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At least 667 records · Page 37Linked to original sources
PubMed2003

A giant melanocytic nevus treated with combined use of normal mode ruby laser and Q-switched alexandrite laser.

We report a combination procedure that can improve the effectiveness of laser removal of giant congenital melanocytic nevi (CMN). A 2-year-old girl with a giant CMN was seen in our outpatient clinic. Histological findings showed a compound nevus without any evidence of malignancy or dysplastic changes. The patient was treated with the normal mode ruby laser and Q-switched alexandrite laser. The lesion was significantly improved in color and cosmetic appearance. Partial hypopigmentation and texture changes were observed. Histological findings showed a marked decrease in the number of junctional melanocytes and the nests in the papillary and reticular dermis. The combined laser treatment is an effective method for the treatment of giant CMN, but further study is warranted to follow-up questions of recurrence and malignant change.

Biopsy, Needle↗
PubMed1989

Adjuvant laser treatment of bladder cancer: 8 years' experience with the Nd-YAG laser 1064 nm.

Following the development of suitable equipment for the endoscopic application of an Nd-YAG laser in this department, the laser has been used routinely in the management of bladder cancer since 1978. To evaluate side effects and efficiency, 252 consecutive laser treatments were evaluated with a minimum follow-up of 12 months. Side effects were few (0.3% perforation) and patients tolerated the treatment very well. The general recurrence rate of T1 tumours varied from 33% for primary carcinomas to 54% for recurrent tumours, but the incidence of local recurrence was only 7%. The long-term results of laser treatment showed a decrease in the local recurrence rate when compared with the results of conservative electocautery resection, but there was no significant influence on the total recurrence rate.

Aged↗
PubMed1998

A practical review of laser-assisted hair removal using the Q-switched Nd:YAG, long-pulsed ruby, and long-pulsed alexandrite lasers.

BACKGROUND: The recent development of numerous laser-assisted hair removal techniques has produced confusion in the field of cutaneous laser surgery. OBJECTIVES: A systematic review of the hair removal laser systems currently available is attempted. Appropriate patient selection, treatment protocols, and discussion of each system's advantages, disadvantages, and complications is provided. CONCLUSIONS: Techniques involving the use of selective Q-switched Nd:YAG and long-pulsed alexandrite and ruby laser systems provide a significant delay in hair growth. With further technologic advances and understanding of proper treatment parameters and intervals, it is expected that permanent hair removal may eventually be possible.

Equipment Design↗
PubMed1998

Carbon dioxide laser resurfacing combined with endoscopic forehead lift, laser blepharoplasty, and transblepharoplasty corrugator muscle resection.

BACKGROUND: Endoscopic forehead lifting has become an increasingly popular method for rejuvenating the upper face, due to its less invasive nature and minimal scars. However, adequate ablation of frown muscles (i.e., corrugator and depressor supercili) is difficult with this approach. The frown muscles are in close proximity to the upper eyelid, and it is possible to oblate them via the blepharoplasty approach using the carbon dioxide laser. OBJECTIVE: The purpose of this paper is to describe the combined approach of endoscopic forehead lifting and carbon dioxide laser resurfacing to rejuvenate the upper face. The former technique addresses the issue of brow elevation and improvement of dynamic glabellar frown lines. The latter technique deals with static wrinkles caused by sun damage. METHODS AND RESULTS: Thirty-seven patients underwent endoscopic forehead lift, transblepharoplasty corrugator ablation, with simultaneous carbon dioxide laser resurfacing of forehead skin. Twenty-eight of 37 patients (76%) achieved excellent results, while nine of 37 (14%) experienced good results. Complications were minimal, being mostly due to inadequate corrugator muscle resection with recurrent frowning. There were no instances of scarring, skin necrosis, or permanent hair loss. CONCLUSION: The combination of endoscopic forehead lifting, transblepharoplasty corrugator muscle resection, and carbon dioxide laser resurfacing is an effective and safe technique for rejuvenating the upper face, producing a natural result with minimal complications.

Adult↗
PubMed1989

Percutaneous Nd:YAG laser coagulation of ventricular myocardium in dogs using a special electrode laser catheter.

