 (P=0.3) and 12 months (P>0.9). In patients with preoperative antegrade ejaculation (n=32), only four cases of de novo retrograde ejaculation were recorded postoperatively. CONCLUSION: MLHoLEP represents a new alternative for men with LUTS/BPO who wish to preserve their ejaculatory function. Patients should be aware that improvement in urinary function may be inferior to the traditional technique, with a higher reintervention rate due to persistent LUTS. LEVEL OF EVIDENCE: Grade 4.

Aquablation versus HoLEP in patients with benign prostatic hyperplasia: a comparative prospective non-randomized study.

PURPOSE: The question of best surgical treatment for lower urinary tract symptoms (LUTS) due to benign prostate hyperplasia (BPH) remains controversial. We compared the outcomes of aquablation and holmium laser enucleation of the prostate ("HoLEP") in a prospective cohort. METHODS: Patients with BPH underwent aquablation or HoLEP according to their preference between June 2020 and April 2022. Prostate volume ("PV"), laboratory results, postvoid residual volume, uroflowmetry, IPSS, ICIQ-SF, MSHQ-EjD, EES and IIEF were evaluated preoperatively and at three, six and 12 months postoperatively. We also analyzed perioperative characteristics and complications via the Clavien Dindo ("CD") classification. RESULTS: We included 40 patients, 16 of whom underwent aquablation and 24 HoLEP. Mean age was 67 years (SD 7.4). Baseline characteristics were balanced across groups, except the HoLEP patients' larger PV. IPSS fell from 20.3 (SD 7.1) at baseline to 6.3 (SD 4.2) at 12 months (p < 0.001) without differences between aquablation and HoLEP. HoLEP was associated with shorter operation time (59.5 (SD 18.6) vs. 87.2 (SD 14.8) minutes, p < 0.001) and led to better PV reduction over all timepoints. At three months, aquablation's results were better regarding ejaculatory (p = 0.02, MSHQ-EjD) and continence function (p < 0.001, ICIQ-SF). Beyond three months, erectile, ejaculatory, continence function and LUTS reduction did not differ significantly between aquablation and HoLEP. CD ≥ grade 3b complications were noted in six patients in aquablation group while only one in HoLEP group (p = < 0.01). CONCLUSIONS: While aquablation revealed temporary benefits regarding ejaculation and continence at three months, HoLEP was superior concerning operation time, the safety profile and volumetric results.

A novel technique for thulium laser enucleation of the prostate: anterior releasing with ThuLEP (ARTh technique).

Thulium laser enucleation of the prostate (ThuLEP) is a highly effective approach to the treatment of benign prostatic hyperplasia. We present here a description of the "ARTh Technique" and the benefits it offers in terms of improved visualization, short operation times, and easy recognition of the dissection plane, describing specifically the anterior release (AR) technique using ThuLEP(Th). Included in this retrospective study were 32 consecutive patients operated on between January 2022-November 2022. Parameters were measured before and after the procedure: the International Prostate Symptom Score(IPSS), maximum flow rate(Qmax), post-void residual urine(PVR) prostate-specific antigen(PSA), prostate volume, operation-time, morcellation-time, catheterization-time and presence of transient urinary incontinence, and compared. The median age of patients undergoing enucleation of the prostate using the ARTh technique was 64 years (range: 44-83). The median prostate volume of the patients was 83.5 ml(50-128 ml), preoperative-IPSS was 24.8(15-33), postoperative-IPSS was 7(5-11), preoperative-Qmax was 8.1 ml/Sects. (5-11.5 ml/sec), postoperative-Qmax was 26.9 ml/Sect. (20.8-34 ml/sec), preoperative-PVR was 145 ml(75-258 ml), postoperative-PVR was 36.2 ml(0-66 ml), total operation time was 51.4 min(28-82 min), enucleation time was 36.9 min(19-51 min) and morcellation time was 15.3 min(8-27 min). The ARTh technique is a safe procedure that allows the surgeon to easily recognize and adhere to the defined dissection plane, thus decreasing operation times, significantly reducing the rate of postoperative transient urinary incontinence (TUI).

