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PubMed1986

Clinical results of terminal salpingostomy with the use of the CO2 laser: report of the Intraabdominal Laser Study Group.

Forty-eight women underwent terminal salpingostomies with a standard operative procedure with the use of the CO2 laser and microsurgical techniques at five centers. Early second-look laparoscopy was performed in all patients 1 to 12 weeks after the laparotomy. The tubal patency rate at the second look was 92% for these 48 patients, with a minimum of 6 months' follow-up study in all patients. Of these patients, ten became pregnant (21%), one with an ectopic pregnancy (10%). All pregnancies occurred within 12 months of the second-look procedure. It is preliminarily concluded from this series that use of the CO2 laser for neosalpingostomy at laparotomy with early second-look laparoscopy provides a term pregnancy rate similar to that previously achieved by nonlaser microsurgical techniques and shortens the time period between the surgical procedure and when conception would be expected to occur.

Adult↗

PubMed2000

The predictability of corneal flap thickness and tissue laser ablation in laser in situ keratomileusis.

OBJECTIVE: To evaluate the relationship between predicted flap thickness and actual flap thickness and between predicted tissue ablation and actual tissue ablation. DESIGN: Prospective, nonrandomized comparative (self-controlled) trial. PARTICIPANTS: A total of 60 patients (102 eyes) who underwent laser in situ keratomileusis (LASIK). MAIN OUTCOME MEASURES: Subtraction pachymetry was used to determine actual corneal flap thickness and corneal tissue ablation depth. Other measurements included flap diameter and keratometry readings. RESULTS: Actual flap thickness was significantly different (P < 0.0001) from predicted flap thickness. Fifteen eyes had a predicted flap thickness of 160 micrometer and a mean actual flap of 105 micrometer (standard deviation [SD], +/-24. 3 micrometer range, 48-141 micrometer). Sixty-four had a predicted flap of 180 micrometer with an actual flap mean of 125 micrometer (SD, +/-18.5 micrometer range, 82-155 micrometer). Seventeen eyes had a predicted flap of 200 micrometer, with an actual flap mean of 144 micrometer (SD, +/-19.3 micrometer range, 108-187 micrometer). In addition, we found that significantly more tissue (P < 0.0001) was ablated than predicted. Linear regression of the observed ablation on predicted ablation yielded the following relationship: actual ablation = 14.5 + 1.5 (predicted ablation). Neither flap diameter nor flap thickness were found to increase with respect to steeper corneal curvatures. CONCLUSIONS: Actual corneal flap thickness was consistently less than predicted regardless of the depth plate used; actual tissue ablation was consistently greater than predicted tissue ablation for the laser used in this study.

Cornea↗

PubMed2001

Laser in situ keratomileusis for myopia up to -11 diopters with up to -5 diopters of astigmatism with the summit autonomous LADARVision excimer laser system.