A novel catheter system was used for intracardiac electrogram recordings, ventricular pacing and continuous-wave Nd:YAG laser (1,064 nm) irradiation of ventricular myocardium in eight dogs. Radiation at a power of 10 W for 3, 5, and 10 seconds was delivered through a 400 microns optical fiber. Power density was 15 W/mm2. A total of 96 laser injuries (12 per dog) were produced in selected sites in both the right and the left normal canine ventricle. Ventricular arrhythmias were noted during 12 of 96 (12.5%) laser pulses. Programmed electrical stimulation performed during control study immediately (all dogs) at 2 days (two dogs), and 4 months (4 dogs) following the experiments showed no episodes of sustained or nonsustained ventricular tachycardia. Radiation energies up to 50 J (10 W over 5 s) caused focal injuries of homogeneous coagulation/fibrosis localized to the target area, without vaporizing tissue and forming craters. Morphometrically and histologically there was a direct relationship between the energy of radiation delivered, and the extent and severity of the injury produced. The maximum size of lesions measured 7/11 mm (diameter/depth). Using a special catheter system laser coagulation of myocardium can be accomplished percutaneously. This method can create controlled subendocardial injuries without major side effects and appears to overcome most disadvantages of transcatheter high energy direct-current shocks when used as a regular course of procedure in ablation of arrhythmogenic tissue in the heart.

Animals↗
PubMed1994

The effect of laser parameters on the zone of thermal injury produced by laser ablation of biological tissue.

A thermal model to predict the effect of laser parameters on the zone of thermal injury produced by laser ablation of biological tissue is presented. The model suggests that the Péclèt number based on the optical penetration depth of laser radiation is the key parameter in determining the resulting zone of thermal injury. We show that the zone of thermal injury is minimized for Péclèt numbers greater than one since the transport of energy via conduction beyond the ablation front is minimized. We also show that for Péclèt numbers less than one, larger zones of thermal damage are unavoidable regardless of the laser pulse duration. The predictions of the model are compared with data available in the literature. Deviations between the model predictions and published data are discussed and the potential effects of the model assumptions, optical scattering, pyrolysis, temporal pulse shape, pulse duration, irradiance and pulse repetition rate are explored.

Bias↗
PubMedDate not supplied

Excitation beyond the monochromatic laser limit: simultaneous 3-D confocal and multiphoton microscopy with a tapered fiber as white-light laser source.

Confocal and multiphoton microscopy are essential tools in modern life sciences. They allow fast and highly resolved imaging of a steadily growing number of fluorescent markers, ranging from fluorescent proteins to quantum dots and other fluorophores, used for the localization of molecules and the quantitative detection of molecular properties within living cells and organisms. Up to now, only one physical limitation seemed to be unavoidable. Both confocal and multiphoton microscopy rely on lasers as excitation sources, and their monochromatic radiation allows only a limited number of simultaneously usable dyes, which depends on the specific number of laser lines available in the used microscope. We have overcome this limitation by successfully replacing all excitation lasers in a standard confocal microscope with pulsed white light ranging from 430 to 1300 nm generated in a tapered silica fiber. With this easily reproducible method, simultaneous confocal and multiphoton microscopy was demonstrated. By developing a coherent and intense laser source with spectral width comparable to a mercury lamp, we provide the flexibility to excite any desired fluorophore combination.

Animals↗
PubMed1997

Scanning laser fundus perimetry before laser photocoagulation of well defined choroidal neovascularisation.

AIM: To assess the centre of fixation before laser photocoagulation of well defined juxtafoveal or extrafoveal choroidal neovascularisation (CNV) secondary to age related macular degeneration (AMD), and to better predict visual function after treatment using scanning laser ophthalmoscope (SLO) fundus perimetry. METHODS: 19 consecutive eyes with juxtafoveal or extrafoveal CNV were examined by fundus perimetry before and after laser treatment with documentation of the fixation point using the SLO. The stability of fixation was defined as standard deviation around the mean fixation point. Overlays of fluorescein angiographic pictures and fundus perimetry were obtained using image analysis software. RESULTS: Fundus perimetry allowed accurate determination of the centre of fixation. Overlays demonstrated the precise geographic relation of the angiographically detectable foveal margin of the CNV and the centre of fixation. Thereby, prediction of the visual outcome with regard to reading ability was facilitated. Stability of fixation did not change significantly after treatment. CONCLUSIONS: Fundus perimetry using the SLO was helpful in patients who underwent laser treatment for juxtafoveal or extrafoveal CNV secondary to AMD and may aid the pretreatment counselling of such patients.

Aged↗
PubMed1999

Selective laser trabeculoplasty v argon laser trabeculoplasty: a prospective randomised clinical trial.

