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Sample records for in-situ keratomileusis lasik

  1. Traumatic corneal flap displacement after laser in situ keratomileusis (LASIK

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    Tsai TH

    2017-04-01

    Full Text Available Tsung-Han Tsai,1 Kai-Ling Peng,1 Chien-Jen Lin2 1Department of Ophthalmology, 2Department of Radiology, Chi Mei Medical Center, Tainan, Taiwan Background: Laser in situ keratomileusis (LASIK is the most common and popular procedure performed for the correction of refractive errors in the last two decades. We report a case of traumatic flap displacement with flap folding which occurred 3 years after LASIK was performed. Previous literature suggests that vision prognosis would be closely related to proper and prompt management of traumatic flap displacement with flap folding 3 years after LASIK.Case presentation: A 23-year-old female presented to our hospital who had undergone uneventful LASIK in both eyes 3 years prior. Unfortunately, she had suffered a blunt trauma in her right eye in a car accident. A late onset of corneal flap displacement was found with upper and lower portion of the flap being folded inside the corneal bed. Surgical intervention for debridement with subsequent reposition of corneal flap was performed as soon as possible in the operating room. A bandage contact lens was placed, and topical antibiotic and corticosteroids were given postoperatively. Two days after the operation, the displaced corneal flap was found to be well attached smoothly on the corneal bed without folds. The best-corrected visual acuity was 6/6 with refraction of −0.75 D to 1.0 D ×175° in her right eye 1 month later.Literature review: We reviewed a total of 19 published cases of late-onset traumatic flap dislocations or displacements after LASIK with complete data from 2000 to 2014.Conclusion: Traumatic displacement of corneal flaps after LASIK may occur after blunt injury with specific direction of force to the flap margin, especially tangential one. According to the previous literature, late-onset traumatic flap displacement may happen at any time after LASIK and be caused by various types of injuries. Fortunately, good visual function could

  2. Diplopia after laser in situ keratomileusis (LASIK) in a patient with a history of strabismus.

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    Heinmiller, Laura J; Wasserman, Barry N

    2013-02-01

    In patients with a history of strabismus, refractive surgery can result in decompensation of ocular alignment, with subsequent diplopia. Refractive surgery in the management of strabismus has been described, although it remains controversial. We present a young adult with past history of strabismus surgery and new-onset diplopia after refractive surgery. Binocular diplopia was treated surgically with laser in situ keratomileusis.

  3. Ceratite por Staphylococcus aureus após ceratomileuse in situ por laser (LASIK: relato de caso Staphylococcus aureus keratitis following laser in situ keratomileusis: case report

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    Alessandra Pinheiro Chaves

    2000-04-01

    Full Text Available Objetivo: Relatar um caso clínico de infecção por S. aureus no pós- operatório de LASIK, o tratamento adotado e a evolução clínica. Relato do caso: Paciente de 26 anos, masculino, submetido a LASIK tórico em OE, evoluindo com ceratite por S. aureus. Após diagnóstico clínico da infecção, realizamos estudo microbiológico e foi instituída a terapêutica adequada. O paciente evoluiu com recuperação da transparência corneana e acuidade visual 20/25, sem correção. Discussão: Infecção no pós-operatório de LASIK, quando diagnosticada precocemente e tratada adequadamente, pode evoluir sem maiores complicações e sem comprometimento visual significativo.Purpose: To report a case of S. aureus keratitis after laser in situ keratomileusis, the management and the outcome. Case report: 26-year-old male underwent toric LASIK OS, evoluing with S. aureus keratitis. After a clinical hypothesis of infection, we performed corneal scrape for lab analysis and proper treatment was given. After successful treatment, the patient showed an improvement in corneal transparency and recovered his visual acuity. Discussion: Infections following laser in situ keratomileusis may not produce visual loss if proper treatment is given.

  4. Confocal comparison of corneal reinnervation after small incision lenticule extraction (SMILE and femtosecond laser in situ keratomileusis (FS-LASIK.

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    Meiyan Li

    Full Text Available PURPOSE: To evaluate corneal reinnervation, and the corresponding corneal sensitivity and keratocyte density after small incision lenticule extraction (SMILE and femtosecond laser in situ keratomileusis (FS-LASIK. METHODS: In this prospective, non-randomized observational study, 18 patients (32 eyes received SMILE surgery, and 22 patients (42 eyes received FS-LASIK surgery to correct myopia. The corneal subbasal nerve density and microscopic morphological changes in corneal architecture were evaluated by confocal microscopy prior to surgery and at 1 week, 1 month, 3 months, and 6 months after surgery. A correlation analysis was performed between subbasal corneal nerve density and the corresponding keratocyte density and corneal sensitivity. RESULTS: The decrease in subbasal nerve density was less severe in SMILE-treated eyes than in FS-LASIK-treated eyes at 1 week (P = 0.0147, 1 month (P = 0.0243, and 3 months (P = 0.0498, but no difference was detected at the 6-month visit (P = 0.5277. The subbasal nerve density correlated positively with central corneal sensitivity in both groups (r = 0.416, P<0.0001, and r = 0.2567, P = 0.0038 for SMILE group and FS-LASIK group, respectively. The SMILE-treated eyes have a lower risk of developing peripheral empty space with epithelial cells filling in (P = 0.0005. CONCLUSIONS: The decrease in subbasal nerve fiber density was less severe in the SMILE group than the FS-LASIK group in the first 3 months following the surgeries. The subbasal nerve density was correlated with central corneal sensitivity.

  5. A PRELIMINARY STUDY FOR SIX SIGMA IMPLEMENTATION IN LASER IN SITU KERATOMILEUSIS (LASIK SURGERIES

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    Mehmet Tolga Taner

    2014-01-01

    Full Text Available The purpose of this study is to show how a private eye care center in Turkey developed a Six Sigma infrastructure to investigate the root causes of complications occuring during LASIK surgeries. To analyze the collected data, main tools of Six Sigma’s Define-Measure-Analyze-Improve-Control(DMAIC improvement cycle such as SIPOC table, Fishbone Diagram and, Failure, Mode and Effect Analysis were implemented. Experience of the refractive surgeons, type of microkeratome and hygiene of microkeratome were identified to be Critical-to-Quality (CTQ factors for a successful LASIK surgery. The most frequent complications of LASIK surgeries were found to be dry eye syndrome, subconjunctival haemorrhage and flap edge melt. The process sigma level was found to be 3.7135.

  6. Wavefront-Guided Laser in Situ Keratomileusis (Lasik) versus Wavefront-Guided Photorefractive Keratectomy (Prk): A Prospective Randomized Eye-to-Eye Comparison (An American Ophthalmological Society Thesis)

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    Manche, Edward E.; Haw, Weldon W.

    2011-01-01

    Purpose To compare the safety and efficacy of wavefront-guided laser in situ keratomileusis (LASIK) vs photorefractive keratectomy (PRK) in a prospective randomized clinical trial. Methods A cohort of 68 eyes of 34 patients with −0.75 to −8.13 diopters (D) of myopia (spherical equivalent) were randomized to receive either wavefront-guided PRK or LASIK in the fellow eye using the VISX CustomVue laser. Patients were evaluated at 1 day, 1 week, and months 1, 3, 6, and 12. Results At 1 month, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), 5% and 25% contrast sensitivity, induction of higher-order aberrations (HOAs), and subjective symptoms of vision clarity, vision fluctuation, ghosting, and overall self-assessment of vision were worse (P0.05). At 1 year, mean spherical equivalent was reduced 94% to −0.27 ± 0.31 D in the LASIK group and reduced 96% to −0.17 ± 0.41 D in the PRK group. At 1 year, 91% of eyes were within ±0.50 D and 97 % were within ±1.0 D in the PRK group. At 1 year, 88% of eyes were within ±0.50 D and 97% were within ±1.0 D in the LASIK group. At 1 year, 97% of eyes in the PRK group and 94% of eyes in the LASIK group achieved an UCVA of 20/20 or better (P=0.72). Refractive stability was achieved in both PRK and LASIK groups after 1 month. There were no intraoperative or postoperative flap complications in the LASIK group. There were no instances of corneal haze in the PRK group. Conclusions Wavefront-guided LASIK and PRK are safe and effective at reducing myopia. At 1 month postoperatively, LASIK demonstrates an advantage over PRK in UCVA, BSCVA, low-contrast acuity, induction of total HOAs, and several subjective symptoms. At postoperative month 3, these differences between PRK and LASIK results had resolved. PMID:22253488

  7. Analysis on second operation after laser in situ keratomileusis

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    Wen-Xuan Pei

    2015-07-01

    Full Text Available AIM: To observe clinical effects between the laser in situ keratomileusis(LASIKsurgery and the laser subepithelial keratomileusis(LASEKsurgery as the second operation after an unsuccessful LASIK surgery. METHODS:Forty-nine patients(98 eyeswith refractive regression after LASIK operation received the second surgery. All patients were divided into two groups: group A and B. Group A(48 eyes of 24 patientsreceived LASIK surgery and group B(50 eyes of 25 patientsreceived LASEK surgery. Inspect the main parameters included visual acuity, refraction, corneal curvature, and the total value of high-aberration after 1wk, 1mo and 1a, t-test of groups was used as statistical analysis method.RESULTS: There was statistically significant(PP>0.05. There developed one case of epithelium in growth after LASIK surgery, and one case of haze Ⅱ after LASEK surgery. CONCLUSION: Both LASIK and LASEK surgery can obtain satisfactory therapeutic results after an unsuccessful LASIK surgery.

  8. Small Incision Lenticule Extraction (SMILE versus Femtosecond Laser-Assisted In Situ Keratomileusis (FS-LASIK for Myopia: A Systematic Review and Meta-Analysis.

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    Zeren Shen

    Full Text Available The goal of this study was to compare small incision lenticule extraction (SMILE with femtosecond laser-assisted in situ keratomileusis (FS-LASIK for treating myopia.The CENTRAL, EMBASE, PubMed databases and a Chinese database (SinoMed were searched in May of 2016. Twelve studies with 1,076 eyes, which included three randomized controlled trials (RCTs and nine cohorts, met our inclusion criteria. The overall quality of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE working group framework. Data were extracted and analysed at three to six months postoperatively. Primary outcome measures included a loss of one or more lines of best spectacle corrected visual acuity (BSCVA, uncorrected visual acuity (UCVA of 20/20 or better, mean logMAR UCVA, postoperative mean spherical equivalent (SE and postoperative refraction within ±1.0 D of the target refraction. Secondary outcome measures included ocular surface disease index (OSDI, tear breakup time (TBUT and Schirmer's 1 test (S1T as dry eye parameters, along with corneal sensitivity.The overall quality of evidence was considered to be low to very low. Pooled results revealed no significant differences between the two groups with regard to a loss of one or more lines in the BSCVA (OR 1.71; 95% CI: 0.81, 3.63; P = 0.16, UCVA of 20/20 or better (OR 0.71; 95% CI: 0.44, 1.15; P = 0.16, logMAR UCVA (MD 0.00; 95% CI: -0.03, 0.04; P = 0.87, postoperative refractive SE (MD -0.00; 95% CI: -0.05, 0.05; P = 0.97 or postoperative refraction within ±1.0 D of the target refraction (OR 0.78; 95% CI: 0.22, 2.77; P = 0.70 within six months postoperatively. The pooled analysis also indicated that the FS-LASIK group suffered more severely from dry eye symptoms (OSDI; MD -6.68; 95% CI: -11.76, -2.00; P = 0.006 and lower corneal sensitivity (MD 12.40; 95% CI: 10.23, 14.56; P < 0.00001 at six months postoperatively.In conclusion, both FS-LASIK and SMILE are safe

  9. Uncorrected and Corrected Distance Visual Acuity, Predictability, Efficacy, and Safety after Femtosecond Laser in Situ Keratomileusis (FS-LASIK) and Refractive Lenticule extraction (ReLEx) for Moderate and High Myopia

    DEFF Research Database (Denmark)

    Vestergaard, Anders; Justesen, Birgitte Larsen; Melsen, Charlotte

    of Ophthalmology, Odense University Hospital, Denmark. Purpose: ReLEx is a relative new corneal refractive procedure, where a stromal lenticule is cut by a femtosecond laser and manually extracted. The purpose of this study was to compare uncorrected and corrected distance visual acuity (UDVA and CDVA), refractive......Title: Uncorrected and Corrected Distance Visual Acuity, Predictability, Efficacy, and Safety after Femtosecond Laser in Situ Keratomileusis (FS-LASIK) and Refractive Lenticule extraction (ReLEx) for Moderate and High Myopia. Vestergaard A., Justesen B., Melsen C., Lyhne N., Department...... and ReLEx treatments were made with a VisuMax® femto-second laser (Carl Zeiss-Meditec, Jena, Germany). In FS-LASIK, the photoablation was performed with a MEL-80 flying spot excimer laser (Carl Zeiss-Meditec, Jena, Germany). In ReLEx, lenticule diameter was 6.50 mm, whereas the FS-LASIK ablation zone...

  10. Small Incision Lenticule Extraction (SMILE) vs. Femtosecond Laser in Situ Keratomileusis (FS-LASIK) for treatment of myopia

    DEFF Research Database (Denmark)

    Hansen, Rasmus Søgaard; Lyhne, Niels; Justesen, Birgitte

    having undergone re-treatment. The SMILE treatments and FS-LASIK flaps were performed with a VisuMax® femtosecond laser (Carl Zeiss-Meditec, Jena, Germany). The FS-LASIK photoablation was performed with a MEL-80 flying-spot excimer laser with eye-tracker (Carl Zeiss-Meditec, Jena, Germany). In SMILE...... of myopia. All treatments were performed at the Department of Ophthalmology, Odense University Hospital from April 2011 to December 2013. Inclusion criteria: CDVA ≤ 0.10 (logMAR) before surgery and no other ocular conditions than myopia with or without astigmatism of maximum 3 D. Exclusion criteria: Eyes...

  11. Small Incision Lenticule Extraction (SMILE) vs. Femtosecond Laser in Situ Keratomileusis (FS-LASIK) for treatment of myopia

    DEFF Research Database (Denmark)

    Hansen, Rasmus Søgaard; Justesen, Birgitte; Lyhne, Niels

    re-treatment. The SMILE treatments and FS-LASIK flaps were performed with a VisuMax® femtosecond laser (Carl Zeiss-Meditec, Jena, Germany). The FS-LASIK photoablation was performed with a MEL-80 flying-spot excimer laser with eye-tracker (Carl Zeiss-Meditec, Jena, Germany). In SMILE, lenticule...... treatments were performed at the Department of Ophthalmology, Odense University Hospital from April 2011 to December 2013. Inclusion criteria: CDVA ≤ 0.10 (logMAR) before surgery and no other ocular conditions than myopia with or without astigmatism of maximum 3 D. Exclusion criteria: Eyes having undergone...

  12. Retinal detachment after laser In Situ keratomileusis

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    Saba Al-Rashaed

    2011-01-01

    Full Text Available Purpose : To report characteristics and outcome of rhegmatogenous retinal detachment (RRD after laser in situ keratomileusis (LASIK for myopia. Materials and Methods : A retrospective chart review of patients who presented with RRD after myopic LASIK over a 10-year period. Results : Fourteen eyes were identified with RRD. Of these, two of 6112 LASIK procedures were from our center. The mean age of patients with RRD was 35.43 years. The mean interval of RRD after LASIK was 37.71 months (range, 4 months to 10 years. The macula was involved in eight eyes and spared in six eyes. Retinal breaks included a macular hole in two eyes, and giant tear in two eyes. Multiple breaks (>2 breaks occurred in 6 cases. Pars plana vitrectomy (PPV was performed in 3 (21.4% eyes, a scleral buckle (SB was performed in 4 (28.5% eyes and 7 (50% eyes underwent combined PPV and SB. Mean follow-up was 15.18 months (range, 1 month to 7 years. The retina was successfully attached in all cases. The final visual acuity was 20/40 or better in 7 (50% eyes, 20/40 to 20/60 in 4 (28.5% eyes, and 20/200 or less in 3 (21.4% eyes. Poor visual outcome was secondary to proliferative vitreoretinopathy, epiretinal membrane, macular scar and amblyopia. Conclusion : The prevalence of RRD after LASIK was low at our institute. Anatomical and visual outcomes were acceptable in eyes that were managed promptly. Although there is no cause-effect relationship between LASIK and RRD, a dilated fundus examination is highly recommended before and after LASIK for myopia.

  13. Diffuse lamellar keratitis associated with iritis 10 months after laser in situ keratomileusis.

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    Keszei, V A

    2001-07-01

    A 35-year-old man developed diffuse lamellar keratitis (DLK) 10 months after laser in situ keratomileusis (LASIK). The DLK was associated with acute iritis, not with manipulation of the LASIK flap or epithelium. This case supports the hypothesis that DLK is a nonspecific inflammatory response of the cornea rather than a specific agent causing the syndrome.

  14. Fibrinous anterior uveitis following laser in situ keratomileusis

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    Parmar Pragya

    2009-01-01

    Full Text Available A 29-year-old woman who underwent laser in situ keratomileusis (LASIK for myopic astigmatism in both eyes presented with severe pain, photophobia and decreased visual acuity in the left eye eight days after surgery. Examination revealed severe anterior uveitis with fibrinous exudates in the anterior chamber, flap edema and epithelial bullae. Laboratory investigations for uveitis were negative and the patient required systemic and intensive topical steroids with cycloplegics to control the inflammation. This case demonstrates that severe anterior uveitis may develop after LASIK and needs prompt and vigorous management for resolution.

  15. Bilateral Simultaneous Rhegmatogenous Retinal Detachment following Laser in situ Keratomileusis

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    Erhan Yumusak

    2016-06-01

    Full Text Available A 21-year-old woman developed simultaneous rhegmatogenous retinal detachment after laser in situ keratomileusis (LASIK in both eyes. She underwent pars plana vitrectomy surgery combined with endolaser photocoagulation and silicone oil tamponade in the right eye. A week later, pneumatic retinopexy was done in the left eye. As the retinal tear did not seal, 360° scleral buckling surgery was performed and retina was attached. Bilateral simultaneous rhegmatogenous retinal detachment after LASIK for correction of myopia can be a serious complication. Patients should be informed about the possibility of this complication.

  16. Utilização da tecnologia de freqüência duplicada em pacientes submetidos a "laser assisted in situ keratomileusis" (LASIK: análise de custo-benefício

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    Duarte Fernanda Bon

    2003-01-01

    Full Text Available OBJETIVO: Verificar existência de alteração funcional das células magnocelulares por meio da tecnologia de freqüência duplicada (FDT, após o incremento de pressão gerado pela técnica de "laser assisted in situ keratomileusis" (LASIK, e avaliar os benefícios de realizar este em pacientes candidatos à cirurgia refrativa, considerando-se os custos envolvidos nos procedimentos. MÉTODOS: Estudo prospectivo em 19 pacientes com ametropias, submetidos à cirurgia "laser assisted in situ keratomileusis", no Hospital Oftalmológico de Sorocaba. Foram realizados 2 exames de tecnologia de freqüência duplicada em ambos os olhos dos pacientes antes da cirurgia por "laser assisted in situ keratomileusis", e um exame após a cirurgia. A avaliação da diferença entre as medidas de MD ("mean deviation" e PSD ("pattern standard deviation" efetuadas pela tecnologia de freqüência duplicada antes e depois da cirurgia refrativa foram avaliadas por meio do teste de t pareado. A diferença entre as medidas de MD (Delta MD foi considerada variável dependente para elaborações de uma avaliação de regressão múltipla. Foi realizada uma análise de custos do exame de tecnologia de freqüência duplicada e da cirurgia "laser assisted in situ keratomileusis". RESULTADOS: Não houve diferença entre as medidas de MD no exame de tecnologia de freqüência duplicada antes e após o procedimento (p= 0,4454 assim como para PSD (p= 0,9716. Nenhuma variável contínua testada influiu significantemente no Delta MD (r²= 4,1%; F= 0,15; p= 0,960. Considerando a realização de 1500 cirurgias de "laser assisted in situ keratomileusis" ao ano no Hospital Oftalmológico de Sorocaba, o custo médio desta cirurgia é de R$ 373,27 e o custo do exame de tecnologia de freqüência duplicada é de R$ 13,15 por paciente. CONCLUSÕES: Não houve diferença estatisticamente significante entre as medidas de MD no exame de tecnologia de freqüência duplicada antes e após o

  17. A prospective, randomized, fellow eye comparison of WaveLight® Allegretto Wave ® Eye-Q versus VISX CustomVue™ STAR S4 IR™ in laser in situ keratomileusis (LASIK): analysis of visual outcomes and higher order aberrations.

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    Moshirfar, Majid; Betts, Brent S; Churgin, Daniel S; Hsu, Maylon; Neuffer, Marcus; Sikder, Shameema; Church, Dane; Mifflin, Mark D

    2011-01-01

    To compare outcomes in visual acuity, refractive error, higher-order aberrations (HOAs), contrast sensitivity, and dry eye in patients undergoing laser in situ keratomileusis (LASIK) using wavefront (WF) guided VISX CustomVue and WF optimized WaveLight Allegretto platforms. In this randomized, prospective, single-masked, fellow eye study, LASIK was performed on 44 eyes (22 patients), with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Postoperative outcome measures at 3 months included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, root-mean-square (RMS) value of total and grouped HOAs, contrast sensitivity, and Schirmers testing. Mean values for UDVA (logMAR) were -0.067 ± 0.087 and -0.073 ± 0.092 in the WF optimized and WF guided groups, respectively (P = 0.909). UDVA of 20/20 or better was achieved in 91% of eyes undergoing LASIK with both lasers while UDVA of 20/15 or better was achieved in 64% of eyes using the Allegretto platform, and 59% of eyes using VISX CustomVue (P = 1.000). In the WF optimized group, total HOA increased 4% (P = 0.012), coma increased 11% (P = 0.065), and spherical aberration increased 19% (P = 0.214), while trefoil decreased 5% (P = 0.490). In the WF guided group, total HOA RMS decreased 9% (P = 0.126), coma decreased 18% (P = 0.144), spherical aberration decreased 27% (P = 0.713) and trefoil decreased 19% (P = 0.660). One patient lost one line of CDVA secondary to residual irregular astigmatism. Both the WaveLight Allegretto and the VISX CustomVue platforms had equal visual and safety outcomes. Most wavefront optimized HOA values trended upward, with a statistically significant increase in total HOA RMS. Eyes treated with the WF guided platform showed a decreasing trend in HOA values.

  18. Laser in situ keratomileusis flap stability in an aviator following aircraft ejection.

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    Richmond, Christopher J; Barker, Patrick D; Levine, Edgar M; Hofmeister, Elizabeth M

    2016-11-01

    We present the case of a 28-year-old male F/A-18F Super Hornet naval flight officer who ejected from an aircraft at 13 000 feet at a speed in excess of 350 knots 7 years after uneventful laser in situ keratomileusis (LASIK). The patient was evaluated the day after the ejection. No LASIK flap complications or epithelial defects were found, and the corrected distance visual acuity was 20/15 in both eyes.

  19. Spontaneous, uncomplicated dissolution of a large cotton fiber in the laser in situ keratomileusis interface

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    Gaurav Prakash

    2012-01-01

    Full Text Available In this article, we report the spontaneous dissolution of a long cotton thread in the laser in situ keratomileusis (LASIK flap interface. In this observational case report, sequential follow-up of a post-LASIK eye with a long cotton fiber noticed in the LASIK interface was performed. The postoperative course was uneventful, with no evidence of infection, uveitis, or any other complications. The cotton thread underwent spontaneous dissolution. Conservative management of a cotton fiber, not causing any symptoms and noticed after the immediate postoperative follow-up period is over, seems to be a possible alternative to flap relift and intervention.

  20. Antiglaucoma drugs for achieving monovision after laser in situ keratomileusis

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    Kazutaka Kamiya

    2009-02-01

    Full Text Available Kazutaka Kamiya, Kimiya ShimizuDepartment of Ophthalmology, University of Kitasato School of Medicine, JapanAbstract: We report on a patient in whom the use of antiglaucoma drugs has been beneficial for the attainment of monovision after laser in situ keratomileusis (LASIK. A 57-year-old woman undergoing LASIK complained of blurred vision in the right eye. After a successful trial of monovision with contact lenses, antiglaucoma drugs (2.5% nipradilol were administered topically to the right eye twice a day to establish monovision. In the right eye, the manifest refraction was changed from −4.0, −1.0 × 80, with an uncorrected visual acuity (UCVA of 0.3 for near vision before treatment, to −2.5, −1.0 × 80, with an UCVA of 0.9 for near vision after treatment, while, in the left eye, it was 0, −1.0 × 100, with an UCVA of 0.9 for far vision. Binocular UCVA was improved from 0.3 for near and 0.9 for distance vision before treatment, to 0.9 for near and 1.0 for distance vision after treatment. No complications were observed and the manifest refraction remained stable during the 6-month follow-up period. The use of antiglaucoma drugs may be helpful for the achievement of monovision by reduction of myopic regression after LASIK.Keywords: antiglaucoma drugs, regression, monovision, LASIK

  1. 飞秒激光制作角膜瓣的激光角膜原位磨镶术的临床观察%Clinical observation of laser in situ keratomileusis (LASIK) with corneal flap created by femtosecond laser

    Institute of Scientific and Technical Information of China (English)

    李春燕; 李志华; 尹海泉

    2011-01-01

    目的 探讨应用飞秒激光制作角膜瓣的准分子激光角膜原位磨镶术(LASIK)的安全性、有效性和可预测性.方法 应用VISX Star S4准分子激光设备和Intralase飞秒激光仪,对屈光不正512例(1016眼)施行飞秒激光制作角膜瓣的LASIK手术.术后随访6~12个月,裂隙灯显微镜及角膜地形图仪检查角膜及角膜屈光改变情况.结果 术后6个月的屈光状态,(等效球镜)为(1.00D~+1.25D),平均为(-0.25±0.75D).923眼(90.85%)的裸眼视力大于或等于1.0,l002眼(98.62%)的裸眼视力等于或超过术前最佳矫正视力.术前与术后结果行t检验显示,二者差异有统计学意义(P<0.01).术中并发症有结膜下出血57眼(5.61%),未见其他并发症.结论 应用飞秒激光制作角膜瓣的LASIK手术是矫正屈光不正的安全和有效的方法,可预测性好.%Objective To investigate the safety, predictability and effectiveness of laser in situ keratomileusis (LASIK) with laser flap created by femtosecond laser. Methods 1016 eyes of 512 patients with refractive error received LASIK with vlSX Star S4 excimer laser system and Intralase femtosecond laser. The period of follow-up ranged from 6 to 12 months. The transparency of cornea and the refractive changes after surgery were examined by slit-lamp microscope and corneal topographic device. Results At 6 months after operation,the mean residual spheroequivalent of refraction was ( - 0.25±0.75 ) D ( range - 1.00D to +1.25D). 923 eyes (90.85%) had uncorrected visual acuity of 1.0 or better, 1002 eyes (98.62%) had uncorrected visual acuity equal to or better than preoperative best corrected visual acuity. The intraoperative complication was subconjunctival hemorrhage (57 eyes, 5.61% ) , and no other complications were found.Conclusion LASIK with corneal flap created by femtosecond laser is a safe and effective procedure for the correction of refractive error. It has good predictability.

  2. O impacto da cirurgia de ceratectomia fotorrefrativa (PRK e ceratomileuse assistida por excimer laser in situ (LASIK na qualidade visual e de vida em pacientes com ametropias The impact of photorefractive excimer laser keratectomy (PRK and laser in situ keratomileusis (LASIK on visual quality and life in patients with ametropias

    Directory of Open Access Journals (Sweden)

    Ricardo Belfort

    2008-02-01

    significantemente para melhor em relação ao préoperatório, com redução substancial do estresse psicológico.PURPOSE: To evaluate the quality of life, vision and stress before and after refractive surgery. METHODS: This is a longitudinal, observational study, where 100 patients were evaluated; 54 espectacles wearers, 21 contact lens users before surgery and 25 controls wearers spectacles or contact lenses, who did not want to undergo refractive surgery during one year despite refractive error. The applied questionnaires were Self Reporting Questionnaires SRQ-20 of quality of life and vision and National Eye Institute Visual Function Questionnaire NEI VFQ-25 for the assessment of mental health. The intervention group answered the questionnaires before surgery, three, six and twelve months after follow-up and the control group answered the questionnaires at six and twelve months after the baseline. The questionnaires of the intervention group were applied by an independent person. RESULTS: In the intervention group (54 spectacle wearers, 39 were treated by photorefractive excimer laserkeratectomy (PRK and 15 by laser in situ keratomileusis (LASIK, of the 21 contact lens users: 12 received photorefractive excimer laser keratectomy and nine were treated by laser in situ keratomileusis (LASIK. The control group remained stable during the study. After three months of follow-up the intervention group showed improvement in quality of life, vision and reduction of stress. After one year of follow-up the assessments of quality of life and mental health were similar to the control group. After three months there was a significant reduction of psychiatric symptomatology in the intervention group. CONCLUSION: Patients operated for correction of ametropia showed a significant improvement in quality of life and mental health assessments.

  3. Review of current indications for combined very high fluence collagen cross-linking and laser in situ keratomileusis surgery

    Directory of Open Access Journals (Sweden)

    Anastasios John Kanellopoulos

    2013-01-01

    Full Text Available In this brief review we will discuss the reasoning and evolution of our current use of combined very high-fluence collagen crosslinking and laser in situ keratomileusis. Several presentations and pertinent publications are reviewed, along with the key steps of the enhanced LASIK procedure. Long term outcome data support the safety and efficacy of LASIK Xtra in stabilizing myopic but also hyperopic LASIK results.In conclusion, we have compelling evidence that LASIK Xtra is a safe and effective adjunct.

