Laser Safety Research Articles

Use of blue laser in a patient with postop restenosis of the choana after multiple surgical interventions for congenital choanal atresia

One of the most common complications following surgical interventions in nasal cavity is synechiae and scarring, which often leads to restenosis, particularly in cases of choanal atresia. Laser technologies, especially blue laser (wavelength 445 nm), represent a promising opportunity in rhinology for addressing these complications. Objective: to study the effectiveness and safety of blue laser for nasal synechiae and stenosis surgery in patients with congenital choanal atresia after multiple surgical interventions. In ENT department of Veltishev Institute 4 children have undergone choanal reconstruction following multiple attempts of choanoplasty. A clinical case of a 6-year-old girl diagnosed with bilateral complete choanal atresia, who underwent six surgical interventions within two years and was admitted with complete choanal restenosis is presented. The most common cause of restenosis after surgery for hoan atresia is the formation of synechiae in the surgical area. Traditional dissection of the synechiae in most cases leads to repeated stenosis. To reduce the recurrence rate in the patient, the authors used a blue laser. The blue laser demonstrated high effectiveness in the surgical treatment of postop restenosis, minimizing surgical trauma, preventing recurrences, and improving the patient’s quality of life. The results confirm the feasibility of using lasers in rhinology as a preferred method for treating restenosis and enhancing respiratory function.

Combined fractional CO2 laser with topical tioconazole versus Q-switched Nd-YAG laser in the treatment of onychomycosis; a randomized comparative trial

AbstractTreatment of onychomycosis includes topical and systemic agents. However, prolonged use of oral treatment could cause adverse effects and topical antifungal agents have limited penetration. To compare the clinical efficacy and the safety of fractional CO2 laser combined with topical tioconazole nail solution versus Q-switched 1064 Nd: YAG laser in the treatment of fingernail onychomycosis. This randomized comparative clinical trial was conducted on 13 patients (47 nails) with fingernail onychomycosis. Patients were randomized to receive either fractional CO2 laser combined with topical tioconazole or Q-Switched Nd: YAG 1064 nm laser every 2 weeks for 3 months followed by a 1-month follow up assessment. Onychomycosis severity index (OSI) score, Dermatology life Quality Index (DLQI) score, patient satisfaction score, dermoscopic evaluation and KOH examination were used for assessment of improvement. OSI showed improvement after treatment in both arms (from 16.17 to 10.92 in fractional CO2 arm (p = 0.026) and 23.13 to 22.43 (p = 0.92)). When comparing both groups OSI score significantly reduced in the fractional CO2 laser combined with tioconazole more than the Q-switched laser group (p = 0.002). The mean DLQI score significantly improved in both groups but no statistically significant difference between the two groups. Significant improvement in patient satisfaction score was noted in both groups. Mycological cure using KOH examination was detected in both groups (44.4% in the CO2 group and 56.5% in the Q-switched group) with no significant difference (P value < 0.05). Ruin pattern keratosis found to be the most dermoscopic pattern to be associated with poor OSI score improvement. Fractional CO2 laser combined with topical tioconazole is more efficient in treatment of onychomycosis than Q-Switched Nd: YAG 1064 nm laser group as regards clinical improvement but both have comparable effect on mycological cure. Their use as adjuvant treatment rather than alone is recommended to ensure mycological cure in onychomycosis.

Safety and efficacy of the yellow sub-threshold micropulse laser for uveitic macular edema: A pilot study.

To assess the safety and efficacy of the yellow sub-threshold micropulse laser (YSML) in eyes with uveitic macula edema (UME). A prospective interventional study. Eyes with non-infectious UME and an unsatisfactory response to prior conventional treatments underwent navigated YSML (NAVILAS®). The treatment was planned on an imported macular OCT scan. The central macular thickness (CMT) and best-corrected visual acuity (BCVA) were recorded immediately before the treatment (baseline) and again after 1 and 3 months. The end of the follow up (FU) was the last available evaluation in the case of no UME recurrence; or when the CMT increase required rescue therapy. Eight eyes of as many patients were included. The mean duration of the FU was 252 days (range: 170-398 days). No adverse events were observed. In the whole cohort the mean values improvement over time was significant for both CMT (p = 0.011) and BCVA (p < 0.001). The indication for a new treatment was stated in 4 eyes (50%) after a mean FU of 277 ± 43 days. This time was statistically comparable with the mean FU of eyes without UME recurrence. At the baseline the non-UME recurrence eyes had a significantly lower mean CMT (326 ± 80 vs 485 ± 112 μm, p = 0.03). The application of YSLM for UME has not previously been mentioned in literature. Our results were promising in terms of both safety and efficacy. This would authorize further studies on the procedure, also as a first line treatment in naif UME cases.