AIMS: To compare the effectiveness of selective laser trabeculoplasty (SLT, a 532 nm Nd:YAG laser) with argon laser trabeculoplasty (ALT) in lowering the intraocular pressure (IOP) in patients with medically uncontrolled open angle glaucoma. METHODS: A prospective randomised clinical trial was designed. Patients were randomised to treatment with either SLT or ALT and were evaluated at 1 hour, 1 week, 1, 3, and 6 months post-laser. RESULTS: There were 18 eyes in each group. Baseline characteristics were similar in both groups. In the SLT group the mean IOP at baseline, 1, 3, and 6 months was 22.8 (SD 3.0), 20.1 (4.6), 19.3 (6.0), and 17.8 (4.8) mm Hg, respectively. In the ALT group, the mean IOP at baseline, 1, 3, and 6 months was 22.5 (3.6), 19.5 (4.7), 19.6 (5.6), and 17.7 (3.3) mm Hg, respectively. There was a greater anterior chamber reaction, 1 hour after SLT v ALT (p< 0.01). Patients with previous failed ALT had a better reduction in IOP with SLT than with repeat ALT (6.8 (2. 4) v 3.6 (1.8) mm Hg; p = 0.01). CONCLUSION: SLT appears to be equivalent to ALT in lowering IOP during the first 6 months after treatment. There is a slightly greater anterior chamber reaction 1 hour after SLT. Patients with previous failed ALT had a significantly greater drop in IOP when treated with SLT v ALT. These results need to be confirmed with a larger sample size.

Adult↗
PubMed2002

Laser augmented by brachytherapy versus laser alone in the palliation of adenocarcinoma of the oesophagus and cardia: a randomised study.

BACKGROUND: Many patients with advanced malignant dysphagia are not suitable for definitive treatment. The best option for palliation of dysphagia varies between patients. This paper looks at a simple technique for enhancing laser recanalisation. AIM: To assess the value of adjunctive brachytherapy in prolonging palliation of malignant dysphagia by endoscopic laser therapy. PATIENTS: Twenty two patients with advanced malignant dysphagia due to adenocarcinoma of the oesophagus or gastric cardia, unsuitable for surgery or radical chemoradiotherapy. METHODS: Patients able to eat a soft diet after laser recanalisation were randomised to no further therapy or a single treatment with brachytherapy (10 Gy). Results were judged on the quality and duration of dysphagia palliation, need for subsequent intervention, complications, and survival. RESULTS: The median dysphagia score for all patients two weeks after initial treatment was 1 (some solids). The median dysphagia palliated interval from the end of initial treatment to recurrent dysphagia or death increased from five weeks (control group) to 19 weeks (brachytherapy group). Three patients had some odynophagia for up to six weeks after brachytherapy. There was no other treatment related morbidity or mortality. Further intervention was required in 10 of 11 control patients (median five further procedures) compared with 7/11 brachytherapy patients (median two further procedures). There was no difference in survival (median 20 weeks (control), 26 weeks (brachytherapy)). CONCLUSIONS: Laser therapy followed by brachytherapy is a safe, straightforward, and effective option for palliating advanced malignant dysphagia, which is complementary to stent insertion.

Adenocarcinoma↗
PubMed1992

Infrared laser tissue ablation: holmium:YAG laser surgery.

The in vivo tissue ablation characteristics of a pulsed holmium:YAG laser (lambda = 1,980 nm) were studied. The laser energy was coupled onto nylon fibers 400 and 600 microns in core diameter. Laser incisions were made on white rats at different sites of the tongue and of the mucous membranes of the oral cavity. Power settings of 500 and 1,000 mJ/2.5-ms pulse at 5 pulses/s were used and the tissue responses examined by light microscopy. Wound healing was studied over a 6-week period. The results of this study are promising for future application of the holmium:YAG laser in otorhinolaryngology.

Animals↗
PubMed1995

Transurethral laser urethrotomy with argon laser: experience with 900 urethrotomies in 450 patients from 1978 to 1993.

From April 1978 to September 1993, the Department of Urology of Giessen Medical School used laser urethrotomy as standard endoscopic treatment in benign urethral strictures. In this period, 900 urethrotomies were performed in 450 patients. The majority of strictures treated were iatrogenic (65%), located in the posterior urethra (62.8%) and classified as short (< or = 1 cm) (71%). Argon laser urethrotomy was carried out in the 12 degrees position according to the technique of internal optical urethrotomy. An indwelling transurethral catheter was left for 48 h after urethrotomy. Uroflowmetry after argon laser urethrotomy revealed the efficacy of the method. A retrospective analysis of the operations was performed. Analysis showed that recurrence appeared on average after 15.2 months (range 1-39) in up to 70.1%. Nearly 50% of recurrence was evident within 1 year following surgery. Recurrence was independent of location, length and etiology of the stricture. We conclude according to our data that argon laser urethrotomy is technically feasible. Due to the high recurrence rate the method offers no advantage over conventional internal optical urethrotomy.

Humans↗
PubMed1990

One-piece contact lens for laser iridotomy at iris base by argon and Nd:YAG laser.

Laser iridotomies at the base of the iris provide a free shunt between the anterior and the posterior chamber remote from the capsule of the lens. Injury to the lens capsule by the Nd:YAG laser is avoided as the iris is not in close apposition. The heterocentric applanatic lens guides the laser beam under the limbal shelf toward the root of the iris. The combined use of a thermal and an ionizing laser is preferred.

