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Primary percutaneous coronary intervention for a left main bifurcation lesion without stenting using excimer laser with optical coherence tomography guidance: a case report
摘要： Optimal strategy for treating bifurcation lesions or lesions with large thrombus in left main disease remains elusive. Excimer laser coronary angioplasty (ELCA) is a therapeutic option for thrombotic lesions in acute coronary syndrome. A 68-year-old man with chest pain was transferred to our emergency department, and subsequently diagnosed as inferior ST-segment elevation myocardial infarction (STEMI). Emergent coronary angiography revealed a 75% stenosis in the left main trunk (LMT). Optical coherence tomography (OCT) showed massive thrombus at the distal LMT to the ostial left anterior descending artery (LAD) and left circumflex artery (LCx). ELCA was performed in the three directions from LMT to proximal LAD, proximal LCx, and obtuse marginal branch. OCT after ELCA showed reduction of thrombus and no apparent plaque rupture or calcification, implying that coronary thrombosis was caused by OCT-defined plaque erosion. Intracoronary electrocardiogram of the LCx showed ST-segment elevation which corresponded to inferior ST-segment elevation, whereas no intracoronary electrocardiogram ST-segment elevation was detected for LAD. Taking all of the data including angiographic appearance, OCT-derived residual lumen size and residual thrombus volume, and strategic options into consideration, we completed percutaneous coronary intervention without stent deployment. He has been free from any cardiac events thereafter for 8 months. Optimal strategy of coronary intervention for bifurcation lesions, especially LMT bifurcations, remains elusive. ELCA may have a potential to safely reduce intracoronary thrombus in patients presenting with acute coronary syndrome with OCT guidance.
关键词： Plaque erosion,Excimer laser coronary angioplasty,Case report,Bifurcation,Left main disease,Stentless
更新于2025-09-19 17:13:59
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Comparison of Excimer Laser Versus Femtosecond Laser Assisted Trephination in Penetrating Keratoplasty: A Retrospective Study
摘要： Introduction: To compare the impact of non-mechanical excimer-assisted (EXCIMER) and femtosecond laser-assisted (FEMTO) trephination on outcomes after penetrating keratoplasty (PK). Methods: In this retrospective study, 68 eyes from 23 females and 45 males (mean age at time of surgery, 53.3 ± 19.8 years) were included. Inclusion criteria were one surgeon (BS), primary central PK, Fuchs’ dystrophy (FUCHS) or keratoconus (KC), no previous intraocular surgery, graft oversize 0.1 mm and 16-bite double running suture. Trephination was performed using a manually guided 193-nm Zeiss Meditec (EXCIMER group: 18 MEL70 excimer laser in the FUCHS, 17 KC) or 60-kHz IntraLaseTM femtosecond laser (FEMTO group: 16 FUCHS, 17 KC). Subjective refractometry (trial glasses) and topography analysis (Pentacam HR; corneal Casia SS-1000 AS-OCT; TMS-5) were performed preoperatively, before removal of the first suture (11.4 ± 1.9 months) and after removal of the second suture (22.6 ± 3.8 months). Results: Before suture removal, mean refractive/AS-OCT topographic astigmatism did not differ significantly between EXCIMER and FEMTO. After suture removal, mean refractive/astigmatism Pentacam/AS-OCT topographic was significantly higher (6.2 ± 2.9 D/7.1 ± 3.2 D/7.4 ± 3.3 D) than in the EXCIMER patients (4.3 ± 3.0 D/4.4 ± 3.1 D/4.0 ± 2.9 D) (p B 0.005). Mean corrected distance visual acuity increased from 0.22 and 0.23 preoperatively to 0.55 and 0.53 before or 0.7 and 0.6 after suture removal in the EXCIMER and FEMTO groups, respectively. Differences between EXCIMER and FEMTO were only pronounced in the KC subgroup. Conclusion: Non-mechanical EXCIMER trephination seems to have advantages regarding postoperative corneal astigmatism and visual acuity compared with FEMTO trephination, especially in KC. A bigger sample size and longer follow-up are needed to evaluate the long-term impact of EXCIMER and FEMTO trephination on postoperative topographic and visual outcomes.