Localized surface plasmon resonance induced nonlinear absorption and optical limiting activity of gold decorated graphene/MoS2 hybrid

The synergistic supremacy of a hybrid nanocomposite made of reduced graphene oxide (rGO), molybdenum disulfide (MoS2) and gold nanoparticles (Au) for Q-switching and optical limiting applications is investigated. Hydrothermally synthesized Au-rGO-MoS2 hybrid with varying concentrations of Au (2.5, 5, 7.5 and 10 wt%) was subjected to interact with Q-switched Nd:YAG nanosecond green laser pulses. The intensity dependent nonlinear absorption studies revealed a switch over in the nonlinear behaviour from saturable absorption (SA) to reverse saturable absorption (RSA) behaviour. SA occurs due to ground state bleaching at comparatively lower laser irradiances serving the need for Q-switching and optical communications. The RSA trait at higher laser irradiance is attributed to sequential two-photon absorption which serves as the platform for optical limiting behaviour prompting laser safety and effective photothermal therapy applications. The strong mid-visible and UV absorption promotes the availability of multiple energy bands for energy transitions of excited state absorption (ESA). Enhanced local fields due to localized surface plasmon resonance effect, structural defects, hierarchical morphology, increased absorption cross-section and plasmon induced energy transfer promotes robust ESA process. These tunable nonlinear optical properties make Au-rGO-MoS2 hybrid promising futuristic candidates for applications in nonlinear photonic devices, ultrafast optical switches and all-optical signal processing systems.

Multi-Wavelength Narrow-Spacing Laser Frequency Stabilization Technology Based on Fabry-Perot Etalon

Classical frequency-stabilized lasers have achieved high-frequency stability and reproducibility; however, their extensive wavelength spacing limits their utility in various scenarios. This study introduces a novel frequency-stabilized laser scheme that integrates a Fabry-Perot etalon (FPE) with digital control technology and wavelength modulation techniques. The FPE, characterized by multiple transmission peaks at minimal frequency intervals, provides stable frequency references for different lasers, thereby enhancing the system’s flexibility and adaptability. An error signal is derived from the first-order differentiation of the FPE’s transmission curve. A 180° phase difference was observed in the feedback output signal when the laser’s central frequency diverged from the reference, determining that the direction of the frequency control was accordingly determined.Employing feedback control, the laser’s output frequency is stabilized at the transmission peak frequency of the FPE. Experimental results demonstrate that this stabilization scheme effectively locks the laser’s output wavelength to different transmission peak frequencies of the FPE, achieving 25 GHz wavelength spacing. The frequency stability is improved by two orders of magnitude on a second-level timescale, maintained within hundreds of kHz, equating to a frequency stability level of 10−10.

Combined fractional CO2 laser with dimethyl sulfoxide (DMSO) 50% versus fractional CO2 Laser alone in the treatment of macular amyloidosis: clinical and histopathological assessment.

Macular amyloidosis (MA) could be of cosmetic concern with a significant psychological impact for patients, and its treatment is challenging. To compare the efficacy and safety of combined fractional CO2 laser with dimethyl sulfoxide (DMSO) 50% versus fractional CO2 laser alone in the treatment of macular amyloidosis. Twenty patients with macular amyloidosis were treated with monthly session of fractional CO2 laser only in one side of the lesion (area A), and fractional laser followed by application of DMSO 50% solution in the other side of the lesion (area B). All patients were evaluated clinically, by dermoscope and histopathology before and 3months after the end of 4 treatment sessions. Both treatments showed significant decrease of pigmentation after treatment (p < 0.001). There was non-significant decrease in rippling on both sides (p = 0.06). The median itching score dropped significantly after treatment from 9 to 3.5 in area A (laser only) and to 2 in area B (laser and DMSO), with non-significant difference between both areas (P = 0.244). Dermoscopic features after treatment showed fading and decreasing in multiple features in both areas A and B, with non-significant difference between the 2 areas. Histopathologically, there was significant reduction in the amyloid deposition after treatment in both areas A and B without significant difference between both areas. both fractional CO2 laser combined with topical DMSO 50% and fractional CO2 laser alone are safe and effective treatment options for MA with significant clinical improvement.

