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At least 847 records · Page 47Linked to original sources
PubMedDate not supplied

Laser in situ keratomileusis for myopic astigmatism with the Nidek EC-5000 laser.

PURPOSE: We studied the efficacy, predictability, and safety of laser in situ keratomileusis (LASIK) for moderate to high simple and compound myopic astigmatism. METHODS: Ninety-two eyes of 46 consecutive patients who had LASIK for myopic astigmatism (64 eyes, astigmatism 3.00 to 9.00 D; myopia 0 to -20.00 D), or simple myopia (28 eyes, myopia -4.00 to -20.00 D; astigmatism 0 to 0.50 D) were retrospectively studied. Mean baseline spherical equivalent refraction (SE) in the myopia group was -8.11 +/- 3.94 D and in the astigmatism group, -8.55 +/- 4.49 D. All eyes underwent LASIK using the Nidek EC-5000 laser by the same surgeon. RESULTS: At 6 months after LASIK in the myopia group versus the astigmatism group, 24 eyes (85%) vs. 54 eyes (84%) were available for follow-up, 12 eyes (50%) vs. 13 eyes (24%) had uncorrected visual acuity (UCVA) of 20/20, 19 eyes (79%) vs. 44 eyes (81%) had UCVA of 20/40, 8 eyes (33%) vs. 18 eyes (33%) had SE within +/- 0.50 D, 15 eyes (62%) vs. 39 eyes (72%) had SE within +/- 1.00 D, and mean SE was -1.22 +/- 1.17 D vs. -0.74 +/- 1.46 D. Mean astigmatism (vertexed to the corneal plane) in the astigmatism group was 2.77 D at 0 degrees before surgery and 0.32 D at 7 degrees at 6 months. None of the myopic eyes and three of the astigmatic eyes (5%) lost > or = 2 lines of best spectacle-corrected visual acuity. CONCLUSION: LASIK with the Nidek EC-5000 laser for myopic astigmatism was reasonably effective, predictable, and safe. Astigmatism was under-corrected with the nomogram implemented in this study.

Adult↗
PubMedDate not supplied

Bilateral simultaneous laser in situ keratomileusis with the Aesculap Meditec MEL 60 laser.

PURPOSE: To report the outcome of bilateral simultaneous excimer laser in situ keratomileusis (LASIK) with the Aesculap Meditec MEL 60 laser for the correction of myopia and hyperopia. METHODS: This retrospective study included 338 eyes of 169 patients who had bilateral simultaneous LASIK performed by one surgeon (D.L.V.). RESULTS: Postoperatively, 20/20 or better visual acuity was achieved by 78.5% (186 eyes) in the <-6.00-D group, and 55.6% (54 eyes) in the > or = -6.00-D group. Postoperatively, the mean spherical equivalent refraction was within +/- 0.50 D for 78% (185 eyes) in the <-6.00-D group (range, -2.25 to +1.25 D), 55% (53 eyes) in the > or = -6.00-D group (range, -2.38 to +1.13 D), and one eye in the hyperopic group. Complications at 3 months included regression in five eyes (1.4%), infiltrates in six eyes (1.7%), primary undercorrection in two eyes (0.6%), superficial punctate keratitis in four eyes (1.1%), ten eyes (2.9%) underwent enhancement, two eyes (0.6%) underwent refractive lensectomy, and four eyes (1.1%) underwent astigmatic keratotomy 3 months postoperatively. Two eyes lost two lines of best spectacle-corrected visual acuity. CONCLUSION: Bilateral simultaneous LASIK with the Aesculap Meditec MEL 60 laser was effective and predictable. It was more economical and convenient for the patient than unilateral LASIK and binocular visual rehabilitation was rapidly restored. No sight threatening complications occurred in this group of patients.

Adult↗
PubMedDate not supplied

Proper positioning of the plume evacuator in the VISX Star3 excimer laser minimizes central island formation in patients undergoing laser in situ keratomileusis.