Humans↗
PubMed1996

The Oxford Laser Prostate Trial: sexual function data from a randomized controlled clinical trial of contact laser prostatectomy.

OBJECTIVE: To examine the effects of contact laser vaporization prostatectomy and transurethral resection of the prostate (TURP) on sexual function and to examine their association with treatment satisfaction. METHODS: Data on sexual function were collected pre-operatively and 3 months after contact laser vaporization prostatectomy or TURP. The sexual outcome was examined in relation to satisfaction with treatment and quality of life. RESULTS: A wide variation in sexual function was seen at baseline with overall 45% of the patients being impotent during the previous year and 49% claiming to not always have erections when stimulated 1 month prior to surgery. At 3 months postoperatively, 4% of the laser and 3% of the TURP patients who were previously potent were now impotent. There were no statistically significant associations between preoperative or postoperative (3 months) sexual function and either age, preoperative catheterization, or prostate volume. CONCLUSION: The impotence rate 1 month prior to surgery is higher than in previous reports, and the impotence rate after contact laser prostatectomy in this sample size is similar to that seen following TURP.

Aged↗
PubMed2003

Correlation between confocal scanning laser ophthalmoscopy and scanning laser polarimetry in open angle glaucoma.

PURPOSE: To correlate the findings of confocal scanning laser ophthalmoscopy and scanning laser polarimetry in diagnosed cases of glaucoma with established visual field defects. METHODS: A total of 53 diagnosed cases of primary open angle glaucoma that had at least two recorded of IOP more than 21 mm Hg on Goldmann applanation tonometry, open angles on gonioscopy and glaucomatous visual field defects on automated perimetry, were examined by confocal scanning laser ophthalmoscopy (HRT-II) and scanning laser polarimetry (GDx-NFA), in random order. RESULTS: The number on GDx advanced analysis had a significant (p < 0.05) correlation with the rim area (r = -0.279; p = 0.043), cup area (r = 0.311; p = 0.023) and the vertical cup: disc ratio (r = 0.376; p = 0.006). The correlation between HRT-II stereometric parameters and GDx advanced analysis parameters was significant (p < 0.05) for more parameters targeting the inferior pole of the disc than the superior pole. Numerically, the worst values of GDx parameters were associated with a worse result on Moorfields regression analysis, but there was poor agreement between the diagnostic labels like within or outside normal limits as obtained on GDx and HRT-II. CONCLUSIONS: Nerve fiber loss as detected on GDx correlates well with topographic optic nerve head changes as measured with the HRT-II. However, automated diagnosis on the two machines showed poor agreement.

Female↗
PubMed1999

Laser treatment of retinal diseases by subthreshold laser effects.

The retinal pigment epithelium (RPE) may play an important role in the therapeutic effect of laser photocoagulation. This suggests a benefit from targeting the RPE instead of the sensory retina. Calculating the actual temperature profile after laser photocoagulation, it can be shown that pulse durations have to be in the order of microseconds (micros) to spare the retina from damage. This is consistent with histological findings after laser exposure with repetitive, 5 micros Nd:YLF laser pulses (527 nm). Therapeutic effects have been shown in patients with diabetic macular edema, drusen, and central serous retinopathy.

Animals↗
PubMedDate not supplied

Laser in situ keratomileusis with the Nidek EC-5000 excimer laser for astigmatism greater than 4.00 D.

PURPOSE: To evaluate laser in situ keratomileusis (LASIK) performed with the Nidek EC-5000 excimer laser in 66 astigmatic eyes with cylinder from 4.00 to 8.00 D. METHODS: LASIK was performed with the Nidek EC-5000 excimer laser in 66 astigmatic eyes with cylinder from 4.00 to 8.00 D. Based on Chayet's nomogram, ablation zone diameters were 5.5 mm (steep meridian ablation) to 7.5 mm (flat meridian ablation). In eyes with simple myopic astigmatism, mixed astigmatism, and compound myopic astigmatism (low sphere), ablation was performed in both meridians. In eyes with simple hyperopic astigmatism, ablation was performed in the flat meridian alone. In eyes with compound hyperopic astigmatism, ablation zone diameter was 5.5 mm and the transition zone was 7.5 mm. RESULTS: Uncorrected visual acuity was 20/40 or better in 89% of eyes and was equal to preoperative best spectacle-corrected visual acuity in 62% of eyes. No eyes lost lines of best spectacle-corrected visual acuity. CONCLUSIONS: Using the Nidek EC-5000 excimer laser, we had satisfactory results in the treatment of astigmatic eyes with cylinder from 4.00 to 8.00 D, based on Chayet's nomogram.

Astigmatism↗