Ablation efficiency and laser safety of a novel superpulsed thulium fiber laser: a in vitro study.

To assess the ablation efficiency of the Superpulsed Thulium Fiber Laser (SP-TFL) and investigate the thermal effects of SP-TFL. A SP-TFLwas employed to evaluate ablation efficiency. Fresh ex-vivo pig kidneys and ureters were utilized to evaluate the renal pelvis and ureter temperature changes, different irrigation rates(0, 15, 38mL/min) and a long pulse width were used. The research indicated that as laser output power increased, ablation rates significantly increased. Ablation rates(mg/min) were higher and the energy per ablated mass(J/mg) was lower at lower frequencies(10-50Hz). Under the same frequency and single pulse energy, super short and short pulse widths demonstrated higher ablation rates at higher frequencies (exceeding 100Hz). The temperature of the renal pelvis and ureter decreased with increasing irrigation rates. In the renal pelvis, without irrigation, the temperature quickly reached the critical threshold of 43℃. The irrigation rate was 15ml/min and power was no more than 18W, the renal pelvis temperature did not reach 43℃. When the irrigation rate were 38ml/min, the temperature did not risen to 43℃. In the ureter, without irrigation, the temperature also quickly reached 43℃. The temperature reached 43℃ when the power exceeded to12W with an irrigation rate of 15ml/min. With an irrigation rate of 38ml/min, the temperature reached 43℃ at a laser power of 30W. The SP-TFL demonstrated promising ablation effectiveness especially for lower frequencies and super short and short pulse widths model. Proper irrigation rates, single pulse energy, frequency and pulse width are crucial during lithotripsy.

Picosecond Alexandrite Laser With Diffractive Lens Array Combined With Long-Pulse Alexandrite Laser for the Treatment of Facial Photoaging in Chinese Women: A Retrospective Study.

Facial photoaging is a type of facial skin aging induced mainly by exogenous factors (ultraviolet radiation) and often manifests itself in the form of hyperpigmentation, telangiectasia, roughness, increase in fine lines/wrinkles, and enlarged pores. Recently, picosecond lasers have become an emerging option for the treatment of facial photoaging, and long-pulse alexandrite lasers (LPAL) have demonstrated promising potential in the treatment of photoaging-related symptoms. This study aimed to evaluate the efficacy and safety of picosecond alexandrite laser (PSAL) with diffractive lens array (DLA) combined with LPAL for facial photoaging. This is a retrospective study of 20 Chinese female patients with facial photoaging who received PSAL with DLA combined with LPAL during a 1-year period. All patients were treated every 4weeks for a total of three treatments. Objective indicators of facial photoaging and patient satisfaction were evaluated before each treatment, and pain scores and adverse effects were recorded after each treatment. Compared with baseline, patients showed significant differences in all facial photoaging indices (p<0.01). After receiving three treatments, there was a 20.1% decrease in the pigmentation index, a 23.9% decrease in the erythema index, a 34.5% decrease in the texture index, a 28.4% decrease in the fine lines index, a 56% decrease in the pore index, a 9.3% elevation and a 17.1% decrease in elasticity R2 and F4, respectively, and a 55% decrease in sebum content. The mean satisfaction score for the three treatments was 4.67 (3.33, 5.00), and the mean visual analogue scale (VAS) pain score was 7.00. No serious adverse effects such as post-inflammatory hyperpigmentation (PIH), hypopigmentation, or blistering were observed at the treatment site during the treatment period. PSAL with DLA combined with LPAL for the treatment of facial photoaging with significant efficacy, high patient satisfaction, and minimal adverse effects.