  4. Complicações per e pós-operatórias em 1000 olhos submetidos a LASIK An analysis of intraoperative and postoperative complications in 1000 laser in situ keratomileusis cases

    Directory of Open Access Journals (Sweden)

    Telma Pereira

    2001-11-01

    Full Text Available Objetivo: Analisar a incidência, tipo, tratamento e evolução das complicações em LASIK. Métodos: Estudo retrospectivo de 1000 olhos submetidos a LASIK usando os microceratótomos Hansatome® ou Automated Corneal Shaper® e os aparelhos de Excimer Laser VISX 20/20B ou Chiron Technolas 217C. Complicações peroperatórias e pós-operatórias precoces e tardias foram analisadas. Resultados: A média do equivalente esférico pré-operatório foi de -4,29 ± 3,20D. A média do seguimento foi de 6,05 ± 6,69 meses. No período peroperatório foram encontradas cinco (0,5% complicações do disco relacionadas ao microceratótomo (3 discos finos, 1 disco com perfuração central e 1 disco pequeno. As complicações mais freqüentes no período pós-operatório precoce foram as dobras de disco (6,4%, seguidas de debris na interface (4,1%, ceratite não específica da interface (1,1%, "haze" (0,4%, crescimento epitelial da interface (0,4% e deslocamento de disco (0,3%. A maioria destes eventos foi prontamente tratada, alcançando-se bons resultados. Para as complicações tardias, relacionadas à refração, foram analisados 655 olhos que apresentavam seguimento mínimo de 3 meses. No último exame, a média do equivalente esférico neste grupo foi de -0,26±0,76D. Oito por cento dos olhos encontravam-se com hipocorreção superior a 1,00D; e 1,67% com hipercorreção > 1,00D. Retratamento foi necessário em 28 olhos (4,27%. Cinco casos (0,76% perderam de 2 ou mais linhas da melhor acuidade visual corrigida. Não foram observadas outras complicações visualmente importantes. Conclusão: LASIK é um procedimento refrativo seguro e com poucas complicações.Purpose: To analyze the incidence, type, management and evolution of complications in laser in situ keratomileusis (LASIK. Methods: Retrospective non-comparative case series. LASIK was performed in 1000 eyes using the Hansatome® or the Automated Corneal Shaper® microkeratomes, and the VISX 20/20B

  5. Variation of contrast sensitivity after femtosecond laser in situ keratomileusis in changes environments

    Directory of Open Access Journals (Sweden)

    Jing Zhou

    2015-01-01

    Full Text Available AIM: To evaluate the difference of contrast sensitivity(CSin photopic and scotopic environments in eyes with myopia and myopic astigmatism operated with femtosecond laser in situ keratomileusis(femto-LASIKand laser in situ keratomileusis(LASIK.METHODS: In a prospective study 160 myopia and myopic astigmatism patients' eyes were involved, which accepted femto-LASIK or LASIK in our hospital from January 2010 to February 2012. The myopia degree was -1.50~-10.00D, the astigmatism degree ≤-6.0D. Eighty eyes were treated with femto-LASIK in group A, and 80 eyes were treated with LASIK in group B, All patients in the treatment group completed the final 6mo of follow-up. The uncorrected visual acuity(UCVAand the best spectacle-corrected visual acuity(BSCVA, objective and manifest refractions, results of slit-lamp examination, the side effects, intraocular pressure, corneal topography, CS in photopic and scotopic environments were noted.RESULTS: All of operations on 160 cases were successful without severe complication after 6 mo follow-up. CS of femto-LASIK group(group Aat each spatial frequency environment were higher than that of LASIK group(group B. In group A, after 1mo the photopic CS, after 3mo of scotopic CS recovered to the preoperative level, 6mo after surgery improved than before the operation. In group B, after 3mo photopic CS to the preoperative level, scotopic CS at 6mo after operation was still not recovered to the preoperative level.CONCLUSION:Femto-LASIK for correction of myopia and myopic astigmatism, in improving the postoperative contrast sensitivity under shade environment has more advantages than LASIK.

  6. Microcapillary sign of flap alignment in femtosecond laser-assisted in situ keratomileusis

    Science.gov (United States)

    Fawzy, Fathy; Wahba, Sherine S; Fawzy, Nader

    2016-01-01

    We present an observational sign that ensures perfect alignment during femtosecond laser-assisted in situ keratomileusis (FS LASIK). Alignment is assured when a microsponge is used to dry the flap and the area of dryness exceeds the area of direct touch of the microsponge. The area might even reach the whole circumference of the flap at the first touch. This sign of alignment can be explained by microcapillary action. This sign was not elicited in flaps created by a microkeratome. PMID:27799731

  7. Keratectasia after laser in situ keratomileusis. Clinicopathological case report.

    Science.gov (United States)

    Kim, Hyojin; Song, In Kyung; Joo, Choun-Ki

    2006-01-01

    To describe the morphological features of a prominent ectasia of the cornea after laser in situ keratomileusis (LASIK). The morphology of the ectatic corneas was examined using corneal topography, light microscopy and transmission electron microscopy in 2 cases who underwent penetrating keratoplasty due to poor visual acuity induced by progressive corneal ectasia after LASIK. On topographic examination, the apex of the corneal surface was observed within the central 3-mm zone, and the smallest thickness was 0.116 and 0.271 mm in each case. On histological examination, the epithelial layer became thinner and detached easily. Bowman's membrane was broken down and folded. An irregular arrangement of the stromal lamellae with fibroblastic keratocytes was found. The fulled fiber cell, a transformed epithelial cell, was visible in a plane on Bowman's layer in the central region. In contrast, the corneal endothelium was intact, and no abnormality was found in both cases. On morphological examination of 2 cases with corneal ectasia, a forward protrusion of both the anterior and posterior corneal surfaces occurred, and epithelial detachment, Bowman's membrane breakage and folding and irregular lamellae were found. The 2 cases had greatly thinned and protruding corneas, yet there was no abnormality in the corneal endothelium. 2006 S. Karger AG, Basel

  8. Laser-Assisted in situ Keratomileusis for Hyperopic Defects

    Directory of Open Access Journals (Sweden)

    Ester Novoa Sánchez

    2014-06-01

    Full Text Available Background: currently, LASIK is one of the most common surgical procedures for refractive disorders, including hyperopic defects. Objective: to assess the results of laser-assisted in situ keratomileusis for the treatment of hyperopic defects. Methods: an ambispective study was conducted in 31 eyes (16 patients operated on for hyperopia and simple and compound hyperopic astigmatism in the Refractive Surgery Unit of the Ophthalmology Department of the Hermanos Ameijeiras Hospital between January 2009 and December 2010. Visual acuity with and without optical correction, spherical and astigmatic component before and after surgery and intra- and postoperative complications were analyzed. Results: patients aged 40 to 49 years predominated; compound hyperopic astigmatism was the most frequent defect; the mean uncorrected visual acuity improved and remained stable up to six months after surgery; the average values were 0.87 for moderate defects and 0.79 for high defects with optical correction. The mean sphero-cylindrical component decreased. The efficacy and safety rates were acceptable for moderate and high degrees of the defects and predictability was 100 % for all degrees of ametropia. Conclusion: LASIK is a safe, effective and predictable procedure to treat patients with moderate and high degrees hyperopia and hyperopic astigmatism.

  9. A prospective, randomized, fellow eye comparison of WaveLight® Allegretto Wave® Eye-Q versus VISX CustomVue™ STAR S4 IR™ in laser in situ keratomileusis (LASIK: analysis of visual outcomes and higher order aberrations

    Directory of Open Access Journals (Sweden)

    Moshirfar M

    2011-09-01

    Full Text Available Majid Moshirfar1, Brent S Betts2, Daniel S Churgin3, Maylon Hsu1, Marcus Neuffer1, Shameema Sikder4, Dane Church5, Mark D Mifflin11John A Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, USA; 2Temple University School of Medicine, Philadelphia, PA, USA; 3University of Arizona College of Medicine – Phoenix, Phoenix, AZ, USA; 4Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; 5Virginia Commonwealth University School of Medicine, Richmond, VA, USAPurpose: To compare outcomes in visual acuity, refractive error, higher-order aberrations (HOAs, contrast sensitivity, and dry eye in patients undergoing laser in situ keratomileusis (LASIK using wavefront (WF guided VISX CustomVue and WF optimized WaveLight Allegretto platforms.Methods: In this randomized, prospective, single-masked, fellow eye study, LASIK was performed on 44 eyes (22 patients, with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Postoperative outcome measures at 3 months included uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, refractive error, root-mean-square (RMS value of total and grouped HOAs, contrast sensitivity, and Schirmers testing.Results: Mean values for UDVA (logMAR were -0.067 ± 0.087 and -0.073 ± 0.092 in the WF optimized and WF guided groups, respectively (P = 0.909. UDVA of 20/20 or better was achieved in 91% of eyes undergoing LASIK with both lasers while UDVA of 20/15 or better was achieved in 64% of eyes using the Allegretto platform, and 59% of eyes using VISX CustomVue (P = 1.000. In the WF optimized group, total HOA increased 4% (P = 0.012, coma increased 11% (P = 0.065, and spherical aberration increased 19% (P = 0.214, while trefoil decreased 5% (P = 0.490. In the WF guided group, total HOA RMS decreased 9% (P = 0.126, coma decreased 18% (P = 0.144, spherical aberration decreased 27% (P = 0.713 and trefoil

  10. Bilateral Iris Atrophy after the Femtosecond Assisted Laser In Situ Keratomileusis Surgery

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    Kenan Olcay

    2015-01-01

    Full Text Available Purpose. To report an unknown complication of laser in situ keratomileusis (LASIK surgery. Case Presentation. A 28-year-old female presented with photophobia and glare to our eye service. She stated in her medical history that she had undergone femtosecond assisted LASIK surgery in both eyes 15 months ago and her symptoms started just after this surgery. On admission, her best-corrected visual acuity was 10/10 in both eyes. She had mydriatic pupils with no direct light reflex. Examination of the anterior segment revealed bilateral iris atrophy projecting within the LASIK ablation zone and a transillumination defect was remarkable on the slit lamp examination. Conclusion. We hypothesized that this condition may have been caused by the abnormally increased IOP that resulted in ischemia in the iris vascular plexus during the suction process of surgery.

  11. Effects of laser in situ keratomileusis on mental health-related quality of life

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    Tounaka-Fujii K

    2016-09-01

    Full Text Available Kaoru Tounaka-Fujii,1 Kenya Yuki,2 Kazuno Negishi,2 Ikuko Toda,3 Takayuki Abe,4 Keisuke Kouyama,4 Kazuo Tsubota2 1Health Center, Keio University, 2Department of Ophthalmology, Keio University School of Medicine, 3Minamiaoyama Eye Clinic, 4Center for Clinical Research, Keio University School of Medicine, Tokyo, Japan Purpose: The aims of our study were to investigate whether laser in situ keratomileusis (LASIK improves health-related quality of life (HRQoL and to identify factors that affect postoperative HRQoL. Materials and methods: A total of 213 Japanese patients who underwent primary LASIK were analyzed in this study. The average age of patients was 35.0±9.4 years. The subjects were asked to answer questions regarding subjective quality of vision, satisfaction, and quality of life (using the Japanese version of 36-Item Short Form Health Survey Version 2 at three time points: before LASIK, 1 month after LASIK, and 6 months after LASIK. Longitudinal changes over 6 months in the outputs of mental component summary (MCS score and the physical component summary (PCS score from the 36-Item Short Form Health Survey Version 2 questionnaire were compared between time points using a linear mixed-effects model. Delta MCS and PCS were calculated by subtracting the postoperative score (1 month after LASIK from the preoperative score. Preoperative and postoperative factors associated with a change in the MCS score or PCS score were evaluated via a linear regression model. Results: The preoperative MCS score was 51.0±9.4 and increased to 52.0±9.8 and 51.5±9.6 at 1 month and 6 months after LASIK, respectively, and the trend for the change from baseline in MCS through 6 months was significant (P=0.03. PCS score did not change following LASIK. Delta MCS was significantly negatively associated with preoperative spherical equivalent, axial length, and postoperative quality of vision, after adjusting for potential confounding factors. Conclusion

  12. Laser in situ keratomileusis in patients with collagen vascular disease: a review of the literature

    Directory of Open Access Journals (Sweden)

    Simpson RG

    2012-11-01

    Full Text Available Rachel G Simpson,1 Majid Moshirfar,2 Jason N Edmonds,2 Steven M Christiansen,2 Nicholas Behunin21The University of Arizona College of Medicine, Phoenix, AZ, USA; 2John A Moran Eye Center, The University of Utah School of Medicine, Salt Lake City, UT, USAPurpose: To evaluate the current United States Food and Drug Administration (FDA recommendations regarding laser in situ keratomileusis (LASIK surgery in patients with collagen vascular diseases (CVD and assess whether these patients make appropriate candidates for laser vision correction, and offer treatment recommendations based on identified clinical data.Methods: A literature search was conducted using PubMed, Medline, and Ovid to identify all existing studies of LASIK in patients with collagen vascular diseases. The search was conducted without date limitations. Keywords used for the search included MeSH terms: laser in situ keratomileusis, LASIK, refractive surgery, ocular surgery, and cataract surgery connected by "and" with the following MeSH and natural-language terms: collagen vascular disease, rheumatic disease, systemic disease, rheumatoid arthritis, systemic lupus erythematosus, Sjögren's syndrome, seronegative spondyloarthropathy, HLA B27, ankylosing spondylitis, reactive arthritis, psoriatic arthritis. The abstracts for all studies meeting initial search criteria were reviewed; relevant studies were included. No prospective studies were found; however, four retrospective case studies were identified that examined LASIK surgery in patients with CVD. Several case reports were also identified in similar fashion.Results: The FDA considers CVD a relative contraindication to LASIK surgery, due largely to the ocular complications associated with disease in the CVD spectrum. However, recent studies of LASIK in patients with CVD indicate LASIK may be safe for patients with very well-controlled systemic disease, minimal ocular manifestations, and no clinical signs or history of dry

  13. 飞秒激光制瓣LASIK术后泪膜变化及相关性分析%Analysis of the tear film changes after laser in situ keratomileusis (LASIK) with corneal flap created by femtosecond laser

    Institute of Scientific and Technical Information of China (English)

    张媛; 贾冰冰; 张岩; 高冬梅; 庞玉珍; 谷树严

    2014-01-01

    Objective To observe the tear film changes on the patients after laser in situ keratomileusis (LASIK) with corneal flap created by femtosecond laser; the correlation among the BUT,Schirmer Ⅰ test and tear meniscus height.Methods The 120 myopic patients (240 eyes) who underwent femtosecond laser surgery from August to September 2013,these patients were followed up for three months.Tear break-up time (BUT) with fluorescein,tear break-up time (BUT) with Oculus corneal topography,Schirmer Ⅰ test,tear meniscus height with Oculus corneal topography and corneal fluorescein staining were recorded preoperatively and postoperatively in the first week,the first month,the second month and the third month.And observed the correlation between tear break-up time (BUT) with fluorescein and tear break-up time (BUT) with Oculus corneal topography,Schirmer Ⅰ test and tear meniscus height with Oculus corneal topography.Results Oculus BUT:There existed obvious difference (P =0.00 <0.05) in the first week compared with the preoperative level.While no such obvious difference (P =0.556,0.663,0.087>0.05) existed in the first month,the second month and the third month compared with the preoperative level.Fluorescein BUT:There existed obvious difference (P =0.033,0.025,0.004<0.05) in the first week,the first month,the second month and the third month compared with the preoperative level.Schirmer Ⅰ test:There existed obvious difference (P =0.000,0.002<0.05) in the first week and the first month compared with the preoperative level.No such obvious difference (P =0.776,0.753>0.05) existed in the second month and the third month compared with the preoperative level.Tear meniscus height (TMH):There cxisted obvious difference (P =0.00<0.05) in the first week and the first month compared with the preoperative level.No such obvious difference (P =0.096,0.229>0.05) existed in the second month and the third month compared with the preoperative level.The correlation of fluorescein

  14. Epiretinal Membrane after Laser In Situ Keratomileusis

    Directory of Open Access Journals (Sweden)

    Miguel Paciuc-Beja

    2013-01-01

    Full Text Available Multiple posterior segment complications can occur after LASIK. Posterior vitreous detachment, macular holes, retinal hemorrhages, retinal detachment, and several other complications have been described. A case of posterior vitreous detachment with epiretinal membrane in a young adult after LASIK is reported. LASIK surgeons must be aware of the possibility of posterior segment complications after surgery.

  15. Epiretinal Membrane after Laser In Situ Keratomileusis

    Science.gov (United States)

    Paciuc-Beja, Miguel; Garcia, Gerardo; Dalma, Jose; Quiroz-Mercado, Hugo

    2013-01-01

    Multiple posterior segment complications can occur after LASIK. Posterior vitreous detachment, macular holes, retinal hemorrhages, retinal detachment, and several other complications have been described. A case of posterior vitreous detachment with epiretinal membrane in a young adult after LASIK is reported. LASIK surgeons must be aware of the possibility of posterior segment complications after surgery. PMID:23691389

  16. Uncorrected and Corrected Distance Visual Acuity, Predictability, Efficacy, and Safety after Femtosecond Laser in Situ Keratomileusis (FS-LASIK) and Refractive Lenticule extraction (ReLEx) for Moderate and High Myopia

    DEFF Research Database (Denmark)

    Vestergaard, Anders; Justesen, Birgitte Larsen; Melsen, Charlotte

    predictability, efficacy and safety after femtosecond LASIK (FS-LASIK) with ReLEx. Setting: Department of Ophthalmology, Odense University Hospital, Denmark. Methods: Retrospective study of results after FS-LASIK and ReLEx (including ReLEx flex, ReLEx pseudo-smile, and ReLEx smile). In total, 228 eyes were...

  17. Vitreoretinal surgery for macular hole after laser assisted in situ keratomileusis for the correction of myopia

    Science.gov (United States)

    Arevalo, J F; Rodriguez, F J; Rosales-Meneses, J L; Dessouki, A; Chan, C K; Mittra, R A; Ruiz-Moreno, J M

    2005-01-01

    Ams: To describe the characteristics and surgical outcomes of full thickness macular hole surgery after laser assisted in situ keratomileusis (LASIK) for the correction of myopia. Methods: 13 patients (14 eyes) who developed a macular hole after bilateral LASIK for the correction of myopia participated in the study. Results: Macular hole formed 1–83 months after LASIK (mean 13 months). 11 out of 13 (84.6%) patients were female. Mean age was 45.5 years old (25–65). All eyes were myopic (range −0.50 to −19.75 dioptres (D); mean −8.4 D). Posterior vitreous detachment (PVD) was not present before and was documented after LASIK on 42.8% of eyes. Most macular hole were unilateral, stage 4 macular hole, had no yellow deposits on the retinal pigment epithelium, had no associated epiretinal membrane, were centric, and had subretinal fluid. The mean diameter of the hole was 385.3 μm (range 200–750 μm). A vitrectomy closed the macular hole on all eyes with an improvement on final best corrected visual acuity (VA) on 13 out of 14 (92.8%) patients. Conclusions: This study shows that vitreoretinal surgery can be successful in restoring vision for most myopic eyes with a macular hole after LASIK. PMID:16234445

  18. Evaluation of retinal nerve fiber layer thickness measurement following laser in situ keratomileusis using scanning laser polarimetry

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    Dada Tanuj

    2007-01-01

    Full Text Available Aim: To evaluate the effect of laser-assisted in situ keratomileusis (LASIK on the measurement of retinal nerve fiber layer thickness by scanning laser polarimetry using customized corneal compensation in myopes. Materials and Methods: Scanning laser polarimetry was performed on 54 eyes of 54 healthy patients with myopia using the glaucoma diagnostics variable corneal compensation (GDx VCC instrument (Laser Diagnostic Technologies, San Diego, California before and a week after LASIK. The various parameters were compared using the Student′s t test. Results: No statistically significant change was observed in any of the retinal nerve fiber layer parameters before and after LASIK. Conclusions: While the measurement of retinal nerve fiber layer thickness by scanning laser polarimetry is affected by anterior segment birefringent properties and LASIK would be expected to produce changes in the same, customized corneal compensation using the GDx VCC seems to adequately compensate for these changes.

  19. Keratectasia following laser in situ keratomileusis in a low-risk patient with benign joint hypermobility syndrome

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    Gustavo Galperin

    2014-04-01

    Full Text Available Here we present the case of a 27-year-old woman with benign joint hypermobility (BJHS syndrome who developed keratectasia after laser in situ keratomileusis (LASIK in both eyes. Both eyes had identical low Randleman risk factor scores. To our knowledge, this is the first report of such a complication in a patient with BJHS. It highlights our incomplete knowledge of the risk factors for keratectasia following LASIK and suggests that BJHS should be considered as a risk factor for keratectasia.

  20. Microcapillary sign of flap alignment in femtosecond laser-assisted in situ keratomileusis

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    Fawzy F

    2016-10-01

    Full Text Available Fathy Fawzy,1,2 Sherine S Wahba,1,3 Nader Fawzy1,4 1Al Watany Eye Hospital, 2Ophthalmology Department, Military Medical Academy, 3Ophthalmology Department, Ain Shams University, Cairo, Egypt; 4Sehkraft Augenzentrum, Cologne, Germany Abstract: We present an observational sign that ensures perfect alignment during femtosecond laser-assisted in situ keratomileusis (FS LASIK. Alignment is assured when a microsponge is used to dry the flap and the area of dryness exceeds the area of direct touch of the microsponge. The area might even reach the whole circumference of the flap at the first touch. This sign of alignment can be explained by microcapillary action. This sign was not elicited in flaps created by a microkeratome. Keywords: capillarity, femtosecond LASIK flap, corneal flap alignment

  1. Visual quality after epipolis laser in situ keratomileusis surgery in mild and moderate myopia

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    Yin-Liang Huang

    2015-07-01

    Full Text Available AIM: To comprehensively evaluate of visual quality after epipolis laser in situ keratomileusis(EPI-LASIKin mild to moderate myopia.METHODS: Sixty cases(120 eyesundergone EPI-LASIK with equivalent diopter(SEwere divided into two groups: mild myopia group(60 eyesand moderate myopia group(60 eyes. Objective visual acuity, aberration, contrast sensitivity and glare sensitivity were measured before and 1wk; 1, 6mo after operation, and made comparative analysis. RESULTS: Postoperative uncorrected visual acuity(UCVAof two groups were better than that of preoperative(PPPPPPPCONCLUSION: Visual quality is poorer in mild myopia patients than that in moderate myopia at early stage after EPI-LASIK. Better visual quality is observed at mid-late stage.

  2. THE MANAGEMENT OF EPITHELIAL INGROWTH AFTER LASER IN SITU KERATOMILEUSIS

    Institute of Scientific and Technical Information of China (English)

    杨斌; 王铮; 陈家祺

    2001-01-01

    Objective. To investigate the treatment of corneal epithelial ingrowth with flap melt after LASIK.Patients and muethod. Thirteen eyes of 13 patients with corneal epithelial ingrowth and flap melt after LASIKwere treated based on the thickness and the extent of melting of the flap. Nine eyes were treated by lifting the flapand scraping the epithelium in the interface. Three eyes underwent allogenic keratomileusis. The flap was re-moved in one eye.Results. Recunence occurred in 2 eyes treated by lifting the flap. The flaps, however, healed normally af-ter retreatment. The grafts healed normally in the allogenic keratomileusis group, except for one eye in which theflap was lost. The c omeal epithelium healed over the stromal bed after the flap was removed. Corneal haze ofgrade 2 was present at 6 months. The uncorrected visual acuity was between 0.3 and 1.0, and the best-correctedvisual acuity lost 1 to 3 lines.Conclusions. C orneal epithelial ingrowth with flap melt is a severe complication after LASIK. However,with proper treatmen, vision can be salvaged in most cases.``

  3. Laser in situ keratomileusis surgery is not safe for military personnel.

    Science.gov (United States)

    Xiao, Jian-He; Zhang, Mao-Nian; Jiang, Cai-Hui; Zhang, Ying; Qiu, Huai-Yu

    2012-01-01

    To investigate the relationship between eye injury and laser in-situ keratomileusis (LASIK) surgery in military personnel. This retrospective study collected the data from 27 evacuation hospitals of Chinese army. All medical records of eye injuries in military personnel admitted to the 27 hospitals between January 2006 and December 2010 were reviewed. Patients'detailed information was analyzed, including the injury time, place, type, cause, as well as examination, treatment and outcome. There were 72 eye-injured patients who had been treated by LASIK before. The incidence was rising year by year. Among them, 69 patients were diagnosed with mechanical ocular injury and 3 with non-mechanical ocular injury; 29 patients had traumatic flap-related complications and 21 patients need surgery. There was statistical difference when compared with those having no refractive surgery history. Visual acuity recovered well at discharge. There is a high risk of potential traumatic flap problems after LASIK and it is not recommended in army service.

  4. STREPTOCOCCUS PNEUMONIAE KERATITIS FOLLOWING LASER IN SITU KERATOMILEUSIS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    A 22-year-old man underwent bilateral laser in situ keratomileusis and developed Streptococcus pneumoniae keratitis after surgery.This complication occurred one day after the procedure in both eyes.Topical and systemic antibiotics were promptly administered.Bacterial culture was performed following corneal flap lift and scraping of the lesions.Afterwards,the therapeutic regimen was readjusted according to the culture results.Streptococcus pneumoniae was identified from the culture.Three months after the sur...

  5. Dislocation, fold and striae of corneal flap with laser assisted in situ keratomileusis after ocular trauma: a case report

    Institute of Scientific and Technical Information of China (English)

    Sang Yanzhi; Liu Xin; Zhong Ming; Zhao Chunyan

    2008-01-01

    Objective: To report the occurrence, management and outcome of late-onset traumatic dehiscence and islocation of laser assisted in situ keratomileusis (LASIK) flaps. Treatment and Results: One patient occurred ate-onset LASIK corneal flap dislocation after ocular trauma 7days after surgery. The flap was lifted, stretched, and epositioned after irrigation and scraping of the stromal bed and the underside of the flap. A bandage contact lens as placed, and topical antibiotic and corticosteroids were given postoperatively. The dislocated corneal flap was successfully repositioned in the case. The dislocated flap was repositioned 7 days after the trauma, and the patient recovered his uncorrected visual acuity (UCVA) of 10/20, 20/20 day 1 and day 20 after the procedure, of 20/20 20 days later and had a well-positioned flap with a clear interface. Diffuse lamellar keratitis developed in the patients hat resolved with the use of topical corticosteroids. Conclusion: Laser in situ keratomileusis corneal flaps are ulnerable to traumatic dehiscence and dislocation, which should be pay more attention to it for us.

  6. Bilateral Epithelial Defects after Laser in situ Keratomileusis. Clinical Features, Management and Outcome

    Directory of Open Access Journals (Sweden)

    Rao Srinivas

    2005-03-01

    Full Text Available PURPOSE: To describe the preoperative characteristics, intraoperative details, management, and postoperative in patients with bilateral epithelial defects after laser in situ keratomileusis (LASIK. METHODS: Retrospective non-comparative case series. RESULTS: Six patients with bilateral epithelial defects after LAISK were part of a cohort of 605 patients undergoing bilateral LASIK at our center from December 2001 to April 2003. The mean age of the patients (5M:1F was 28.5 7.9 years, and the average pretreatment myopic spherical equivalent (SE refraction was 7.3 0.7 D (-4, -12.25D. An epithelial flap was present in 6 eyes and an epithelial defect with a mean diameter of 3 mm (2mm, 6mm was seen in 6 eyes. In four patients the epithelial disturbance was bilaterally similar. All defects occurred in the inferior cornea and the epithelial flaps had the hinge positioned superiorly. None of the patients had ocular or systemic risk factors that could have resulted in this complication. A bandage contact lens was used in 6 eyes. At last follow-up of 5.5 9.5 months (0.25, 21 months, unaided visual acuity was 6/9 or better in 10 eyes. Best spectacle-corrected visual acuity (BSCVA was maintained in 8 eyes, while 4 eyes lost one line of BSCVA. Recurrent corneal erosions were not reported in the follow-up period. CONCLUSIONS: These patients represent a hitherto unrecognised group of individuals who appear to have a subclinical weakness of adhesion of the corneal epithelium to the underlying structures, which is not evident on clinical examination. This results in bilateral epithelial disturbances after LASIK. Appropriate management results in satisfactory clinical outcomes. Other options for treatment of the fellow eye of such patients include the use of a different microkeratome, release of suction during the reverse pass of the Hansatome microkeratome, and photorefractive keratectomy if the refractive error is low.

  7. Corneal collagen crosslinking for ectasia after laser in situ keratomileusis: long-term results.

    Science.gov (United States)

    Yildirim, Aydin; Cakir, Hanefi; Kara, Necip; Uslu, Hasim; Gurler, Bulent; Ozgurhan, Engin Bilge; Colak, Hatice Nur

    2014-10-01

    To report the long-term results of corneal collagen crosslinking (CXL) treatment for post-laser in situ keratomileusis (LASIK) ectasia. Turkiye Hospital Eye Clinic and Fatih University Medical Faculty, Department of Ophthalmology, Istanbul, Turkey. Retrospective case series study. Consecutive patients with ectasia after LASIK were treated with CXL. The main outcome measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical and cylindrical refractions, and simulated keratometry (K) values. The study enrolled 20 eyes (14 patients; 7 women) with a mean age of 34.8 years ± 6.0 (SD) (range 25 to 45 years) and mean follow-up of 42 months (range 36 to 60 months). The UDVA and CDVA improved significantly, from 0.78 ± 0.61 logMAR to 0.53 ± 0.36 logMAR (P=.007) and from 0.27 ± 0.23 logMAR to 0.19 ± 0.13 logMAR, respectively (P≤.028). No eye lost 1 or more Snellen lines of UDVA or CDVA. Although the mean spherical refraction was not significantly different at the last visit (P=.074), the mean cylindrical refraction decreased significantly (P=.036). The maximum K value decreased from 46.0 ± 4.4 diopters (D) at baseline to 45.6 ± 3.8 D at the last visit (P=.013). By the last visit, the maximum K value decreased (≥1.0 D) in 5 eyes and remained stable in 15 eyes. No serious complications occurred. Corneal collagen crosslinking yielded long-term stability in cases with post-LASIK corneal ectasia without significant side effects. Improvements in visual acuity, cylindrical refraction, and maximum K values occurred. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2014 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  8. Accuracy of Corneal Power Measurements for Intraocular Lens Power Calculation after Myopic Laser In situ Keratomileusis

    Science.gov (United States)

    Helaly, Hany A.; El-Hifnawy, Mohammad A. M.; Shaheen, Mohamed Shafik; Abou El-Kheir, Amr F.

    2016-01-01

    Purpose: To evaluate the accuracy of corneal power measurements for intraocular lens (IOL) power calculation after myopic laser in situ keratomileusis (LASIK). Methods: The study evaluated 45 eyes with a history of myopic LASIK. Corneal power was measured using manual keratometry, automated keratometry, optical biometry, and Scheimflug tomography. Different hypothetical IOL power calculation formulas were performed for each case. Results: The steepest mean K value was measured with manual keratometry (37.48 ± 2.86 D) followed by automated keratometry (37.31 ± 2.83 D) then optical biometry (37.06 ± 2.98 D) followed by Scheimflug tomography (36.55 ± 3.08). None of the K values generated by Scheimflug tomography were steeper than the measurements from the other 3 instruments. Using equivalent K reading (EKR) 4 mm with the Double-K SRK/T formula, the refractive outcome generated 97.8% of cases within ± 2 D, 80.0% of cases within ± 1 D, and 42.2% of cases within ± 0.5 D. The best combination of formulas was “Shammas-PL + Double-K SRK/T formula using EKR 4 mm.” Conclusion: Scheimflug tomography imaging using the Holladay EKR 4 mm improved the accuracy of IOL power calculation in post-LASIK eyes. The best option is a combination of formulas. We recommended the use the combined “Shammas-PL ± Double-K SRK/T formula using EKR 4 mm”h for optical outcomes. PMID:26957851

  9. [The early post-operative wound healing mode study of the rabbit cornea after flap-free epiploic laser in-situ keratomileusis].