关键词： Excimer,Visual acuity,Femtosecond,Laser,Penetrating keratoplasty,Ophthalmology,Astigmatism
更新于2025-09-19 17:13:59
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Success of combined cataract extraction plus excimer laser trabeculotomy exceeds that of combined ab interno trabeculectomy with the trabectome or cataract extraction alone
摘要： Purpose To determine the efficacy of cataract surgery alone and combined with two minimally invasive glaucoma surgery (MIGS) procedures (phaco-ELT and phaco-aiT). Methods Data was collected from 12/2007 to 02/2012 in this retrospective, non-randomized, comparative single surgery center study. Reduction in IOP and hypotensive medication (AGD), change in visual acuity, success rates, and complications were computed by comparing preoperative data with data at 1 year postoperatively. Results A total of 245 eyes of 245 subjects were included. Study eyes underwent phaco alone (38 eye) or combined phaco-ELT (105 eye) and phaco-aiT (102 eye). Phaco alone, combined phaco-ELT, and combined phaco-aiT lowered IOP by 1.5 ± 4.0 mmHg, 4.3 ± 5.6, and 5.3 ± 4.5 mmHg, respectively (P < 0.01). Survival time of phaco-ELT outreached survival time of phaco alone and combined phaco-aiT (20.6 ± 1.0 vs. 13.2 ± 0.4 and 12.9 ± 0.6 month, respectively). No serious complications or adverse events occurred. None of the cases required a subsequent procedure within the first year to lower IOP further. Conclusions All three surgical procedures lowered IOP and reduced medication. However, the IOP-lowering efficacy of the two combined MIGS procedures exceeded the effect of phaco alone. A combined phaco and MIGS procedures seem reasonable to consider whenever a cataract surgery in an eye with glaucoma or ocular hypertension is considered. In addition, the combined MIGS procedure effectively lowers IOP whenever a target IOP in the mid-teens is sufficient. In this study, the nonthermal phaco-ELT procedure showed superior efficacy at 1 year over phaco alone and phaco-aiT in the Kaplan–Meier statistics.
关键词： Cataract,Excimer laser trabeculostomy,Glaucoma,Excimer laser trabeculotomy,Ab interno trabeculotomy with the trabectome,Minimally invasive glaucoma surgery
更新于2025-09-16 10:30:52
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Microchannel Fabrication in Fused Quartz by Backside Laser-Induced Plasma Ablation Using 248 nm KrF Excimer Laser
摘要： Laser-induced plasma ablation (LIPA) using a 248 nm KrF excimer laser was investigated for microchannel fabrication. Examination of the morphology in relation to ablation performance was emphasized, and a synthetic LIPA mechanism model was proposed based on the results. Backside LIPA with a metal target on the bottom can be attributed to a combination of two phenomena: laser-induced plasma vaporization thermal ablation from the metal target below and enhanced laser–glass direct interaction from the plasma residuum. The laser absorption enhancement of quartz substrate resulting from the metal residuum was validated clearly using absorption spectrum measurements. The influence of laser parameters on the etching quality during LIPA was also analyzed for processing optimization. Finally, fused quartz glass microchannels of outstanding surface quality and dimension uniformity were implemented. The channel depth was 28 μm, and the bottom surface roughness was better than several hundred nanometers.