Maximum permissible levels of laser radiation as a tool for ensuring the sanitary and epidemiological well-being of the population

Introduction. Laser radiation is the youngest production factor, but not the most harmless. The rapid development of modern laser technologies and their introduction into various fields of science and technology has allowed lasers entering widely into everyday human life, as well as into the sphere of culture, fine arts, and the show industry. Thus, the development of a unified algorithm for calculating the maximum permissible levels (MPL) of laser radiation is becoming particularly relevant. The purpose of this work is to assess the subjective feelings of persons exposed to laser radiation at levels not exceeding the maximum permissible levels and clarify the methodology for calculating acceptable levels of laser radiation. Materials and methods. Graphical modelling was used to develop an algorithm for calculating the MPL. To assess the subjective perception of laser radiation, a survey of 20–25 years five hundred eighteen people was used according to a specially designed questionnaire. Results. Exposure to laser radiation at levels not exceeding the MPL caused unpleasant sensations in the eyes of the participants of the show, temporary violation of colour perception, temporary blindness, headache. An algorithm for calculating the MPL of laser radiation has been developed, consisting of six stages, which allows optimizing the computational component of laser safety assessment in the implementation of State sanitary and Epidemiological supervision and control. Limitations. The age range of the study participants is 20–25 years old. Conclusion. It is proposed to revise the standards of MPL for the population based on the temporary effects of radiation. This will minimize the negative impact on the organ of vision in terms of reversible changes and qualitatively improve the hygienic assessment of laser radiation. The developed algorithm for calculating the permissible levels of laser radiation will help minimize errors and reduce the time spent by specialists when assessing the safety of exposure to laser radiation on the body.

Safety and efficacy of subthreshold micropulse yellow laser for persistent subretinal fluid after scleral bucking a randomized clinical trial

Persistent subretinal fluid (PSF) after scleral bucking of rhegmatogenous retinal detachment may delay recovery and affect the final visual quality, but with no effective treatment. This study firstly investigated the safety and efficacy of 577 nm yellow subthreshold micropulse laser (SML) on PSF after scleral bucking surgery. This double-masked randomized clinical trial was conducted from December 2020 to October 2022 at Chongqing Aier Eye Hospital. Participants with PSF last for 1 month after scleral bucking surgery with break closed and retina reattachment were recruitment. These participants were treated by 577 nm yellow SML or sham treatment. Funduscopy, optical coherence tomography (OCT) volume change, best corrected vision acuity (BCVA) and visual field test were evaluated for six mouths follow-up. A total of 24 participants were randomized into SML group or Sham group equally. Compared with Sham group, the OCT volume within 6 mm of macular fovea was significantly less in SML group 6 months after therapy (P = 0.048). There were no statistically significant differences of OCT volume at 1, 2 and 3 months from baseline between groups. BCVA of ETDRS letters had no statistically significant difference. Pattern Standard Deviation amelioration (P = 0.039) had statistically significance in SML group compared with Sham group. There were no complications in the 2 groups. These preliminary findings suggest that 577 nm yellow SML therapy could accelerate PSF absorption after scleral bucking surgery.Trial registration: Chinese Clinical Trial Registry No. ChiCTR2000037838, 02/09/2020, https://www.chictr.org.cn/showproj.html?proj=51885.

54268 Assessment of picosecond laser safety and patient satisfaction for facial rejuvenationi in skin phototypes IV-VI

54268 Assessment of picosecond laser safety and patient satisfaction for facial rejuvenationi in skin phototypes IV-VI

High-powered 675-nm laser: Safety and efficacy in clinical evaluation and in vitro evidence for different skin disorders.

Laser technology is a viable therapeutic option for treating a number of skin pathologic conditions, including pigmented lesions, vascular lesions and acne scars. In this work, through in vitro and clinical investigationswe test the efficacy, the safety and the speed of treatment of high-powered laser system emitting a 675-nm in the management of various skin condition. In vitro experiments were performed irradiating adult human dermal fibroblasts cells (HDFa) with 675-nm laser for 24, 48 and 72h with different fluences and Ki-67+ cells were counted. The confocal microscopy images of control and treated samples were acquired. Clinical skin rejuvenation/diseases treatments with 675nm laser device were performed with different laser parameters in 11 patients with pigmented lesions, 5 patients with acne scars and 23 patients for skin rejuvenation. Data were evaluated with the validated global score using 5-point scales (GAIS) and patient's satisfaction scale. The application of the high-power 675nm laser has proven effective in stimulating cell proliferation in in vitro experiments and it led to good results for all skin pathologies. GAIS showed values between 3 and 4 points for all treated pathologies, all scores between '75%-good improvements' and '100%-excellent improvements'. The treatment time was reduced by 50% compared to the old parameters setting, resulting in a faster and good patient's satisfying technique. No serious adverse effects were recorded. the preclinical and clinical data confirm the efficacy and safety of this high-powered 675nm laser for several skin condition.