OBJECTIVE: To assess the safety and effectiveness of the Summit Autonomous LADARVision active tracking narrow beam excimer laser system for laser in situ keratomileusis (LASIK) correction of myopia and astigmatism. DESIGN: A multicenter, prospective noncomparative case series. PARTICIPANTS: This cohort consisted of 177 eyes corrected for spherical myopia up to -11 diopters (D) and 170 eyes corrected for myopia up to -11 D spherical equivalent with astigmatism up to -5 D. INTERVENTION: Treatments were performed at four sites in the United States using a 6-mm optic zone for spherical myopes and a 5.5-mm optic zone with a 1-mm blend for astigmats. MAIN OUTCOME MEASURES: Visual acuity, subjective refraction, vector analysis, subject satisfaction, intraocular pressure, complications, and adverse reactions. RESULTS: Six-month follow-up was available on 157 spherical eyes and 113 astigmatic eyes. For spherical myopes, uncorrected visual acuity (UCVA) was 20/20 or better in 60.5%, 20/25 or better in 80.3%, and 20/40 or better in 93.9%. The mean spherical equivalent was -0.29 +/- 0.45 D with 75.2% +/- 0.50 D and 94.9% +/- 1.00 D of intended. A loss of two lines of best spectacle-corrected visual acuity (BSCVA) occurred in 0.6%, and no eyes lost greater than two lines of BSCVA. For astigmatic myopes, UCVA was 20/20 or better in 52.0%, 20/25 or better in 74.5%, and 20/40 or better in 94.1%. The mean spherical equivalent was -0.23 +/- 0.49 D with 75.2% +/- 0.50 D and 95.6% +/- 1.00 D of intended. A loss of two lines of BSCVA occurred in 0.9%, and no eyes lost greater than two lines of BSCVA. Vector analysis showed that 99% of the intended cylinder was corrected on average with a mean angle of error of 4.2 degrees. Refractive stability was achieved between 1 and 3 months in 97.5% of spherical eyes and 99.4% of astigmatic eyes and confirmed between 3 and 6 months in 100% of both spherical and astigmatic eyes. CONCLUSIONS: Eyes treated for myopia up to -11 D of spherical equivalent with or without astigmatism up to -5 D show early refractive stability, good UCVA outcomes, no significant loss of BSCVA, accurate correction of astigmatism, and slight undercorrection without a change from the photorefractive keratectomy algorithm and with a single treatment.

Adult↗

PubMed2001

Laser in situ keratomileusis with the VISX Star laser for myopia over -10.0 diopters.

PURPOSE: To evaluate the efficacy, predictability, stability, and safety of laser in situ keratomileusis (LASIK) for myopia over -10.00 diopters (D). SETTING: The Eye Institute of Utah, Salt Lake City, Utah, USA. METHODS: The prospective study included 332 eyes of 183 patients having LASIK with the VISX Star laser to correct myopia of -10.00 to -18.00 D. The eyes were divided into 3 groups according to the preoperative refraction: Group A (n = 208), -10.00 to -11.90 D; Group B (n = 94), -12.00 to -14.00 D; Group C (n = 30), -14.10 to -18.00 D. The mean follow-up was 12.0 months +/- 5.6 (SD) (range 6 to 37 months). RESULTS: Overall, the mean spherical equivalent decreased 96%, from -11.69 +/- 1.46 D preoperatively to -0.37 +/- 0.80 D postoperatively. The mean astigmatism decreased 72%, from 1.66 +/- 1.22 D to 0.46 +/- 0.53 D. At the last visit, 84.0% of eyes were within +/-1.00 D of emmetropia and 96.4% were within +/-2.00 D. An overcorrection of more than +1.00 D was experienced by 1.8% of patients. The uncorrected visual acuity (UCVA) was 20/20 or better in 45.8% of eyes and 20/40 or better in 89.5%. Six eyes (1.8%) lost 2 or more lines of best corrected visual acuity; this included 1 eye in which iatrogenic keratectasia developed 18 months after LASIK retreatment. Retreatment was done in 37.0% of eyes at a mean of 6.3 +/- 5.3 months (3 to 32 months) after the initial treatment. At the last examination, 86.0% of eyes in Groups A and B and 70.0% in Group C were within +/-1.00 D of emmetropia. A significant difference was found between Groups A and C (P =.032). The UCVA was 20/20 in 52.0% of Group A eyes, 38.0% of Group B eyes, and 23.0% of Group C eyes. The difference between Groups A and C was significant (P =.001), but the difference between Groups A and B was not (P =.055). CONCLUSIONS: In this study, LASIK was effective in correcting myopia up to -14.00 D. The efficacy, predictability, and safety were significantly less in eyes with myopia greater than -14.00 D.

Adult↗

PubMed2003

Corneal bed perforation by laser ablation during laser in situ keratomileusis.

A 34-year-old man was referred to our department with corneal perforation after multiple laser in situ keratomileusis procedures for myopia. Corneal perforation occurred at the time of laser application during the fourth surgery, and the anterior chamber became completely flat. The perforation was sealed shortly thereafter and the corneal edema disappeared in 3 weeks, but there was an 86 microm forward shift of the cornea associated with an 8.0 diopter myopic shift during the subsequent 6 months. No further forward bulging of the cornea was observed. The refraction had stabilized up to 2 years postoperatively, but corneal irregular astigmatism limited the patient's best spectacle-corrected visual acuity.