    Science.gov (United States)

    Liu, Xi; DU, Zhi-yu; Xiang, Yi-min; Huang, Zheng

    2009-10-01

    To evaluate the wound healing mode of rabbit corneal epithelium after Epi-LASIK(epiplolic laser in-situ keratomileusis) and Flap-free Epi-LASIK(Flap-free epiploic laser in-situ keratomileusis). Twenty-four New Zealand white rabbits (48 eyes) were randomly divided into four groups. There were six rabbits in every group, which were randomly treated with Epi-LASIK in one eye and Flap-free Epi-LASIK in the other by VISX20/20 excimer laser. Other three rabbits (6 eyes) without any treatment were used as control. The corneal epithelium wound healing mode was observed at 1, 2, 4, 7 days after surgery by light microscope and electron microscope. The number of keratocytes cells in the central anterior stroma were counted by hematoxylin-eosin-stained. The expression of basic fibroblast growth factor (bFGF) in corneal stroma were assessed by Immunohistochemistry staining. Cornea stromal cell apoptosis was evaluated by terminal deoxyribonuc-1-eotidyl transferase-mediated deoxynuridine triphosphate nick end labeling (TUNEL) assay.All the data was analysised by t-test to evaluate the different of wound healing mode after Epi-LASIK and Flap-free Epi-LASIK. The findings of light microscope and electron microscope investigation demonstrated that, at the first day after surgery, there was one layer of neogenesis of the corneal epithelial cells covering the area of surgery in Flap-free Epi-LASIK specimens. It would increase gradually after 7 days. At the first day after the surgery, the base membrane of the corneal epithelium was tightly attached to the stroma in Epi-LASIK specimens. At the second day after the surgery, there was edema observed on the epithelium flap in the Epi-LASIK specimens. There were more keratocytes cells found at 4 days after surgery in Flap-free Epi-LASIK group (33.85 +/- 3.39) than that in Epi-LASIK group (t = -2.315, P corneal wound healing.

  10. Rainbow glare after laser-assisted in situ keratomileusis: a review of literature

    Directory of Open Access Journals (Sweden)

    Moshirfar M

    2016-11-01

    Full Text Available Majid Moshirfar,1,2 Jordan D Desautels,3 Tyler S Quist,4 David F Skanchy,5 Mark T Williams,6 Ryan T Wallace7 1Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT, 2HDR Research Center, Hoopes Vision, Draper, UT, 3Tufts University School of Medicine, Boston, MA, 4University of Utah School of Medicine, Salt Lake City, UT, 5McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 6University of California, San Francisco School of Medicine, San Francisco, CA, 7Brigham Young University, Provo, UT, USA Abstract: This article reviews the current literature pertaining to rainbow glare (RG, including incidence rate, clinical presentation, etiology, prognosis, and management. RG is a rare optical complication of femtosecond laser-assisted in situ keratomileusis that results in patients seeing an array of spectral bands surrounding point sources of light under mesopic and scotopic conditions. The mechanism is thought to be a consequence of the formation of a transmissive diffraction grating on the posterior surface of the corneal flap created by the FS laser. RG has a good prognosis and is usually self-limiting. Persistent RG with concomitant residual refractive error may warrant lifting the flap and photoablating the posterior surface of the flap. Patients with persistent RG and no residual refractive error should be considered candidates for phototherapeutic keratectomy on the posterior flap surface. Keywords: rainbow glare, femtosecond, LASIK, keratomileusis, phototherapeutic keratectomy

  11. Central corneal thickness measurements using Orbscan II, Visante, ultrasound, and Pentacam pachymetry after laser in situ keratomileusis for myopia.

    Science.gov (United States)

    Ho, Thomas; Cheng, Arthur C K; Rao, Srinivas K; Lau, Silvania; Leung, Chris K S; Lam, Dennis S C

    2007-07-01

    To compare corneal pachymetry assessment using 4 measurement methods in eyes after laser in situ keratomileusis (LASIK) for myopia. Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, Hong Kong SAR. Fifty-two consecutive patients (103 eyes) who had LASIK for the correction of myopia had Orbscan II (Bausch & Lomb), Visante (Carl Zeiss Meditec), Pentacam (Oculus, Inc.), and ultrasound (US) pachymetry (Sonomed, 200P) 6 months after surgery. Data were analyzed using the paired sample t test, Bland-Altman plots, and linear regression. The mean postoperative pachymetry measured by US, Orbscan (0.89 acoustic factor), Pentacam, and Visante pachymetry were 438.2 microm+/-41.18 (SD), 435.17+/-49.63 microm, 430.66+/-40.23 microm, and 426.56+/-41.6 microm, respectively. Compared with the US measurement, Pentacam and Visante measurements significantly underestimated corneal thickness by a mean of 7.54+/-15.06 microm (P<.01) and 11.64+/-12.87 microm (P<.01), respectively. There was no statistically significant difference between US and Orbscan measurements. Pentacam and Visante measurements of corneal thickness 6 months after LASIK were significantly less than those obtained using Orbscan and US pachymetry, although all 4 measurement methods showed a high correlation with each other.

  12. Long-term safety and efficacy follow-up of prophylactic higher fluence collagen cross-linking in high myopic laser-assisted in situ keratomileusis

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    Kanellopoulos AJ

    2012-07-01

    Full Text Available Anastasios John KanellopoulosLaservision.gr Institute, Athens, Greece, and New York University Medical School, New York, NY, USABackground: The purpose of this study was to evaluate the safety and efficacy of ultraviolet A irradiation cross-linking on completion for cases of high myopic laser-assisted in situ keratomileusis (LASIK.Methods: Forty-three consecutive LASIK cases treated with femtosecond laser flap and the WaveLight excimer platform were evaluated perioperatively for uncorrected visual acuity, best corrected spectacle visual acuity, refraction, keratometry, topography, total and flap pachymetry, corneal optical coherence tomography, and endothelial cell count. All eyes at the completion of LASIK had cross-linking through the repositioned flap, with higher fluence (10 mW/cm2 ultraviolet light of an average 370 µm wavelength and 10 mW/cm2 fluence applied for 3 minutes following an earlier single instillation of 0.1% riboflavin within the flap interface. Mean follow-up duration was 3.5 (range 1.0–4.5 years.Results: Mean uncorrected visual acuity changed from 0.2 to 1.2, best corrected spectacle visual acuity from 1.1 to 1.2, spherical equivalent from -7.5 diopters (D to -0.2 D, keratometry from 44.5 D to 38 D, flap pachymetry from 105 µm to, total pachymetry from 525 to 405, and endothelial cell count from 2750 to 2800. None of the cases developed signs of ectasia or significant regression during follow-up.Conclusion: Prophylactic collagen cross-linking for high-risk LASIK cases appears to be a safe and effective adjunctive treatment for refractive regression and potential ectasia. This application may be viewed as prophylactic customization of the biomechanical behavior of corneal collagen.Keywords: prophylactic collagen cross-linking, laser-assisted in situ keratomileusis, high-risk, post-LASIK ectasia

  13. Incidence of corneal infections after laser in situ keratomileusis and surface ablation when moxifloxacin and tobramycin are used as postoperative treatment.

    Science.gov (United States)

    Ortega-Usobiaga, Julio; Llovet-Osuna, Fernando; Djodeyre, Mohammad Reza; Llovet-Rausell, Andrea; Beltran, Jaime; Baviera, Julio

    2015-06-01

    To assess the incidence, culture results, and visual outcomes of infectious keratitis after laser in situ keratomileusis (LASIK) and surface ablation when topical moxifloxacin was added to postoperative prophylaxis with tobramycin. Clínica Baviera, Instituto Oftalmológico Europeo, Bilbao, Spain. Retrospective case series review. The medical records of 55 255 patients (108 014 eyes) who had LASIK and surface ablation were reviewed to identify cases of infectious keratitis. The incidence, risk factors, clinical course, days to diagnosis, treatment, and final visual outcomes were recorded. These data were compared with previously published data of 221 437 eyes that received postoperative tobramycin alone. Post-LASIK infectious keratitis was diagnosed in 10 eyes (9 patients) and post-surface ablation infectious keratitis in 11 eyes (10 patients). The onset of infection was early in 40.00% of cases after LASIK and in 36.36% after surface ablation. Cultures were positive in 2 cases after surface ablation. Immediate flap lifting and irrigation with antibiotics were performed in all eyes after LASIK. The final corrected distance visual acuity was 20/20 or better in 7 cases after LASIK (70.00%) and 7 cases after surface ablation (63.64%) and 20/40 or better in all cases after LASIK or surface ablation. The incidence of infectious keratitis decreased from 0.025% to 0.011% (P surface ablation. Infectious keratitis was less frequent after LASIK than after surface ablation. The frequency of infection, mainly early-onset infection, was lower when the postoperative treatment was tobramycin and moxifloxacin rather than tobramycin alone. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  14. Early changes in ocular surface and tear inflammatory mediators after small-incision lenticule extraction and femtosecond laser-assisted laser in situ keratomileusis.

    Directory of Open Access Journals (Sweden)

    Shaohui Gao

    Full Text Available To characterize the early ocular-surface changes or tear inflammatory-mediators levels following small-incision lenticule extraction (ReLEx smile and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK.Forty-seven myopic subjects were recruited for this prospective study. Fifteen underwent ReLEx smile and thirty-two underwent FS-LASIK. Corneal fluorescein (FL staining, tear break-up time (TBUT, Schirmer I test (SIT, ocular surface disease index (OSDI and central corneal sensitivity were evaluated in all participants. Tears were collected and analyzed for interleukin-6 (IL-6, tumor necrosis factor-α (TNF-α, nerve growth factor (NGF and intercellular adhesion molecule-1 (ICAM-1 levels using multiplex magnetic beads. All measurements were preformed preoperatively and 1 day, 1 week, 1 month and 3 months postoperatively.FL scores in ReLEx smile group were lower than those of FS-LASIK group 1 week postoperatively (P = 0.010. Compared to the FS-LASIK group, longer TBUT were observed in ReLEx smile group 1 month (P = 0.029 and 3 months (P = 0.045 postoperatively. No significant differences were found in tear secretion for the two groups (P>0.05. OSDI scores were higher in FS-LASIK group 1 month after surgery (P = 0.020. Higher central corneal sensitivity was observed in ReLEx smile group 1 week, 1 month and 3 months (P0.05. Moreover, IL-6 and NGF levels correlated with ocular surface changes after ReLEx smile or FS-LASIK.In the early postoperative period, ReLEx smile results in milder ocular surface changes than FS-LASIK. Furthermore, the tear inflammatory mediators IL-6 and NGF may play a crucial role in the ocular surface healing process following ReLEx smile and FS-LASIK.

  15. Influence of microkeratome parameters on the stromal bed and flap edge quality in laser in situ keratomileusis

    Directory of Open Access Journals (Sweden)

    Heichel J

    2013-12-01

    Full Text Available Jens Heichel,1 Frank Wilhelm,2 Kathleen S Kunert,3 Rabea Schlueter,4 Ute Stuhltraeger,1 Thomas Hammer5 1Department of Ophthalmology, University Hospital of Martin Luther University Halle/Wittenberg, Halle (Saale, Germany; 2Augen im Zentrum, Greifswald, Germany; 3Department of Ophthalmology, Helios Klinikum Erfurt, Erfurt, Germany; 4Institute of Microbiology, Ernst-Moritz-Arndt-University, Greifswald, Germany; 5Augenzentrum Frohe Zukunft, Halle (Saale, Germany Purpose: Femtosecond lasers have become the standard for laser-assisted in situ keratomileusis (LASIK flap creation, but advanced mechanical microkeratomes are still an alternative, more cost-effective way to create the flap. The SCHWIND Carriazo-Pendular microkeratome is one of the most commonly used microkeratomes. The influence of different cutting parameters (head-advance speeds, cutting heads on morphology of LASIK cuts was investigated. Setting: Experimental study performed at the University Eye Hospital of the Martin Luther University Halle/Wittenberg, Halle (Saale, Germany. Methods: The Carriazo-Pendular microkeratome was used on freshly enucleated porcine eyes for lamellar keratotomy. After flap removal, the cutting edge and stromal bed were evaluated from scanning electron micrographs using an individualized scoring system. Four different settings of microkeratome parameters were compared. For each setting, eight cuts were evaluated (n=32. Results: Different oscillation frequencies and head-advance speeds did not influence the cutting qualities. A higher oscillation/feed rate ratio seemed to be advantageous for a smoother interface. Concerning different cuttings heads, a deeper keratotomy led to sharper cutting edges. The thinner the flap, the more irregularities in the stromal bed appeared. Complications did not occur. Conclusion: The Carriazo-Pendular microkeratome is a safe tool with which to create a LASIK flap and is a good alternative to a costly femtosecond laser. Deeper

  16. Accuracy of refractive outcomes in myopic and hyperopic laser in situ keratomileusis: Manifest versus aberrometric refraction.

    Science.gov (United States)

    Reinstein, Dan Z; Morral, Merce; Gobbe, Marine; Archer, Timothy J

    2012-11-01

    To compare the achieved refractive accuracy of laser in situ keratomileusis (LASIK) performed based on manifest refraction with the predicted accuracy that would have been achieved using WASCA aberrometric refraction with and without Seidel correction factor for sphere. London Vision Clinic, London, United Kingdom. Comparative case series. Myopic eyes and hyperopic eyes had LASIK based on manifest refraction. Two aberrometric refractions were obtained preoperatively: Seidel, which includes spherical aberration in the sphere calculation, and non-Seidel. Bland-Altman plots were used to show the agreement between aberrometric and manifest refractions. Predicted LASIK outcomes had aberrometric refraction been used were modeled by shifting the postoperative manifest refraction by the vector difference between the preoperative manifest and aberrometric refractions. This study included 869 myopic eyes and 413 hyperopic eyes. The mean differences (manifest minus aberrometric) in spherical equivalent were +0.03 diopters (D) ± 0.48 (SD) (Seidel aberrometric) and +0.45 ± 0.42 D (non-Seidel aberrometric) for myopia and -0.20 ± 0.39 D and +0.39 ± 0.34 D, respectively, for hyperopia. The mean differences in cylinder magnitude were -0.10 ± 0.27 D and 0.00 ± 0.25 D, respectively. The percentage of eyes within ±0.50 D of the attempted correction was 81% (manifest), 70% (Seidel), and 67% (non-Seidel) for myopia and 71% (manifest), 61% (Seidel), and 64% (non-Seidel) for hyperopia. The achieved refractive accuracy by manifest refraction was better than the predicted accuracy had Seidel or non-Seidel aberrometric refractions been used for surgical planning. Using the Seidel method improved the accuracy in myopic eyes but not in hyperopic eyes. Dr. Reinstein is a consultant to Carl Zeiss Meditec AG and has a proprietary interest in the Artemis technology (Arcscan Inc., Morrison, Colorado, USA) through patents administered by the Cornell Center for Technology Enterprise and

  17. Comparison of Intraocular Pressure before and after Laser In Situ Keratomileusis Refractive Surgery Measured with Perkins Tonometry, Noncontact Tonometry, and Transpalpebral Tonometry

    Directory of Open Access Journals (Sweden)

    Isabel Cacho

    2015-01-01

    Full Text Available Purpose. To compare the intraocular pressure (IOP before and after Laser In Situ Keratomileusis (LASIK, measured by Diaton, Perkins, and noncontact air pulse tonometers. Methods. Fifty-seven patients with a mean age of 34.88 were scheduled for myopia LASIK treatment. Spherical equivalent refraction (SER, corneal curvature (K, and central corneal thickness (CCT and superior corneal thickness (SCT were obtained before and after LASIK surgery. IOP values before and after surgery were measured using Diaton, Perkins, and noncontact air pulse tonometers. Results. The IOP values before and after LASIK surgery using Perkins tonometer and air tonometers were statistically significant (p0.05 for IOP values measured with Diaton tonometer. CCT decreases significantly after surgery (p<0.05 but no statistical differences were found in SCT (p=0.08. Correlations between pre- and postsurgery were found for all tonometers used, with p=0.001 and r=0.434 for the air pulse tonometer, p=0.008 and r=0.355 for Perkins, and p<0.001 and r=0.637 for Diaton. Conclusion. Transpalpebral tonometry may be useful for measuring postsurgery IOP after myopic LASIK ablation because this technique is not influenced by the treatment.

  18. Long-term evaluation of eyes with central corneal thickness <400 µm following laser in situ keratomileusis

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    Djodeyre MR

    2016-03-01

    Full Text Available Mohammad Reza Djodeyre,1 Jaime Beltran,2 Julio Ortega-Usobiaga,3 Felix Gonzalez-Lopez,4 Ana Isabel Ruiz-Rizaldos,1 Julio Baviera2 1Department of Refractive Surgery, Clinica Baviera, Zaragoza, 2Department of Refractive Surgery, Clinica Baviera, Valencia, 3Department of Research and Development, Clinica Baviera, Bilbao, 4Department of Refractive Surgery, Clinica Baviera, Madrid, Spain Purpose: To study long-term refractive and visual outcomes of laser in situ keratomileusis (LASIK in eyes with a postoperative thin central cornea.  Methods: In this retrospective observational case series, we studied 282 myopic eyes with a normal preoperative topographic pattern and postoperative thin corneas (<400 µm that had at least 3 years of follow-up after LASIK in three private clinics. The main outcome measures were safety, efficacy, predictability, percent tissue altered, and complications.  Results: The mean postoperative central corneal thickness was 392.05 µm (range: 363.00–399.00 µm. After a mean follow-up of 6.89±2.35 years (standard deviation, the safety index was 1.17, the efficacy index was 0.94, and predictability (±1.00 diopter [D] was 73.49. The mean residual stromal bed thickness was 317.34±13.75 µm (range: 275–356 µm, the mean flap thickness was 74.76±13.57 µm (range: 55–124 µm, and the mean percent tissue altered was 37.12%±3.62% (range: 27.25%–49.26%. No major complications were recorded.  Conclusion: LASIK with a resultant central cornea thickness <400 µm seems to be effective, safe, and predictable provided that preoperative topography is normal and the residual stromal bed thickness is >275 µm. Keywords: LASIK, thin, cornea, ectasia, myopia, pachymetry, topography

  19. Comparison of eye-tracking success in laser in situ keratomileusis after flap creation with 2 femtosecond laser models.

    Science.gov (United States)

    Luengo Gimeno, Federico; Chan, Cordelia M L; Li, Lim; Tan, Donald T H; Mehta, Jodhbir S

    2011-03-01

    To determine the efficiency of an eye tracker after laser in situ keratomileusis (LASIK) flap creation with 1 of 2 femtosecond laser models. Tertiary referral center, Singapore National Eye Center, Singapore. Randomized clinical trial. The LASIK flap was created with an IntraLase (Group A) or a VisuMax (Group B) femtosecond laser. An Advanced Control Eye Tracker was initiated 3 times to obtain iris recognition. Eye tracking was considered successful if the eye movements could be followed despite the presence or absence of an opaque bubble layer (OBL). Univariate-multivariate logistic regression analysis was performed. Preoperatively, the mean values (ranges) of the 87 eyes were sphere, -5.64 diopters (D) ± 2.17 (SD) (-9.75 to -0.25 D); cylinder 1.65 ± 1.63 D (-3.75 to 0.00 D); optical zone, 6.34 ± 0.20 mm (5.6 to 7.0 mm); keratometry, 43.48 ± 1.32 D (40.1 to 42.8 D); flap thickness, 109.30 + 5.21 μm (90 to 115 μm). Eye tracking was successful in 38 (90.5%) of 42 eyes in Group A and 43 (95.6%) of 45 eyes in Group B. No specific type of OBL was seen in either group. The LASIK was completed in all eyes. There was a statistically significant association between positive tracking and a smaller optical zone (P=.03). There were no statistically significant differences in eye tracking between the 2 femtosecond lasers. Eye tracking was achieved in more than 90% of cases after LASIK flap creation with 1 of 2 femtosecond laser models, even in the presence of an OBL. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  20. EFFECTS OF PREOPERATIVE SOFT CONTACT LENS WEAR ON HIGHER-ORDER ABERRATIONS AFTER LASER IN SITU KERATOMILEUSIS

    Institute of Scientific and Technical Information of China (English)

    YU Jing; CHEN Hui; CHENG Xin-liang; WANG Fang

    2008-01-01

    Objective To evaluate the effects of preoperative soft contact lens (SCL) wear on higher-order aberrations(HOAs)correction after wavefront-guided and conventional laser in situ keratomileusis (LASIK).Methods A prospective randomized double-masked comparative study was conducted in 180 eyes of 90 patients scheduled for LASIK, including 92 eyes of 46 patients with previous SCL wear. The patients were divided into four groups: no SCL-conventional group, SCL-conventional group, no SCL-wavefront group and SCL-wavefront group. Preoperative and postoperative examinations included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), contrast sensitivity and HOAs.Results The UCVA and BSCVA were 20/20 in all patients at 6 months postoperatively. And 36.3%, 22.7%, 18.1% and 35.4% gained one line or more of BSCVA in no SCL-wavefront group, SCL-wavefront group, no SCL-conventional group and SCL-conventional group, respectively. Both the safety index and efficacy index surpassed one in 4 groups and were highest in no SCL-wavefront group. The increase in root-mean-square (RMS) values of HOAs was significantly lower in no SCL-wavefront group and higher in SCL-wavefront group. At 6 months postoperatively, the increase in RMS of HOAs (RMSh) were 0.67, 1.58, 1.17 and 1.28 in no SCL-wavefront group, SCL-wavefront group, no SCL-conventional group and SCL-conventional group, respectively.Conclusion Preoperative contact lens wear has significant influence on the efficacy of HOAs correction in wavefront-guided LASIK. Patients with contact lens wear preoperatively should be cautious when scheduled for wavefront-guided LASIK.

  1. LASIK

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  2. LASIK

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    Full Text Available ... Devices Home Medical Devices Products and Medical Procedures Surgery Devices LASIK LASIK Share Tweet Linkedin Pin it ... provide objective information to the public about LASIK surgery. See other sections of this site to learn ...

  3. Intraoperative and early postoperative flap-related complications of laser in situ keratomileusis using two types of Moria microkeratomes.

    Science.gov (United States)

    Karabela, Yunus; Muftuoglu, Orkun; Gulkilik, Ibrahim Gokhan; Kocabora, Mehmet Selim; Ozsutcu, Mustafa

    2014-10-01

    The purpose of this study is to describe the incidence, management, and visual outcomes of intraoperative and early postoperative flap-related complications of laser in situ keratomileusis (LASIK) surgery using two types of Moria M2 microkeratomes. This retrospective analysis was performed on 806 primary LASIK cases. The intraoperative and early postoperative flap-related complications were identified and categorized according to type of Moria microkeratome. There were 52 intraoperative and early postoperative complications--one case of partial flap (0.124 %), one case of free flap (0.124 %), one case of small flap (0.124 %), 13 cases of epithelial defect (1.61 %), 12 cases of flap striae (1.49 %), 10 cases of diffuse lamellar keratitis (1.24 %), 10 cases of interface debris (1.24 %), three cases of epithelial ingrowth (0.37 %), and one case of microbial infection (0.124 %). The overall incidence of flap complications was 6.45 %. There were 27 right eye (6.73 %) and 25 left eye (6.17 %) complications. The incidence of complications with the Moria automated metallic head 130 microkeratome was 4.22 % and with the Moria single-use head 90 microkeratome was 2.23 %. We observed one culture-negative interface abscess which was cured with surgical cleaning and intensive medical treatment. The most common complication encountered was epithelial defects, followed by flap striae. Our study showed that LASIK with a microkeratome has a relatively low incidence of intraoperative and early postoperative flap complications. The authors have no financial interest in any of the issues contained in this article and have no proprietary interest in the development of marketing of or materials used in this study.

  4. Long-term efficacy of excimer laser in situ keratomileusis in the management of children with high anisometropic amblyopia

    Institute of Scientific and Technical Information of China (English)

    LIN Xiao-ming; YAN Xiao-he; WANG Zheng; YANG Bin; CHEN Qi-wen; SU Jin-ai; YE Xue-lian

    2009-01-01

    Background Children with anisometropic amblyopia are often noncompliant with traditional treatment including spectacules and contact lenses.This study was to evaluate the long-term efficacy of excimer laser in situ keratomileusis (LASIK) for children with high anisometropic amblyopia.Methods A retrospective analysis of 24 children with high unilateral anisometropic amblyopia,who underwent LASIK during the period between August 2000 and September 2005 in our hospital,was conducted.The mean age of these children was (7.4±1.9) years (range 5-14 years) and the mean follow-up period was (33.3±14.2) months (range 18.5-74.2 months).After LASIK,visual acuity,refraction and far or near stereoacuity were analyzed.Near stereoacuity was measured by the random-dot butterfly stereogram and the pre-school random-dot stereogram,while far stereoacuity was measured by the synoptophore with Yan's random-dot stereogram.Results Mean preoperative uncorrected visual acuity was 0.06±0.05,while mean postoperative uncorrected visual acuity was elevated to 0.43±0.33.Mean preoperative best-corrected visual acuity was 0.26±0.22,while mean postoperative best-corrected visual acuity was elevated to 0.67±0.40.For patients with myopic anisometropia,preoperative mean spherical equivalent refraction was (-8.01±2.70) D while postoperative value significantly reduced to (-1.32±2.47) D.For patients with hyperopic anisometropia,preoperative mean spherical equivalent refraction was (+7.35±1.55) D while postoperative value significantly reduced to (+3.30±0.86) D.These results demonstrated that there was statistical difference in these parameters between preoperative and postoperative tests.At the last follow-up,20 patients had near stereoacuity,and the mean near stereoacuities measured by the random-dot butterfly stereogram and the preschool random-dot stereogram were (149.00±152.93)" and (201.05±235.94)",respectively.In contrast,11 patients had far stereoacuity,and the mean far stereoacuity

  5. Comparison of DLK incidence after laser in situ keratomileusis associated with two femtosecond lasers: Femto LDV and IntraLase FS60

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    Tomita M

    2013-07-01

    Full Text Available Minoru Tomita,1–3 Yuko Sotoyama,1 Satoshi Yukawa,1 Tadayuki Nakamura1 1Shinagawa LASIK Center, Chiyoda-ku, Tokyo, Japan; 2Department of Ophthalmology, Wenzhou Medical College, Wenzhou, People’s Republic of China; 3Eye Can Cataract Surgery Center, Manila, Philippines Purpose: To compare the incidence of diffuse lamellar keratitis (DLK after laser in situ keratomileusis (LASIK with flap creation using the Femto LDV and IntraLase™ FS60 femtosecond lasers. Methods: A total of 818 consecutive myopic eyes had LASIK performed using either Femto LDV or IntraLase FS60 for flap creation. The same excimer laser, the Allegretto Wave® Eye-Q Laser, was used for correcting refractive errors for all patients. In the preoperative examination, uncorrected distance visual acuity, corrected distance visual acuity, and manifest refraction spherical equivalent were measured. At the postop examination, the same examinations were performed along with a slit-lamp biomicroscopic examination, and patients with DLK were classified into stages. For the statistical analysis of the DLK occurrence rate and the visual and refractive outcomes, the Mann-Whitney’s U-test was used. Results: In the Femto LDV group with 514 eyes, 42 (8.17% had DLK. In the IntraLase FS60 group with 304 eyes, 114 (37.5% had DLK. There was a statistically significant difference in the DLK incidence rate between these groups (P < 0.0001. Both groups had excellent visual and refractive outcomes. Although low levels of DLK were observed for both groups, they did not affect visual acuity. Conclusion: While there were significantly fewer incidences of low level DLK when using Femto LDV, neither femtosecond laser induced high levels of DLK, and any postoperative DLK cleared up within 1 week. Therefore, both lasers provide excellent results, with no clinical differences, and both excel at flap creation for LASIK. Keywords: LASIK, Ziemer, Femto LDV, DLK, IntraLase FS60, femtosecond laser

  6. A retrospective analysis of the postoperative use of loteprednol etabonate gel 0.5% following laser-assisted in situ keratomileusis or photorefractive keratectomy surgery

    Directory of Open Access Journals (Sweden)

    Salinger CL

    2015-11-01

    Full Text Available Clifford L Salinger,1 Michael Gordon,2 Mitchell A Jackson,3 Theodore Perl,4 Eric Donnenfeld5 1VIP Laser Eye Center, Palm Beach Gardens, FL, 2Gordon Weiss Schanzlin Vision Institute, San Diego, CA, 3Jacksoneye, Lake Villa, IL, 4Corneal Associates of New Jersey, Fairfield, NJ, 5Ophthalmic Consultants of Long Island, Garden City, NY, USA Background: While loteprednol etabonate ophthalmic gel 0.5% (LE gel is approved for treatment of postoperative ocular inflammation and pain, there have been no reported studies in patients undergoing laser-assisted in situ keratomileusis (LASIK or photorefractive keratectomy (PRK.Methods: This was a retrospective chart review conducted at five refractive surgical centers in the USA. Data were collected from primary LASIK or PRK surgery cases in which LE gel was used postoperatively as the clinician’s routine standard of care and in which patients were followed-up for up to 6 months. Data extracted from charts included patient demographics, surgical details, LE gel dosing regimen, pre- and postsurgical refractive characteristics, intraocular pressure (IOP measurements, and visual acuity. Primary outcomes included postoperative IOP elevations, adverse events, and early discontinuations.Results: Data were collected on 189 LASIK eyes (96 patients and 209 PRK eyes (108 patients. Mean (standard deviation [SD] years of age at surgery was 36.0 (11.7 and 33.9 (11.3 in LASIK and PRK patients. LE gel was prescribed most often four times daily during the first postoperative week, regardless of procedure; the most common treatment duration was 7–14 days in LASIK and ≥30 days in PRK patients. No unusual corneal findings or healing abnormalities were reported. Mean postoperative uncorrected distance visual acuity was 20/24 in LASIK and 20/30 in PRK eyes. Mild/trace corneal haze was reported in 20% of PRK patients; two PRK patients with moderate/severe corneal haze were switched to another corticosteroid. Mean postoperative

  7. Comparison of the corneal biomechanical effects after small-incision lenticule extraction and Q value guided femtosecond laser-assisted laser in situ keratomileusis

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    2016-04-01

    Full Text Available AIM:By comparing the changes of biomechanical properties of the cornea after small-incision lenticule extraction(SMILEand those after Q value guided femtosecond laser-assisted laser in situ keratomileusis(FSLASIK, to study the stability of biomechanical properties of the cornea after these two kinds of surgery and provide objective data for clinical operation.METHODS: Prospective comparative cases. One hundred and two cases(200 eyeswith myopia and myopic astigmatism were divided into 2 groups, 51 cases(100 eyesfor SMILE, and 51 cases(100 eyesfor Q value guided FS-LASIK. Corneal hysteresis(CHand the corneal resistance factor(CRFwere quantitatively assessed with the Ocular Response Analyzer(ORApreoperatively and 1d, 2wk, 1 and 3mo postoperatively.RESULTS: The decrease in CH and the CRF were statistically significant in both groups(PP>0.05. There were no statistically significant differences between the biomechanical changes in the two groups at any time(P>0.05.CONCLUSION: Both SMILE and Q value guided FS-LASIK can cause biomechanical decreases in the cornea. After 1d postoperatively, the decreases are nearly stable. There are no significant differences between the effect of SMILE and Q value guided FS-LASIK on the biomechanical properties of the cornea.