Comparative study in treatment of acne scars fractional carbon dioxide laser versus micro needling fractional radio frequency - A retrospective study.

Efficacy of fractional carbon dioxide laser and microfractional radiofrequency in treatment of acne scars is well substantiated. The objective of this study was to compare the efficacy and safety of carbon dioxide laser versus microfractional radiofrequency in treatment of acne scars in skin type 3,4. Thirty-two patients of skin types 3-4 with grade 3 and 4 atrophic acne scars, of which 16 were treated with fractional carbon dioxide (CO2) laser and 16 were treated with microfractional radiofrequency were retrospectively analyzed. All patients received either treatment 4 sessions at an interval of 4-6 weeks. Objective assessment was done with qualitative and quantitative Goodman and baron acne scar grading system by assessment of photographs at baseline and 3 months after last session. All the data collected were entered in a Microsoft Excel worksheet and analyzed using R Software R-4.2.1. The study variables acne scar grades were described using frequency with percentage, acne scar scores were described using Mean with Standard deviation, and Median with interquartile range (IQR) (Q1-Q3). Since the data were ordinal, which is non-normal, hence, non-parametric tests are applied. To compare grades between the groups, Mann-Whitney U-test was applied. There was no difference in the last session (after the treatment) between the groups, the Mann- Whitney U-test was 109.5 with P-value of 0.484 >0.05. Therefore, there was no statistically significant difference between the microfractional radiofrequency and carbon dioxide laser group. There were 2 (12.5%) cases reported with post-inflammatory hyperpigmentation in the CO2 laser group and zero cases in the microfractional radiofrequency group.

Efficacy and safety of triple diode laser in hair growth reduction

ABSTRACT Background &amp; Objective: Laser treatment for hair removal is a very common procedure in dermatology. Ruby, diode, alexandrite, Nd yag, and intense pulse light are frequently used for hair reduction. For more effective results a combination of wavelengths is used. The purpose of this study is to determine the efficacy and safety of triple diode lasers in hair growth reduction. Methodology: This interventional longitudinal study comprises of total 82 patients using a non-probability convenience sampling technique, the mean age of the patients was 28.73, the age range was between 17 to 56 years, and all patients in this study were female of skin phenotype between III to V. Each session was done one month apart for four months, and hair growth reduction was assessed by using GAIS (Global Aesthetic Improvement Scale Assessment) score by two independent dermatologists in 4th session. Results: Hair growth reduction was observed in all the enrolled patients from the first session. Out of 82 patients, 63.4% of patients are of skin phenotype IV, 23.2% patients are of skin phenotype III whereas 13.4% are skin phenotype V. After four sessions 41 patients (50%) showed excellent results, and 41 patients (50%) showed good results. None of these patients experienced any long-term side effects. Conclusion: Triple diode laser is a safe and effective modality in hair growth reduction at all body sites in skin phenotype III- V with minimal side effects.

Comparison of the efficacy and safety of a 730-nm picosecond titanium sapphire laser and a 1064-nm picosecond neodymium yttrium aluminum garnet laser for the treatment of acquired bilateral nevus of Ota-like macules: A split-face, evaluator-blinded, randomized, and controlled pilot trial.

The picosecond neodymium yttrium aluminum garnet laser (PNYL) has been successfully used in treating acquired bilateral nevus of Ota-like macules (ABNOM). The 730-nm picosecond titanium sapphire laser (PTSL) is an emerging tool for pigmentary disorders. However, no studies have compared two different wavelengths of picosecond laser for the treatment of ABNOM. To compare the efficacy and safety of the 730-nm PTSL with the 1064-nm PNYL in the treatment of ABNOM. Fifteen participants with ABNOM were randomized to undergo a single session of either the 730-nm PTSL on one side of the face and 1064-nm PNYL on the other side. Efficacy and safety assessments were performed by blinded visual evaluations at baseline, 12 weeks, and 24 weeks posttreatment. Participants' satisfaction and adverse effects were recorded. Compared to baseline, The 730-nm PTSL-treated side showed better improvement than that of the 1064-nm PNYL-treated side at 24 weeks posttreatment (1.67 ± 1.047 vs. 0.87 ± 0.640, p = 0.027). There were no significant differences in pain sensation and participants' satisfaction between the two laser treatments. The 730-nm PTSL is more effective than the 1064-nm PNYL in the treatment of ABNOM.