Adult↗

PubMed1991

Experimental studies on the development and propagation of shock waves created by the interaction of short Nd:YAG laser pulses with a titanium target. Possible implications for Nd:YAG laser phacolysis of the cataractous human lens.

The formation and propagation of shock waves created by the interaction of high powered Nd:YAG laser pulses with a titanium target are photographed and analyzed. The titanium target is located at the distal end of a probe, similar to an irrigation/aspiration probe used in cataract surgery, and the Nd:YAG laser is delivered by a cladded 300 microns quartz fiber. This device, and the results of this study, are being applied to develop a device for fragmenting nuclear material for cataract extraction.

Cataract Extraction↗

PubMed1992

Aqueous humor analysis after Nd:YAG laser capsulotomy with the laser flare-cell meter.

Using the laser flare-cell meter (Kowa FC-1000), we conducted a prospective study analyzing the effect of Nd:YAG posterior capsulotomy on the quantity of aqueous particles, aqueous flare, and intraocular pressure in 65 eyes (58 patients). Aqueous particles increased at six hours, followed by flare rise which was significant at 18 hours after capsulotomy. Only 22 eyes (34%) had a significant flare rise over prelaser values. Anti-inflammatory therapy was necessary in only one patient. The mean intraocular pressure value did not rise significantly after capsulotomy. Acute intraocular hypertension (AIOHT) (> 7 mm Hg increase) occurred between three and six hours after laser therapy in 12 patients (19%), was related in time to particle rise, and always responded to a single dose of acetazolamide. Acute intraocular hypertension was strongly correlated with elevated aqueous particles (P < .0001) and somewhat correlated with flare rise (P < .036), but was not correlated with the intraocular lens position (bag or sulcus fixation). Our findings strongly suggest that trabecular meshwork clogging by debris generated by the capsulotomy is the mechanism at the origin of AIOHT.

Adult↗

PubMed1986

Long-term results of Nd:YAG laser posterior capsulotomy with the Swiss laser.

The Microruptor II (MR-II) Nd:YAG laser developed by Fankhauser was evaluated in a national multicenter prospective study of posterior capsulotomy. Results are reported on 3,711 patients who underwent Nd:YAG laser photodiscission. Ninety-two percent of patients experienced an improvement in vision at some point following photodiscission and the postoperative complications of persistent cystoid macular edema and glaucoma occurred at rates of 2.5% and 0.2%, respectively, indicating the safety and efficacy of the MR-II for posterior capsulotomy.

Adolescent↗

PubMed1996

Topical interferon alpha 2b for corneal haze after excimer laser photorefractive keratectomy. The Melbourne Excimer Laser Group.

PURPOSE: To determine whether topical interferon alpha 2b (IFN-alpha) prevents corneal haze after excimer laser photorefractive keratectomy (PRK). SETTING: Tertiary referral ophthalmic hospital. METHOD: A prospective, double-blind, placebo-controlled, randomized study of 31 patients was undertaken. After surgery in a single institution, patients received a drop of either a placebo or IFN-alpha (5 x 10(6) IU/ml) four times daily for 4 weeks. The main outcome measures were corneal haze, refraction, and visual acuity. RESULTS: The major side effect of interferon alpha treatment was a significant delay in epithelial healing by a mean of 2 days. The means of the average post-treatment clinical scores for haze in all patients up to 12 months after surgery were 0.46 +/- 0.25 for the IFN-alpha group and 0.64 +/- 0.43 for the placebo group (P = .20). Of patients with a correction of greater than 5.00 diopters (D), the IFN-alpha group had significantly less haze over the course of the study (0.39 +/- 0.23 versus 0.98 +/- 0.50; P = .03). After 12 months, the mean absolute spherical equivalent in the two groups was not significantly different (1.02 +/- 1.13 D versus 1.44 +/- 2.64 D). There was a tendency toward better uncorrected visual acuity in the INF-alpha group (P < .10, Kolmogorov-Smirnov). CONCLUSION: Topical IFN-alpha may merit further investigation as a treatment to reduce corneal haze after excimer laser PRK for corrections greater than 5.00 D.