Thulium fiber laser enucleation of the prostate: a systematic review of the current outcomes.

INTRODUCTION: One recent addition to different lasers used for endoscopic enucleation of the prostate is the thulium fiber laser (TFL). The purpose of this systematic review is to present the feasibility, safety and efficacy of TFL Enucleation of the Prostate (ThuFLEP). EVIDENCE ACQUISITION: PubMed®, Scopus® and Cochrane® primary databases were systematically screened. The search strategy used the PICO (Patients, Intervention, Comparison, Outcome) criteria. Patients should be adults with benign prostatic obstruction (BPO) undergoing ThuFLEP. While comparative studies reporting comparison of ThuFLEP to other BPO treatments were included, cohort studies with no comparison group were also accepted. Outcomes including enucleation time and complication rates were reported. EVIDENCE SYNTHESIS: Twelve studies met all the predefined criteria and were included in the final qualitative synthesis. Mean operative time and enucleation time ranged from 46.6±10.2 to 104.5±33.6 and from 38.8±17.9 to 66.0±24.9 minutes, respectively. Most of the complications were Grade I or Grade II ones. Although TFL was found to present some advantages over older BPO treatments, its outcomes were comparable with other endoscopic enucleation approaches. CONCLUSIONS: ThuFLEP seems to be a feasible, safe and efficient approach for BPO symptoms management. Limited evidence showed that although ThuFLEP was associated with a reduced total operative time, it was also associated with worse IPSS improvement at 1-year follow-up, when compared with MOSESTM Holmium Laser Enucleation of the Prostate (HoLEP). These findings confirm the well-established opinion that the enucleation technique itself is more important than the technology which is used.

Enhancing continence post holmium laser enucleation of the prostate: assessment of novel technique through randomized clinical trial.

BACKGROUND: Transient urinary incontinence (UI) is distressing event following holmium laser enucleation of the prostate (HoLEP). Novel technique namely, veil sparing HoLEP (VS-HoLEP), was proposed to improve early continence outcome. In this trial (NCT03494049), VS-HoLEP was compared to standard HoLEP (St-HoLEP). METHODS: VS-HoLEP entails early apical separation with sparing of ventral apical mucosal veil proximal to the verumontanum. Eligible symptomatic BPH patients were randomly allocated to St-HoLEP (91) and VS-HoLEP (89). The primary outcome was UI as depicted by one-hour pad test at one month postoperatively. Other outcome measures include all perioperative parameters, complications, and urinary outcome measures at different follow-up points. RESULTS: Median preoperative prostate size was 138 (50:282) and 128 (50:228) mL in St-HoLEP and VS-HoLEP groups respectively. At one month the number of patients with positive one-hour pad test was 21 (23.1%) and 10 (11.4%) in St-HoLEP and VS-HoLEP groups respectively (P 0.047). The difference was significantly in favor of VS-HoLEP considering the number of patients reporting UI, the number of patients with positive one-hour pad test as well as the grade of UI reported at one and 4 months. The difference was not statistically significant at 12 months. The median time to patients' reported continence was 8 (1-52) and 1.5 (1-52) weeks in St-HoLEP and VS-HoLEP groups respectively (P≤0.005). The technique independently predicted positive one-hour pad test at one and four months respectively. At twelve months presence of DM (diabetes mellitus) and more percent PSA reduction independently predicted positive one-hour pad test. CONCLUSIONS: Veil sparing HoLEP enhances significantly early postoperative urine continence both subjectively and objectively. Optimization of the surgical technique could cut short the number of leaking patients and reduce the degree as well as the duration of transient postoperative urine leak.

[Treatment of early capsular blockage syndrome with Nd:YAG laser anterior capsulotomy containing neodymium-doped yttrium aluminum garnet in a case].