PURPOSE: To identify risk factors in a series of patients who developed steep central islands after laser in situ keratomileusis (LASIK). METHODS: We analyzed and compared the refractive and topographic outcome of a study group composed of 83 eyes of 44 patients who underwent LASIK using the VISX Star3 excimer laser with a refraction-matched control group of 83 eyes treated later. The vacuum aspirator of the excimer laser was abnormally positioned during the surgeries performed in the study group. RESULTS: Mean preoperative spherical equivalent refraction in the study group was -6.75 +/- 2.50 D. Four eyes with a mean preoperative spherical equivalent refraction of -9.27 +/- 2.29 D developed steep central islands. Thirty-three (38%) of 83 eyes treated needed retreatment for residual myopia or myopic astigmatism. In the control group, mean preoperative spherical equivalent refraction was -6.76 +/- 2.50 D. Ninety-three percent of eyes were within +/- 1.00 D of target refraction. Five (6.02%) of 83 eyes required retreatment and no eyes developed central islands. CONCLUSION: The abnormally positioned vacuum aspirator coupled with the higher preoperative refractive correction were the likely causative factors for central island formation and the increased incidence of undercorrection in these patients.

Astigmatism↗
PubMedDate not supplied

Laser subepithelial keratomileusis for myopia of -6 to -10 diopters with astigmatism with the MEL60 laser.

PURPOSE: To evaluate the efficacy, predictability, and safety of laser subepithelial keratomileusis (LASEK) for treatment of high myopia with astigmatism. METHODS: LASEK was performed in 61 eyes of 36 consecutive patients with myopic spherical equivalent refraction of -6.00 to -10.00 D using the Aesculap-Meditec MEL60 excimer laser. Data were collected prospectively with a follow-up of 6 to 17 months. Main outcome measures recorded were UCVA, BSCVA, residual refractive error, corneal haze, and complications. RESULTS: Ninety-six percent of eyes achieved 20/40 or better UCVA at 1 month. At 12 months, 64% of eyes achieved 20/20 and 92% achieved 20/40 or better UCVA. Two eyes lost 2 lines of BSCVA at 6 or 12 months. Accuracy of correction was +/- 0.50 D from emmetropia in 82% of eyes, and +/- 1.00 D in 90% at 12 months. No eye showed more than grade 1 haze. Grade 1 haze was observed in three eyes at 12 months. One patient had mild postoperative keratitis, which was successfully treated. CONCLUSIONS: LASEK with the Aesculap-Meditec MEL60 excimer laser appeared to be safe, effective, and highly predictable in treating high myopia.

Adult↗
PubMedDate not supplied

Relative efficacy of the argon green, argon blue-green, and krypton red lasers for 10-0 nylon subconjunctival laser suture lysis.

BACKGROUND AND OBJECTIVE: To determine the optimal wavelength for subconjunctival laser suture lysis. MATERIALS AND METHODS: 130 black monofilament 10-0 nylon sutures were sewn subconjunctivally into the bare sclera of enucleated rabbit globes. The lowest energy levels facilitating laser suture lysis were determined for the argon green (514.5 NM), argon blue-green (488.0 NM, 514.5 NM), and krypton red (647.1 NM) wavelengths. In addition, absorption spectroscopy was performed on the suture material and conjunctiva using the Perkin Elmer W/VIS Lambda 2 spectrometer. RESULTS: Krypton red produced the fewest buttonhole defects, and it was also the most efficient energy source for suture lysis (P = 0.0001) under nontenectomized conjunctiva. Absorbance spectra studies revealed peak absorbance at 628 NM for the 10-0 nylon suture material. CONCLUSIONS: Based on animal and absorption spectroscopy studies, krypton red may be a safer and more efficient wavelength for subconjunctival laser suture lysis.

Animals↗
PubMed2000

Temporary tarsorrhaphy suture to prevent or treat scleral show and ectropion secondary to laser resurfacing or laser blepharoplasty.