Removal of black tattoos by Picosecond Q-switched Nd-YAG laser in the middle eastern skin type IV: prospective study

Tattoo removal is considered a challenging field in cosmetic dermatology. Picosecond Q-switched Nd-YAG lasers targeting unique chromophores effectively manage this condition without serious complications. To evaluate the efficacy and safety of Picosecond Q-switched Nd-YAG laser in the treatment of black tattoos in the skin of middle eastern mostly skin type IV. The study was carried out on 20 patients with skin type IV the most common in middle eastern area with professional black tattoos. They were treated by Picosecond Nd-YAG laser (2 sessions 8 weeks apart). The percentage of improvement ranged from 20.0 to 95.0 (with a mean of 61 ± 24.6). 8 patients (40%) showed excellent improvement, 4 patients (20%) showed marked improvement, 4 patients (20%) showed moderate improvement, and 4 patients (20%) showed mild improvement. No severe side effects were detected. Picosecond Nd-YAG laser was an effective and safe technique in the treatment of professional black tattoos; with only 2 sessions most patients reached excellent to moderate response with minimal side effects.

Subthreshold Micropulse Laser Versus Oral Spironolactone in Chronic Central Serous Chorioretinopathy: A Quasi-Randomized Controlled Trial.

To compare the efficacy and safety of subthreshold micropulse laser (SML) and spironolactone therapy for treating chronic central serous chorioretinopathy (CSC). This was a quasi-randomized controlled trial. Eligible patients were quasi-randomized at a 1:1 ratio to receive SML or oral spironolactone and were assessed at 3months after treatment. A total of 84 patients (90 eyes) were randomly assigned to receive SML (n = 45) or spironolactone (n = 39) initially. At last follow-up, 59.5% of patients in the SML group had complete resolution of subretinal fluid (SRF) compared to 43.6% in spironolactone group (P = 0.362). The mean visual acuity did not significantly improve between the two groups (0.38 ± 0.44 vs. 0.43 ± 0.43 logMAR). The central retinal thickness was decreased from 335.06 ± 120.25µm to 222.15 ± 94.90µm in the SML group and from 308.02 ± 90.69µm to 257.27 ± 102.28µm in the spironolactone group. After treatment, subfoveal choroidal thickness, total choroidal area, and stromal and luminal choroidal area were significantly lower in the spironolactone group as compared to the SML group. During the entire visit, the recurrence rate of SRF was 9.1% in the SML group compared to 35.3% in the spironolactone group. Slight adverse events occurred more frequently in the spironolactone group (0% vs. 16%). Both SML and oral spironolactone were effective and safe treatments to ameliorate retinal anatomical structures for chronic CSC. A lower recurrence rate and fewer adverse effects were observed in the SML group, and better choroidal structure recovery was seen in the spironolactone group. The investigation of SML and oral spironolactone may inform evidence-based clinical decisions for chronic CSC patients.

Safety and efficacy of lasers compared to cold knife in direct visual internal urethrotomy: a systematic review and Meta-analysis.

Cold knife urethrotome was introduced in 1971 and it had an 80% success rate. New advancements in this field have shed light on the use of various lasers such as carbon dioxide, Nd: YAG, KTP, Argon, Ho: YAG, and excimer lasers. It has been observed that cold knife urethrotomy has a higher recurrence rate than laser urethrotomy, but the superiority of either treatment modality has not been established yet. Data were thoroughly searched through PubMed, Scopus, and clinicaltrials.gov. We also used clinicaltrials.gov for ongoing and published research. The data was analyzed via R studio version 2023.12.1 (oceanstorm). For dichotomous variables, Odds Ratio (OR) were used to pool data and standardized mean difference was used for continuous variables with 95% confidence intervals (CIs). A total of 14 studies including 1114 participants were included in this meta-analysis. The results of the combined analysis revealed significant relation with a mean difference of 0.99 (95% CI: 0.37; 1.62), and favored laser group. The overall results have shown the laser to have a significant favorable profile demonstrating a recurrence, Odds Ratio of 0.42 (95% CI:0.27;0.65). Patients with laser therapy had a lower risk of complication rate (OR 0.49, 95% Cl: 0.35; 0.67). All the findings obtained by the analysis in this study favour lasers significantly over the cold knife technique especially when mean Qmax, with recurrence and complications taken into account.