Administration, Topical↗

PubMed1994

Comparison of laser Doppler perfusion imaging, laser Doppler flowmetry, and thermographic imaging for assessment of blood flow in human skin.

In this study we compared three non-invasive methods of measuring skin perfusion, thermographic imaging (TI), laser Doppler flowmetry (LDF) and the new technique of laser Doppler imaging (LDI). Seven normal volunteers were studied in a temperature-controlled room with an ambient temperature of 22 +/- 1 degree C. Images of the left hand were recorded using LDI followed by TI. LDF was then used on two standard locations on the fingers and back of the hand. The measurements were then repeated for a hot (37 degrees C) and then a cold (10 degrees C) challenge. A significant linear correlation (r = 0.960, p < 0.01, with 95% confidence limit of 0.35-0.77, n = 38) was found between LDF and LDI. However, LDF and LDI did not correlate well with TI (r = 0.577, p < 0.01, with 95% confidence limit of 0.32-0.76, n = 38). The LDI method was found to be highly reproducible (mean +/- 1 SD; 625 +/- 30, with coefficient of variation 5%). The blood flow and temperature distribution of skin of the hand was then recorded using TI and LDI in 10 patients (mean age +/- SD, 41.7 +/- 9.9) with scleroderma and eight normal volunteers (mean age +/- SD, 30.6 +/- 6.5). The overall mean blood flow and temperature in the hands of patients with scleroderma (mean +/- SD 444 +/- 265 flux, 29.3 +/- 3.3 degrees C) was significantly (p < 0.0001) lower compared with the normal volunteers (mean +/- SD, 912 +/- 390 flux, 34.0 +/- 3.2 degrees).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1999

Transmyocardial laser revascularization with the CO2 laser: one year results of a randomized, controlled trial.

Transmyocardial laser revascularization (TMR) was compared to continued medical management in 198 patients with symptomatic end-stage coronary artery disease in a 1:1 randomized prospective study. Angina class, quality of life, and myocardial perfusion significantly improved following TMR over a 12-month period of follow-up. Continued medical management was associated with a higher incidence of unstable anginal episodes, repeat hospitalizations, worsening anginal class and myocardial perfusion. This study demonstrates the superiority of TMR over medical management in the treatment of chronic stable angina. With appropriate patient selection and perioperative management, TMR with the CO2 laser is associated with a very low operative risk.

Coronary Disease↗

PubMed2003

Laser desorption and imaging of proteins from ice via UV femtosecond laser pulses.

We have employed 200-fs, 400-nm laser pulses to desorb intact protein molecular ions directly from a frozen aqueous matrix. The resulting spectra obtained using a variety of proteins varying in molecular weight from 1060 (bradykinin) to 5778 Da (insulin) are compatible with those obtained with traditional matrix-assisted laser desorption/ionization experiments. High-quality spectra could be generated using a fluence of 4.0-9.0 J/cm2 to desorb proteins from an aqueous solution frozen onto metal substrates with a sensitivity in the femtomole range. Although the mechanism behind this effect is still not clear, we speculate that it involves explosive boiling of the ice layer due to rapid heating of the substrate. Imaging experiments conducted on the ice layer suggest that the yield of protein is approximately independent of the film thickness and is very reproducible from shot to shot. The results are particularly significant since they open the possibility of examining a range of biomaterials directly from the in vivo aqueous environment.

Ice↗

PubMed2006

Studies of site selective hydrogen atom abstractions by Cl atoms from isobutane and propane by laser flash photolysis/IR diode laser spectroscopy.