The temporary tarsorrhaphy suture is introduced as a simple effective technique to prevent scleral show or ectropion secondary to laser skin resurfacing or laser blepharoplasty. In all but severe cases of prior existing scleral show or ectropion, the temporary tarsorrhaphy suture has been completely effective. It is also successfully used to prevent scleral show and ectropion for patients with poor lid snap and loss of elasticity of the lower eyelid at the time of laser skin resurfacing and blepharoplasty. A 5-0 Prolene suture is placed through the gray line to approximate the upper and lower eyelids and is left in place for 5 days. This supports the lower eyelid during the critical period of dermal and epidermal regeneration and during the formation of new collagen and elastin.

Aged↗
PubMed2000

[Eight year results of excimer laser correction for irregular astigmatism by linear excimer laser photoablations of the cornea in cases of keratoconus].

PURPOSE: The purpose of this study was to evaluate changes of the corneal curvature as a result of linear incisions with excimer laser and also to evaluate durability of the achieved effect, including the changes in visual acuity, topographic maps of the corneal curvature and keratometric changes at the location of keratoconus 2, 4, 8, 16, 24 weeks postoperatively. MATERIAL AND METHODS: At the First Department and Clinic of Ophthalmology, Silesian Medical School in Katowice, 294 patients went through ophthalmological examinations. 164 patients (187 eyes) with the III degree of keratoconus according to the Amsler scale, including 69 women (77 eyes) and 95 men (110 eyes), were classified for the excimer laser surgery with the method of linear, corneal incisions with MEL-60 (Aesculap-Meditec). The eyes did not tolerate contact lenses at all or because of peripheral location of the keratoconus. The patients were from 16 to 60 years of age (the mean age was 27.9 years). RESULTS: According to the statistical results, there were no difference between the effects of treatment between men and women. Correlation between the results of the surgery and the patients age showed that the latter did not have any effect on the final result. Lack of correlation between the height of the absolute corneal curvature at the keratoconus and the achieved change after the surgery was reported, thus changes of the corneal curvature parameters do not depend on its parameters before the surgical procedure. Absolute visual acuity of patients was improving and reached maximally 0.252 of the unit. As a result of the single surgery, the maximum change of keratometric values was 4.949 D, and the minimum was 3.611 D. In the case of the secondary surgery, the maximum keratometric value at the axis of the incision was 8.55 D and the minimum one was 7.101 D. CONCLUSION: To sum up, we can say that the favourable effect of decreasing the irregular corneal astigmatism with the method of linear laser fotoablations was maintained throughout the whole observation period, which allowed to shift in time planned corneal transplantation.

Adolescent↗
PubMed2000

[Individual selection of the total dose of laser energy in percutaneous laser disk nucleotomy].

On the basis of studies on concentration and mobility of ions in the solution (conductometry technique) an individual selection is suggested of the total dose of laser energy during the percutaneous laser disk nucleotimy sessions. The conductometry technique permits arriving at an objective decision on both completion/continuation of the operation and change in the laser energy rate.

Diskectomy, Percutaneous↗
PubMed2002

[Lasers in dentistry 2. Diagnosis of dental caries with lasers].

When enamel, dentine and substances in caries lesions are exposed to (laser) light of a specific colour, fluorescence may be induced. This principle is at the basis of two caries diagnostic methods, DIAGNOdent and Quantitative Laser (Light-induced) Fluorescence (QLF). Only the DIAGNOdent is commercially available. Bacterial porphyrins evoke fluorescence when illuminated with red light and the intensity of the emitted light is related to the size of the caries lesion. Published research indicates that the DIAGNOdent is particularly suitable for detecting small bacteria containing caries lesions, and to monitor such lesions. QLF is based on the fluorescence decrease in demineralised enamel upon exposure to blue-violet (laser) light. The intensity of the emitted light is related to the amount of mineral loss in the caries lesion. Using QLF the mineral loss in caries lesions can be measured quantitatively. Like the DIAGNOdent, QLF is particularly suitable to monitor caries lesions.

Dental Caries↗
PubMed2001

The Ramathibodi nasal filter in a simulated human airway: evaluated with laser smoke particles and a laser diode dust portable monitor.