Safety and Effectiveness of Laser in Situ Keratomileusis Using the Teneo 317 Model 2 for Correcting Myopia and Myopic Astigmatism: Results of the U.S. FDA Clinical Trial.

To evaluate the safety and effectiveness of a new aspheric ablation profile for correcting myopia and myopic astigmatism. This prospective, multicenter study included patients who underwent laser in situ keratomileusis (LASIK) using a new aspheric ablation profile of the Technolas Teneo 317 (Model 2) excimer laser (version 1.28 US SW) by Technolas Perfect Vision, Bausch+Lomb, Inc. No nomogram adjustments were made, and the patient's manifest refraction was entered into the laser (for treatment). Postoperative assessments included visual and refractive outcomes. Patients were asked to complete the Patient-Reported Outcomes With LASIK (PROWL) questionnaire preoperatively and postoperatively. A total of 333 eyes from 168 patients with a mean age of 33 ± 7 years were included. At postoperative 9 months, uncorrected and corrected distance visual acuities of 20/25 or better were seen in 97.8% and 100% of eyes, respectively. None of the eyes lost two or more lines of corrected distance visual acuity. The mean manifest spherical refraction improved from -5.67 ± 2.52 diopters (D) preoperatively to -0.04 ± 0.32 D postoperatively, with 92.7% of eyes achieving residual refractive error within ±0.50 D. Residual refractive cylinder within ±0.50 and ±1.00 D was seen in 93% and 99.4% eyes, respectively. The refractive outcomes were stable throughout the follow-up of 9 months. The proportion of patients satisfied with their vision rose from 27.7% preoperatively to 98.1% postoperatively. LASIK performed using a new aspheric ablation profile of the Technolas Teneo 317 (Model 2) excimer laser is safe and effective for correcting myopia and myopic astigmatism, yielding excellent visual and refractive outcomes that were stable over 9 months. [J Refract Surg. 2024;40(8):e544-e553.].

Prospective non-randomized comparison of transurethral laser en bloc resection vs. conventional resection of bladder tumors larger than 3 cm.

En bloc resection of bladder tumor (ERBT) is an established surgical treatment method for patients with non-muscle invasive bladder cancer (NMIBC) in tumors less than 3 cm. Data regarding the efficacy and safety of ERBT on larger than 3 cm tumors are sparse and its efficacy compared to conventional transurethral resection (TURBT) remains unclear. The aim of this study was to prospectively compare the feasibility, safety and oncological outcomes of laser (Tm-fiber) ERBT and TURBT in patients with primary bladder lesions ≥3 cm. A cohort of 45 patients who underwent surgery for primary NMIBC between February 2018 and March 2022 was collected prospectively. There was no randomization. All procedures were performed by two experienced surgeons. Inclusion criteria were as follows: age >18 years, primary Ta or T1 bladder tumor with a diameter of ≥3 cm, no more than 3 tumors and no history of upper tract urothelial carcinoma. Exclusion criteria were carcinoma in situ or invasion into muscle layer (≥T2). ERBT was performed with thulium fiber laser (IPG, Russia). Primary endpoints included efficacy with recurrence-free survival (RFS) at 3, 6 and 12 months. Secondary endpoints were safety parameters, perioperative data and specimen quality (the presence of muscle layer in specimens). Twenty-eight patients underwent laser ERBT and 17 conventional TURBT. The location and size of the tumors were comparable in both groups. The success rate was 93.3% in the ERBT group with two cases of conversion from ERBT to TURBT. Detrusor muscle was present in 92.8% patients in the ERBT group versus 70.5% in the TURBT group (P=0.04). Obturator nerve reflex was observed only in the TURBT group: 17.6% vs. 0.0% (P=0.02). The frequency of other complications was comparable between the two groups. RFS was not statistically different between the two methods at 3 (93.9% vs. 94.1%, P=0.87), 6 (89.3% vs. 82.3%, P=0.5) and 12 months (89.3% vs. 70.6%, P=0.11). Laser ERBT is a feasible and safe procedure to manage bladder tumors larger than 3 cm. While it seems safer than TURBT, its effect on efficacy remains to be assessed in larger trials.