  8. Comparison of corneal sensitivity, tear function and corneal staining following laser in situ keratomileusis with two femtosecond laser platforms

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    Petznick A

    2013-03-01

    Full Text Available Andrea Petznick,1 Annabel Chew,2 Reece C Hall,2 Cordelia ML Chan,2 Mohamad Rosman,1,2 Donald Tan,1–3 Louis Tong,1–4 Jodhbir S Mehta1–31Singapore Eye Research Institute, Singapore; 2Singapore National Eye Centre, Singapore; 3Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; 4Duke-NUS Graduate Medical School, SingaporePurpose: To evaluate longitudinal changes in corneal sensitivity, tear function, and corneal staining in patients who underwent laser in situ keratomileusis (LASIK using two different femtosecond lasers.Methods: In a prospective, randomized clinical trial, contralateral eyes of 45 patients underwent flap creation by either VisuMax or IntraLase™ femtosecond laser. Corneal sensitivity, tear break up time (TBUT, Schirmer’s test, and corneal fluorescein staining were assessed preoperatively and at 1 week, 1 month, and 3 months postoperatively.Results: There were no statistical differences in any clinical outcome measure between the two femtosecond lasers (P > 0.05, although there was a trend towards slightly lower reductions for corneal sensitivity and TBUT in VisuMax-operated eyes. Overall, corneal sensitivity was significantly reduced at 1 week (P 0.05.Conclusion: This study showed that changes in corneal sensitivity, tear function, and corneal staining were statistically similar in LASIK using VisuMax and IntraLase femtosecond lasers for flap creation. However, the trend towards faster recovery of corneal sensitivity and TBUT observed in VisuMax-operated eyes may be attributable to improved technical specifications.Keywords: femtosecond laser, corneal sensitivity, tear film break-up time, Schirmer’s, corneal staining

  9. DIAGNOSIS AND TREATMENT FOR DEGENERATIVE RETINOSCHISIS OF MEDIUM TO HIGH MYOPIA IN YOUNG ADULTS PRIOR TO LASER-ASSISTED IN SITU KERATOMILEUSIS SURGERY

    Institute of Scientific and Technical Information of China (English)

    孙昕; 冯佩丽; 闫焱

    2013-01-01

    <正>Objective To discuss the characteristics of degenerative retinoschisis in young adults with medium to high myopia prior to laser-assisted in situ keratomileusis(LASIX) surgery and the significance of preventive photocoagulation.Methods A total of 32 eyes in 19 patients suffering from myopia combined with degenerative retinoschisis were included.The mean best-corrected visual acuity was 0.82±0.13 and the mean spherical equivalent of the subjective refraction was -(6.50±3.98) Diopter. The patients underwent preventive photocoagulation 1 month before the laser surgery for myopia.Results All the eyes that received preventive photocoagulation for retinoschisis had no further progression or retinal detachment during 4-year period of follow-up.Conclusion The degenerative retinoschisis in young adults should be recognized and treated with preventive photocoagulation.This may prevent further damage of visual field and other complications of slowly progressive retinoschisis after LASIK surgery.

  10. LASIK

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    Full Text Available ... Pin it Email Print Report a Problem LASIK is a surgical procedure intended to reduce a person's ... contact lenses. The goal of this Web site is to provide objective information to the public about ...

  11. LASIK

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    Full Text Available ... practices to follow, and questions to ask your doctor before undergoing LASIK surgery. This web site also ... risks and how can I find the right doctor for me? What should I expect before, during, ...

  12. LASIK

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    Full Text Available ... surgery. See other sections of this site to learn about what you should know before surgery, what ... surgery and other important information. The video includes images of common visual problems that a LASIK patient ...

  13. LASIK

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    Full Text Available ... to the public about LASIK surgery. See other sections of this site to learn about what you ... is folded back revealing the stroma, the middle section of the cornea. Pulses from a computer-controlled ...

  14. LASIK

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    Full Text Available ... glasses or contact lenses. The goal of this Web site is to provide objective information to the ... ask your doctor before undergoing LASIK surgery. This web site also provides information on FDA’s role in ...

  15. LASIK

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    Full Text Available ... is replaced. There are other techniques and many new terms related to LASIK that you may hear ... Website Policies U.S. Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993 1-888- ...

  16. LASIK

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    Full Text Available ... site is to provide objective information to the public about LASIK surgery. See other sections of this site to learn about what ... U.S. Food and Drug Administration 10903 New Hampshire ...

  17. Comparison of efficacy, safety, and predictability of laser in situ keratomileusis using two laser suites

    Directory of Open Access Journals (Sweden)

    Meidani A

    2016-08-01

    Full Text Available Alexandra Meidani,1–3 Chara Tzavara3 1Hypervision Laser Centre, 2Eye Day Clinic, 3Department of Hygiene, University of Athens Medical School, Centre for Health Services Research, Epidemiology and Medical Statistics, Athens, Greece Purpose: The main aim of this study was to compare the efficacy, safety, and predictability of femtosecond laser-assisted in situ keratomileusis performed by two different laser suites in the treatment of myopia for up to 6 months.Methods: In this two-site retrospective nonrandomized study, myopic eyes that underwent laser-assisted in situ keratomileusis using IntraLase FS 60 kHz formed group 1 and those using WaveLight FS200 femtosecond laser system formed group 2. Ablation was performed with Visx Star S4 IR and WaveLight EX500 Excimer lasers, respectively, in groups 1 and 2. Both groups were well matched for age, sex, and mean level of preoperative refractive spherical equivalent (MRSE. Uncorrected distance visual acuity, corrected distance visual acuity, and MRSE were evaluated preoperatively and at 1 week, 1 month, and 6 months after treatment.Results: Fifty-six eyes of 28 patients were included in the study. At 6-month follow-up postop, 78.6% of eyes in group 1 and 92.8% of eyes in group 2 achieved an uncorrected distance visual acuity of 20/20 or better (P=0.252. 35.7% and 50% in group 1 and group 2, respectively, gained one line (P=0.179. No eye lost lines of corrected distance visual acuity. Twenty-five eyes in group 1 (92.7% and 27 eyes in group 2 (96.3% had MRSE within ±0.5 D in the 6-month follow-up (P>0.999. The mean efficacy index at 6 months was similar in group 1 and group 2 (mean 1.10±0.12 [standard deviation] vs 1.10±0.1 (P=0.799. The mean safety index was similar in group 1 and group 2 (mean 1.10±0.10 [standard deviation] vs 1.10±0.09 (P=0.407.Conclusion: The outcomes were excellent between the two laser suites. There were no significant differences at 6-month follow-up postop between the two

  18. Láser in situ keratomileusis en la corrección de miopía y astigmatismo residual posqueratotomía radial en casos seleccionados Laser in situ keratomileusis to correct myopia and residual astigmatism after radial keratotomy in selected cases

    Directory of Open Access Journals (Sweden)

    Eneida Pérez Candelaria

    2010-01-01

    Full Text Available OBJETIVO: Evaluar la seguridad y la eficacia del tratamiento con láser in situ keratomileusis en pacientes con defectos residuales posqueratotomía radial. MÉTODOS: Se realizó un estudio descriptivo de tipo prospectivo longitudinal a 55 ojos de 31 pacientes con miopía y/o astigmatismo residuales posqueratotomía radial reoperados con láser in situ keratomileusis en el Servicio de Cirugía Refractiva del Instituto Cubano de Oftalmología "Ramón Pando Ferrer" desde enero a junio del 2007. En la selección de los pacientes, se utilizaron estrictos criterios de inclusión y exclusión utilizándose las variables: error refractivo residual en equivalente esférico medio, la agudeza visual sin corrección y la mejor agudeza visual corregida preLASIK y posLASIK, así como las complicaciones transoperatorias y postoperatorias. El seguimiento promedio de los pacientes fue de 12 ± 3 meses. RESULTADOS: El equivalente esférico posLASIK disminuyó notablemente en el primer día del posoperatorio y se mantuvo estable en la última consulta. La agudeza visual sin corrección posLASIK fue 1,0 (20/20 en 22 ojos (40 % y > 0,5 (20/40 en 44 ojos (80 %. En 11 ojos (20 %, la mejor agudeza visual corregida mejoró 1 línea en la cartilla de Snellen. Se presentócomo complicación intraoperatoria un ojo con perforación central del flap corneal y dentro de las complicaciones postoperatorias se reportaron detritus y restos hemáticos en la interfase en 2 ojos, pliegues finos del colgajo en un solo ojo y epitelización de la interfase fuera del eje visual igualmente, en un solo ojo. CONCLUSIONES: El Láser in situ keratomileusis puede ser usado exitosamente en la corrección de la miopía y el astigmatismo posqueratotomía radial en casos debidamente seleccionados.OBJECTIVE: To evaluate the safety and the efficacy of the Laser in Situ Keratomileusis treatment in patients with residual defects after radial keratotomy. METHODS: A prospective, longitudinal and

  19. LASIK

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    Full Text Available ... and Human Services U.S. Food and Drug Administration A to Z Index Follow FDA En Español Search ... sharing options Linkedin Pin it Email Print Report a Problem LASIK is a surgical procedure intended to ...

  20. LASIK

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    Full Text Available ... and Human Services U.S. Food and Drug Administration A to Z Index Follow FDA En Español Search ... sharing options Linkedin Pin it Email Print Report a Problem LASIK is a surgical procedure intended to ...

  1. LASIK后角膜瓣皱褶和折叠的处理%Management of folds and striae in the cornea flap after laser in situ keratomileusis,

    Institute of Scientific and Technical Information of China (English)

    刘云川; 吴欣怡; 张丽; 马蓉; 崔迎春; 王洪娟

    2008-01-01

    目的 探讨准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)后早期角膜瓣皱褶和折叠的有效处理方法.方法 对LASIK术后11例角膜瓣皱褶的原因及处理进行回顾性分析.所有的患者需经手术重新复位,在显微镜下采用去离子水冲洗角膜瓣加戴角膜接触镜24 h.术后观察角膜瓣状况、屈光变化、裸眼视力和最佳矫正视力.结果 经过处理的所有患者裸眼视力均达到或超过术前最佳矫正视力.角膜透明,未见明显皱褶,角膜瓣位置正常,无上皮植入.结论 角膜瓣皱褶和折叠是LASIK术后较严重的并发症.早期诊断和正确快速的处理是获得最佳视力的关键.用去离子水重新复位角膜瓣并佩戴角膜接触镜治疗LASIK术后早期角膜瓣皱褶和折叠是安全简单有效的方法.%Objective To investigate the efficient treatment of cornea flap folds and striae after laser in situ keratomileusis (LASIK).To review the management and results of cases with severe flap wrinkling or dislodgment after LASIK.Methods Eleven patients with cornea flap folds and striae after LASIK are described.To make retrospective analysis of etiology and treatment in 11 cases who had cornea flap folds and striae after LASIK.Surgical repositioning of the flap was performed in all cases.Under the operating microscope the flap was refloated and hydrated with sterile deionized water for 2 minutes without stretching or ironing the flap.A bandage contact lens was then applied for 24 hours.Flap status,refractive changes,and final uncorrected and best corrected visual acuities were used to evaluate the outcome of flap repositioning.Results Relocation flap and bandage contact lens were used in such cases.Scraping epithelial and hydrating the cornea flap with sterile deionized water were used under operation.Twenty-four hours after treatment with sterile deionized water and a bandage contact lens,the cornea was smooth and wrinkle free.All patients

  2. Visual Outcomes, Quality of Vision, and Quality of Life of Diffractive Multifocal Intraocular Lens Implantation after Myopic Laser In Situ Keratomileusis: A Prospective, Observational Case Series

    Science.gov (United States)

    2017-01-01

    Purpose. To report visual performance and quality of life after implantation of a bifocal diffractive multifocal intraocular lens (MIOL) in postmyopic laser in situ keratomileusis (LASIK) patients. Methods. Prospective, observational case series. Patients with prior myopic LASIK who had implantation of Tecnis ZMA00/ZMB00 MIOL (Abbott Medical Optics) at Hong Kong Sanatorium and Hospital were included. Postoperative examinations included monocular and binocular distance, intermediate and near visual acuity (VA), and contrast sensitivity; visual symptoms (0–5); satisfaction (1–5); spectacle independence rate; and quality of life. Results. Twenty-three patients (27 eyes) were included. No intraoperative complications developed. Mean monocular uncorrected VA at distance, intermediate, and near were 0.13 ± 0.15 (standard deviation), 0.22 ± 0.15, and 0.16 ± 0.15, respectively. Corresponding mean values for binocular uncorrected VA were 0.00 ± 0.10, 0.08 ± 0.13, and 0.13 ± 0.10, respectively. No eyes lost >1 line of corrected distance VA. Contrast sensitivity at different spatial frequencies between operated and unoperated eyes did not differ significantly (all P > 0.05). Mean score for halos, night glare, starbursts, and satisfaction were 1.46 ± 1.62, 1.85 ± 1.69, 0.78 ± 1.31, and 3.50 ± 1.02, respectively. Eighteen patients (78%) reported complete spectacle independence. Mean composite score of the quality-of-life questionnaire was 90.31 ± 8.50 out of 100. Conclusions. Implantation of the MIOL after myopic LASIK was safe and achieved good visual performance.

  3. Examination and management of corneal topography before laser in situ keratomileusis surgery%LASIK术前角膜地形图检查及处理

    Institute of Scientific and Technical Information of China (English)

    汤明霞

    2012-01-01

    Objective To explore the significance of corneal topography before laser in situ keratomileusis (LAS1K) surgery. Methods The comeal topography examination was performed to 500 patients (920 eyes) with myopia or with astigmatism. Before surgery the patients were grouped and handled according to Rabirtowitz standard. The intraoperative conditions, the number of kerato-conus, refractive regression cases and time were observed. Results Intraoperative corneal flap making accidents were not seen, keratoconus was not founded after surgery, and most refrative regressions occurred in 1 year after operation. In patients with higher K value, higher myopia and older age, refrative regression occurred easily after surgery. Conclusion Preoperative corneal topography examination before LASIK surgery is of clinical importance.%目的 探讨角膜地形图检查在准分子激光原位磨镶术(LASIK)术前的重要意义.方法 对欲行LASIK治疗的近视或伴散光的500例(920只眼)进行术前角膜地形图检查,术前根据Rabinowitz标准将患者进行分组并处理,观察各组手术病例术中情况,术后1年内发生圆锥角膜和屈光回退的例数、时间.结果 术中未出现制作角膜瓣意外,术后未发现圆锥角膜,术后回退时间多发生在1年后,K值较高、高度近视、年龄偏大的患者较易发生回退.结论 术前角膜地形图检查对LASIK 术有重要的检查意义.

  4. Comparative evaluation of visual outcomes and corneal asphericity after laser-assisted in situ keratomileusis with the six-dimension Amaris excimer laser system

    Science.gov (United States)

    Piao, JunJie; Li, Ying-Jun; Whang, Woong-Joo; Choi, Mihyun; Kang, Min Ji; Lee, Jee Hye; Yoon, Geunyoung; Joo, Choun-Ki

    2017-01-01

    Purpose To compare the visual and refractive outcomes after laser-assisted in situ keratomileusis (LASIK) surgery for correction of myopia or myopic astigmatism using a six-dimensional Amaris excimer laser. Methods In this retrospective cohort study, we enrolled 47 eyes of 28 patients (age: 19–36 years) with myopia or myopic astigmatism. We used the Custom Ablation Manager protocol and performed ablations with the SCHWIND AMARIS system. LASIK flaps were cut with an iFS Advanced Femtosecond Laser. Mean static (SCC) and dynamic cyclotorsion (DCC) were evaluated. Visual and refractive outcomes were evaluated during 6 months’ follow-up. Corneal asphericity (Q-value) was analyzed at 4 months postoperatively. Results The spherical equivalent (SE) reduction was statistically significant reduce 1 day after refractive surgery (P Free mode (AF) and 90% in the Corneal Wavefront mode (CW). SCC measurements were within ± 5 degrees in 57% (AF) and 68% (CW) of eyes. Mean DCC was within ± 1 degree in 96% (AF) or 95% (CW) of cases. At 6 months, the uncorrected distance visual acuity was 20/25 or better in all eyes. At last follow-up, both steep and flat keratometry values had significantly flattened in both groups (P < 0.001). Corneal asphericity also increased significantly during the postoperative period for an 8-mm corneal diameter (P < 0.001). Conclusions LASIK for myopia or myopic compound astigmatism correction using the six-dimensional AMARIS 750S excimer laser is safe, effective, and predictable. Postoperative corneal asphericity can be analyzed by linear regression to predict the changes in postoperative corneal asphericity with this approach. PMID:28187180

  5. 大龄近视患者行LASIK的体会%Experience of laser in situ keratomileusis on aged-myopia

    Institute of Scientific and Technical Information of China (English)

    张蓉; 张莉

    2013-01-01

    AIM: To probe the visual effects of laser in situ keratomileusis (LASIK) operation design on aged-myopic patients with falling adjustment abilities. METHODS: Among the 32 subjects 63 eyes with ametropia and presbyopia, 27 were completely corrected by monocular LASIK operation on the 53 eyes, to the optimum distant vision of the dominant eye, while the near-sighted vision of the non-dominant eye was under corrected by -0. 5--2. 00D. The distant vision of the other 5 subjects was completely corrected by binocular LASIK operation on the 10 eyes. Three months after the operation, subjects were closely observed. RESULTS: Three months after the operation, among the former group, the distant vision of dominant and non-dominant eyes were found with range from 1. 0 to 1. 2, and from 0. 3 to 0. 6 respectively. Their near - sighted vision of dominant and non-dominant eyes was 0. 6 and 1.0, respectively. Among the latter group, the distant vision of both eyes was found to be completely corrected. CONCLUSION: When operated on aged - myopic patients with falling adjustment abilities, LASIK should incorporate patient's requirement and age in its operation design.%目的:讨大龄近视伴调节力下降患者行准分子激光原位角膜磨镶术(LASIK)的手术设计对视力的影响.方法:光不正伴老视的患者32例63眼中27例53眼行单眼LASIK主视眼按最佳矫正远视力完全矫正,非主视眼近视欠矫-0.5~-2.00D,5例10眼双眼远视力全部矫正.观察术后3mo视力.结果:后3mo,27例53眼远视力主视眼1.0~1.2,非主视眼0.3~0.6;近视力主视眼0.6,非主视眼1.0.5例10眼双眼远视力完全矫正.结论:ASIK矫正大龄调节力下降患者,在设计手术方案时需按患者要求、年龄等综合考虑.

  6. Power vector analysis of the outcomes of laser subepithelial keratomileusis and laser in situ keratomileusis for high myopia astigmatism%矢量法分析LASEK和LASIK矫正高度散光的疗效

    Institute of Scientific and Technical Information of China (English)

    干德康; 周行涛; 戴锦晖; 瞿小妹; 于志强; 褚仁远

    2009-01-01

    目的 应用Thibos矢量法比较准分子激光上皮瓣下角膜磨镶术(laser subepithelial keratomileus-is,LASEK)和准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)矫正高度散光(≥-2.75 D)的疗效.方法 LASEK59例(59眼),LASIK37例(37眼).分析两组患者术前和术后裸眼视力(uncorrected visualacuity,UCVA)、最佳矫正视力(best corrected visual acuity,BCVA)、屈光度(S球镜,C柱镜,M等效球镜)和模糊指数B的差别.结果 除LASIK组BCVA外,所有患者术前和术后UCVA、BCVA、S、M、C、B差异均有统计学意义.术后两组间S、C、M、B差异均无统计学意义,BCVA较术前无一例发生下降2行.结论 LASEK和LASIK手术方式均安全、手术效果可靠,是治疗高度散光的有效方法.Thibos矢量分析能够全面地描述眼屈光异常和屈光手术疗效.(中国眼耳鼻喉科杂志,2009,9:23-25)

  7. Photorefractive Keratectomy with Adjunctive Mitomycin C for Residual Error after Laser-Assisted In Situ Keratomileusis Using the Pulzar 213 nm Solid-State Laser: Early Results.

    Science.gov (United States)

    Ng-Darjuan, Maya Fe; Evangelista, Raymond P; Agahan, Archimedes Lee D

    2013-01-01

    Purpose. To evaluate the accuracy, efficacy, stability, and safety of photorefractive keratectomy (PRK) enhancement using the Pulzar 213 nm solid-state laser (SSL) with adjunctive Mitomycin C in eyes previously treated with laser assisted in situ keratomileusis (LASIK) with residual error of refraction. Methods. This is a prospective noncomparative case series of 16 eyes of 12 patients who underwent PRK for residual refractive error after primary LASIK. Mitomycin C 0.02% was used after the PRK to prevent haze formation. Outcomes measured were pre- and postoperative manifest refraction spherical equivalent (MRSE), uncorrected (UDVA) and best-corrected distance visual acuity (CDVA), and slit lamp evidence of corneal complications. Results. The mean UDVA improved from 20/70 preoperatively to 20/30 postoperatively. The average gain in lines for the UDVA was 2.38. After six months of followup, the postoperative MRSE within 0.50 D in 56% (9) of eyes and 94% (15) eyes were within 1.0 diopters of the intended correction. No eyes developed haze all throughout the study. Conclusion. PRK enhancement with adjunctive use of Mitomycin C for the correction of residual error of refraction after LASIK using the Pulzar 213 nm solid-state laser is an accurate, effective, and safe procedure.

  8. The history of LASIK.

    Science.gov (United States)

    Reinstein, Dan Z; Archer, Timothy J; Gobbe, Marine

    2012-04-01

    Keratomileusis, brainchild of Jose I. Barraquer Moner, was conceived and developed as the first stromal sculpting method to correct refractive error in 1948. The word "keratomileusis" literally means "sculpting" of the "cornea." Barraquer's first procedures involved freezing a disc of anterior corneal tissue before removing stromal tissue with a lathe. Over the years, the procedure continued to develop, first through the Barraquer-Krumeich-Swinger non-freeze technique where tissue was removed from the underside of the disc by a second pass of the microkeratome. In-situ keratomileusis was later developed by passing the microkeratome a second time directly on the stromal bed. The procedure became known as automated lamellar keratoplasty with the invention of an automated microkeratome and was further refined by replacing the disc without sutures and later by stopping the microkeratome before the end of the pass to create a hinged flap, as first demonstrated in 1989. The history of the excimer laser dates back to 1900 and the quantum theory, eventually leading to the discovery that 193-nm ultraviolet excimer laser pulses could photoablate tissue without thermal damage. Ultrastructural and wound healing studies confirmed that large area ablation could be performed in the central cornea. This was described as photorefractive keratectomy in 1986 and the first sighted eyes were treated in 1988. An excimer laser was first used to sculpt from the stromal bed under a hinged flap created manually using a trephine and scalpel in 1988. The incorporation of a microkeratome in 1990 finally led to laser in situ keratomileusis-LASIK-as we know it today.

  9. Laser in situ keratomyleusis (LASIK for correction of myopia and hypermetropia: Our one year experience

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    Vukosavljević Miroslav

    2009-01-01

    Full Text Available Background/Aim. Laser in situ keratamileusis (LASIK is the most commonly used refractive surgical method worldwide. The aim of this study was to examine the effectiveness and safety of LASIK in the correction of myopia and hyperopia. Methods. The study included myopic and hyperopic eyes with preoperative best corrected visual acuity (BCVA = 1 (20/20, of the total number of 322 divided into 2 groups - 1 myopic eyes (n = 241 which were divided into 4 subgroups according to the myopia strength: a ≤ -1.75 D (n = 23, b from -2 to -3.75 D (n = 81, c from -4 to -6.75 D (n = 113, d ≥ -7 D (n = 24; 2 hyperopic eyes (n = 81 which were divided into 3 subgroups according to the hyperopia strength: a ≤ +1.75D (n = 10, b from +2 to +3.75 D (n = 46, c ≥ +4 D (n = 25. Myopic and hyperopic eyes with preoperative BCVA ≤ 0.9 (eyes with ambliopia were excluded from the study, as well as eyes with astigmatism > 1.5 D. To assess the effectiveness of LASIK we examined the percentage of eyes in the mentioned subgroups, which derived uncorrected visual acuity (UCVA 6 month after the intervention to the following: a UCVA = 1 (20/20 and b UCVA ≥ 0.5 (20/40. To assess the safety of LASIK we examined the frequency of intraoperative and postoperative complications. A prospective study was performed in a 6-months follow-up period. Results. Refractive spherical equivalent (RSE of myopic eyes was in the range from -0.75 D to -12 D. In the first subgroup preoperative mean value of RSE with standard deviation (mean RSE ± SD was -1.39 ± 0.36 D, and 6 months after the LASIK 100% of the eyes had UCVA = 20/20. In the second subgroup preoperative mean RSE ± SD was -2.85 ± 0.50 D, and 6 months after LASIK 93% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA ≥ 20/40. In the third subgroup preoperative mean RSE ± SD was -5.03 ± 0.75 D, and 6 months after the LASIK 90% of the eyes had UCVA = 20/20, but 100% of the eyes had UCVA ≥ 20/40. In the fourth

  10. Successful femtosecond LASIK flap creation despite multiple suction losses

    Science.gov (United States)

    Syed, Zeba A.; Melki, Samir A.

    2014-01-01

    Summary We present a case of successful completion of a laser in situ keratomileusis (LASIK) procedure despite 5 episodes of suction loss during femtosecond flap creation in a 30-year-old man with no risk factors. The patient had an uncorrected distance visual acuity of 20/20 in both eyes at his 2-month follow-up visit. Our experience in this case shows that multiple suction losses during femtosecond LASIK flap creation do not preclude completion of a successful procedure with excellent visual outcomes. Caution and technique modification are advised if multiple laser passes are applied to avoid creating multiplanar flaps. PMID:25097457

  11. 穿透性角膜移植治疗LASIK术后继发圆锥角膜%Penetrating keratoplasty for secondary keratoconus after Laser in situ keratomileusis

    Institute of Scientific and Technical Information of China (English)

    姚晓明; 黎明; 于莉; 齐卫; 诸凤娇; 袁凤波; 姚迪

    2010-01-01

    目的 观察穿透性角膜移植治疗准分子激光原位角膜磨削术(Laserin situkeratomileusis,LASIK)术后继发圆锥角膜的效果.方法 对6例LASIK术后确诊为继发圆锥角膜的患者进行穿透性角膜移植术,选用直径7~7.5mm植片,与植床等大.术后随访1~5年,观察和评价其疗效.结果 本研究6例患者LASIK术前角膜厚度平均为394.9μm.术后圆锥发生时间(13±3.4)个月,穿透性角膜移植术后,中央角膜厚度平均为504.7μm,视力明显增进,随访期内未见圆锥角膜复发.讨论我们建议,进行LASIK对术中切削时,角膜基质床的厚度不应小于270μm,角膜总厚度不应小于400μm.对LASIK术后继发圆锥角膜患者行穿透性角膜移植术,植床直径与角膜植片等大,术后再选择性拆除缝线,将有助于降低术后免疫排斥反应发生率和圆锥复发,减少手术源性散光,提高视力.%Objective To investigate the therapeutic effect of penetrating keratoplasty (PKP) for secondary keratoconus after Laser in situ keratomileusis (LASIK). Methods Six eyes of secondary keratoconus after LASIK undergoing PKP were analyzed with 7.5mm transplant which had the same diameter that positively matching the recipient bed. The therapeutic effect had been monitored and assessed for the follow-up 1 to 5 years. Results Post-operatively, the six patients had an average 504.7+8.3μ m of central cornea thickness.The visual acuity improved obviously and there was no recurrence of keratoconus during the follow-up period.Conclusions It is encouraged that during the PKP, the thickness of stromal bed should be less than 270μ m,and the overall thickness of cornea after photoablation should be greater than 400μ m. For the ectatic corneas followed by LASIK, it is essential to replace the abnormal cornea by a same diameter donor button, and the sutures will be removed under the guidance of corneal topography. A lower occurrence of immunological rejection, iatrogenic

  12. Analysis of high-order aberration after both side laser in situ keratomileusis operation in treating high myopia%双面准分子激光原位角膜磨镶术治疗高度近视眼术后高阶像差分析

    Institute of Scientific and Technical Information of China (English)

    高莉; 张振华

    2012-01-01

    目的 比较双面准分子激光原位角膜磨镶术(both side lasik,BSL)和准分子激光原位角膜磨镶术(Laser in situ keratomileusis,lasik)治疗高度近视眼术后高阶像差的变化.方法 选择BSL和lasik两种术式对高度近视眼手术治疗61例,122只眼.其中,BSL手术30例,60只眼;lasik手术31例,62只眼.使用NIDEK公司生产的OPD-SCAN波前像差分析议,测量术前和术后一周、一个月和三个月暗室6~7 mm自然瞳孔直径的波前像差.结果 1 BSL和lasik两组术前总高阶像差、C7、C8和C12均方根值(RMS值)比较,均P>0.05,差异无统计学意义.2术后一周、一个月和三个月时BSL和lasik两组的总高阶像差、C7、C8和C12RMS值均较术前差异有统计学意义(P<0.01).3.术后一周、一个月和三个月BSL和lasik两组之间总高阶像差、C7、C8和C12RMS值比较,P值均>0.05差异无统计学意义.结论 BSL和lasik两种手术方法治疗高度近视眼,术后高阶像差增加幅度相近似.%Objective To compare the high-order aberration after both side laser in situ keratomileusis (BSL) and laser in situ keratomileusis (Lasik) operation in treating high myopia. Methods BSL and Lasik were both.performed in 61 (122 eyes) patients with high myopia.Among which 30 patients (60 eyes) were randomly selected as BSL group,and 31 patients (62 eyes) were selected as Lasik group.The wavefront aberration were measured in darkroom with normal pupil at preoperatively,1 week,1 month and 3 months postoperatively by OPD-SCAN object aberration apparatus produced in NIDEK company. Results The root mean square (RMS) value of high-order aberration,C7,C8 and C12 in BSL group and Lasik group were not statistically significant at preoperatively (P >0.05).The RMS value of C7,C8 and C12 in BSL group and Lasik group were statistically increased at 1 week,1 month and 3 months postoperatively (P <0.01).The RMS value of C7,C8 and C12 in BSL group and Lasik group were not significantly

  13. The Incidence of Central Serous Chorioretinopathy after Photorefractive Keratectomy and Laser In Situ Keratomileusis

    Directory of Open Access Journals (Sweden)

    Majid Moshirfar

    2012-01-01

    A chart review was performed to identify all patients with CSCR and a previous history of LASIK or PRK. Results. Over the 6-year study period, 1 of 4,876 eyes which had LASIK or PRK at the Moran Eye Center was diagnosed with CSCR. One other patient was referred from an outside center, developed CSCR symptoms one month after PRK. Both patients were managed conservatively with a final visual acuity of 20/20 or better. All other patients presented 4 or more years after refractive surgery. Conclusions. We report the first 2 CSCR cases developing within one month after PRK. The low incidence argues against a causal association. Topical corticosteroids or anxiety may elevate cortisol levels presenting therapeutic challenges for the management of CSCR after PRK or LASIK.

  14. A Rare Devastating Complication of Lasik: Bilateral Fungal Keratitis

    Directory of Open Access Journals (Sweden)

    H. Taylan Sekeroglu

    2010-01-01

    Full Text Available Purpose. To report an unusual case of severe bilateral fungal keratitis following laser in situ keratomileusis (LASIK. Method. A 48-year-old man developed bilateral diffuse corneal infiltration two weeks after LASIK. The corneal scrapings revealed fungal filaments but cultures were negative. Results. The corneal ulceration was improved on the left eye whereas spontaneous perforation occurred and finally evisceration was needed on the right eye despite topical and systemic antifungal treatment. Conclusions. Fungal keratitis, especially with bilateral involvement, is a very rare and serious complication of LASIK surgery. Clinical suspicion is crucial because most of fungal keratitis are misdiagnosed as bacterial keratitis and can lead serious visual results, even eye loss.