The Ramathibodi nasal filter was specially designed as a personal respiratory protective device. It was attached to a simulated human airway composed of a nasal and pharyngeal model, airway passage and lung model machine. The system was run in a laser smoke particles environment. The laser smoke particles with suspended particulate matter size of less than 15, 10 and 2.5 microns (PM15, PM10 and PM2.5) were selected. The amount of each particle size in the simulated human airway with and without the Ramathibodi nasal filter was measured continuously by a laser diode portable dust monitor. One hundred sample sizes were analyzed by a descriptive statistical method at the Department of Otolaryngology, Ramathibodi Hospital from January to November 1999. The graphic distribution patterns of each residual particle size in the simulated human airway with and without the Ramathibodi nasal filter were compared. The filtration efficacy of the Ramathibodi nasal filter should be tested further by this experimental model. The device could be applied intermittently in adult nasal vestibules.

Dust↗
PubMed2002

[Lasers in dentistry 3. The use of lasers for the prevention of dental caries].

Studies in our laboratories have demonstrated that specifically chosen CO2 laser treatment of dental enamel can markedly inhibit subsequent caries-like progression compared to controls in a laboratory model. Optimum caries inhibition in enamel appears to be achieved by pretreatments that produce surface temperatures in the range of 800-1200 degrees C. For clinical application the surface enamel heating must not lead to consequent pulp chamber temperature rises of > 4 degrees C. To meet these conditions a pulsed laser is required with a sufficiently high absorption coefficient (wavelength = 9.3 or 9.6 microns), pulse duration of 5-100 microseconds, 10-25 pulses per spot, repetition rate of 10-30 pulses per second, and low but effective fluence (approximately 1-5 J/cm2/pulse). A human intra-oral study has confirmed inhibition of caries progression in the human mouth. The clinical potential is good for caries preventive treatments by specific carbon dioxide laser conditions.

Absorption↗
PubMed2002

[Alternative methods for prevention and treatment of dental caries using laser and magnetic laser exposure].

Alternative methods for prevention and treatment of dental caries are presented, based on the use of laser and magnetic laser exposure (patent No. 2053818, in Russia) with a new generation laser device with Optodan microprocessor monitoring (patent No. 2014107, Russia). The methods are intended for wide clinical application in children and adolescents in pedodontic departments and outpatient centers and particularly for group and individual use in dental rooms at school.

Contraindications↗
PubMed2003

[Lasers in dentistry. 9. Safety in laser use].

The laser has become an effective new tool in dentistry. Besides the positive effects for which it is applied, the laser is also capable of causing damage to the patient, the user and the bystanders. In this paper the different types of laser-specific hazards are explained. The concept of the nominal hazard distance is introduced and used to analyse the practical risks and suggest safety measures to be taken.

Equipment Safety↗
PubMed2000

Validation of scanning laser Doppler flowmetry against single point laser Doppler flowmetry in the measurement of human gastric serosal/muscularis perfusion.

BACKGROUND: Single point laser Doppler (LDF) has been employed intra-operatively to measure gastro-intestinal tissue perfusion, but despite reports that it may have a role in predicting post-operative complications consequent upon hypo-perfusion, methodological drawbacks have prevented its routine clinical application. Scanning laser Doppler flowmetry (SLDF) may address these drawbacks, but this new development has not been previously validated in human gastro-intestinal tissue. AIMS: This study assessed the ability of Scanning laser Doppler flowmetry to measure human gastric perfusion. METHODS: 10 patients undergoing oesophageal resection were studied. In each 6 measurements of gastric corporal serosal/muscularis were made over 30 seconds using the previously validated single point LDF technique. A single 1 cm2 SLDF scan was made of the same area prior to any vascular division. These measurements were repeated after partial gastric devascularisation and the two techniques' measurements then compared. RESULTS: Correlation between the 2 methods was good (coefficient of correlation was 0.955 (p<0.01). The mean bias (scan - single point PUs) was -3 PUs (95% CIs 16.3 to 45 PUs) and the limits of agreement were -64 to 58 PUs. The coefficients of variation for the 6 sets of single point measurements made in each patient ranged between 3.0% and 30.4% (mean = 12.5%). CONCLUSION: These results validate SLDF as a method of measuring gastric tissue perfusion intra-operatively.

