PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Lasers”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

[Laser trabeculotomy and laser iridectomy. 3 Years' experience with the Glaucoma Research Laser (Britt) (author's transl)].

This report presents a 3-year study of treatment of the anterior portion of the eye with the Glaucom Research Laser, Model 152, made by Britt Corp. Los Angeles. This study deals specifically with laser trabeculotomy and iridectomy. In this period of time 176 eyes were treated with trabeculotomy and 60 with iridectomy. All types of glaucoma were represented. The technique and the results are demonstrated. This pulsed Argon laser permits surgery with a high rate of success without any serious complications.

Anesthesia↗
PubMed1978

[Laser lesions of the anterior segment of the rabbit eye. Studies of cornea, iris, lens and sclera using an argon, ruby and YAG-laser].

The anterior segment of the eye of 100 rabbits was exposed to radiation from Argon, Ruby and YAG lasers. The healing process of liminal and supraliminal lesions was evaluated histologically. The iris is the most sensitive tissue for all three lasers (threshold radiant exposure, Argon: 0.004 kJ/cm2, Ruby: 0.01 kJ/cm2, YAG: 0.05 kJ/cm2). Higher energies necessary for lesions in the transparent media were available only with the Argon and YAG lasers. The Argon laser failed to produce lesions in the lens, and threshold radiant exposure for the central cornea was 8 kJ/cm2. The thresholds for YAG lasers lesions in the central cornea and lens were of the same magnitude. The marked absorption of energy by the iris may lead to an accumulation of heat, resulting in lesions of adjacent tissues or a reduction of threshold for those lesions: The threshold in the peripheral cornea was ten times lower than in the center with the Argon laser, four times lower for the YAG laser. The thresholds for Argon and YAG laser lesions in the peripheral sclera lay between the thresholds for the iris and for the peripheral cornea. A safety standard for the anterior segment of the eye should be based on the lowest threshold (Argon laser lesion of the iris). The application of a factor 100 results in a maximal permissible exposure of 40 mJ/cm2. The influence of the beam diameter could not be evaluated.

Animals↗
PubMed1976

Calculation of retinal temperature distributions resulting from laser irradiation of the eye: I. Continuous lasers.

The paper develops a simple analytic expression for the maximum temperature rise attained in the retina as a function of laser power, exposure duration, retinal absorption parameters and image radius. It is assumed that the laser beam has a Gaussian intensity distribution and is absorbed, following Beer's law, in both the pigment epithelium and the choroid layers of the eye. The final expression is mathematically accurate to 1% and is valid for image radii ranging from 20 to 500 mum and for exposure times from 30 ms to infinity. Consequently, this analysis is ideally suited to the interpretation of laser threshold damage experiments using shuttered gas lasers operated in their uniphase mode. Finally, the problem of defining a safe exposure level to laser radiation is considered. However, the lack of available information on minimum retinal image diameter and maximum absorption coefficient permits only an estimate of this parameter to be made.

Lasers↗
PubMed2026

Efficacy and safety of thulium fiber laser versus conventional holmium:YAG laser in anatomical endoscopic enucleation of the prostate: a systematic review and pairwise meta-analysis.

PURPOSE: Anatomical endoscopic enucleation is an established treatment for benign prostatic obstruction. Whether thulium fiber laser enucleation (ThuFLEP) improves outcomes over conventional holmium:YAG laser enucleation (HoLEP) remains uncertain. We compared the efficacy and safety of ThuFLEP versus non-MOSES-modulated HoLEP. METHODS: We performed a PRISMA-compliant systematic review and pairwise meta-analysis of randomised and comparative cohort studies comparing ThuFLEP and conventional HoLEP in adult men. Six databases were searched. Outcomes included International Prostate Symptom Score (IPSS), IPSS quality-of-life score, maximum urinary flow rate (Qmax), post-void residual volume, hospital stay, and complications. Risk of bias and certainty of evidence were assessed with RoB 2/ROBINS-I and GRADE. RESULTS: Seven non-overlapping comparative populations in eight publications included 3,509 patients. ThuFLEP was associated with a small statistically significant reduction in IPSS at 3 months (mean difference [MD] -1.04 points, 95% confidence interval [CI] -1.81 to -0.28) of uncertain clinical relevance. Qmax differences were small and directionally inconsistent across follow-up (favouring HoLEP at 3 months and ThuFLEP at 6 and 12 months) and derived mainly from retrospective cohorts, with neutral randomised subgroups. Stress and urge urinary incontinence were less frequent overall (RR 0.75, 95% CI 0.58 to 0.96, and RR 0.39, 95% CI 0.22 to 0.68), but both estimates depended on one large registry cohort and were not robust to its exclusion. Most other complications and hospital stay showed no clear between-group difference. Limitations include few studies per outcome, heterogeneity, sparse safety events, inconsistent prostate-specific antigen reporting, and mostly low/very low certainty evidence. CONCLUSION: ThuFLEP and conventional HoLEP are clinically comparable with no definitive superiority of either laser. Platform selection should be individualised according to surgeon expertise, institutional resources, and patient characteristics. Future trials should standardise cost-effectiveness outcomes and investigate whether the distinct laser-tissue interactions impact adenoma clearance, PSA reduction, enucleation completeness, and long-term durability.