  15. Accuracy of corneal power measurements for intraocular lens power calculation after myopic laser In situ Keratomileusis

    Directory of Open Access Journals (Sweden)

    Hany A Helaly

    2016-01-01

    Conclusion: Scheimflug tomography imaging using the Holladay EKR 4 mm improved the accuracy of IOL power calculation in post.LASIK eyes. The best option is a combination of formulas. We recommended the use the combined “Shammas-PL ± Double-K SRK/T formula using EKR 4 mm”h for optical outcomes.

  16. Adjuvant corneal crosslinking to prevent hyperopic LASIK regression

    Directory of Open Access Journals (Sweden)

    Aslanides IM

    2013-03-01

    Full Text Available Ioannis M Aslanides, Achyut N MukherjeeEmmetropia Mediterranean Eye Clinic, Heraklion, Crete, GreecePurpose: To report the long term outcomes, safety, stability, and efficacy in a pilot series of simultaneous hyperopic laser assisted in situ keratomileusis (LASIK and corneal crosslinking (CXL.Method: A small cohort series of five eyes, with clinically suboptimal topography and/or thickness, underwent LASIK surgery with immediate riboflavin application under the flap, followed by UV light irradiation. Postoperative assessment was performed at 1, 3, 6, and 12 months, with late follow up at 4 years, and results were compared with a matched cohort that received LASIK only.Results: The average age of the LASIK-CXL group was 39 years (26–46, and the average spherical equivalent hyperopic refractive error was +3.45 diopters (standard deviation 0.76; range 2.5 to 4.5. All eyes maintained refractive stability over the 4 years. There were no complications related to CXL, and topographic and clinical outcomes were as expected for standard LASIK.Conclusion: This limited series suggests that simultaneous LASIK and CXL for hyperopia is safe. Outcomes of the small cohort suggest that this technique may be promising for ameliorating hyperopic regression, presumed to be biomechanical in origin, and may also address ectasia risk.Keyword: CXL

  17. Chronic dry eye symptoms after LASIK: parallels and lessons to be learned from other persistent post-operative pain disorders.

    Science.gov (United States)

    Levitt, Alexandra E; Galor, Anat; Weiss, Jayne S; Felix, Elizabeth R; Martin, Eden R; Patin, Dennis J; Sarantopoulos, Konstantinos D; Levitt, Roy C

    2015-04-21

    Laser in-situ keratomileusis (LASIK) is a commonly performed surgical procedure used to correct refractive error. LASIK surgery involves cutting a corneal flap and ablating the stroma underneath, with known damage to corneal nerves. Despite this, the epidemiology of persistent pain and other long-term outcomes after LASIK surgery are not well understood. Available data suggest that approximately 20-55% of patients report persistent eye symptoms (generally regarded as at least 6 months post-operation) after LASIK surgery. While it was initially believed that these symptoms were caused by ocular surface dryness, and referred to as "dry eye," it is now increasingly understood that corneal nerve damage produced by LASIK surgery resembles the pathologic neuroplasticity associated with other forms of persistent post-operative pain. In susceptible patients, these neuropathological changes, including peripheral sensitization, central sensitization, and altered descending modulation, may underlie certain persistent dry eye symptoms after LASIK surgery. This review will focus on the known epidemiology of symptoms after LASIK and discuss mechanisms of persistent post-op pain due to nerve injury that may be relevant to these patients. Potential preventative and treatment options based on approaches used for other forms of persistent post-op pain and their application to LASIK patients are also discussed. Finally, the concept of genetic susceptibility to post-LASIK ocular surface pain is presented.

  18. Láser in situ keratomileusis en la corrección de miopía y astigmatismo residual posqueratotomía radial en casos seleccionados Laser in situ keratomileusis to correct myopia and residual astigmatism after radial keratotomy in selected cases

    OpenAIRE

    Eneida Pérez Candelaria; Ximena Paula Sarmiento Nogales; Isabel Cristina Lantigua Maldonado; Marrel García Martín; Lorelei Ortega Díaz

    2010-01-01

    OBJETIVO: Evaluar la seguridad y la eficacia del tratamiento con láser in situ keratomileusis en pacientes con defectos residuales posqueratotomía radial. MÉTODOS: Se realizó un estudio descriptivo de tipo prospectivo longitudinal a 55 ojos de 31 pacientes con miopía y/o astigmatismo residuales posqueratotomía radial reoperados con láser in situ keratomileusis en el Servicio de Cirugía Refractiva del Instituto Cubano de Oftalmología "Ramón Pando Ferrer" desde enero a junio del 2007. En la sel...

  19. [Post-laser in situ keratomileusis refractive changes induced by glaucoma in the absence of keratectasia].

    Science.gov (United States)

    Martínez-de-la-Casa, J M; Rodríguez-Uña, I; González-Pastor, E; Díaz-Valle, D; García-Feijóo, J

    2014-10-01

    We report the case of a 34 year-old man with progressive loss of visual acuity in his left eye, who was diagnosed with pigmentary glaucoma with an intraocular pressure of 32mmHg. Eight years previously, the patient had undergone refractive surgery (LASIK). Hypotensive treatment led to a significant refractive change accompanied by flattening of the corneal curvature. We propose that a high intraocular pressure acting on a cornea weakened by refractive surgery can provoke corneal steepening, inducing refractive changes even in the absence of keratectasia. Copyright © 2011 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  20. Femtosecond laser-assisted in situ keratomileusis multifocal ablation profile using a mini-monovision approach for presbyopic patients with hyperopia

    Directory of Open Access Journals (Sweden)

    Vastardis I

    2016-07-01

    Full Text Available Iraklis Vastardis,1 Brigitte Pajic-Eggspühler,1 Jörg Müller,1,2 Zeljka Cvejic,2 Bojan Pajic,1–4 1Swiss Eye Research Foundation, Orasis Eye Clinic, Aargau, Reinach, Switzerland; 2Faculty of Physics, University of Novi Sad, Novi Sad, Serbia; 3Department of Ophthalmology, Geneva University Hospitals, Geneva, Switzerland; 4Medical Faculty, Military Medical Academy, University of Defence, Belgrade, Serbia Purpose: To report the visual outcomes of the femtosecond laser-assisted multifocal aspheric corneal ablation profile using a mini-monovision approach and to evaluate if corneal multifocality was effective, and to report the relative benefits of this approach.Patients and methods: Bilateral femtosecond laser-assisted in situ keratomileusis using a multifocal aspheric corneal ablation profile was performed on 19 hyperopic patients (38 eyes. They were divided into two groups based on eye dominance: dominant eye (DE group targeting emmetropia and the nondominant eye (NDE group targeting -0.5 D slight myopia. The uncorrected distance visual acuity (UDVA, uncorrected intermediate visual acuity (UIVA, uncorrected near visual acuity (UNVA, and retreatment rates were reported from baseline to 6 months.Results: The UNVA, UIVA, and UDVA improved significantly in both groups (Kruskal–Wallis test, DE and NDE: P<0.00001, P<0.000005, and P=0.00001, respectively. Corrected distance visual acuity (CDVA baseline was better in both groups in comparison to UDVA at 6 months (Wilcoxon test, DE: P<0.001, 95% confidence interval (CI of the median 0.0–0.0 LogMAR and 0.1000–0.1218 LogMAR and NDE: P=0.010, 95% CI of the median 0.0–0.0 LogMAR and 0.00–0.10 LogMAR. There was a significant loss of lines between CDVA baseline and UDVA at 6 months in both groups (DE group: 68% of eyes lost one line or more; NDE group: 58% of eyes lost one line or more. The corrected near visual acuity baseline compared to UNVA at 6 months was not statistically important

  1. Same-day intrastromal corneal ring segment and collagen cross-linking for ectasia after laser in situ keratomileusis: long-term results.

    Science.gov (United States)

    Yildirim, Aydin; Uslu, Hasim; Kara, Necip; Cakir, Hanefi; Gurler, Bulent; Colak, Hatice Nur; Ozgurhan, Engin Bilge

    2014-05-01

    To report the long-term results of combined same-day intrastromal corneal ring segment placement and corneal collagen cross-linking (CXL) for postoperative laser in situ keratomileusis (LASIK) ectasia. Retrospective, interventional case series. This retrospective, interventional cases series was performed in Turkiye Hospital Eye Clinic and the Department of Ophthalmology, Fatih University Medical Faculty Hospital, Istanbul, Turkey. Sixteen eyes of 14 patients with postoperative ectasia after LASIK were enrolled. All consecutive patients were treated with femtosecond laser-assisted intrastromal corneal ring segment implantation and followed by same-day corneal collagen cross-linking for ectasia occurring after LASIK. Main outcome measures included uncorrected distance visual acuity, corrected distance visual acuity, spherical and cylindrical refraction, and simulated keratometry values. The mean age ± standard deviation of the 10 women and 4 men was 33.0 ± 6.5 years (range, 23 to 44 years), and the mean follow-up was 43 months (range, 36 to 62 months). The uncorrected distance visual acuity improved significantly from 1.18 ± 0.42 logarithm of the minimal angle of resolution (logMAR) units to 0.44 ± 0.22 logMAR (P 8 D at the last visit, and the minimum keratometry value decreased from 44.3 ± 4.7 D to 41.5 ± 3.5 D (P < .001 for both). No serious complications were shown during follow-up. Implantation of intrastromal corneal ring segment implantation combined with same-day corneal collagen cross-linking was a safe and effective treatment for ectasia occurring after LASIK. It also significantly improved the visual acuity, refraction, and keratometry values. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Globe Rupture of a Post-LASIK Keratectasia Eye From Blunt Trauma.

    Science.gov (United States)

    Cheung, Albert Y; Heidemann, David G

    2016-12-01

    To report a case of globe rupture in a patient with post-laser in situ keratomileusis (LASIK) ectasia after blunt trauma. Observational case report. A 42-year-old man with a history of post-LASIK ectasia sustained paracentral corneal rupture secondary to blunt trauma from a fist to his left eye (OS). Slit-lamp examination revealed rupture in the posterior stroma (inferior paracentral) of the OS with an overlying intact LASIK flap; however, the inferior edges of the LASIK flap were Seidel positive. The anterior chamber was flat. Although he was initially managed with cyanoacrylate glue and a bandage contact lens, the patient eventually required tectonic penetrating keratoplasty. The postoperative course was unremarkable, and over 1 year later, the visual acuity OS was 20/25 with -7.50 + 2.00 × 0.50. Globe rupture from blunt trauma has not been shown to be more common in patients with a history of LASIK. Although blunt trauma to the post-LASIK globe would generally incur a similar risk of rupture to that of the normal eye, keratectasia after LASIK may predispose the globe to rupture.

  3. Management of a Traumatic Flap Dislocation Seven Years after LASIK

    Directory of Open Access Journals (Sweden)

    Majid Moshirfar

    2011-01-01

    Full Text Available Seven years after uneventful laser in situ keratomileusis (LASIK, a 48-year-old woman presented one week after being hit with an iron cord with blurry vision, pain, and irritation. The injury resulted in traumatic flap dislocation, epithelial ingrowth, and macrostriae. Following epithelial removal, the flap was refloated and repositioned. Nine interrupted sutures were used to secure the flap. Three-weeks after surgery with no sutures remaining, the epithelial ingrowth and macrostriae had resolved with a visual acuity of 20/20.

  4. 近视性屈光参差LASIK前后立体视觉的评价%Clinical investigation on the stereopsis of myopic anisometropia patients treated with laser in situ keratomileusis

    Institute of Scientific and Technical Information of China (English)

    吴章友; 潘红飙; 万川

    2008-01-01

    目的 用多种方法测准分子激光原位角膜磨镶术,矫治近视性屈光参差患者术前及术后远、近立体视觉,从视觉最高级形式的角度评价LASIK矫正近视性屈光参差患者的临床应用价值.方法 对112例近视性屈光参差患者,手术前和LASIK手术3个月后,采用颜氏随机点立体视觉检查图检查近立体视锐度、交叉视差、非交叉视差,Titmus立体视觉检查图、金贵昌双眼立体视觉检查图检查近立体视觉,同视机随机点立体图片检查远立体视觉.结果 LASIK术后3个月,91.9%患者裸眼远视力达到或超过术前最佳矫正视力.3种方法检查术后远、近立体视锐度均明显增进.立体视觉的增进显著,有统计学意义(P<0.05).结论 LASIK手术能重建、改善和促进立体视觉功能,有效地矫治屈光参差,手术安全、治疗效果肯定.%Objective With several methods, pre-and post-operative far and near stereopsis were tested in patients with myopic anisometropia undergone laser in situ keratomileusis (LASIK). So clinical effects of this treatment were evaluated at the highest level of vision function. Method 112 myopic anisometropia patients were enrolled in the research before the operation and 3 months after anisometropia were abolished by LASIK. Near stereopsis, crossed disparity and uncrossed disparity were measured by Yan's random-dot stereograms. Near stereopsis was also measured by Titmus stereograms and Jinguichang random-dot stereograms. Far stereopsis was measured by synoptophore. Results 3 months after LASIK, UCVAs of 91.9% patients were the same as or better than those of preoperative. Far and near stereopsis were improved obviously measured by all three methods. There is significant difference in the improvement of stercopsis. Conclusion With the treatment of myopic anisometropia by LASIK,most patients got much improvement in far and near stereopsis. LASIK could rebuild,improve and promote the stereopsis, and treat

  5. Clinical effect observation of wavefront-guided femtosecond laser in situ keratomileusis for correcting high myopia%波前像差引导的飞秒激光LASIK手术矫正高度近视的效果

    Institute of Scientific and Technical Information of China (English)

    崔敏; 周奇志

    2013-01-01

    目的:探讨波前像差引导的飞秒激光准分子激光原位角膜磨镶术( laser in situ keratomileusis , LASIK)手术矫正高度近视的效果。方法:随机选取2012-10/12在重庆爱尔眼科医院行波前像差引导的飞秒激光LASIK手术的高度近视患者(近视-6.0~-10.0DS,散光≤-2.0DC)32例58眼作为试验组。同期接受飞秒激光LASIK手术的高度近视患者(近视-6.0~-10.0DS,散光≤-2.0DC)28例56眼作为对照组。术后随访6mo,比较两组的裸眼视力( uncorrected visual acuity,UCVA),屈光度数,总高阶像差(high order aberrations ,HOA),球差和彗差。结果:术后6mo,所有患者UCVA均≥0.8,其中UCVA≥1.0者波前组91.4%,对照组87.5%,差异无统计学意义( P=0.360);UCVA≥1.2者波前组60.3%,对照组57.1%,差异无统计学意义( P=0.729);UCVA≥1.5者波前组17.2%,对照组12.5%,差异无统计学意义( P=0.477)。波前组的彗差低于对照组,差异有统计学意义(P=0.021)。两组UCVA,等效球镜度,总HOA和球差的比较无统计学差异(P>0.05)。结论:波前像差引导的飞秒激光LASIK手术与常规飞秒激光LASIK手术相比,虽然可以降低术后彗差的产生,但在提高术后UCVA,矫正高度近视度数,降低术后HOA和球差方面没有优势。%AIM:To investigate the outcome of wavefront-guided laser in situ keratomileusis ( LASIK ) with femtosecond laser for correcting high myopia METHODS: Thirty-two patients ( 58 eyes ) with high myopia ( myopia degree: -6.0 ~-10.0DS, astigmia degree≤ -2.0DC) underwent wavefront-guided LASIK using femtosecond laser in Chongqing Aire Eye Hospital from October to December in 2012 were collected as wavefront group, and 28 patients ( 56 eyes ) with high myopia ( myopia degree: -6.0 ~-10.0DS, astigmia degree ≤ -2.0DC) receiving LASIK with femtosecond laser

  6. Therapeutic Effects of Undercorrection by LASIK Following RK and PRK for Correction of High Myopia

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to investigate the therapeutic effects of undercorrection following radial keratotomy (RK) and photorefractive keratectomy (PRK) for correction of high myopia by excimer laser in situ keratomileusis (LASIK), LASIK was performed on 32 eyes of 16 patients undergoing RK 2 years ago and 38 eyes of 20 patients undergoing PRK 1 year ago. The postoperative uncorrected visual was better than or equal to the preoperative spectacle corrected visual acuity in 49 of 70 eyes (70. 00 %) and achieved the best status of refraction in 64 of 70 (91.43 0%). The best postoperatively corrected visual in all operated eyes were equal to their preoperative ones respectively or just lost 1 line. No severe complication occurred during and after operation. It was suggested that LASIK was a better method for treatment of undercorrection following RK and PRK.

  7. 角膜地形图引导和非球面切削LASIK术后视觉质量问卷分析%Questionnaire analysis of visual quality after corneal topography guided and aspherical cutting laser in situ keratomileusis

    Institute of Scientific and Technical Information of China (English)

    闻华明; 李海祥

    2011-01-01

    Objective To analyze the questionnaire of visual quality after com puter assisted corneal topography guide optimized refractive keratectomy ( ORK-CAT) and the comeal aspherical cutting optimized refractive keratectomy( ORK-Aph) excimer laser in situ keratomileusis ( LASIK) . Methods One hundred and thirty-three patients ( 257 eyes) from the myopia laser treatment center of the Affiliated Hospital of Zunyi Medical College were measured and randomly divided into three groups,in which 35 ca ses( 69 eyes) were received routine LASIK ( convention group) ,51 cases(98 eyes) re ceived ORK-CAT personality LASIK( ORK-CAT group) , another 47 cases ( 90 eyes) re ccived ORK-Aph personality LASIK ( ORK-Aph group). The subjective visual quality questionnaire ( SVQ) was designed and carried out at 1 week,1 month and 3 months af ter operation,the svo included the night vision satisfaction and visual quality complaint scores( visual vague, glare, halation, diplopia, blurred night vision) . Results SVQ showed there was statistical difference in night vision satisfaction among three groups at 1 week , 1 month and 3 months after operation( all P < 0. 05 ) , and there was also sta tistical difference in visual quality complaint scores among three groups at 1 month and 3 months after operation( all P< 0. 05 ) , the ORK-CAT group and ORK-Aph group were better than the convention group ( both P < 0. 05 ) , the night vision satisfaction and visual quality complaint scores of ORK-CAT group at 3 months after operation were 79. 14 and 50. 62 , which were better than 69. 20 and 65. 28 0f ORK-Aph group ( both P < 0. 05 ) . At lower myopia , there was no statistical difference in the mean rank of visual quality complaint scores and night vision satisfaction among three goups( P > 0. 05 ) ; At medium myopia,the mean rank of ORK-CAT group( 25 cases) were superior than that of ORK-Aph group ( 23 cases) and conventional group ( 1 3 cases) in visual quality complaint, scores and night vision

  8. Comparison of visual performance between conventional LASIK and wavefront-guided LASIK with iris-registration

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing; ZHOU Yue-hua; WANG Ning-li; LI Rui

    2008-01-01

    Background Laser in situ keratomileusis(LASIK)has become an efficient and commonly performed procedure to reduce refractive errors.In order to further increase the postoperative visual quality,the wavefront-guided refractive surgery has been a research hotspot in customized surgery. This study was conducted to compare the visual acuity,higher-order aberration,and contrast sensitivity of wavefront-guided LAStK with iris-registration and conventional LASIK.Methods Two hundred and eleven myopic eyes of 109 patients were enrolled in this prospective study and randomly divided into two groups:the wavefront-guided LASIK(wg LASIK)group(94 eyes)and conventional LASIK group(117 eyes).A Wavescan Wavefront aberrometer was used to analyze Zernike coefficients and the root-mean-square(RMS)of higher order aberrations with 6.0 mm pupil size,and Optec 6500 visual function instrument was used to measure contrast sensitivity(CS)under 5 spatiaI frequencies before and after surgery in both groups.Results The uncorrected visual acuity(UCVA)and the mean spherical equivalent(SE)in wg LASIK group were significantly better than those in conventional LASIK(UCVA,z=2.339,P=0.019;SE,t=2.838,P=0.005)at 3 months after surgery.Moreover,the increase in Z3-3,Z3 1,Z3 3,Z4 0,Z5 -1,Z5 1,Z5 5 and Z6 -6 in wg LASIK group was statistically smaller than that in conventional LASIK group(P<0.05).In wg LASIK group,eyes with a higher amount of the preoperative RMS of the higher order aberrations(RMSh≥0.30 μm)showed a statistically lower increase(13.5%)than those in conventional LASIK group at 3 months after surgery(33.3%)(P=0.004).And the values of 4th order spherical aberration(4thSA)and the root mean square of 6th order aberration(RMS6)in wg LASIK group were significantly lower than those in conventional group in eyes which had higher preoperative astigmatism(≥1.0D)(4thSA,P=0.03;RMS6,P=0.02).Wg LASIK group showed better CS values than the correspondingly preoperative values at all spatial frequencies

  9. Small Incision Lenticule Extraction (SMILE) vs. Femtosecond Laser in Situ Keratomileusis (FS-LASIK) for treatment of myopia

    DEFF Research Database (Denmark)

    Hansen, Rasmus Søgaard; Justesen, Birgitte; Lyhne, Niels;

    treatments were performed at the Department of Ophthalmology, Odense University Hospital from April 2011 to December 2013. Inclusion criteria: CDVA ≤ 0.10 (logMAR) before surgery and no other ocular conditions than myopia with or without astigmatism of maximum 3 D. Exclusion criteria: Eyes having undergone...... of astigmatism, and results were overall comparable 3 months after surgery. Financial disclosures: None....

  10. Effects of Pentacam on the posterior corneal surface height changes after LASEK and LASIK operation

    Directory of Open Access Journals (Sweden)

    Qing-Song Zhang

    2014-05-01

    Full Text Available AIM: To explore the application of Pentacam excimer laser epithelial keratomileusis(LASEKand excimer laser in situ keratomileusis(LASIKafter the changes of posterior corneal surface height.METHODS: Retrospective analysis of clinical data of 100 patients with myopia by using LASEK and LASIK for the treatment of the 50 patients(100 eyesin our hospital from January 2013 to June 2013, surface height changes after preoperative and postoperative 3 months were compared by measuring Pentacam corneal analysis system.RESULTS: Three months after operation, the LASEK posterior corneal surface height was 7.4±5.0mm, significantly higher than 5.6±3.4mm before operation, LASIK posterior corneal surface height was 7.5±5.1mm, significantly higher than 5.5±3.5mm before operation, the differences were statistically significant(PP>0.05.CONCLUSION: LASEK and LASIK on corneal posterior surface forward, LASIK is slightly obvious in early period.

  11. Visual outcomes of conductive keratoplasty to treat hyperopia and astigmatism after laser in situ keratomileusis and photorefractive keratectomy

    Directory of Open Access Journals (Sweden)

    Alireza Habibollahi

    2011-01-01

    Conclusions : CK is a predictable and reliable method to correct hyperopia after LASIK and PRK, however cylinder correction may induce irregular and unpredictable outcomes and a modified nomogram is required for further studies.

  12. A modified risk assessment scoring system for post laser in situ keratomileusis ectasia in topographically normal patients

    Directory of Open Access Journals (Sweden)

    Mohammad Miraftab

    2014-01-01

    Conclusion: Our modified ectasia risk scoring system for patients with normal corneal topography can predict post LASIK ectasia risk with acceptable sensitivity and specificity. However, there are still unidentified risk factors for which further studies are required.

  13. LASIK em pacientes adultos com alta anisometropia: relato de casos LASIK for high anisometropia in adults: case report

    Directory of Open Access Journals (Sweden)

    Patrícia Ioschpe Gus

    2006-04-01

    Full Text Available OBJETIVO: Avaliar a eficácia da técnica laser in situ keratomileusis (LASIK na redução de anisometropia em adultos, para os quais os tratamentos convencionais não tiveram sucesso. MÉTODOS: Série de casos de três olhos de três pacientes adultos, dois do sexo feminino e um do sexo masculino, com idade entre 28 e 49 anos (média de 38,3 anos, os quais foram submetidos à técnica de LASIK. Dois pacientes foram acompanhados por dezoito meses e um por seis meses após a cirurgia. RESULTADOS: Comparando a acuidade visual corrigida do pré-operatório com a acuidade visual não corrigida do pós-operatório, um olho ganhou duas linhas de visão, um olho manteve-se igual e um olho perdeu uma linha de visão. Todos os olhos se mantiveram sem ametropia esférica, e o astigmatismo não excedeu -0,75 D no pós-operatório. CONCLUSÃO: A técnica LASIK mostrou-se eficaz na correção de alta anisometropia em adultos, melhorando a acuidade visual e as queixas astenopéicas, e diminuindo a anisometropia.PURPOSE: To evaluate the efficacy of the laser in situ keratomileusis (LASIK technique in the reduction of anisometropy in adults, for whom conventional treatment was not successful. METHODS: A sequence of cases of three eyes of three adult patients, two females and one male, age ranging from 28 and 49 years (average 38.3 years, who underwent LASIK. Two patients were followed up for eighteen months and one for six months. RESULTS: Comparing the corrected visual acuity before surgery with the non-corrected visual acuity after surgery, one eye gained two lines of vision, one eye remained the same and one eye lost one line of vision. All eyes remained without spheric refraction, and astigmatism did not exceed - 0.75 D after surgery. There has been an improvement in the symptoms of asthenopia in the three patients. CONCLUSION: The LASIK technique proved to be efficient in the correction of anisometropy in adults, improving visual accuity and asthenopia

  14. Clinical results of wavefront-guided laser in situ keratomileusis 3 months after surgery%波前像差引导的LASIK手术的临床效果观察

    Institute of Scientific and Technical Information of China (English)

    Michael Mrochen; Maik Kaemmerer; Theo Seiler

    2001-01-01

    Objective:To investigate the visual and refractive outcome of wavefront-guided laser in situ keratomileusis(LASIK) to correct myopic astigmatism.Methods:This prospective study comprised 35 eyes of 28 patients who had a mean preoperative spherical refraction of -4.8 diopters(D)±2.3(SD) and a cylinder of (-1.1±0.9)D. Preoperative and postoperative wavefront analysis was performed with a Tscherning aberrometer. A scanning-spot laser with a 1.0mm spot size and a 200Hz repetition rate was used. The eye-tracking system had a response time of less than 6 milliseconds. The treatment area diameter ranged from 6.0 to 7.0mm with a transition zone of 1.0mm.Results:At 3 months,68.0% of the eyes were within ±0.5D of emmetropia and 93.5% were within ±1.0D. Uncorrected visual acuity was 20/20 or better in 93.5% of eyes. No eye lost more than 1 line of low-contrast,glare,and best spectacle-corrected visual acuity(BSCVA). Supernormal vision(BSCVA of 20/10 or better) was achieved in 16.0% of eyes. The correction of higher-order aberrations(spherical aberration,coma) was insufficient,with an inverse factor of the overall root-mean-square wavefront error of 1.44±0.74. Coma was better corrected than spherical aberration.Conclusion:Wavefront-guided LASIK is a promising technique that offers the potential to correct refractive errors,to improve visual acuity,and to increase the quality of vision,especially under mesopic conditions. Studies that include selective overcorrection of different Zernike components are needed to achieve better correction of the aberrations. Prospective controlled clinical studies must clarify the major benefits of wavefront-guided LASIK.%目的:观察波前像差引导的LASIK手术矫正近视性散光的效果。方法:28例35只眼,平均术前球镜屈光度为(-4.8±2.3)D,柱镜屈光度为(-1.1±0.9)D。手术前和手术后均使用Tscherning像差计测量,分析波前像差。应用1.0mm光斑、频率200Hz的飞点扫描准分

  15. Expression of matrix metrallproteinase-2 in human tears fluid after LASIK

    Directory of Open Access Journals (Sweden)

    Ai-Wei Chen

    2014-12-01

    Full Text Available AIM: To monitor long-term changes of matrix metalloproteinase-2(MMP-2in human tears fluid after laser in situ keratomileusis(LASIK. METHODS: Thirty-two myopia cases(64 eyesunderwent uneventful LASIK were enrolled in the study. Tear fluid were collected and MMP-2 expression was analyzed by Western-bolt assay preoperatively and postoperatively on 15d, at 1, 3mo, and 1a. RESULTS: LASIK increased the concentration of MMP-2 in human tear fluid. At 15d postoperatively, the magnitude of MMP-2 was 1.4 times that of preoperative, thereafter subsided, but didn't return to preoperative level by 3mo(PP>0.05. CONCLUSION: MMP-2 is significantly expressed in human tear fluid after LASIK, then subsided with time, but didn't return to preoperative level by 3mo and almost recovered up to 1a, indicating wound healing of LASIK would continue up at least 3mo after surgery and almost recovered 1a postoperatively.

  16. Role of percent peripheral tissue ablated on refractive outcomes following hyperopic LASIK

    Science.gov (United States)

    Stapleton, Fiona; Versace, Patrick

    2017-01-01

    Objectives To determine the effect of hyperopic laser in situ keratomileusis (H-LASIK) on corneal integrity, by investigating relationships between proportionate corneal tissue ablated and refractive outcomes at 3 months. Methods 18 eyes of 18 subjects treated with H-LASIK by Technolas 217c Excimer Laser were included in the study. Orbscan II Topography System was used to determine corneal volume and pachymetry 3mm temporally (3T). The volume of corneal tissue ablated was determined from the laser nomogram. Univariate associations between age, treatment, corneal volume, overall proportion of tissue removed, proportion of tissue removed at 3T, residual bed thickness at 3T and refractive outcomes 3 months post-LASIK were examined and independent factors associated with refractive outcomes determined using linear regression models. Results At 3 months post-LASIK, the mean difference to expected refractive outcome was -0.20 ± 0.64 (Range -2.00 to +1.00). In univariate analysis, difference to expected refractive outcome was associated with proportion of tissue removed at 3T (Pcorneal steepening. Future hyperopic LASIK procedures could consider proportionate volume of corneal tissue removed at 3T in addition to laser nomograms to achieve improved refractive outcomes. PMID:28151939

  17. SMILE与LASIK矫正低中度散光效果的矢量分析和比较%Vector analysis and comprison of small incision lenticule extraction versus laser in-situ keratomileusis for low to moderate myopic astigmatism

    Institute of Scientific and Technical Information of China (English)

    张佳媚; 王雁; 陈晓琴; 李晓晶; 徐路路; 窦瑞

    2016-01-01

    Background Small incision lenticule extraction (SMILE) is lack of eye-tracking system and there is controversy in the treatment of astigmatism.It is very important to understand its correction effctiveness for myopic astigmatism.Objective This study was to evaluate the clinical outcomes in the correction of myopic astigmatism between SMILE and femtosecond laser assisted laser in situ keratomileusis (FS-LASIK).Methods In this retrospective study,95 eyes of 51 patients and 69 eyes of 40 patients with myopic astigmatism underwent the SMILE surgery and FS-LASIK surgery respectively in Tianjin Eye Hospital from December 2013 to July 2014 under the informed consent.No significant differences were found in spherical power,astigmatic power and spherical equivalent (SE) between the SMILE group and FS-LASIK group before surgery (all at P>0.05).The uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),manifest refraction,slit-lamp microscopy,intraocular pressure and corneal topography were measured before surgery and 1 day,1 week,1 month,3 months after surgery.Vector analysis was used to calculate the components of astigmatism before and after surgery.Correction index (CI),index of success (IOS),angle of error (AofE) and flattening index (FI) were used to evaluate the correction effectiveness of astigmatism.Safety index and efficacy index were used to evaluate the recovery status of visual acuity.The corrected effectiveness was compared between the two groups,and the correlations of kappa angle with measured parameter were assessed by Spearman rank correlation analysis.Results The mean spherical power,astigmatic power and SE were (0.003±0.106),(-0.063 ± 0.126) and (-0.029 ± 0.101) D in the SMILE group,which were significantly lower than (0.112 ± 0.212),(-0.091 ± 0.142) and (0.067 ± 0.198)D in the FS-LASIK group (Z =-4.328,-3.197,both at P<0.05).Vector analysis showed the postoperative with-the-rule astigmatism in the SMILE group and oblique

  18. In vivo Confocal Microscopy Report after Lasik with Sequential Accelerated Corneal Collagen Cross-Linking Treatment.

    Science.gov (United States)

    Mazzotta, Cosimo; Balestrazzi, Angelo; Traversi, Claudio; Caragiuli, Stefano; Caporossi, Aldo

    2014-01-01

    We report the first pilot qualitative confocal microscopic analysis of a laser in situ keratomileusis (Lasik) treatment combined with sequential high-fluence accelerated corneal collagen cross-linking, denominated Lasik XTra, by means of HRT II laser scanning in vivo confocal microscopy after a 6-month follow-up. After obtaining approval from the Siena University Hospital Institutional Review Board, a 33-year-old female patient underwent a Lasik XTra procedure in her left eye. Confocal analysis demonstrated induced slight corneal microstructural changes by the interaction between UV-A, riboflavin and corneal stromal collagen, beyond the interface to a depth of 160 µm, without adverse events at the interface and endothelial levels. This application may be considered a prophylactic biomechanical treatment, stiffening the intermediate corneal stroma to prevent corneal ectasia and stabilizing the clinical results of refractive surgery. According to our preliminary experiences, this combined approach may be useful in higher-risk Lasik patients for hyperopic treatments, high myopia and lower corneal thicknesses.