A 62-year-old female patient presented with no improvement in vision 10 days after undergoing cataract extraction in the right eye. The unaided visual acuity in the right eye was 0.1, and examination with a slit lamp revealed the presence of the intraocular lens with an increased gap between the intraocular lens and the posterior capsule. Anterior segment optical coherence tomography showed a distance of 3.236 mm between the posterior capsule and the posterior surface of the intraocular lens. Based on the medical history, ocular examination, and auxiliary examinations, a diagnosis of right eye capsular blockage syndrome was made. Nd:YAG laser capsulotomy was performed at the anterior capsule outside the optical zone of the intraocular lens. One week later, the posterior capsule adhered to the posterior surface of the intraocular lens, and there was a significant improvement in vision compared to before the procedure.

An energy efficiency assessment of Yttrium-aluminum-garnet laser in vitro.

To study the effect range of the Nd:YAG laser through various levels of cloudy medium for targets with varying grayscale values in vitro. The coated paper cards with grayscale values of 0, 50, 100, and 150 were used as the laser's targets, which were struck straightly with varying energies using three burst modes (single pulse, double pulse, and triple pulse). Six filters (transmittances of 40, 50, 60, 70, 80, and 90) were applied to simulate various levels of cloudy refractive medium. Image J software was used to measure the diameters and regions of the laser spots. The ranges of the Nd:YAG laser spots increased with energy in the same burst mode (P < 0.05). Under the same amount of energy, the ranges of the Nd:YAG laser spot increased with the grayscale value of the targets (P < 0.05). The greater the transmittance of the filters employed, the larger the range of the Nd: YAG laser spots produced. Assuming that the total pulse energy is identical, the effect ranges of multi-pulse burst modes were significantly larger than those of single-pulse burst mode (P < 0.05). The effect range of a Nd:YAG laser grows with increasing energy and the target's grayscale value. A cloudy refractive medium has a negative impact on the effect range of the Nd: YAG laser. The single pulse mode has the narrowest and safest efficiency range.

How I Do It: Teaching holmium laser enucleation of the prostate (HoLEP).

Holmium laser enucleation of the prostate (HoLEP) is considered a size-independent technique to treat benign prostatic hyperplasia. This safe and effective procedure is increasingly being adopted in urology training programs worldwide, yet limited teaching strategies have been described. Endoscopic handling during HoLEP allows for a simultaneous interaction between the surgeon and trainee, facilitating a guided teaching strategy with increasing difficulty as experience grows. In this article, we describe our stepwise approach for teaching HoLEP as part of a structured surgical training curriculum. We also evaluate the association of our method with intraoperative efficiency parameters and immediate postoperative surgical outcomes of 200 HoLEP procedures.

Holmium laser enucleation of the prostate for a case of transition zone prostate cancer.

Standard treatment approaches for localized prostate cancer remain limited to active surveillance, radiotherapy, and radical prostatectomy. We present a case of transition zone prostate cancer that was treated with holmium laser enucleation of the prostate, a procedure that is normally reserved for the management of benign prostatic hyperplasia.

Evaluation of the learning curve for Thulium laser enucleation of the prostate in a contemporary cohort.

PURPOSE: To assess the learning curve of Thulium laser enucleation of the prostate (ThuLEP) of a single surgeon. METHODS: Hundred patients suffering from benign prostatic hyperplasia were treated by the same surgeon. In all cases, a well-trained urologist was present in the operating room. Patients urinary function was assessed preoperatively using the International Prostate Symptoms Score (IPSS), maximum flow rate and Post-Void Residual volume. Preoperative prostate volume was recorded. Enucleation and morcellation efficiency and complication rate were evaluated. Patients were divided into 5 cohorts of 20 consecutive cases to assess changes in outcomes through time. RESULTS: Mean age of patients was 73.1 years (SD 17.5) and mean prostate volume was 89.7 ml (SD 55.1). Overall, mean enucleation and morcellation efficiency were 1.7 (SD 2.9) and 5.1 (SD 2.7) g/min. A statistically significant increase in enucleation efficiency was observed when comparing cohort 1 vs 2 (0.9 vs 1.3 g/min, p = 0.03) and cohort 2 vs 3 (1.3 vs 1.7 g/min, p = 0.02). A statistically significant increase in morcellation efficiency was observed when comparing cohort 1 vs 2 (2.8 vs 3.7 g/min, p = 0.02) and cohort 2 vs 3 (3.7 vs 4.9 g/min, p = 0.03). In both cases, no significant differences were observed when comparing the following cohorts. Complication rate showed no significant differences throughout the caseload. CONCLUSIONS: In our single-surgeon experience, we observed a learning curve of nearly 60 cases for the ThuLEP procedure in presence of a well-trained surgeon. Complication rate was low from the beginning of surgical experience.