关键词： excimer laser,plasma,fused quartz glass,laser ablation,microstructure
更新于2025-09-16 10:30:52
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Application of Excimer Laser Coronary Atherectomy Guided by Optical Coherence Tomography in the Treatment of a Severe Calcified Coronary Lesion
摘要： The therapeutic effect of excimer laser technology is mainly achieved by the following three kinds of actions: photochemical, photothermal, and photomechanical effects. The depth of action is 0.1 mm. Excimer laser technology can break the molecular bonds of tissues and produce small debris, including water, gas, and small particles (90% <10 μm). The laser advantages include delivery of flexible catheters in curvature anatomy, precision of controlled penetration into the lesion, and circumferential or eccentric distribution of laser rays, which create a smooth “pilot channel.” In addition, the laser interacts favorably with a thrombus and uniquely suppresses platelet activity, thus reducing the risk of thrombosis within the newly revascularized site. Previous studies have shown that ELCA can be used for the treatment of coronary thrombosis in patients with acute coronary syndrome, chronic total occlusion lesions, saphenous vein graft occlusions, stent restenosis, and mild?to?moderate calcifications. A 0.9?mm eccentric catheter is a xenon?chlorine (excimer)?pulsed laser catheter that is capable of delivering higher energy density with lower heat production (smaller area of ablation) and has been suggested as a treatment option for these calcified lesions. This catheter could deliver excimer energy (wave length, 308 nm; pulse length, 185 nanoseconds) from 30 to 80 mJ/mm2 (fluences) at pulse repetition rates (frequency) from 25 to 80 Hz using a 10?s on and 5?s off lasing cycle. This finding compares with other excimer catheter technology (1.4?, 1.7?, and 2.0?mm catheters) delivering 30–60 mJ/mm2 at 25–40 Hz using a 5?s on and 10?s off lasing cycle. These improvements in laser energy delivery were proposed to maximize tissue penetration while controlling complications within acceptable limits. ELCA is usually performed during intracoronary saline infusion to minimize the risk of vapor bubble formation that can lead to arterial dissection; however, a case report discussed the injection of contrast before laser activation for treating an underexpanded stent (negating the established instruction for use that mandates meticulous contrast removal from the guiding catheter before activation). Due to the known effect of contrast on amplification of laser waves, this maneuver can extend the depth of energy distribution to soften the calcium. Indeed, such laser manipulation may cause complications as well, from spasm and dissections to perforations.
关键词： Excimer Laser Coronary Atherectomy,Optical Coherence Tomography,Severe Calcified Coronary Lesion
更新于2025-09-16 10:30:52
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Increasing Laser-Doping Depth of Al in 4H-SiC by Using Expanded-Pulse Excimer Laser
摘要： Al doping into 4H-SiC performed by irradiating pulse-width-expanded excimer laser to an Al film deposited on the 4H-SiC surface is investigated. An optical pulse stretcher was constructed to produce the laser pulse whose peak intensity was reduced as half as that of the original pulse and pulse width was expanded from 55 ns to 100 ns. The irradiation of the expanded pulses is found to reduce the ablation of the materials from the surface and enable irradiation of multiple shots. As a result, Al doping depth is significantly increased. The multiple shots of the expanded pulses are also found to decrease the sensitivity to spatial non-uniformity of laser intensity and increase the uniformity of doped region.
关键词： excimer laser,p-type silicon carbide,aluminum doping,silicon carbide,laser doping,optical pulse stretcher
更新于2025-09-16 10:30:52
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Etch Performance of KRF Excimer Laser Micromachining Characterization on Silicon Material
摘要： Excimer laser micromachining enables us to overcome the conventional lithography-based microfabrication limitations and simplify the process of creating three dimensional (3D) microstructures.The objective of this study is to investigate the relation between the number of laser pulses, number of laser passes through the channel of ablation site and their etch performance. Parameters such as frequency, fluence and velocity were retained as constants. In this paper, we present a parametric characterization study on silicon using KrF excimer laser micromachining. From the result, the etch rate change were recorded as the two major laser parameters (Number of laser pulses and number of laser passes) were varied. Both parameters were showing declination profile however from comparing both graphs, it showed that etch rate dropped more steeply when varied number of laser passes rather than number of pulses.