The kinetics of chlorine atom abstractions from normal and selectively deuterated propane and isobutane have been measured at room temperature and 195 K using a laser flash photolysis system, and following the course of the reaction via IR diode laser absorption measurements of HCl product. In conjunction with the kinetic measurements, a comparison of the HCl signal heights from pairs of measurements on normal and selectively deuterated systems has allowed the determination of the branching fractions of the reactions at the primary, secondary (propane) and tertiary (isobutane) positions. The kinetic data (all in units of cm(3) molecule(-1) s(-1)) for the reaction of Cl atoms with propane ((1.22 +/- 0.02) x10(-10), 195 K; (1.22 +/- 0.03) x10(-10) 298 K) and isobutane ((1.52 +/- 0.02) x10(-10), 195 K; (1.25 +/- 0.04) x10(-10), 298 K) are generally in good agreement with literature data. No data are available for comparison with our measurements for the reactions of Cl atoms with CH(3)CD(2)CH(3) ((1.02 +/- 0.03) x10(-10), 195 K; (1.09 +/- 0.02) x10(-10), 298 K) or (CH(3))(3)CD ((1.32 +/- 0.03) x10(-10), 195 K; (1.12 +/- 0.04) x10(-10), 298 K). Rate coefficients at 195 K for the reactions of Cl atoms with ethane ((5.04 +/- 0.08) x10(-11) and n-butane ((2.19 +/- 0.03) x10(-10)) were also measured. The branching fractions for abstraction at the primary position increased with temperature for both propane ((40 +/- 3)% at 195 K to (48 +/- 3)% at 298 K) and isobutane ((49 +/- 4)% at 195 K to (62 +/- 5)% at 298 K). The direct measurements from this study are in good agreement with most calculations based on structure activity relationships.

Butanes↗

PubMed1997

A prospective randomized trial evaluating endoscopic Nd:YAG laser prostate ablation with or without potassium titanyl phosphate (KTP) laser bladder neck incision.

OBJECTIVE: To investigate whether performing a potassium titanyl phosphate (KTP) laser bladder neck incision (BNI) in conjunction with a Nd:YAG endoscopic ablation of the prostate (ELAP) compared with an ELAP alone, improves early post-operative voiding rates and clinical outcome. PATIENTS AND METHODS: A prospective randomized trial that was both double-blind and power-determined (80%) compared 88 patients with benign prostatic enlargement undergoing ELAP and those undergoing KTP BNI and ELAP. A dual-wavelength KTP/532TM (Laserscope) laser was used with Add/Stat side-firing fibres. A urethral catheter was inserted post-operatively and was removed after 18 h. Patients unable to void at this stage were then re-catheterized, discharged and readmitted 2 weeks later for catheter removal. Patients were followed up at 3 month intervals. RESULTS: Post-operatively, 80% of the patients undergoing KTP BNI and ELAP were able to void on catheter removal at 18 h, compared with only 57% of the patients undergoing ELAP alone (P < 0.05, chi-square). After 1 month, two patients from the former and four from the latter group failed to void and required further surgery. At 3 months, there was a significant improvement in the post-void residual volume, maximum flow rate, symptom and quality-of-life scores compared to the pre-operative values for both groups (P < 0.005). However, there was a greater improvement in the flow rate and symptom score in patients undergoing KTP BNI and ELAP (P < 0.05). CONCLUSION: This study shows the benefit of performing a KTP BNI with ELAP in terms of early voiding rates and initial clinical outcome, and this treatment is recommended.

Aged↗

PubMed2000

Does endoscopic laser ablation of the prostate stand the test of time? Five-year results from a multicentre randomized controlled trial of endoscopic laser ablation against transurethral resection of the prostate.