The Efficiency of Erbium Lasers in the Removal of Root Canal System and Surface Biofilms: A Systematic Review and Meta-Analysis.

Background: Studies have shown positive effects of erbium lasers in removal of biofilms. A review article was required with quantitative data for confirmation of their effects, but there is still no a comprehensive study reviewing their effects based on the root canal and implant surface. This systematic review and meta-analysis was conducted to evaluate the efficiency of erbium lasers in removal of the root canal system and surface biofilms. Methods: Studies were searched with keywords in databases of PubMed, Scopus, Europe PMC, Cochrane Central, Embase, and Web of Science and screened by referees. Data were included based on mean ± standard deviation and size of control and laser groups. Effect sizes were assessed as standardized mean differences and calculated for each study and for the root and dental surface. Laser characteristics and bacteria were considered as moderators. Results: Nineteen articles in the current study comprised 565 samples (283 control samples and 282 laser samples). The analyses showed the significant effects of erbium lasers on bacterial biofilms on the implant surface [-0.496, 95% confidence interval, CI (-0.720 to -0.273); I2 = 26.94; p = 0.029; Q = 13.28] and root canal [-0.551, 95% CI (-0.656 to -0.445); I2 = 23.89; p = 0.031; Q = 10.46]. Results showed that highest efficiency lasers were obtained at higher wavelengths of 2940 nm, 75-100 mJ energy, and 100-150 µsec and <50-Hz pulses. Conclusions: Erbium lasers can be used to remove biofilms on dental implant surfaces and root canal systems and are safe options for untouchable sites in the root canal.

Solid state, pulsed-wave 355 nm UV laser atherectomy debulking in the treatment of infrainguinal peripheral arterial disease: The Pathfinder Registry.

BACKGROUND: Atherectomy is an important option for debulking atherosclerotic plaque from diseased arteries in patients with infrainguinal arterial disease. Laser atherectomy uses a high-powered laser to remove the plaque from the arteries to restore blood flow. AIMS: The Pathfinder multicenter registry was initiated to evaluate the safety and efficacy of the 355 nm laser atherectomy system in a real-world setting for the treatment of de novo, re-stenotic and in-stent restenosis (ISR) lesions in infrainguinal arteries of patients with peripheral artery disease (PAD). METHODS: The study was a prospective, single-arm, multicenter, open-label registry study for patients treated with the 355 nm laser system. Clinical and lesion characteristics, procedural safety and efficacy data, and baseline, 6-, and 12-month outcomes data, including Ankle Brachial Index (ABI), Rutherford class, and Walking Impairment Questionnaires (WIQ), were collected. The primary efficacy endpoint was the achievement of ≤30% final residual stenosis at the index lesion postatherectomy and adjunctive therapy evaluated by an angiographic Core Lab. The primary safety endpoint was the percentage of subjects who did not experience periprocedural major adverse events (PPMAEs) before discharge. RESULTS: One hundred and two subjects with 121 lesions treated with the 355 nm laser device at 10 centers were included in the analysis. Mean age was 68.4 ± 10.21 years, 61.8% of subjects were male, 44.6% had critical limb ischemia (CLI), and 47.3% had tibial lesions. The mean residual stenosis at the end of the procedure was 24.4 ± 15.5 with 69 lesions (69.0%) achieving technical procedural success (<30% stenosis); similar rates were observed for subjects with ISR (25.5 ± 14.9), chronic total occlusion (CTO) (28.1 ± 17.0), and severe calcification (36.5 ± 21.6) lesions. Mean ABI, Rutherford, and WIQ scores were improved at both 6 and 12 months. Ninety-seven of 102 subjects (95.1%) met the primary safety endpoint of not experiencing a PPMAE before discharge. CONCLUSIONS: The initial data from the Pathfinder Registry demonstrates the 355 nm laser system is safe and effective in a real-world setting for performing atherectomy in patients with infrainguinal PAD.