关键词： Krypton fluoride,silicon,KrF,excimer laser
更新于2025-09-16 10:30:52
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Factors predicting successful customized excimer laser treatment in irregular corneas
摘要： Purpose: To identify factors associated with a successful wavefront-guided customized treatment (WG-CT) with an excimer laser in highly aberrated corneas. Setting: VISSUM Alicante Spain. Design: Retrospective consecutive noncomparative case series. Methods: Treatment was performed with the WG-CT Amaris excimer laser using the ORK-CAM software for the calculation of the ablation profile. Eyes of patients with significantly aberrated corneas, including postrefractive and keratoplasty procedures or high irregular astigmatism with significant higher-order aberrations (HOAs) that had WG-CT were included. Refractive outcomes, HOAs, and visual outcomes were recorded. Statistical analysis was performed to identify factors associated with technical (based on HOAs) or refractive outcome success. Results: The study included 55 treatments of 51 eyes (35 patients). The postoperative uncorrected distance visual acuity was 0.2 logarithm of the minimum angle of resolution or better in 72% of the eyes, and the postoperative residual manifest refraction spherical equivalent was ±0.50 diopter in 56% of the eyes, whereas 11% of the eyes lost 1 line or more in corrected distance visual acuity. Successful reduction in the total root mean square (RMS) of HOAs occurred in 36 eyes (65%), and these eyes had a significantly higher preoperative RMS of HOAs (1.45 ± 0.93 μ vs 0.91 ± 0.34 μ, P = .003) and preoperative coma-like aberrations (1.09 ± 0.83 μ vs 0.55 ± 0.28 μ, P = .001). In multivariate analysis, posthyperopic treatment eyes were less likely to achieve refractive outcome success (odds ratio = 0.09, P = .02). Conclusions: WG-CT in highly aberrated corneas had a limited refractive predictability. Eyes with preoperative coma-like aberrations are more likely to benefit from a reduction in HOAs. Post-hyperopic treatment is associated with a higher rate of refractive surprises.
关键词： excimer laser,refractive surgery,irregular corneas,wavefront-guided customized treatment,higher-order aberrations
更新于2025-09-16 10:30:52
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Bilaterale, gleichzeitige rhegmatogene Netzhautabl?sung nach Laser-in-situ-Keratomileusis
摘要： Bei einer 21-j?hrigen Frau trat nach einer Laser-in-situ-Keratomileusis (LASIK) beider Augen bilateral gleichzeitig eine rhegmatogene Netzhautabl?sung auf. Sie unterzog sich daraufhin einer Pars-plana-Vitrektomie in Kombination mit Endolaser-Photokoagulation und Silikon?l-Tamponade im rechten Auge. Eine Woche sp?ter wurde am linken Auge eine pneumatische Retinopexie durchgeführt. Da sich der Netzhautriss nicht verschloss, wurde eine 360°-Sklera-Eindellung durchgeführt und die Netzhaut so befestigt. Die bilaterale simultane rhegmatogene Netzhautabl?sung nach LASIK zur Myopiekorrektur kann eine schwerwiegende Komplikation darstellen. Die Patienten sollten über die M?glichkeit dieser Komplikation aufgekl?rt werden.
关键词： Excimer-Laser,Netzhautabl?sung,Myopie
更新于2025-09-16 10:30:52
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Laser Vision Correction for Regular Myopia and Supracor Presbyopia: A Comparison Study
摘要： A study to compare femto-presbyLASIK to standard myopia femto-LASIK refractive surgical correction with a total of 45 candidates was performed. The goal was to identify a more speci?c set of indications for presbyopia LASIK treatments. The results showed thoroughly good uncorrected visual acuity for myopia (decimal: 1.01 ± 0.15) as well as for presbyLASIK (decimal: 0.78 ± 0.17) corrections. Astigmatism was comparable in both groups and did not change signi?cantly from preoperative (0.98D ± 0.53 SD) to postoperative (1.01D ± 0.50 SD). Our study results suggest, that presbyLASIK treatment is as safe and e?ective as regular LASIK myopia correction and can hence be recommended to treat presbyopia.
关键词： excimer laser,presbyopia,follow-up,refractive surgery,presbyLASIK,supracor,clinical results,lasik,myopia
更新于2025-09-16 10:30:52