  19. In vivo Confocal Microscopy Report after Lasik with Sequential Accelerated Corneal Collagen Cross-Linking Treatment

    Directory of Open Access Journals (Sweden)

    Cosimo Mazzotta

    2014-04-01

    Full Text Available We report the first pilot qualitative confocal microscopic analysis of a laser in situ keratomileusis (Lasik treatment combined with sequential high-fluence accelerated corneal collagen cross-linking, denominated Lasik XTra, by means of HRT II laser scanning in vivo confocal microscopy after a 6-month follow-up. After obtaining approval from the Siena University Hospital Institutional Review Board, a 33-year-old female patient underwent a Lasik XTra procedure in her left eye. Confocal analysis demonstrated induced slight corneal microstructural changes by the interaction between UV-A, riboflavin and corneal stromal collagen, beyond the interface to a depth of 160 µm, without adverse events at the interface and endothelial levels. This application may be considered a prophylactic biomechanical treatment, stiffening the intermediate corneal stroma to prevent corneal ectasia and stabilizing the clinical results of refractive surgery. According to our preliminary experiences, this combined approach may be useful in higher-risk Lasik patients for hyperopic treatments, high myopia and lower corneal thicknesses.

  20. Curative observation of Epi-LASIK and LASIK for high myopia%Epi-LASIK和LASIK矫治高度近视的疗效比较

    Institute of Scientific and Technical Information of China (English)

    吴登雷; 张芹; 潘晓英

    2012-01-01

    Objective: To explore curative effect after microkeratome excimer laser epithelial keratomile -usis (Epi-LASIK) and laser in situ keratomileusis (LASIK) for high myopia, and to evaluate the safety and efficacy of Epi-LASIK and LASIK. Methods; Used United States VISX StarS4 laser, and Moria flat push type micro corneal epithelial knife making corneal flap was used for Epi -LASIK, with 0. 02% mitomycin C sponge soaked in. LASIK used Moria rotating type corneal knife making 110 μm corneal flap. The patients was followed up more than 6 months, and compared postoperative symptoms , visual acuity, refraction, and so on. Results; One week postoperative ,the proportion of UCVA≥0. 8 of Epi-LASIK (47. 8% ) was less than LASIK (95.8%) , the difference was statistically significant (x2 =27.056, P = 0.000) ; no statisti-cally significant differences were found in those of Epi-LASIK(95. 7% , 97. 8% , 97. 8%) and LASIK (97. 9% , 97. 9% , 97. 9% ) after 1,3,6 months. After 1 week, the diopter difference was statistically sig-nificant (t = -7. 123 ,P = 0. 000) ; after 1,3,6 months the diopter difference was not statistically signifi -cant. Conclusion; LASIK was still the mainstream of current treatment of myopia . Epi-LASIK was an effective and safe procedure for high myopia. Although the recovery of visual acuity was slower than LASIK , it had a wide range of operation indication , its long-term efficacy still remains to be seen.%目的:比较微型角膜刀准分子激光角膜上皮瓣下磨镶术(Epi-LASIK)与准分子激光原位角膜磨镶术(LASIK)矫治高度近视的疗效.评估两种术式的安全性和有效性.方法:采用美国VISX StarS4激光机,Epi-LASIK组采用Moria平推型微型角膜上皮刀制作角膜上皮瓣,用浸有0.02%丝裂霉素C的海绵片,LASIK组采用Moria旋转型角膜板层刀制作110 μm厚度角膜瓣.随访6月以上,对两组术后症状、视力、屈光等进行比较.结果:术后1周Epi-LASIK组裸眼视力(uncorrected visual

  1. A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function.

    Science.gov (United States)

    Hatch, Bryndon B; Moshirfar, Majid; Ollerton, Andrew J; Sikder, Shameema; Mifflin, Mark D

    2011-01-01

    To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. At 6 months, mean values for UDVA (logMAR) were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.

  2. Avaliação das alterações biomecânicas da córnea antes e após lasik em pacientes míopes e hipermetrópes utilizando Moriá® Sub-Bowman's Keratomileusis (SBK

    Directory of Open Access Journals (Sweden)

    Bruno de Freitas Valbon

    2012-10-01

    Full Text Available OBJETIVO: Avaliar e comparar as alterações biomecânicas da córnea por meio do Ocular Response Analyzer® (ORA Reichert Ophtalmics Instruments, Buffalo, New York, USA antes e após Lasik com Moriá ® Sub Bowman Keratomileusis (SBK One Use Plus (OUP em pacientes míopes e hipermetrópes. MÉTODOS: Foram estudados 33 olhos, sendo 19 olhos míopes e 14 olhos hipermetrópes submetidos à cirurgia refrativa com técnica Lasik com flap fino (100 µ utilizando Moriá SBK OUP. O ORA foi realizado no pré-operatório e 1 mês após a cirurgia para avaliar a biomecânica da córnea. O CH (Corneal Hysteresis, CRF (Corneal Resistance Factor, IOPg (goldmann gold standard, Goldmann correlated intraocular pressure a IOPcc (corneal compensated intraocular pressure e mais 38 variáveis biomecânicas da córnea derivadas do sinal de resposta foram avaliados. O Teste de Kolmogorov-Smirnov foi utilizado para avaliar a distribuição normal. O teste de Wilcoxon foi utilizado para comparar as variáveis antes e após a cirurgia para cada grupo. As diferenças entre as medidas pré e pós-operatórias dos olhos míopes foram comparadas com as diferenças obtidas nos olhos hipermetrópes, utilizando-se o teste de Mann-Whitney. Foi considerado como estatisticamente significante p < 0,05%. RESULTADOS: Houve diferença significativa antes e após Lasik em olhos míopes e hipermetrópes na variável IOPg(Wilcoxon, p <0,05, porém não houve em IOPcc. Somente em olhos míopes houve diferenças significativas em CH e CRF, antes e após Lasik com Moriá SBK OUP, como também 9 parâmetros derivados do ORA Waveform_Sinal Gráfico (aspect1, h1, dive1, path1, p1area1, W11, H11, and w2 path11; Wilcoxon, p <0,05. Em olhos hipermetrópes houve diferenças antes e após Lasik das seguintes variáveis: aspect2, h2, dive2, mslew2 e H21 (Wilcoxon p<0,05.Diferenças nas variáveis IOPg e p1area, antes e após Lasik foram maiores em olhos míopes do que hipermetrópes (Mann-Whitey, p

  3. PRK versus LASIK para correção de miopia baixa e moderada PRK versus LASIK for correction of low and moderate myopia

    Directory of Open Access Journals (Sweden)

    Adriana dos Santos Forseto

    2000-08-01

    Full Text Available Objetivo: Comparar, por meio de um estudo prospectivo e bilateral randomizado, a eficácia, segurança e previsibilidade das técnicas de ceratectomia fotorrefrativa (PRK e "excimer laser in situ keratomileusis" (LASIK para o tratamento da miopia baixa e moderada. Métodos: Foram incluídos dezessete pacientes (34 olhos com equivalente esférico (EE refracional entre -2,00 e -6,00 dioptrias (D. Cada paciente foi submetido a PRK em um olho e LASIK no outro. Ambos os olhos foram tratados no mesmo dia pelo mesmo cirurgião, com o excimer laser VISX 20/20B e o microceratótomo automatizado da Chiron. Resultados: No pré-operatório, a média do EE refracional foi semelhante nos dois grupos (-3,57±1,17D e -3,71±0,98D, para PRK e LASIK, respectivamente. Dor pós-operatória foi referida somente nos casos de PRK (8 olhos: 47,1%. O seguimento pós-operatório médio foi de 14±5 meses (6 a 24 para o grupo de PRK, e 14±6 meses (3 a 24 para o de LASIK. A média do erro refrativo residual foi semelhante nos dois grupos (-0,34±0,45D e -0,29±0,52D, para PRK e LASIK, respectivamente. No primeiro dia pós-tratamento, 15 olhos (100% do grupo de LASIK e 2 (13,3% de PRK apresentavam acuidade visual sem correção (AV s/c ³ 20/40 (n=15. Ao último exame, 15 olhos (88,2% de LASIK contra 11 (64,7% de PRK atingiram AV s/c ³ 20/20 (n=17. Não houve perda da melhor acuidade visual corrigida. Conclusão: Neste estudo, tanto o PRK quanto o LASIK mostraram-se ser tecnicamente seguros, eficazes e previsíveis para a correção da miopia baixa e moderada. A técnica de LASIK foi a preferida na análise subjetiva dos pacientes, pela recuperação visual mais precoce associada a menor dor no pós-operatório.Purpose: To compare, through a prospective, randomized and bilateral study, the effectiveness, safety and predic-tability of photorefractive keratectomy (PRK and excimer laser in situ keratomileusis (LASIK for correction of low and moderate myopia. Methods

  4. Analysis of Macular and Retinal Nerve Fiber Layer Thickness in Children with Refractory Amblyopia after Femtosecond Laser-assisted Laser In situ Keratomileusis: A Retrospective Study

    Directory of Open Access Journals (Sweden)

    Peng-Fei Zhao

    2017-01-01

    Conclusions: The foveal center retinal edema after FS-LASIK is mild and reversible in children, that mostly occurred in the high myopic group with no effect on the visual acuity, and is always relieved within 1 week.

  5. LASIK surgery of granular corneal dystrophy type 2 patients leads to accumulation and differential proteolytic processing of transforming growth factor beta-induced protein (TGFBIp)

    DEFF Research Database (Denmark)

    Poulsen, Ebbe Toftgaard; Nielsen, Nadia Sukusu; Jensen, Morten Mørk;

    2016-01-01

    at position 124 in mature TGFBIp leads to granular corneal dystrophy type 2 (GCD2). Homozygous GCD2 cases develop massive protein accumulation early in life whereas heterozygous GCD2 cases become affected much later and generally with a much less severe outcome. However, if heterozygous GCD2 patients undergo...... laser-assisted in situ keratomileusis (LASIK) surgery protein accumulation is accelerated and they develop massive protein accumulations a few years after surgery. Here, we present the protein profile of aggregate-containing corneal tissue from GCD2 patients with a history of LASIK surgery using LC......-MS/MS. Label-free quantification of corneal extracellular matrix proteins showed accumulation of TGFBIp. This was supported by 2DE and immunoblotting against TGFBIp that revealed the accumulation of full-length TGFBIp. In addition, a high molecular weight TGFBIp complex was more apparent in GCD2 patients after...

  6. The effect of preoperative keratometry on visual outcomes after moderate myopic LASIK.

    Science.gov (United States)

    Christiansen, Steven M; Neuffer, Marcus C; Sikder, Shameema; Semnani, Rodmehr T; Moshirfar, Majid

    2012-01-01

    To evaluate visual outcomes in moderately myopic eyes with flat and steep corneas (preoperatively) that have been treated with laser-assisted in situ keratomileusis (LASIK). Records of ninety-six eyes with average preoperative keratometry (K) values between 39.9 and 42.0 diopters (D) (flat) were matched with 103 eyes with preoperative K values between 46.0 and 47.2 D (steep) that underwent LASIK between March 2007 and March 2010 for moderate myopia, and were retrospectively reviewed. The primary outcome measures used to determine the effect of preoperative keratometry on visual prognosis were refraction, visual acuity, change in keratometry (ΔK), and change in spherical equivalent (ΔSE), measured at 1, 3, 6, and 12 months postoperatively. Significant differences were found at 6 months postoperatively between the flat group and steep group in SE (P = 0.029), sphere (P = 0.018), ΔK (P = 0.002), percentage of eyes achieving SE of -0.25 to + 0.25 D (P = 0.0125), -0.26 to -0.50 D (P = 0.003), -0.51 to -1.00 D (P = 0.044), and the percentage of eyes achieving uncorrected distance visual acuity of 20/15 or better (P = 0.0006). Moderately myopic eyes with flatter corneas preoperatively have better visual prognosis following LASIK compared with moderately myopic eyes with steeper corneas.

  7. Sands of Sahara after LASIK in Avellino Corneal Dystrophy

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    Flavio Mantelli

    2012-01-01

    Full Text Available We report the case of a patient diagnosed with Avellino corneal dystrophy (ACD who developed diffuse interstitial keratitis following excimer laser insitu keratomileusis (LASIK. ACD is an autosomal dominant corneal dystrophy characterized by multiple asymmetric stromal opacities that impair vision. Accepted treatments for this condition include corneal transplantation and phototherapeutic keratectomy (PTK. Our patient underwent LASIK at another institution to correct myopia. LASIK and photorefractive keratectomy (PRK are usually contraindicated in ACD for the high risk of disease recurrence and postoperative complications. The patient came to our attention lamenting blurry vision, decreased visual acuity, and photophobia. Ophthalmologic examination revealed bilateral interstitial keratitis, also known as “sands of Sahara”, a seldom-seen complication of LASIK characterized by fine and diffuse granular infiltrates at the surgical flap interface.The risk of developing interstitial keratitis, as in the case presented here, represents another valid reason for avoiding LASIK in patients with ACD.

  8. Correlation between Post-LASIK Starburst Symptom and Ocular Wavefront Aberrations

    Institute of Scientific and Technical Information of China (English)

    LIU Yong-Ji; MU Guo-Guang; WANG Zhao-Qi; WANG Yan

    2006-01-01

    Monochromatic aberrations in post laser in-situ keratomileusis (LASIK) eyes are measured. The data are categorized into reference group and starburst group according to the visual symptoms. Statistic analysis has been made to find the correJation between the ocular wavefront aberrations and the starburst symptom. The rms aberrations of the 3rd and 4th orders for the starburst group are significantly larger than those for the reference group. The starburst symptom shows a strong correlation with vertical coma, total coma, spherical aberrations. For 3-mm pupil size and 5.8-mm pupil size, the modulation transfer function (MTF) of the starburst group are lower than those of the reference group, but their visual acuities are close. MTF and PSF analyses are made for two groups, and the results are consistent with the statistical analysis, which means the difference between the two groups is mainly due to the third- and fourth-order Zernike aberrations.

  9. Rate of ectasia and incidence of irregular topography in patients with unidentified preoperative risk factors undergoing femtosecond laser-assisted LASIK

    Directory of Open Access Journals (Sweden)

    Moshirfar M

    2013-12-01

    Full Text Available Majid Moshirfar,1 Jared G Smedley,2 Valliammai Muthappan,1 Allison Jarsted,3 Erik M Ostler1 1John A Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2College of Human Medicine, Michigan State University, Lansing, MI, USA; 3Department of Ophthalmology, State University of New York Upstate Medical University, Syracuse, NY, USA Purpose: To report the rate of postoperative ectasia after laser-assisted in situ keratomileusis (LASIK with femtosecond laser-assisted flap creation, in a population of patients with no identified preoperative risk factors. Methods: A retrospective case review of 1,992 eyes (1,364 patients treated between March 2007 and January 2009 was conducted, with a follow up of over 4 years. After identifying cases of ectasia, all the patient charts were examined retrospectively for preoperative findings suggestive of forme fruste keratoconus (FFKC. Results: Five eyes of four patients with post-LASIK ectasia were identified. All eyes passed preoperative screening and received bilateral LASIK. One of the five patients developed ectasia in both eyes. Three patients retrospectively revealed preoperative topography suggestive of FFKC, while one patient had no identifiable preoperative risk factors. Upon review of all the charts, a total 69 eyes, including four of the five eyes with ectasia, were retrospectively found to have topographies suggestive of FFKC. Conclusion: We identified four cases of post-LASIK ectasia that had risk factors for FFKC on reexamination of the chart and one case of post-LASIK ectasia with no identifiable preoperative risk factors. The most conservative screening recommendations would not have precluded this patient from LASIK. The rate of purely iatrogenic post-LASIK ectasia at our center was 0.05% (1/1,992, and the total rate of post-LASIK ectasia for our entire study was 0.25% (1/398. The rate of eyes with unrecognized preoperative FFKC that developed post-LASIK ectasia was 5.8% (1/17. Keywords

  10. The Effect of LASIK Procedure on Peripapillary Retinal Nerve Fiber Layer and Macular Ganglion Cell-Inner Plexiform Layer Thickness in Myopic Eyes

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    Maja Zivkovic

    2017-01-01

    Full Text Available Purpose. To evaluate the effect of applied suction during microkeratome-assisted laser in situ keratomileusis (LASIK procedure on peripapillary retinal nerve fiber layer (RNFL thickness as well as macular ganglion cell-inner plexiform layer (GC-IPL thickness. Methods. 89 patients (124 eyes with established myopia range from −3.0 to −8.0 diopters and no associated ocular diseases were included in this study. RNFL and GC-IPL thickness measurements were performed by spectral domain optical coherence tomography (SD OCT one day before LASIK and at 1 and 6 months postoperatively. Results. Mean RNFL thickness prior to LASIK was 93.86±12.17 μm while the first month and the sixth month postoperatively were 94.01±12.04 μm and 94.46±12.27 μm, respectively. Comparing results, there is no significant difference between baseline, one month, and six months postoperatively for mean RNFL (p>0.05. Mean GC-IPL thickness was 81.70±7.47 μm preoperatively with no significant difference during the follow-up period (82.03±7.69 μm versus 81.84±7.64 μm; p>0.05. Conclusion. RNFL and GC-IPL complex thickness remained unaffected following LASIK intervention.

  11. Retinal peripheral changes after LASIK Alterações da retina periférica após LASIK

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    João Jorge Nassaralla Junior

    2008-06-01

    Full Text Available PURPOSE: To better define the effect of laser in situ keratomileusis (LASIK on myopic eyes and the risk and incidence of retinal complications after surgery. METHODS: In a prospective study, 200 eyes of 100 patients, 49 male and 51 female, with a mean age of 29.7 years, had a complete posterior pole examination before and at 1 week, 1, 3 and 12 months after bilateral simultaneous LASIK for the correction of myopia. Mean spherical equivalent was 7.75D (range 1.00 to -17.25D. Before LASIK, preventive treatment was carried out on predisposing lesions to retinal complications, with laser photocoagulation. RE: Before surgery, the ophthalmic features were: 86 eyes (43% presented no peripheral abnormalities; 49 eyes (24.5% had lattice degeneration; 18 eyes (9%, white without pressure; 5 eyes (2.5%, white with pressure; 33 (16.5%, oral chorioretinal degenerations; 6 (3%, paving stone; 45 (22.5%, posterior vitreous detachment; 20 (10%, retinal vitreous traction; and 12 (6%, round holes. Comparing the incidence of ophthalmic features before and at one year after surgery, there was not a statistical significant difference (P>0.05. CONCLUSION: Although retinal pathologic conditions have been described as complications after LASIK, our data did not reveal a cause-effect relationship between the refractive error corrective procedure and retinal complications. The retinal changes found after LASIK in this series of patients, appear to reflect the predisposition of myopes. Both patient and doctor should be aware that, even after the refractive error correction, the risk of complications related to the myopic eye would persist.OBJETIVO: Definir melhor o efeito da técnica laser in situ keratomileusis (LASIK em olhos míopes, o risco e a incidência de complicações retinianas após a cirurgia. Este estudo foi realizado no Instituto de Olhos de Goiânia. MÉTODOS: Em um estudo prospectivo, 200 olhos de 100 pacientes, 50 homens e 50 mulheres, com idade média de

  12. The effect of preoperative keratometry on visual outcomes after moderate myopic LASIK

    Directory of Open Access Journals (Sweden)

    Christiansen SM

    2012-03-01

    Full Text Available Steven M Christiansen1, Marcus C Neuffer1, Shameema Sikder2, Rodmehr T Semnani1, Majid Moshirfar11John A Moran Eye Center, University of Utah, Salt Lake City, UT, 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MA, USAPurpose: To evaluate visual outcomes in moderately myopic eyes with flat and steep corneas (preoperatively that have been treated with laser-assisted in situ keratomileusis (LASIK.Patients and methods: Records of ninety-six eyes with average preoperative keratometry (K values between 39.9 and 42.0 diopters (D (flat were matched with 103 eyes with preoperative K values between 46.0 and 47.2 D (steep that underwent LASIK between March 2007 and March 2010 for moderate myopia, and were retrospectively reviewed. The primary outcome measures used to determine the effect of preoperative keratometry on visual prognosis were refraction, visual acuity, change in keratometry (ΔK, and change in spherical equivalent (ΔSE, measured at 1, 3, 6, and 12 months postoperatively.Results: Significant differences were found at 6 months postoperatively between the flat group and steep group in SE (P = 0.029, sphere (P = 0.018, ΔK (P = 0.002, percentage of eyes achieving SE of −0.25 to + 0.25 D (P = 0.0125, −0.26 to −0.50 D (P = 0.003, −0.51 to −1.00 D (P = 0.044, and the percentage of eyes achieving uncorrected distance visual acuity of 20/15 or better (P = 0.0006.Conclusion: Moderately myopic eyes with flatter corneas preoperatively have better visual prognosis following LASIK compared with moderately myopic eyes with steeper corneas.Keywords: keratometry, cornea, LASIK, refractive surgery

  13. LASIK X PRK após cirurgia de descolamento de retina

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    Rodovalho Adriano Jorge Mattoso

    2003-01-01

    Full Text Available OBJETIVO: Comparar os resultados obtidos pelas técnicas de "laser in situ keratomileusis" (LASIK e "photorefractive keratectomy" (PRK na correção de miopia e astigmatismo em olhos previamente submetidos à cirurgia de descolamento de retina (DR com "buckle" escleral. MÉTODOS: Vinte e cinco olhos de 22 pacientes com alterações refracionais significativas após a cirurgia de DR foram submetidos à cirurgia refrativa. Em 14 olhos de 13 pacientes foi realizado LASIK e em 11 olhos de 9 pacientes, PRK. O intervalo mínimo entre a cirurgia de DR e a cirurgia refrativa foi de 12 meses. O tempo de seguimento foi de, pelo menos, 12 meses. RESULTADOS: Doze meses após a cirurgia, a média do equivalente esférico (EE no grupo submetido ao LASIK diminuiu de -6,49 D antes da cirurgia para -0,17 D e a média do cilindro de -1,10 D para -0,23 D. A média do EE no grupo submetido ao PRK foi reduzida de -5,35 D para +0,02 D e a média do cilindro, de -1,38 D para -0,54D. Em ambos os grupos, 11 olhos apresentaram melhora da acuidade visual sem correção de pelo menos 4 linhas. CONCLUSÃO: Tanto o LASIK quanto o PRK foram seguros e eficazes para a correção do erro refracional induzido após a cirurgia de DR. Nossos resultados não apresentaram diferenças significativas entre os procedimentos. Estudos posteriores envolvendo maior amostragem e seguimento mais prolongado contribuirão para melhor avaliação da cirurgia refrativa em pacientes submetidos à cirurgia com "buckle" escleral.

  14. A prospective, contralateral comparison of photorefractive keratectomy (PRK versus thin-flap LASIK: assessment of visual function

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    Hatch BB

    2011-04-01

    Full Text Available Bryndon B Hatch1, Majid Moshirfar1, Andrew J Ollerton1, Shameema Sikder2, Mark D Mifflin11John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USAPurpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs in eyes with stable myopia undergoing either photorefractive keratectomy (PRK or thin-flap laser in situ keratomileusis (LASIK (intended flap thickness of 90 µm using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively.Methods: In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, contrast sensitivity, and complications.Results: At 6 months, mean values for UDVA (logMAR were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466. UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600. Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156 or CDVA (P = 0.800 at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears.Conclusion: Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.Keywords: photorefractive keratectomy, thin-flap LASIK, visual

  15. Longitudinal Evaluation of Cornea With Swept-Source Optical Coherence Tomography and Scheimpflug Imaging Before and After Lasik.

    Science.gov (United States)

    Chan, Tommy C Y; Biswas, Sayantan; Yu, Marco; Jhanji, Vishal

    2015-07-01

    Swept-source optical coherence tomography (OCT) is the latest advancement in anterior segment imaging. There are limited data regarding its performance after laser in situ keratomileusis (LASIK). We compared the reliability of swept-source OCT and Scheimpflug imaging for evaluation of corneal parameters in refractive surgery candidates with myopia or myopic astigmatism. Three consecutive measurements were obtained preoperatively and 1 year postoperatively using swept-source OCT and Scheimpflug imaging. The study parameters included central corneal thickness (CCT), thinnest corneal thickness (TCT), keratometry at steep (Ks) and flat (Kf) axes, mean keratometry (Km), and, anterior and posterior best fit spheres (Ant and Post BFS). The main outcome measures included reliability of measurements before and after LASIK was evaluated using intraclass correlation coefficient (ICC) and reproducibility coefficients (RC). Association between the mean value of corneal parameters with age, spherical equivalent (SEQ), and residual bed thickness (RBT) and association of variance heterogeneity of corneal parameters and these covariates were analyzed. Twenty-six right eyes of 26 participants (mean age, 32.7 ± 6.9 yrs; mean SEQ, -6.27 ± 1.67 D) were included. Preoperatively, swept-source OCT demonstrated significantly higher ICC for Ks, CCT, TCT, and Post BFS (P ≤ 0.016), compared with Scheimpflug imaging. Swept-source OCT demonstrated significantly smaller RC values for CCT, TCT, and Post BFS (P ≤ 0.001). After LASIK, both devices had significant differences in measurements for all corneal parameters (P ≤ 0.015). Swept-source OCT demonstrated a significantly higher ICC and smaller RC for all measurements, compared with Scheimpflug imaging (P ≤ 0.001). Association of variance heterogeneity was only found in pre-LASIK Ant BFS and post-LASIK Post BFS for swept-source OCT, whereas significant association of variance heterogeneity was noted for all measurements except Ks and

  16. Late onset post-LASIK keratectasia with reversal and stabilization after use of latanoprost and corneal collagen cross-linking

    Directory of Open Access Journals (Sweden)

    Tor Paaske Utheim

    2012-01-01

    Full Text Available We report a case of late onset keratectasia after laser in situ keratomileusis (LASIK and its quick reversal and stabilization after use of latanoprost and riboflavin/ultraviolet-A corneal collagen cross-linking (CXL. A 39-year-old man with normal intraocular pressure developed a rapid deterioration of vision in his left eye 6 years after LASIK-retreatment for high myopic astigmatism. Keratectasia was diagnosed by corneal topography and ultrasound pachymetry. After two months of treatment with latanoprost and a minor intraocular pressure reduction, uncorrected distance visual acuity improved from 20/100 to 20/20 and corneal topography showed reversal of keratectasia. CXL was performed after the reversal to achieve long-term stabilization. At 1, 3, 6, 13 and 39 months followup exams after the CXL, stable vision, refraction, and topography were registered. This case shows that keratectasia may rapidly occur several years after LASIK and that a quick reversal and stabilization may be achieved by use of latanoprost followed by CXL.

  17. Clinical observation of haze after epipolis laser in situ keratomileusis%Epi-LASIK术后Haze形成的临床观察

    Institute of Scientific and Technical Information of China (English)

    张亚丽; 左天南; 刘蕾; 胡明; 李招娜

    2009-01-01

    央厚度上无统计学差异.结论 EpiLASIK术后Haze发生率及密度均较低,术后是否发生Haze与屈光度数,切削深度和切削率有关.%ncidence and density of Haze in Epi-LASIK.Higher myopia,deeper ablation and higher ablation depth/corneal thickness ratio obviously influenee the Haze formation.