Root surface roughness evaluation following application of different periodontal instruments and Er:YAG laser: A profilometry and SEM study.

AIM: The aim of the present study was to evaluate the efficacy of 30°-angled Er:YAG laser tip and different periodontal instruments on root surface roughness and morphology in vitro. METHODS: Eighteen bovine teeth root without carious lesion were decoronated from the cementoenamel junction and seperated longitidunally. A total of 36 obtained blocks were mounted in resin blocks and polished with silicon carbide papers under water irrigation. These blocks were randomly assigned into 3 treatment groups. In Group 1, 30°-angled Er:YAG laser (2.94 µm) tip was applied onto the blocks with a 20 Hz, 120 mJ energy output under water irrigation for 20 s. In Groups 2 and 3, the same treatment was applied to the blocks with new generation ultrasonic tip and conventional curette apico-coronally for 20 s with a sweeping motion. Surface roughness and morphology were evaluated before and after instrumentation with a profilometer and SEM, respectively. RESULTS: After instrumentation, profilometric analysis revealed significantly higher roughness values compared to baseline in all treatment groups(p < 0.05). Laser group revealed the roughest surface morphology followed by conventional curette and new generation ultrasonic tip treatment groups (p < 0.05). In SEM analysis, irregular surfaces and crater defects were seen more frequently in the laser group. CONCLUSION: Results of the study showed that the use of new generation ultrasonic tip was associated with smoother surface morphology compared to 30°-angled Er-YAG laser tip and conventional curette. Further in vitro and in vivo studies with an increased sample size are necessary to support the present study findings.

Efficacy and safety of first-line or second-line selective laser trabeculoplasty for normal-tension glaucoma: a multicentre cohort study.

BACKGROUND/AIMS: This study aimed to investigate and compare the efficacy and safety of first-line and second-line selective laser trabeculoplasty (SLT) in Japanese patients with normal-tension glaucoma (NTG). METHODS: 100 patients with NTG were enrolled in this study. Patients were treated with SLT as a first-line or second-line treatment for NTG. Main outcome measures were intraocular pressure (IOP) reduction rate, outflow pressure improvement rate (ΔOP), success rate at 1 year and complications. Success was defined as ΔOP≥20% (criterion A) or an IOP reduction ≥20% (criterion B) without additional IOP-lowering eye-drops, repeat SLT or additional glaucoma surgeries. The incidence of transient IOP spike (>5 mm Hg from the pretreatment IOP), conjunctival hyperaemia, inflammation in the anterior chamber and visual impairment due to SLT were assessed. RESULTS: A total of 99 patients (99 eyes) were initially enrolled in this study, including 74 eyes assigned to the first-line SLT group and 25 eyes to the second-line SLT group. The mean IOP of 16.3±2.1 mm Hg before SLT decreased by 17.1%±9.5% to 13.4±1.9 mm Hg at 12 months after SLT in the first-line group (p<0.001), and the mean IOP of 15.4±1.5 mm Hg before SLT decreased by 12.7%±9.7% to 13.2±2.0 mm Hg at 12 months after SLT (p=0.005) in the second-line group. Both groups showed significant reductions in IOP. Higher pre-SLT IOP and thinner central corneal thickness were associated with greater IOP reduction. The success rate at 1 year was higher in the first-line compared with the second-line group, with lower pretreatment IOP and the use of IOP-lowering medication before SLT being associated with treatment failure. Most post-treatment complications were minor and transient. CONCLUSIONS: SLT may be an effective and safe treatment option for NTG, as either a first-line or second-line treatment. TRIAL REGISTRATION NUMBER: The study was registered in the UMIN-CTR (UMIN Test ID: UMIN R000044059).