OBJECTIVE: To determine the long-term objective and subjective outcome of patients with benign prostatic enlargement (BPE) treated by endoscopic laser ablation of the prostate (ELAP), as part of a multicentre randomized controlled trial of ELAP against TURP. PATIENTS AND METHODS: Initially, 151 patients with BPE were randomized to undergo either ELAP or TURP, starting in March 1992. ELAP was performed using the Urolasetrade mark fibre (Bard, Covington, GA, USA) in conjunction with a Nd:YAG laser source. All patients who had originally participated in the study were approached 5 years later to obtain a urological history, American Urological Association (AUA) symptom score and two measurements of urinary flow rate, with an ultrasonographic assessment of the postvoid residual urine volume (PVR). RESULTS: The mean duration of follow-up was 61 months; 109 patients were traced, comprising 69 who were alive and well, and had undergone no further bladder outlet surgery, 26 who had required revision surgery, 12 who were dead or terminally ill and three who had dementia. Both ELAP and TURP produced sustained improvements in mean AUA score, maximum flow rate and PVR, with respective values at 5 years of 6.3, 17.8 mL/s and 76 mL, and 6.5, 20.0 mL/s and 55 mL. Eighteen of 47 ELAP patients (38%) and eight of 51 (16%) TURP patients underwent revision surgery within the follow-up. CONCLUSION: ELAP and TURP produced similar subjective and objective outcomes at 5 years. The re-operation rate after ELAP was more than double that after TURP and suggests that ELAP should not be used routinely in the management of men with BPE.

Endoscopy↗

PubMed1998

[Laser-tyndallometry in eyes with acute retinal necrosis syndrome. Erlanger Laser-tyndallometry study group].

PURPOSE: Acute retinal necrosis syndrome (ARN) is a rapidly progressive viral necrotic retinitis. We used noninvasive measurement of aqueous flare to quantify blood-ocular barrier breakdown in eyes with ARN und to follow the inflammatory activity and treatment effects. PATIENTS AND METHODS: We report on seven patients (5 males und 2 females, age: 16 to 57 years) with ARN that were treated in our institution between 1991 to 1996. Aqueous flare was quantified regularly during treatment using the laser flare-cell meter (Kowa, FC-1000) following pupillary dilation. RESULTS: Aqueous flare was highly significantly increased in eyes with ARN (145.5 +/- 139.7, range 30 to 367 photon counts/ms). Contralateral, unaffected eyes showed normal flare values (3.6 +/- 0.8 photon counts/ms, p < 0.0001; normals: 4.1 +/- 1.1 photon counts/ms). Flare values correlated with inflammatory activity before and during antiviral treatment. In two patients with ARN caused by herpes simplex-virus aqueous flare values were extremely increased (367 and 316 photon counts/ms), and retinal necrosis was rapidly progressive despite antiviral therapy. One patient developed early ARN in his contralateral eye with flare values increasing from 3.5 to 22.0 photon counts/ms, which quickly normalized following antiviral treatment. CONCLUSIONS: Measurement with the laser flare-cell meter allows quantification of blood-ocular barrier breakdown in eyes with ARN und may be useful for monitoring inflammatory activity during treatment.

Adolescent↗

PubMed1995

[Are we measuring the right intraocular pressure after excimer laser photorefractive laser keratoplasty in myopia?].

BACKGROUND: It is possible that the traditional method to determine the intraocular pressure after excimer-laser PRK is inaccurate. Measuring the pressure in the temporal part of the cornea might give the true values. METHODS: Intraocular pressure was measured with a Goldmann Applanation Tonometer and with the Tonopen, before and after PRK for myopia in the central and in the temporal parts of the cornea. The paired student t-test was used for statistical analysis. RESULTS: The results of central and temporal measurements before treatment were identical with both instruments. After PRK, central values were 2 to 3 mm Hg lower than temporal values when measured with a Goldmann Tonometer, and about 2 mm lower when measured with the Tonopen. The differences were highly significant (p < 0.0001 and p = 0.004 respectively). CONCLUSIONS: The intraocular pressure measured in the usual manner after excimer-laser PRK is lower than the temporally measured pressure. These differences could be caused by absence of the Bowman's membrane, thinning of the cornea and/or change of its topography.

Cornea↗

PubMed1989

[A modified laser system for laser angioplasty using a sapphire tip].

This study deals with 26 patients on whom successful laser angioplasty of peripheral vascular occlusions had been carried out, using an Nd-YAG high energy laser system (100 watts) with a sapphire point. The technical requirements are presented and the primary success and complication rates in our material are discussed.

Angioplasty, Balloon↗