  18. 准分子激光原位角膜磨镶术后角膜后表面前突的影响因素%Factors affecting the forward shift of the posterior corneal surface in laser in situ keratomileusis

    Institute of Scientific and Technical Information of China (English)

    张光明; 张明昌; 胡燕华; 聂绍松

    2012-01-01

    目的 描述准分子激光原位角膜磨镶术(LASIK)后角膜后表面前突并探讨影响其前突程度的因素.方法 前瞻性系列病例研究.2006年12月至2007年2月在华中科技大学同济医学院附属协和医院眼科行LASIK手术患者82例(通过3年的观察,无一例出现圆锥角膜),其中男38例,女44例,年龄18~44岁,平均(24.2±5.5)岁,取右眼数据进行分析.采用OrbscanⅡz、Goldman眼压计、超声角膜测厚仪分别测量这82眼手术前后角膜地形图、眼压以及角膜厚度.采用t检验和Pearson相关分析与线性回归等统计学方法.结果 ①LASIK术后角膜后表面最佳拟合球面半径缩短(113.32±66.87) μm,平均前突(71.97±28.70)μm,术前术后角膜后表面曲率差为(0.93±0.54)D.②LASIK手术后角膜后表面都有不同程度轻微前突,其程度与术前眼压呈正相关(r=0.461,P<0.01);与术后角膜瓣下残余基质厚度呈负相关(r=-0.453,P<0.01).③在36个月观察中,无一例发生角膜扩张,但术后角膜后表面都不同程度向前突出.结论 角膜后表面前突是LASIK术后角膜变薄的必然反应,其程度与术前眼压呈正相关,与术后角膜瓣下残余基质厚度呈负相关.%Objective To investigate the forward shift of the posterior corneal surface and related influential factors after laser in situ keratomileusis (LASIK).Methods It was a prospective case series study.Eighty-two patients with myopia (38 males and 44 females) who had undergone LASIK at Union Hospital between December 2006 and February 2007 were retrospectively reviewed.The average age was 24.2±5.5 years,ranging from 18 to 44 years.No case of keratoconus was found during 3 years of follow-up.Intraocular pressure,corneal thickness and topography measurements were obtained with a Goldmann tonometer,ultrasonic corneal pachymeter and Orbscan Ⅱ z before and after surgery.All surgery was performed by the same surgeon using a 217Z100 Bausch & Lomb.Results After

  19. Sensibilidade corneana e secreção lacrimal após LASIK Corneal sensivity and tear secretion after LASIK

    Directory of Open Access Journals (Sweden)

    Marcelo Guimarães Brandão Rêgo

    2003-01-01

    Full Text Available OBJETIVO: Avaliar as alterações que ocorrem na sensibilidade corneana e secreção lacrimal após a cirurgia de "laser in situ keratomileusis" (LASIK. MÉTODOS: Foram examinados 38 olhos de 19 pacientes, 9 homens e 10 mulheres submetidos à cirurgia de LASIK para correção de miopia com equivalente esférico médio de -3,79 D (± 1,29 D. A sensibilidade corneana foi medida com o estesiômetro de Cochet-Bonnet, na região central da córnea. A secreção lacrimal foi avaliada pelos testes de Schirmer I, secreção basal, medida do tempo de rotura do filme lacrimal, e sintomatologia apresentada. Os exames foram realizados antes e após 7, 30, 90, 180 e 270 dias da cirurgia ou até que os níveis pré-operatórios fossem atingidos. RESULTADOS: Antes da cirurgia, o valor mediano da sensibilidade tátil corneana foi de 60,0 mm (variando de 50 a 60 mm; o teste de Schirmer I apresentou mediana de 21,5 mm (variando de 10 a 30 mm; o teste de secreção basal obteve mediana de 11,5 mm (variando de 6 a 20 mm; o tempo de rotura do filme lacrimal alcançou mediana de 16,0 segundos (variando de 8 a 22 segundos. Todos os pacientes recuperaram seus valores pré-operatórios de sensibilidade corneana e secreção lacrimal entre 90 e 180 dias após a cirurgia. Durante os 9 meses de seguimento, 5 pacientes (10 olhos não apresentaram qualquer sintoma relacionado a olho seco. CONCLUSÃO: Após a cirurgia de LASIK a sensibilidade corneana e a secreção lacrimal podem ficar reduzidos por até 6 meses. Neste período, 73,6% dos pacientes apresentaram sintomas de olho seco. Estudos futuros são necessários para avaliar os efeitos destas alterações sobre a fisiologia corneana.PURPOSE: To analyze the changes in corneal sensitivity and tear secretion after "laser in situ keratomileusis" (LASIK. METHODS: Thirty-eight eyes from nineteen patients, 9 men and 10 women, were submitted to myopic LASIK. The mean spherical equivalent before surgery was -3.79D (± 1

  20. Três anos pós-LASIK em crianças anisométropes de 8 a 15 anos de idade Three years after LASIK in anisometropic children from 8 to 15 years old

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    Belquiz R. Amaral Nassaralla

    2003-01-01

    Full Text Available OBJETIVO: Determinar a segurança, eficácia, previsibilidade e estabilidade da técnica "laser in situ keratomileusis" (LASIK, três anos após a cirurgia, para a correção de alta anisometropia em crianças, para as quais os tratamentos convencionais não obtiveram êxito. MÉTODOS: Nove olhos de nove pacientes, três meninos e 6 meninas, com idade média de 11,5 anos (variando de 8 a 15 anos, foram submetidos à técnica LASIK utilizando-se o excimer laser Chiron Technolas 217. O tempo mínimo de seguimento foi de 36 meses. RESULTADOS: Três anos após o LASIK, a acuidade visual sem correção (AVSC melhorou pelo menos 5 linhas em todos os olhos; cinco olhos (55,5% apresentavam AVSC de 20/50 ou melhor. Seis olhos (66,6%, apresentavam acuidade visual com correção (AVCC de 20/50 ou melhor e cinco olhos (55,5% ganharam pelo menos 1 linha na AVCC. Devido a ambliopia, nenhum olho apresentou AVSC de 20/20 ou melhor. A média do equivalente esférico pré-operatório foi reduzida de -7,66 (± 3,75 D para -1,02 (± 1,26 D e a do astigmatismo, de -3,11 (± 2,09 D para -0,75 (± 0,25 D. A maior anisometropia encontrada foi de 1,5 D. CONCLUSÕES: Após três anos de seguimento, a técnica LASIK parece ser opção segura e eficaz na correção de alta anisometropia em crianças entre 8 e 15 anos de idade, para os quais os tratamentos convencionais não obtiveram êxito. A progressão do erro refracional relacionada à idade não impediu o uso da correção visual adequada.PURPOSE: To determine the safety, efficacy, predictability and stability of laser in situ keratomileusis (LASIK, three years after surgery, to correct high myopia or high myopic astigmatism in children with high anisometropia in whom conventional treatments had failed. METHODS: Nine eyes of 9 patients, 3 boys and 6 girls with a mean age of 11.5 years (range, 8 to 15 years underwent LASIK using the Chiron Technolas 217 excimer laser. Minimum follow-up was 36 months. RESULTS: Three

  1. Rescue of Primary Incomplete Microkeratome Flap with Secondary Femtosecond Laser Flap in LASIK

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    E. A. Razgulyaeva

    2014-01-01

    Full Text Available For laser-assisted in situ keratomileusis (LASIK retreatments with a previous unsuccessful mechanical microkeratome-assisted surgery, some surgical protocols have been described as feasible, such as relifting of the flap or the creation of a new flap and even the change to a surface ablation procedure (photorefractive keratectomy (PRK. This case shows the use of femtosecond technology for the creation of a secondary flap to perform LASIK in a cornea with a primary incomplete flap obtained with a mechanical microkeratome. As we were unable to characterize the interface of the first partial lamellar cut, a thick flap was planned and created using a femtosecond laser platform. As the primary cut was very thick in the nasal quadrant, a piece of loose corneal tissue appeared during flap lifting which was fitted in its position and not removed. Despite this condition and considering the regularity of the new femtosecond laser cut, the treatment was uneventful. This case report shows the relevance of a detailed corneal analysis with an advanced imaging technique before performing a secondary flap in a cornea with a primary incomplete flap. The femtosecond laser technology seems to be an excellent tool to manage such cases successfully.

  2. Segmentation of 830- and 1310-nm LASIK corneal optical coherence tomography images

    Science.gov (United States)

    Li, Yan; Shekhar, Raj; Huang, David

    2002-05-01

    Optical coherence tomography (OCT) provides a non-contact and non-invasive means to visualize the corneal anatomy at micron scale resolution. We obtained corneal images from an arc-scanning (converging) OCT system operating at a wavelength of 830nm and a fan-shaped-scanning high-speed OCT system with an operating wavelength of 1310nm. Different scan protocols (arc/fan) and data acquisition rates, as well as wavelength dependent bio-tissue backscatter contrast and optical absorption, make the images acquired using the two systems different. We developed image-processing algorithms to automatically detect the air-tear interface, epithelium-Bowman's layer interface, laser in-situ keratomileusis (LASIK) flap interface, and the cornea-aqueous interface in both kinds of images. The overall segmentation scheme for 830nm and 1310nm OCT images was similar, although different strategies were adopted for specific processing approaches. Ultrasound pachymetry measurements of the corneal thickness and Placido-ring based corneal topography measurements of the corneal curvature were made on the same day as the OCT examination. Anterior/posterior corneal surface curvature measurement with OCT was also investigated. Results showed that automated segmentation of OCT images could evaluate anatomic outcome of LASIK surgery.

  3. Complicações primárias da interface do 'flap' de LASIK

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    Renata Loures Bueno de Moraes

    2016-02-01

    Full Text Available RESUMO Laser in situ Keratomileusis (LASIK é uma das técnicas mais aceitas na cirurgia refrativa atualmente. Sua previsibilidade, reprodutibilidade, segurança e baixos índices de efeitos colaterais justificam a ampla difusão dessa técnica. Trata-se de um procedimento cirúrgico a laser cujo objetivo consiste na modificação da estrutura corneana, permitindo uma mudança do ponto focal do olho. Dessa forma, é possível corrigir ametropias tais como a miopia, astigmatismo e pequenos graus de hipermetropia. A técnica do LASIK consiste na criação de um flap corneano por meio da utilização de um microcerátomo ou do laser de femtossegundo. Em seguida, é realizada a aplicação do excimer laser sobre o leito estromal com posterior reposicionamento do flap, criando-se uma interface entre as lamelas anterior e posterior da córnea. Apesar das inúmeras vantagens, existem patologias que resultam de complicações primárias da interface do flap, que podem causar confusão no momento do diagnóstico, por possuírem semelhanças quanto à sua apresentação clínica. O objetivo desse trabalho é definir, caracterizar e comparar tais entidades com intuito de facilitar o diagnóstico diferencial dessas patologias evitando a adoção de um tratamento equivocado. Como resultado do estudo, são apresentadas recomendações quanto à conduta nos casos de cada patologia de interface, com investigação por meio da anamnese e exame clínico, a fim de permitir diagnóstico diferencial entre as principais entidades primárias da interface do procedimento LASIK.

  4. Effects of different cutting centers on LASIK surgery in myopic patients

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    Yan-Wei Liu

    2017-07-01

    Full Text Available AIM:To investigate the effect of different cutting centers on the visual acuity, refractive diopter and visual quality of patients undergoing laser assisted in situ keratomileusis(LASIK. METHODS: A total of 80 patients(160 eyeswith myopia treated by elective LASIK were divided into two groups. Thirty-six cases(72 eyeswith visual axis corneal reflection point(VACRPas the cutting center were included into the VACRP group while 44 cases(88 eyeswith pupil center(PCas the cutting center were included into the PC group. The uncorrected visual acuity(UCVA, the best corrected visual acuity(BCVA, refractive diopter, corneal aberration \\〖total corneal and anterior corneal surface higher-order aberrations(HOA, spherical aberration(Z40, vertical coma(Z3-1, horizontal coma(totZ31and offset of cutting centers were determined before surgery and 1mo after surgery. RESULTS: There was no difference in the probability of UCVA ≥ 0.1, BCVA and refractive diopter between the two groups at 1mo after surgery(P>0.05. The astigmatism and cutting center deviation of VACRP group were lower than those of PC group(P40, totZ3-1, totZ31, froHOA, froZ3-1、froZ31 and froZ40 were lower in VACRP group than PC group at 1mo after surgery(PCONCLUSION: The UCVA of patients treated with both cutting centers for LASIK is good but VACRP has more advantages in reducing the offset of cutting center and improving postoperative visual quality.

  5. In vivo confocal microscopy and tear cytokine analysis in post-LASIK ectasia.

    Science.gov (United States)

    Pahuja, Natasha Kishore; Shetty, Rohit; Deshmukh, Rashmi; Sharma, Anupam; Nuijts, Rudy M M A; Jhanji, Vishal; Sethu, Swaminathan; Ghosh, Arkasubhra

    2017-04-27

    Corneal keratectasia is one of the complications associated with laser in situ keratomileusis (LASIK) that results in vision impairment. The pathogenesis of post-LASIK ectasia (PLE) remains underexplored. We report the tear cytokine profile and in vivo confocal microscopy (IVCM) findings in eyes with PLE. This retrospective study included age-matched 7 (14 eyes) post-LASIK controls (PLCs) and 6 (12 eyes) PLE subjects. Corneal topography was used to categorise the subjects into PLC and PLE groups. Ocular Surface Disease Index (OSDI) scores obtained were based on standard questionnaire and IVCM images were used to determine corneal dendritic cells density (DCD) and sub-basal nerve plexus morphology. Inflammatory cytokines/chemokines in the tears were quantified using flow cytometry based cytometric bead array. Pentacam-based scores, OSDI scores and corneal DCD were significantly (pPLE compared with PLC. Discomfort-related subscale of OSDI score exhibited a positive correlation with total corneal DCD in the PLE cohort. The fold difference of chemokine (C-C motif) ligand/monocyte chemotactic protein-1 (CCL2/MCP1) (3.4±0.6) was found to be significantly (pPLE cohorts and a positive correlation between CCL2/MCP1 levels and total corneal DCD was also observed in the PLE cohort. The current study found a significant difference in the tear film cytokine profile between normal and PLE eyes. Presence of increased corneal dendritic cells and altered tear cytokines suggests an ongoing inflammatory response in PLE. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  6. LASIK术后视网膜脱离的临床观察%Clinical observation on retinal detachment after LASIK

    Institute of Scientific and Technical Information of China (English)

    秦波; 成洪波; 赵铁英; 胡建荣

    2006-01-01

    目的:探讨准分子激光原位角膜磨镶术(LASIK)后视网膜脱离的临床特点及其手术治疗效果.方法:回顾性分析我院行LASIK手术的18 342眼(9598例)中发生视网膜脱离的患者的临床资料.所有近视患者在LASIK手术前均无角膜病等疾患,术前进行详细的眼底检查.术后平均随诊20mo,对LASIK术后发生的视网膜脱离的临床特点及治疗进行考察.结果:一共有6例患者(6眼)发生了视网膜脱离,包括2男4女,LASIK术后的视网膜脱离发生率为0.33‰.这些患者在LASIK手术前的平均近视度数为-9.33D,6眼都没有进行手术前预防性光凝治疗.脱离发生与LASIK手术的平均间隔时间为9.2mo,所有视网膜脱离发生没有其他诱因.治疗采用玻璃体切割术联合其他视网膜复位手术方法,复位手术后平均随诊9.3mo,6例视网膜脱离均一次复位成功(100%).结论:LASIK术后的视网膜脱离发生率不高.近视眼中视网膜脱离的发生与其行LASIK手术间没有确定的相关关系,但医生仍应警惕LASIK术前可能引起脱离的视网膜病变并予以处理.%AIM: To investigate the characteristics and surgical management of retinal detachment (RD) after laser-assisted in situ keratomileusis (LASIK) in myopia.METHODS: Documents of patients with RD observed in 18342 eyes (9 598 patients) who underwent LASIK were retrospectively reviewed. None of the patients had history of corneal or other diseases before LASIK and preoperative fundus examination was performed. Patients were followed for a mean of 20 months and the clinical features of the eyes which developed RD after LASIK were investigated.RESULTS: Six patients including 2 males and 4 females developed RD, and the incidence of RD after LASIK was 0.33‰. Mean pre-LASIK myopia in these 6 eyes was 9.33D.None of these eyes had prophylactic treatment history of any retinal lesions. Mean time interval between LASIK and RD development was 9.2 months. All RDs happened

  7. Corneal endothelial changes after accelerated corneal collagen cross-linking in keratoconus and postLASIK ectasia

    Science.gov (United States)

    Badawi, Amani E

    2016-01-01

    Purpose The purpose of this study was to evaluate the effects of accelerated cross-linking (CXL) on corneal endothelium in keratoconus and postlaser-assisted in situ keratomileusis (LASIK) ectasia. Design This study is a prospective nonrandomized controlled study. Setting This study was conducted in Mansoura Ophthalmic Center (Mansoura University) and Al-Mostakbal Ophthalmic Center, Mansoura, Egypt. Methods In total, 40 eyes with progressive keratoconus and 10 eyes with postLASIK ectasia were subjected to an accelerated CXL (10 mW/cm2 for 9 minutes). Qualitative and quantitative analyses of the corneal endothelial cells were conducted before CXL and 3, 6, and 12 months after CXL by using a specular microscope (Tomy EM-3000). Results There was a significant reduction in endothelial cell count particularly at 3 and 6 months postCXL. In addition, the coefficient of variance was also statistically significantly higher at 3 and 6 months postoperatively than the preCXL value. There was a slight change in the percentage of hexagonal cells. Conclusion The use of accelerated CXL (10 mW/cm2 for 9 minutes) has a transient negative impact on endothelial cell density and/or endothelial morphology. PMID:27757009

  8. A randomized clinical evaluation of the safety of Systane® Lubricant Eye Drops for the relief of dry eye symptoms following LASIK refractive surgery

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    Daniel Durrie

    2008-12-01

    Full Text Available Daniel Durrie, Jason StahlDurrie Vision, Overland Park, Kansas, USAPurpose: To evaluate the safety of Systane® Lubricant Eye Drops in relieving the symptoms of dry eye following laser-assisted in situ keratomileusis (LASIK surgery.Methods: This was a randomized, double-masked, single-center, placebo-controlled, contralateral eye study of 30 patients undergoing LASIK surgery. The mean age of patients was 42.4 ± 10.7 years, and the mean spherical equivalent was −3.29 (range, +1.75 to −7.38. Patients’ right and left eyes were randomized to receive either Systane® or placebo – a preserved, thimerosal-free saline solution – beginning from the day of surgery and ending 30 days following surgery. Outcome measures included tear film break up time (TFBUT, visual acuity, degree of corneal and conjunctival staining, and treatment-related adverse events.Results: Preoperatively, placebo-treated eyes had statistically significantly higher sum corneal staining score than Systane®-treated eyes (p = 0.0464; however, the difference was clinically insignificant (p = 0.27. Two weeks post operatively, the average TFBUT in the Systane®-treated eyes was 1.23 seconds longer than that of the placebo-treated eyes (p = 0.028. All other evaluated variables were comparable between the two treatments. No adverse events were reported in the study.Conclusion: Systane® Lubricant Eye Drops are safe for use following LASIK surgery to relieve the discomfort symptoms of dry eye associated with the procedure.Keywords: Systane®, safety, dry eye, LASIK

  9. Comparison of the femtosecond laser and mechanical microkeratome for flap cutting in LASIK.

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    Xia, Li-Kun; Yu, Jie; Chai, Guang-Rui; Wang, Dang; Li, Yang

    2015-01-01

    To compare refractive results, higher-order aberrations (HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis (LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism. In this prospective, non-randomized study, 120 eyes with myopia received a LASIK surgery with the VisuMax femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function (CSF) curves, HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery. At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was 113.05±5.89 µm (attempted thickness 110 µm), and 148.36±21.24 µm (attempted thickness 140 µm) in mechanical microkeratome procedure. An uncorrected distance visual acuity (UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in logMAR lines of corrected distance visual acuity (CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant (P>0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery (Plaser and the mechanical microkeratome for LASIK flap cutting are safe and effective to correct myopia, with no statistically significant difference in the UDVA, CDVA during 6mo follow-up. Refractive results remained stable after 1mo post-operation for both groups. The femtosecond laser may have advantages over the microkeratome in the flap thickness predictability, fewer induced HOAs, better CSF, and longer

  10. Comparison of the femtosecond Laser and mechanical microkeratome for flap cutting in LASIK

    Institute of Scientific and Technical Information of China (English)

    Li-Kun; Xia; Jie; Yu; Guang-Rui; Chai; Dang; Wang; Yang; Li

    2015-01-01

    · AIM: To compare refractive results, higher-order aberrations(HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis(LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism.·METHODS: In this prospective, non-randomized study,120 eyes with myopia received a LASIK surgery with the Visu Max femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function(CSF) curves,HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery.·RESULTS: At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was113.05 ±5.89 μm(attempted thickness 110 μm), and148.36 ±21.24 μm(attempted thickness 140 μm) in mechanical microkeratome procedure. An uncorrected distance visual acuity(UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in log MAR lines of corrected distance visual acuity(CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant(P >0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery(P <0.01). The CSF values of the femtosecond treated eyes were also higherthan those of the microkeratome treated eyes at all space frequency(P <0.01). The mean ocular surface disease index scores in both groups were increased at 1wk, and recovered to preoperative level at 1mo after surgery. The mean tear breakup time(TBUT) of the femtosecond treated eyes were markedly longer than those of

  11. Predictability and stability of refraction with increasing optical zone diameter in hyperopic LASIK

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    Mostafa A El-Helw

    2010-05-01

    Full Text Available Mostafa A El-Helw, Ahmed M EmarahCairo University, Cairo, EgyptObjective: We undertook a prospective nonrandomized study to assess refractive outcome and patient satisfaction with hyperopic laser in situ keratomileusis (LASIK using variable optical zone diameters in correction of hyperopia of more than 4.00 diopters.Methods: Fourteen adults (comprising 28 hyperopic eyes underwent hyperopic LASIK correction for hyperopia of more than 4.00 diopters. The sample was divided into two groups. Group 1 included the right eyes of the 14 patients who underwent hyperopic LASIK using a 6.5 mm optical zone diameter. Group 2 comprised the left eyes of the same patients with the only difference being that the optical zone diameter was 6.0 mm.Results: The mean age of the patients was 36.42 ± 5.10 years. Group 1 eyes had a median (range preoperative uncorrected visual acuity (UCVA of 0.79 (0.52 and best-corrected visual acuity (BCVA of 0.15 (0.08. Group 2 had a median preoperative UCVA of 0.79 (0.60 and BCVA of 0.15 (0.08. The median postoperative UCVA in Group 1 was 0.17 (0.21 and BCVA was 0.15 (0.13. In Group 2, the median postoperative UCVA was 0.30 (0.32 and BCVA was 0.15 (0.26. Group 1 had a median preoperative refraction of +5.37 (1.75 diopters and the median postoperative refraction at one week was −0.23 (1.25 diopters, at three months was +0.75 (0.75 diopters, and at six months was +0.75 (1.00 diopters. Group 2 had a median preoperative refraction of +5.00 (1.75 diopters, and the median postoperative refraction at one week was +0.13 (1.5 diopters, at three months was +1.00 (0.75 diopters and at six months +1.25 (1.25 diopters. The difference was statistically significant between groups 1 and 2. The difference within each group was also significant. Group 1 eyes were stabilizing after the three-month period in contrast with Group 2 in which the refractive changes continued throughout the follow-up period.Conclusion: Larger optical zone diameter in

  12. Anel corneano intra-estromal para baixa miopia: estudo comparativo com a técnica de LASIK

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    Forseto Adriana dos Santos

    2004-01-01

    Full Text Available OBJETIVO: Avaliar prospectivamente a eficácia e segurança dos segmentos de anéis corneanos intra-estromais (ICRS para a correção de baixa miopia e comparar os resultados obtidos com a técnica de laser in situ keratomileusis (LASIK. MÉTODOS: Estudo prospectivo, bilateral e não randomizado. Quatorze pacientes com equivalente esférico entre -1,00 e -4,50 D foram submetidos ao implante de ICRS em um olho e à técnica de LASIK no olho contralateral. As avaliações pós-operatórias foram realizadas com um e sete dias, um, três, seis, 12 e 24 meses. RESULTADOS: Ao último exame, 64,29% dos olhos (9/14 do grupo ICRS e 85,71% (12/14 após o LASIK estavam entre ± 0,50 D da correção desejada (p=0,385. Acuidade visual sem correção >20/20 foi obtida em quatro dos 14 olhos (28,57% do grupo ICRS, e em 12 dos 14 olhos (85,71% do grupo LASIK (p=0,002¹. Durante o seguimento, não foram observadas variações refracionais superiores a 1,00 D, entre dois exames consecutivos, em ambos os grupos, ou perda significante da melhor acuidade visual corrigida. Maior indução de astigmatismo foi encontrada nos olhos implantados com ICRS. Ao exame de 24 meses, o grupo ICRS apresentou valores inferiores no exame de sensibilidade ao contraste, especialmente nas freqüências espaciais mais altas (p=0,032¹ em 18 cpd. Foram relatadas mais queixas subjetivas no período pós-operatório precoce de ICRS em relação ao LASIK. CONCLUSÕES: Os ICRS foram considerados eficazes na correção de baixa miopia, porém sua segurança foi limitada pela indução de astigmatismo no pós-operatório, e seus resultados foram inferiores aos do grupo controle.

  13. Visual, aberrometric, photic phenomena, and patient satisfaction after myopic wavefront-guided LASIK using a high-resolution aberrometer

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    Moussa S

    2016-12-01

    Full Text Available Sarah Moussa, Alois K Dexl, Eva M Krall, Eva M Arlt, Günther Grabner, Josef Ruckhofer Department of Ophthalmology, Paracelsus Medical University Salzburg, Salzburg, Austria Purpose: The purpose of this study was to evaluate the visual, refractive, and aberrometric outcomes as well as the level of patient satisfaction and photic phenomena after myopic laser in situ keratomileusis (LASIK surgery using wavefront-guided (WFG ablations based on measurements obtained with a high-resolution aberrometer. Patients and methods: This study was a prospective analysis including 253 eyes of 127 patients (aged between 19 years and 54 years undergoing WFG LASIK using the STAR S4 IR Excimer Laser System combined with the iDesign System and iFS Femtosecond Laser. Visual, refractive, and aberrometric outcomes during a 2-month follow-up as well as patient satisfaction and photic phenomena were evaluated by means of a questionnaire. Results: A total of 85% (215/253 and 99% (251/253 of eyes achieved a postoperative (Postop uncorrected distance visual acuity of 20/16 and 20/20, respectively, and all eyes achieved an uncorrected distance visual acuity of 20/25. Postop spherical equivalent values were within ±0.25 D and ±0.50 D in 97% and 100% of eyes, respectively. Likewise, manifest cylinder was <0.25 D in 97% (245/253 of eyes. A statistically significant reduction was found in the total root mean square (P<0.001 and in the level of primary spherical aberration (P=0.001. Postop difficulties related to vision were graded as minimal, with low levels of photic phenomena and high levels of patient satisfaction. The level of difficulty to perform daily activities and the level of glare perceived by patients while driving car were significantly decreased (P<0.001. Conclusion: WFG LASIK surgery using the technology evaluated is predictable and effective for the correction of myopia and leads to high levels of patient satisfaction. Keywords: LASIK, patient

  14. 去除上皮瓣的微型角膜刀法准分子激光角膜上皮瓣下磨镶术后早期兔角膜的修复方式研究%The early post-operative wound healing mode study of the rabbit cornea after flap-free epipolis laser in-situ keratomileusis

    Institute of Scientific and Technical Information of China (English)

    刘玺; 杜之渝; 向一旻; 黄正

    2009-01-01

    Objective To evaluate the wound healing mode of rabbit corneal epithelium after Epi-LASIK(epipolis laser in-situ keratomilensis ) and Flap-free Epi-LASIK (Flap-free epipolis laser in-situ keratomileusia).Methods Twenty-four New Zealand white rabbits(48 eyes) were randomly divided into four groups.There were six rabbits in every group, which were randomly treated with Epi-LASIK in one eye and Flap-free Epi-LASIK in the other by VISX20/20 excimer laser.Other three rabbits(6 eyes) without any treatment were used as control.The corneal epithelium wound healing mode was observed at 1,2,4,7 days after surgery by light microscope and electron microscope.The number of keratocytes cells in the central anterior stroma were counted by hematoxylin-cesin-stained.The expression of basic fibroblast growth factor (bFGF) in corneal stroma were assessed by Immunohistochemistry staining.Cornea stromal cell apoptosis was evaluated by terminal deoxyribonuc1eotidyl transferase-mediated deoxynuridine triphosphate nick end labeling (TUNEL) assay.All the data was analysised by t-test to evaluate the different of wound healing mode after Epi-LASIK and Flap-free Epi-LASIK.Results The findings of light microscope and electron microscope investigation demonstrated that, at the first day after surgery, there was one layer of neogenesis of the corneal epithelial cells covering the area of surgery in Flap-free Epi-LASIK specimens.It would increase gradually after 7 days.At the first day after the surgery, the base membrane of the corneal epithelium was tightly attached to the stroma in Epi-LASIK specimens.At the second day after the surgery, there was edema observed on the epithelium flap in the Epi-LASIK specimens.There were more keratocytes cells found at 4 days after surgery in Flap-free Epi-LASIK group (33.85±3.39) than that in Epi-LASIK group (t=-2.315,P<0.05).The expression of bFGF in Flap-free Epi-LASIK group at 2,4 days after surgery were 101.75±8.07 and 110.56±9.00, which were more

  15. Combined treatment with flap amputation, phototherapeutic keratectomy, and collagen crosslinking in severe intractable post-LASIK atypical mycobacterial infection with corneal melt.

    Science.gov (United States)

    Kymionis, George D; Kankariya, Vardhaman P; Kontadakis, Georgios A

    2012-04-01

    A 23-year-old woman was referred for management of intractable post-laser in situ keratomileusis (LASIK) keratitis due to atypical mycobacteria in the left eye. Corrected distance visual acuity was 20/20 in the right eye and counting fingers at 3 meters in the left eye. Slitlamp examination revealed multiple infiltrates in the flap interface and severe corneal stromal melting with thinning. Despite maximum antibiotic therapy for 7 days, the keratitis continued to worsen. A penetrating keratoplasty (PKP) was scheduled. While waiting for a corneal graft, corneal collagen crosslinking (CXL) with riboflavin and ultraviolet-A was proposed as an alternative treatment. Flap amputation and limited phototherapeutic keratotomy (PTK) (10 μm) were also performed. One week postoperatively, all infiltrates and stromal edema had resolved. At 3 months, the uncorrected distance visual acuity improved to 20/35. Corneal crosslinking after flap amputation and limited PTK was an effective treatment for severe intractable post-LASIK keratitis with corneal melting and obviated PKP.

  16. Cataractogenesis after Repeat Laser in situ Keratomileusis

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    Ahmad M. Mansour

    2012-08-01

    Full Text Available There has been the unsubstantiated clinical impression that laser refractive surgery accelerates cataract development along with solid experimental data about the cataractogenic effects of excimer laser treatment. We present the first documented case of significant cataract formation in a young myope after repeat excimer laser ablation necessitating phacoemulsification with a posterior chamber implant. Proposed explanations include focusing of the ablation wave on the posterior capsule (acoustic wave lens epithelial damage, photooxidative stress of the lens (ultraviolet and inflammatory oxidative stress, and corticosteroid-induced cataract (lens toxicity.

  17. 新型三维眼前节分析仪Sirius和Pentacam测量准分子激光角膜原位磨镶术后眼前节参数的对比研究%Comparison of anterior segment measuring parameters in myopia after laser in situ keratomileusis between Sirius and Pentacam

    Institute of Scientific and Technical Information of China (English)

    徐真; 黄锦海; 成拾明; 冯一帆; 王勤美

    2013-01-01

    者的结果一致性欠佳,95%CI为-27.70~6.20 mm3. 结论 Sirius和Pentacam测量LASIK术后眼前房参数结果的重复性和稳定性好,此外两种方法测量的角膜曲率、角膜厚度和ACD具有很好的一致性,两种测量结果的差异在临床上可以接受,二者可以互相替代使用,但在测量角膜最薄点位置及ACV时两种方法的测量结果差异较大,临床上相互替代使用时需谨慎.%Background Sirius system,a new Scheimpflug camera combined with Placido topography,improved the capability of imaging the anterior eye segment significantly.However,the study of assessing the repeatability and agreement between Sirius and Pentacam is still lack up to now.Objective This study was to evaluate the repeatability and agreement of the anterior ocular segment measuring parameters by Sirius and Pentacam in myopia received laser in situ keratomileusis (LASIK).Methods Thirty-five myopic eyes of 35 patients received LASIK were included in School of Optometry and Ophthalmology Eye Hospital from 2010 May through 2010 July.Corneal power flat keratometry (Kf),step keratometry (Ks),mean keratometry (Km),thinnest corneal thickness(TCT),the location of TCT,anterior chamber depth (ACD) and anterior chamber volume (ACV) were measured by Sirius and Pentacam in all the eyes,respectively.The repeatability of the measuring results were evaluated using intraclass correlation coefficients (ICC) and Cronbach's coefficient alpha (CoA),and the agreement of measuring parameters between Sirius and Pentacam was analyzed using Bland-Altman plot.Results Both Sirius and Pentacam demonstrated high intraobserver repeatability,with all ICC and CoA more than 0.90.No significant differences were found in Kf values and Ks values between the two methods (t =-1.533,-1.750,P>0.05).Km value was (39.14 ± 1.95) D by Sirius measurement,which was sígnificantly higher than (39.05 ± 1.91) D by Pentacam measurement (t =3.572,P =0.001).The TCT was (457.6 ± 40.9) μm by Sirius method,showing a

  18. LASIK eye surgery

    Science.gov (United States)

    ... When LASIK was first done, a special automated knife (a microkeratome) was used to cut the flap. ... scarring or permanent problems with the cornea's shape, making it impossible to wear contact lenses Decrease in ...