Humans↗
PubMed1979

CO2 laser in vitreoretinal surgery: 1. Quantitative investigation of the effects of CO2 laser radiation on ocular tissue.

Scleral, lens, and vitreoretinal tissue was incised using CO2 laser radiation in a controlled and predictable fashion without producing untoward effects on neighboring ocular tissue. The penetration depth of infrared radiation into normal human vitreous was measured and was found to be exceedingly small. A quantitative correlation was observed between the CO2 laser power and the depth of penetration in scleral-chorio-retinal wall incisions and in lens tissue from human eyebank eyes. The results of this investigation suggest that the CO2 laser may be useful in intravitreal surgery, full-thickness scleral-chorio-retinal wall resections, transvitreal chorioretinal biopsy, and even dissolution of cataracts.

Animals↗
PubMed2026

Comparison of a 755-nm picosecond laser and a 1565-nm nonablative fractional laser for the treatment of atrophic acne scars: a 20-week prospective, randomized, split-face clinical study.

To compare the efficacy and safety of a 755-nm picosecond laser with a diffractive lens array (P-DLA) and a 1565-nm nonablative fractional laser (NAFL) for the treatment of atrophic acne scars. Twenty-seven patients with atrophic acne scars underwent three sessions of randomized split-face treatment with P-DLA and NAFL at 4-week intervals. Patients were followed up at 1, 2, and 3 months after the final treatment. Efficacy was assessed using the &#xc9;chelle d'&#xc9;valuation Clinique des Cicatrices d'Acn&#xe9; (ECCA) grading scale, the Investigator's Global Assessment (IGA) score, patients' self-rated improvement, and overall satisfaction. Treatment-related adverse reactions were recorded daily by patients until resolution. Both modalities demonstrated significant improvements in scar appearance based on ECCA score, IGA score, and patients' self-rated improvement (P&#x2009;<&#x2009;0.001). No statistically significant differences in efficacy were observed between the two treatments. However, the P-DLA group showed higher patient satisfaction (P&#x2009;=&#x2009;0.035) and a more favorable safety profile, including shorter durations of erythema and edema and the absence of crusting. Both P-DLA and NAFL were effective and safe for the treatment of atrophic acne scars, with similar efficacy. P-DLA offered better tolerability.

Humans↗
PubMed1979

[Hemostatic effects of the argon laser on the gastric wall in the dog. I. Preliminary study: effects of the laser on the normal gastric wall].

The authors describe the pathological lesions caused by argon laser emitted rays on the healthy gastric mucosa in 22 dogs. They compare 126 photocoagulated areas while varying the intensity and the exposure time of the laser ray in order to determine the ideal constants of an efficient photocoagulation, devoid of risk and with rapid healing of the lesions.

Animals↗
PubMed1979

[Results of helium-neon laser radiation action on the hematopoietic system experimentally and in the laser therapy of surgical diseases].

The investigation of effects of the red light of the helium-neon laser on hemopoiesis of experimental animals has provided data on the activation of erythropoiesis and the presence of the leucocyte redistribution reaction in the peripheral blood. No pathological changes in the morphological composition of the peripheral blood were detected in patients with a deforming arthrosis and patients with gastric ulcer in the process of laser therapy. Favourable changes were noted.

Animals↗
PubMed1979

[Hemostatic effects of the argon laser on the gastric wall of the dog. II. Effects of the laser on 53 hemorrhagic ulcers of the gastric mucosa].

The authors made a histopathological study of 53 haemorrhagic ulcers of the gastric mucosa of the dog, photocoagulated using an Argon laser apparatus (delivering a power of 6 watts at the tip of the fibre). Haemostasis was obtained in less than 10 sec. in all cases where photocoagulation was performed by small applications of 1.5 sec. to the edges of the ulcer. There were no cases of perforation or muscularis damage. Healing of the lesions was complete or well under way at 15 days.

Animals↗
PubMedDate not supplied

Intravenous procaine as a supplement to general anesthesia for carbon dioxide laser resection for carbon dioxide laser resection of laryngeal papillomas in children.

Procaine suppresses the cough reflex, decreases laryngeal irritability, and has general anesthetic properties. For these reasons, 14 pediatric patients undergoing CO2 laser resection of laryngeal papillomas were studied in which an intravenous infusion of procaine (1 mg/kg/min) was added to N2O-O2 halothane/enflurane general anesthesia immediately following endotracheal intubation. These patients were compared to nine patients receiving the same anesthesia without procaine. The mean age of both groups was 11 years. There was no difference between the groups in duration of anesthesia or surgery. Emergence, however, averaged 15 minutes in study patients compared to 36 minutes in the control group (p less than 0.01). There was no difference in anesthetic concentrations required to maintain satisfactory operative conditions in the two groups. Muscle relaxants were required intraoperatively in seven control patients but in none of the study patients. The surgeon ranked the operative conditions excellent in all study patients but poor in seven of the nine control patients. Five of the latter required postoperative treatment of laryngeal complications, including reintubation in three. Only one of the study patients had postoperative stridor. No evidence of procaine toxicity was noted in the study patients with total doses ranging from 500--3600 mg. Intravenous procaine is useful in pediatric patients having endoscopic laryngeal operations.

Anesthesia, Inhalation↗