Esophagectomy↗
PubMed2003

[Interstitial laser coagulation for benign prostatic hyperplasia: clinical results of the Indigo diode laser system].

We report our experience with interstitial laser coagulation of the prostate (ILCP) using an Indigo 830j diode laser system for benign prostatic hyperplasia (BPH). From March 1998 to November 2000, we treated 45 patients between 51 and 95 years old (average 71.5) with symptomatic BPH. The mean prostatic volume before ILCP was 62.0 cm3. We experienced no serious complications. Three months after ILCP, the mean international prostate symptom score (I-PSS) quality of life (QOL) index and post-void residual volume (PVR) decreased significantly from 18.0 to 9.2, from 4.4 to 2.1 and from 103.6 ml to 44.5 ml, respectively. The mean maximum flow rate (MFR) increased from 7.6 ml/sec at baseline to 9.2 ml/sec 3 months after ILCP, but the difference was not statistically significant. Before and after ILCP, 8 patients were available to evaluate pressure-flow study data. The detrusor pressure at the maximum flow rate decreased significantly from 118.3 cmH2O at baseline to 78.6 cmH2O 3 months after ILCP. The improvement of the I-PSS, QOL index, MFR and PVR continued and at 24 months reached 5.7, 1.8, 11.6 ml/sec and 54.6 ml, respectively. In our assessment of the questionnaire addressing the patient's satisfaction after the treatment, the majority of the patients who answered the questionnaire were pleased with the results of ILCP. We assessed the relation of the overall treatment efficacy with the number of punctures and the total amount of the laser energy delivered, but we did not find any relation. Our clinical results suggest that the ILCP using Indigo 830j is an effective modality and the short-term treatment efficacy is favorable.

Aged↗
PubMedDate not supplied

[The laser therapy and laser acupunture of patients with chronic recurrent aphthous stomatitis].

Laser therapy and laser acupuncture of the biologically active sites were administered to 24 patients with chronic recurrent aphthous stomatitis. The biologically active sites were selected individually with due consideration for the underlying somatic condition. Good results were achieved in the patients with the fibrous form of chronic aphthous stomatitis. Secretory and serum immunoglobulin levels were monitored over the course of laser treatment.

Acupuncture Points↗
PubMed1992

[Efficacy and tolerability of apraclonidine (ALO 2145, 1%) in the prevention of early ocular hypertonia, after trabeculoretraction using argon laser and posterior capsulotomy using Nd:YAG laser].

ALO 2145 (Apraclonidine Chlorhydrate)*, is a new hypotensive agent; it acts as a selective alpha-2-adrenergic agonist to produce a marked reduction in intraocular pressure with minimal effect on the cardiovascular system. 38 patients undergoing ocular laser surgery were allocated to treatment with either ALO 2145 1% (n = 20), or to placebo (n = 18), in a double-masked fashion. One drop of study medication was instilled into the operative eye one hour before laser surgery, and one drop immediately after the laser surgery. ALO 2145 treated eyes exhibited a significantly lower mean intraocular pressure increase in the immediate postoperative phase, compared with placebo treated eyes. ALO 2145 also significantly reduced the postoperative incidence of intraocular pressure spikes, defined as intraocular pressure increases of more than 10 mmHg over baseline (17% of cases for active treatment vs 60% of cases for placebo). ALO 2145 1% was shown to be effective and well tolerated in the dosage regimen employed in this study.

Adrenergic alpha-Agonists↗
PubMedDate not supplied

[Optimization of energy parameters of ultrasound and laser cataract surgery with a preliminary transcorneal endocapsular YAG-laser impact exerted on the cataract lens nuclei].

The values of the main energy and time parameters of ultrasound and laser fragmentation of different-hardness cataract-lens nuclei were analyzed in patients of various age groups after a preliminary transcorneal endocapsular YAG-laser treatment of the lens. The results show, in all cases, lower key energy and time characteristics, which primarily concerns a total energy index of the ultrasound and laser effect of no less than 20% versus the ordinarily used parameters.

Adult↗