  19. [Comparison of clinical results between LASIK method and ICL implantation in high myopia].

    Science.gov (United States)

    Hrubá, H; Vlková, E; Horácková, M; Svacinová, J

    2004-05-01

    In a retrospective study the authors evaluate clinical results of the LASIK (laser in situ keratomileusis) and the implantation of the implantable posterior chamber contact lens phakic IOL (ICL) (STAAR Surgical) to correct high myopia. The purpose of the study was to assess which of those two methods is more reliable in patients to correct myopia in the range -10.0 to -23.0 diopters. The LASIK method was presented of a group of 70 eyes of 48 patients with preoperative spherical equivalent average of -12.9 +/- 3.8 diopters (Dsf) and average astigmatism of -0.99 +/- 1.2 cylindrical diopters (Dcyl). The group was divided into two parts: one part was with the desired postoperative emmetropia--46 eyes (65.7%), and part two was with the desired postoperative residual myopia up to -3.0 Dsf--24 eyes (34.3%). The method of ICL implantation was presented of a group of 36 eyes of 21 patients with preoperative spherical equivalent average of -15.21 +/- 4.0 Dsf and average astigmatism of -0.92 +/- 0.69 Dcyl. Also this group was divided into two parts: One part was with the desired postoperative emmetropia--25 eyes (69.4%), and part two was with the desired postoperative residual myopia up to -3.0 Dsf--11 eyes (30.6%). The developments of postoperative refraction in time (1 week to 3 years after the surgery), the final postoperative refraction and its stability and (6 months to 3 years after the surgery) as well as the occurrence of complications in both studied groups were evaluated. In the assessment of the postoperative refraction development in groups of desired emmetropia, the average uncorrected visual acuity (UCVA), average postoperative spherical equivalent and astigmatism were evaluated. In the groups with desired residual myopia the average best-corrected visual acuity (BCVA), average postoperative spherical equivalent, and astigmatism were followed. Three years after the surgery in groups with desired emmetropia, the average postoperative spherical equivalent was -0

  20. Analysis on tear film after LASIK by femtosecond laser with Oculus corneal topography%Oculus角膜地形图仪对飞秒激光LASIK术后泪膜的分析

    Institute of Scientific and Technical Information of China (English)

    张媛; 贾冰冰; 张岩; 高冬梅; 庞玉珍

    2014-01-01

    AIM:To observe the changes of tear film on the patients after laser in situ keratomileusis ( LASIK) with corneal flap created by femtosecond laser with Oculus corneal topography. METHODS:Totally 120 myopic patients (240 eyes) were collected who underwent femtosecond laser surgery LASIK from August to September 2013, and these patients can be followed up for 3mo. Tear break-up time ( BUT) and tear meniscus height ( TMH ) with Oculus corneal topography were recorded preoperatively and postoperatively at 1wk;1, 2 and 3mo. RESULTS: Oculus BUT: there existed obvious differences (P=0. 012, 0. 000, 0. 023 0. 05 ) existed in 3mo compared with the preoperative level. TMH:there existed obvious differences (P=0. 025, 0. 019, 0. 0260. 05 ) existed in 3mo compared with the preoperative level. CONCLUSION: Femtosecond laser surgery affects the stability of the tear film at a certain time and a certain extent. The mechanism related to many factors. It is temporary and lighted.%目的:观察Oculus角膜地形图仪检查飞秒激光制瓣准分子激光原位角膜磨镶术( laser in situ keratomileusis, LASIK)术后泪膜的变化。  方法:收集2013-08/09于我院行飞秒激光制瓣LASIK并随访3 mo的患者120例240眼,观察术前、术后1 wk;1,2,3 mo患者的 Oculus 角膜地形图仪检查的泪膜破裂时间( tear break-up time,BUT)、Oculus角膜地形图仪检查的泪河高度( tear meniscus height,TMH)。  结果:Oculus BUT:术后1 wk;1,2 mo与术前相比有显著差异( P=0.012,0.000,0.0230.05)。泪河高度:术后1wk;1,2mo与术前相比有显著差异( P=0.025,0.019,0.0260-05)。  结论:飞秒激光制瓣准分子激光原位角膜磨镶术在一定时间和一定程度上影响泪膜的稳定性,发生机制与多种因素有关,持续时间比较短,症状比较轻。

  1. Effects of 3% trehalose as an adjuvant treatment after LASIK

    Directory of Open Access Journals (Sweden)

    Mateo Orobia AJ

    2017-02-01

    Full Text Available Antonio J Mateo Orobia,1–3 Paula Casas Pascual,1,4 José Á Cristóbal Bescós,1 Diana Perez García,1,4 Carlos Peiro Embid,1,4 M Ángeles del Buey Sayas,1,4 Valentyna Korobko Kulikova,1 Noelia Lafuente Ojeda5 1Department of Ophthalmology, Hospital Quirón, 2Department of Ophthalmology, Hospital Universitario Miguel Servet, 3Instituto de Investigación Sanitaria de Aragón (IIS, 4Department of Ophthalmology, Hospital Clínico Universitario Lozano-Blesa, 5Department of Anesthesiology, Hospital Universitario Miguel Servet, Zaragoza, Spain Purpose: To evaluate the effect of 3% trehalose as an adjuvant in the standard treatment after laser-assisted in situ keratomileusis.Design: Interventional prospective comparative single-blind study.Setting: Department of Ophthalmology, Hospital Quirón Zaragoza, Spain.Methods: A total of 26 eyes (13 patients were included, of which 12 eyes (group 1 received conventional treatment with lubricant drops of hyaluronic acid (0.15% and 14 eyes (group 2 received, additionally, an ophthalmic solution of 3% trehalose. Pre- and postoperative quality-of-life tests and vital stains, tear breakup time, and osmolarity measurements were made.Results: We obtained statistically significant differences between the groups in the Symptom Assessment in Dry Eye test in all visits with respect to severity, and in the postoperative day 1 visit with respect to frequency, in all cases favoring the trehalose treatment. The values of osmolarity were not significantly different between groups. However, we did find significant differences in the Oxford scale in day 90 for the trehalose treatment (P<0.001, and in the National Eye Institute scale in day 30 (P=0.02.Conclusion: The results of this exploratory study indicate that the adjuvant treatment with 3% trehalose could be superior with respect to the standard treatment, with improvements in the objective and subjective parameters of tear quality. Keywords: dry eye syndrome, trehalose

  2. A Comparison of the American Society of Cataract and Refractive Surgery post-myopic LASIK/PRK Intraocular Lens (IOL calculator and the Ocular MD IOL calculator

    Directory of Open Access Journals (Sweden)

    Hsu M

    2011-09-01

    Full Text Available David L DeMill1, Majid Moshirfar1, Marcus C Neuffer1, Maylon Hsu1, Shameema Sikder21John A Moran Eye Center, University of Utah, Salt Lake City, UT, USA; 2Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USABackground: To compare the average values of the American Society of Cataract and Refractive Surgery (ASCRS and Ocular MD intraocular lens (IOL calculators to assess their accuracy in predicting IOL power in patients with prior laser-in-situ keratomileusis (LASIK or photorefractive keratectomy.Methods: In this retrospective study, data from 21 eyes with previous LASIK or photorefractive keratectomy for myopia and subsequent cataract surgery was used in an IOL calculator comparison. The predicted IOL powers of the Ocular MD SRK/T, Ocular MD Haigis, and ASCRS averages were compared. The Ocular MD average (composed of an average of Ocular MD SRK/T and Ocular MD Haigis and the all calculator average (composed of an average of Ocular MD SRK/T, Ocular MD Haigis, and ASCRS were also compared. Primary outcome measures were mean arithmetic and absolute IOL prediction error, variance in mean arithmetic IOL prediction error, and the percentage of eyes within ±0.50 and ±1.00 D.Results: The Ocular MD SRK/T and Ocular MD Haigis averages produced mean arithmetic IOL prediction errors of 0.57 and –0.61 diopters (D, respectively, which were significantly larger than errors from the ASCRS, Ocular MD, and all calculator averages (0.11, –0.02, and 0.02 D, respectively, all P < 0.05. There was no statistically significant difference between the methods in absolute IOL prediction error, variance, or the percentage of eyes with outcomes within ±0.50 and ±1.00 D.Conclusion: The ASCRS average was more accurate in predicting IOL power than the Ocular MD SRK/T and Ocular MD Haigis averages alone. Our methods using combinations of these averages which, when compared with the individual averages, showed a trend of decreased mean arithmetic IOL

  3. Topography-guided hyperopic and hyperopic astigmatism femtosecond laser-assisted LASIK: long-term experience with the 400 Hz eye-Q excimer platform

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ

    2012-06-01

    Full Text Available Anastasios John KanellopoulosDepartment of Ophthalmology, New York University Medical School, New York, NY, and LaserVision.gr Eye Institute, Athens, GreeceBackground: The purpose of this study was to evaluate the safety and efficacy of topography-guided ablation using the WaveLight 400 Hz excimer laser in laser-assisted in situ keratomileusis (LASIK for hyperopia and/or hyperopic astigmatism.Methods: We prospectively evaluated 208 consecutive LASIK cases for hyperopia with or without astigmatism using the topography-guided platform of the 400 Hz Eye-Q excimer system. The mean preoperative sphere value was +3.04 ± 1.75 (range 0.75–7.25 diopters (D and the mean cylinder value was –1.24 ± 1.41 (–4.75–0 D. Flaps were created either with Intralase FS60 (AMO, Irvine, CA or FS200 (Alcon, Fort Worth, TX femtosecond lasers. Parameters evaluated included age, preoperative and postoperative refractive error, uncorrected distance visual acuity, corrected distance visual acuity, flap diameter and thickness, topographic changes, higher order aberration changes, and low contrast sensitivity. These measurements were repeated postoperatively at regular intervals for at least 24 months.Results: Two hundred and two eyes were available for follow-up at 24 months. Uncorrected distance visual acuity improved from 5.5/10 to 9.2/10. At 24 (8–37 months, 75.5% of the eyes were in the ±0.50 D range and 94.4% were in the ±1.00 D range of the refractive goal. Postoperatively, the mean sphere value was –0.39 ± 0.3 and the cylinder value was –0.35 ± 0.25. Topographic evidence showed that ablation was made in the visual axis and not in the center of the cornea, thus correlating with the angle kappa. No significant complications were encountered in this small group of patients.Conclusion: Hyperopic LASIK utilizing the topography-guided platform of the 400 Hz Eye-Q Allegretto excimer and a femtosecond laser flap appears to be safe and effective for

  4. Evaluation of intrastromal corneal ring segments for treatment of post-LASIK ectasia patients with a mechanical implantation technique

    Directory of Open Access Journals (Sweden)

    Zeki Tunc

    2011-01-01

    Full Text Available Aim: To evaluate the clinical outcomes of Keraring segment implantation in patients with post- laser-assisted in situ keratomileusis (LASIK ectasia, using a mechanical implantation technique. Materials and Methods: Twelve eyes of 10 patients with post-LASIK ectasia were enrolled. Intracorneal ring segments (ICRS were implanted after dissection of the tunnel using Tunc′s specially designed dissector under suction. A complete ophthalmic examination was performed, including uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, spherical equivalent, keratometric (K readings, inferosuperior asymmetry index (ISAI, and ultrasound pachymetry. All 3, 6, and 12-month follow-ups were completed, and statistical analysis was performed. Results: The mean preoperative UDVA for all eyes was 1.28 ± 0.59 logMAR. At 12 months, the mean UDVA was 0.36 ± 0.19 logarithm of the Minimum Angle of Resolution (logMAR (P=0.002, and the mean preoperative CDVA was 0.58 ± 0.3 logMAR, which improved to 0.15 ± 0.12 (P=0.002 at 1 year. There was a significant reduction in cylindrical refractive and spherical equivalent refractive error from -5.29 ± 2.47 diopters (D and -5.54 ± 5.04 D preoperatively to -1.47 ± 0.71 D and -0.74 ± 1.07 D (P=0.001, P=0.002, respectively, at 1 year. In the same period, the mean K- readings improved from 47.93 ± 4.84 D to 40.87 ± 2.36 D (P=0.002, and the mean ISAI improved from 5.34 ± 3.05 to 2.37 ± 1.68 (P=0.003. No significant changes in mean central corneal thickness were observed postoperatively. There were no major complications during or after surgery. Conclusion: ICRS implantation using a unique mechanical dissection technique is a safe and effective treatment for post-LASIK ectasia. All parameters showed improvement at 1-year follow-up.

  5. 利多卡因注射液滴眼用于激光角膜原位磨镶术表面麻醉的效果研究%The effect of Lidocaine on topical anesthesia for LASIK

    Institute of Scientific and Technical Information of China (English)

    李淑萍; 刘运甲; 李志强

    2011-01-01

    Objective To discuss the effect of 2% Lidocaine solution for injection on topical anesthesia for laser in situ keratomileusis (LASIK). Methods Totally 100 cases (200 eyes) were randomly divided into two groups,2% Lidocaine group and Oxybuprocaine group. Each group contained 50 cases ( 100eyes). LASIK was done under the topical anesthesia of those two medicine respectively. The anesthetic effect was assessed by the feeling of pain and tactile perception of the patients. Results The surgery was done smoothly in 98 eyes under Lidocaine anesthesia. There was mild pain in two eyes during the surgery. The pain disappeared when an additional drop of Lidocaine was used. In Oxybuprocaine group, the surgery was done smoothly in 99 eyes. There was mild discomfort in one eye, and the surgery was done without additional treatment. Conclusion 2% Lidocaine injection can provide good topical anesthetic effect for LASIK.%目的 探讨2%利多卡因注射液滴眼用于准分子激光角膜原位磨镶术(LASIK)表面麻醉的效果.方法 100例(200眼)随机分成利多卡因组和奥布卡因组,每组50例(100眼).两组分别在两种药物的表面麻醉下进行LASIK,根据术中患者对疼痛和触觉的感受评价麻醉效果.结果 利多卡因组中98眼能顺利完成手术,2眼稍感疼痛,追加滴利多卡因1滴后顺利完成手术.奥布卡因组99眼顺利完成手术,1眼稍感不适,未做处理,也顺利完成手术.结论 2%利多卡因注射液滴眼用于LASIK表面麻醉效果良好.

  6. Analysis of changes of Kappa angle in patient with myopia of different position during Laser Assisted in-situ keratomi leusis (LASIK)%准分子激光术中不同体位Kappa角变化分析

    Institute of Scientific and Technical Information of China (English)

    齐惠; 黄一飞; 蒋晶晶; 姜严明; 王丽强

    2013-01-01

    目的 探究近视患者坐位、仰卧位时kappa角的大小,坐位与仰卧位时kappa角变化关系.方法 临床病例对照研究.对201 1年7~12月在解放军总医院激光近视治疗中心符合行激光近视手术的患者215(395只眼),按近视程度分为低度、中度、高度三组.术前行Oculus Pentacam眼前节分析系统检查,获得坐位时kappa角在角膜的水平和垂直偏移量,术中患者仰卧位在角膜瓣制作完成掀瓣前开启鹰视酷眼激光仪x和y轴跟踪调节程序,获得患者卧位时kappa角水平和垂直方向的偏移量,进行低度、中度、高度分组统计.结果 (1)坐位正kappa角223只眼(56.4%),仰卧位正kappa角343只眼(86.8%).(2) kappa角与屈光度的关系采用单因素方差分析,低度、中度、高度三组患者的kappa角水平偏移量差异无统计学意义(P>0.05),垂直偏移量差异有统计学意义(P<0.05).(3)坐位与仰卧位kappa角关系采用配对t检验,水平、垂直偏移量差异有显著性且均有统计学意义(P<0.05).(4) kappa角坐位与仰卧位垂直偏移量与近视度数差异有统计学意义(R坐位=-0.109,R仰卧位=-0.172 P<0.05).结论 坐位与仰卧位kappa角水平、垂直偏移量具有相关性.近视度数越大kappa角垂直偏移量越大.在行屈光手术时应考虑到体位变化对kappa角的影响.%Objective To investigate the change of Kappa angle in patient with myopia of sitting and supine position during laser assisted in-situ keratomi leusis (LASIK).Method A total of 215 patients with myopic included 395 eyes who underwent LASIK were divided into low,middle and high myopia groups according to different diopters.The horizontal and vertical offsets of kappa angle in sitting position of preoperative analytical system examination were measured by Oculus Pentacam.During the operation the X and Y axis tracking modulation of ALLEGRETTO Wavelight Excimer Laster System were opened for getting horizontal and vertical

  7. Under-flap stromal bed CXL for early post-LASIK ectasia: a novel treatment technique.

    Science.gov (United States)

    Wallerstein, Avi; Adiguzel, Eser; Gauvin, Mathieu; Mohammad-Shahi, Nima; Cohen, Mark

    2017-01-01

    Collagen cross-linking (CXL) for post-laser-assisted in situ keratomileusis (LASIK) ectasia (PLE) is traditionally performed either epi-on or epi-off on the corneal surface. This study describes a novel technique in treating early PLE with under-flap CXL (ufCXL) to the stromal bed and reports on 6-month outcomes. Case series of seven patients (eight eyes) with topography-diagnosed early PLE treated with ufCXL. Inclusion criteria were early, mild PLE defined as new-onset postoperative manifest refraction cylinder ≤1.50 D, with new topographic inferior steepening consistent with ectasia, uncorrected distance visual acuity (UDVA) of 20/40 or better, and corrected distance visual acuity (CDVA) of 20/25 or better. Existing LASIK flap was lifted, riboflavin was applied directly to the stromal bed, flap was repositioned, and 18 mW/cm(2) ultraviolet light was applied for 3 minutes to the corneal surface. Post-ufCXL manifest refraction, UDVA and CDVA, corneal cylinder, Kmax, and corneal irregularity index were compared with pre-ufCXL measurements. Patients had a pre-ufCXL sphere of 0.09±0.48 D and cylinder of -0.78±0.49 D. At 6 months, post-ufCXL sphere (0.06±0.8 D; P=0.89) and cylinder (-1.09±0.76 D, P=0.26) were unchanged. Cumulative post-ufCXL UDVA was unchanged, achieving 20/20, 20/30, and 20/40 in 25%, 88%, and 88%, respectively, compared with 13%, 63%, and 88% pre-ufCXL (P=0.68). Post-ufCXL CDVA was unchanged (P=0.93) with a gain of one line in two eyes, a loss of one line in one eye, and five eyes unchanged. The efficacy index (P=0.76), safety index (P=0.89), Kmax (P=0.94), and corneal irregularity index (P=0.73) were also unchanged. Preliminary results with ufCXL for early PLE are promising, demonstrating maintenance of visual accuracy, efficacy, safety, Kmax, and cylinder, with much quicker recovery times than surface CXL.

  8. Effect of suction on macular thickness and retinal nerve fiber layer thickness during LASIK used femtosecond laser and Moria M2 microkeratome

    Institute of Scientific and Technical Information of China (English)

    Jing; Zhang; Yue-Hua; Zhou

    2015-01-01

    ·AIM: To compare the effect of suction on the macular thickness and retinal nerve fiber layer(RNFL) thickness during laser in situ keratomileusis(LASIK) used Ziemer FEMTO LDV femtosecond laser(Ziemer group) and Moria M2 automated microkeratome(Moria group) for flap creation.· METHODS: Fourier-domain optical coherence tomography(FD-OCT) was used to measure macular thickness, ganglion cell complex thickness and RNFL thickness of 204 eyes of 102 patients with the Ziemer femtosecond laser(102 eyes) and the Moria M2microkeratome(102 eyes) before surgery and 30min; 1,3d; 1wk; 1, 3mo; 1y after surgery.· RESULTS: The average foveal thickness and parafoveal retinal thickness 30 min after the surgery were statistically more than that before surgery(Ziemer P <0.001,P =0.003 and Moria P=0.001, P=0.006) and the effect was less in the Ziemer group than that in the Moria group(P all <0.05). The ganglion cell complex thickness was not significantly changed in both groups(P all >0.05). The RNFL thickness was statistically less 30 min after surgery in both groups(P=0.014, P <0.001), but the influence was less in Ziemer group than that in Moria group(P =0.038).However, the RNFL thickness had recovered to the preoperative level only 1d after surgery.·CONCLUSION: The suction of femtosecond laser and mechanical microkeratome led to the increase in macular central fovea thickness and the decrease in RNFL thickness values at the early stage after LASIK. The effect of suction on macular and the RNFL thicknesses in Ziemer group is smaller than that in Moria group.

  9. 有晶状体眼后房型人工晶状体植入和准分子激光原位角膜磨削术矫正超高度近视的临床评价%Evaluations of Extreme Myopia Correction with Phakic Posterior Chamber Intraocular Lens and Laser in Situ Keratomileusis

    Institute of Scientific and Technical Information of China (English)

    沈晔; 李毓敏; 王竞

    2004-01-01

    目的:比较和评价有晶状体眼后房型人工晶状体(Phakic Posterior Chamber Intraocular Lens,PPCIOL)植入和准分子激光原位角膜磨削术(Laserin situ Keratomileusis,Lasik)矫正高度近视的有效性、安全性和稳定性.方法:高度近视患者43例,随机分为PPCIOL组和Lasik组,分别行可植入接触镜(Implantable Contact Lens,ICL)植入术和Laisk,随访并比较两组有效性和安全性指数,两年屈光度回退≤2 D的生存率,低对比度视力和眩光视力的改变.结果:PPCIOL组术前平均等效球面屈光度(-16.77±3.37)D(-11.75~-25.75 D);Lasik组术前平均等效球镜度(-13.8±2.71)D(-9.37~-23.75 D).术后1个月两组有效性无统计学差异,PPCIOL组安全性指数高于Lasik组(P<0.001),2 a时屈光度回退率分别为0、32.56%(P<0.001),术后3个月低对比视力和眩光视力PPCIOL组较术前提高比Lasik组明显(P<0.001).PPCIOL组有1例2眼术后6个月时有晶状体前囊混浊,两组未见其他并发症.结论:有晶状体眼后房型人工晶状体植入矫正超高度近视有效,安全性和稳定性较Lasik更好,并能获得良好的视觉质量.

  10. Early outcomes of corneal sensitivity changes in different corneal regions after laser in situ keratomileusis with femtosecond laser%飞秒激光LASIK术后早期不同部位角膜敏感性变化研究

    Institute of Scientific and Technical Information of China (English)

    魏升升; 王雁; 耿维莉; 金颖; 左彤; 刘洋辰; 薛超

    2012-01-01

    Objective To evaluate the recovery of central corneal sensitivity and peripheral corneal sensitivity in the early period time after LASIK with femtosecond flaps.Methods In this study,40 cases which underwent LASIK with femtosecond flaps were included.Central,superior,inferior,nasal and temporal comeal sensitivity was measured using a Cochet-Bonnet esthesiometer (Luneau Ophthalmologie) before and 1 week,1 month and 3 months after LASIK with femtosecond flaps.The results were analyzed with Kruskal Wallis H test and Mann-Whitney test by SPSS13.0 software.Results Central,superior,inferior,nasal and temporal comeal sensitivity decreased significantly in the early period time after LASIK with femtosecond flap (P <0.05).At every time points of postoperative,superior corneal sensitivity and central,inferior,nasal and temporal corneal sensitivity had significant difference (P <0.05).Three months postoperative,central corneal sensitivity was significant lower than the superior,inferior,nasal,temporal.There were no correlations between central corneal sensitivity and central corneal ablation depth,central corneal depth,preoperative spherical equivalent (r =0.005;-0.105; 0,03,P =0.97; 0.38; 0.80). Conclusions Corneal sensitivity is significant decreased in the early period time after LASIK with femtosecond flaps.Comeal sensitivity at the location of the hinge of corneal flaps is decreased lower than other places and the recovery of central corneal sensitivity is slower than other places.There are no correlations between central corneal sensitivity and central corneal ablation depth,central corneal depth,preoperative spherical equivalent.%目的 评估飞秒激光LASIK术后早期角膜中央和周边区敏感性的恢复情况.方法 观察飞秒激光LASIK手术的患者40例(71只眼),分别在术前、术后1周、1月、3月使用Cohet-Bonnet角膜知觉计检查角膜中央、上方、下方、鼻侧和颞侧五个部位的敏感性,统计方法采用Kruskal Wallis H

  11. Cicatrización estromal y reinervación corneal por microscopia confocal en LASIK posterior a queratotomía radial de 15 años de evolución Stromal scaring and corneal re-inervation by using confocal microscopy in Lasik after radial postkeratotomy of 15 years of evolution

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    María del Carmen Benítez Merino

    2012-06-01

    operated on by radial keratotomy, with no further complications and re-operated on with Laser in Situ keratomileusis (SHWIND Esiris. The characteristics of the corneal structures and the regeneration of corneal nervous fibers were studied by means of confocal microscopy with Confoscan S4. Summary measures were used. Results: The stromal scaring was limited on the edge of the flap; there was an increase of the keratocyte activity in the stromal channel during the first weeks of the postoperative period and a decrease of the keratocyte density caused by apoptosis observed up to one year of evolution. Before Lasik, the number of nervous plexuses was normal in more than 80% of the corneas with incisional corneal surgery. In the first 3 postoperative months there was no nervous regeneration; but this process began between 6th and 8th months, with evident alteration of the morphology and quantity of nervous plexuses per field of confocal microscopy a year after surgery. Conclusion: The evolution of the microscopic characteristics of the cornea, which were studied with microscopy confocal in patients operated on by Lasik after radial keratotomy, was similar to that described in patients who had not undergone this type of surgery. The nervous regeneration began after 6 months when nervous nodes and progressive increase of corneal sensitivity occurred.

  12. Placido disk-based topography versus high-resolution rotating Scheimpflug camera for corneal power measurements in keratoconic and post-LASIK eyes: reliability and agreement

    Science.gov (United States)

    Penna, Rachele R.; de Sanctis, Ugo; Catalano, Martina; Brusasco, Luca; Grignolo, Federico M.

    2017-01-01

    AIM To compare the repeatability/reproducibility of measurement by high-resolution Placido disk-based topography with that of a high-resolution rotating Scheimpflug camera and assess the agreement between the two instruments in measuring corneal power in eyes with keratoconus and post-laser in situ keratomileusis (LASIK). METHODS One eye each of 36 keratoconic patients and 20 subjects who had undergone LASIK was included in this prospective observational study. Two independent examiners worked in a random order to take three measurements of each eye with both instruments. Four parameters were measured on the anterior cornea: steep keratometry (Ks), flat keratometry (Kf), mean keratometry (Km), and astigmatism (Ks-Kf). Intra-examiner repeatability and inter-examiner reproducibility were evaluated by calculating the within-subject standard deviation (Sw) the coefficient of repeatability (R), the coefficient of variation (CoV), and the intraclass correlation coefficient (ICC). Agreement between instruments was tested with the Bland-Altman method by calculating the 95% limits of agreement (95% LoA). RESULTS In keratoconic eyes, the intra-examiner and inter-examiner ICC were >0.95. As compared with measurement by high-resolution Placido disk-based topography, the intra-examiner R of the high-resolution rotating Scheimpflug camera was lower for Kf (0.32 vs 0.88), Ks (0.61 vs 0.88), and Km (0.32 vs 0.84) but higher for Ks-Kf (0.70 vs 0.57). Inter-examiner R values were lower for all parameters measured using the high-resolution rotating Scheimpflug camera. The 95% LoA were -1.28 to +0.55 for Kf, -1.36 to +0.99 for Ks, -1.08 to +0.50 for Km, and -1.11 to +1.48 for Ks-Kf. In the post-LASIK eyes, the intra-examiner and inter-examiner ICC were >0.87 for all parameters. The intra-examiner and inter-examiner R were lower for all parameters measured using the high-resolution rotating Scheimpflug camera. The intra-examiner R was 0.17 vs 0.88 for Kf, 0.21 vs 0.88 for Ks, 0.17 vs 0

  13. Keratophakia and keratomileusis--clinical results.

    Science.gov (United States)

    Swinger, C A; Barraquer, J I

    1981-08-01

    A random, retrospective study was performed on 158 patients. who underwent keratophakia and keratomileusis for the correction of refractive errors. The primary indication for surgery was high anisometropia. Data on corneal curvature modification, refraction, accuracy, stability, and complications are reported. Both keratophakia and hypermetropic keratomileusis are capable of fully correcting aphakic hyperopia. Myopic keratomileusis corrected up to 16 diopters of myopia in this series. Lamellar refractive keratoplasty appears to have no significant detrimental effect on visual acuity. The majority of myopic patients had an improved best-corrected visual acuity postoperatively. High or irregular astigmatism was not noted following this surgery. The stability of the postoperative curvature appeared to be good with both keratophakia and myopic keratomileusis. Complications in this series were minimal, and one resulted in decreased vision postoperatively. Inaccuracy in achieving the desired refractive result appeared to be the major disadvantage of these techniques.

  14. Refractive keratoplasty. Keratophakia and keratomileusis.

    Science.gov (United States)

    Troutman, R C; Swinger, C

    1982-01-01

    Early experience with the refractive keratoplasty techniques of José Barraquer--keratophakia and hypermetropic keratomileusis is presented. In contradistinction to the alloplastic lens substitutes currently being employed for the integral correction of aphakia, Barraquer's techniques would seem to offer a more permanent, more physiologic, full-time optical correction of the aphakic state. Their use is limited only by the condition of the patient's cornea and, in fact, may be applied not only in aphakia but also in phakic eyes with higher degrees of hyperopia or myopia. In the opinion of the authors, the refractive keratoplasty techniques of Barraquer can be performed by any well-instructed ophthalmic surgeon. These techniques offer to many patients a satisfactory, and potentially a physiologically superior alternative to alloplastic lens substitute for aphakic correction.

  15. Refractive keratoplasty: keratophakia and keratomileusis.

    Science.gov (United States)

    Troutman, R C; Swinger, C

    1978-01-01

    We have presented our early experience with the refractive keratoplasty techniques of Doctor Jose Barraquer--keratophakia and hypermetropic keratomileusis. In contradistinction to the alloplastic lens substitutes currently being employed for the integral correction of aphakia, his techniques would seem to offer a more permanent, more physiologic, full-time optical correction of the aphakic state. Their use is limited only by the condition of the patient's corneaa and, in fact, may be applied not only in aphakia but also in phakic eyes with higher degrees of hyperopia or myopia. In the opinion of the authors, the refractive keratoplasty techniques of Barraquer can be perfored by any well-instructed ophthalmic surgeon. These techniques offer to many patients a satisfactory and potentially a physiologically superior alternative to alloplastic lens substitute for aphakic correction.

  16. Queratitis lamelar difusa después del Lasik Diffuse lamellar keratitis after LASIK

    Directory of Open Access Journals (Sweden)

    Lorelei Ortega Díaz

    2010-12-01

    Full Text Available OBJETIVO: Describir el comportamiento de la queratitis lamelar difusa como complicación después de emplear la técnica quirúrgica queratomileusis in situ con láser. MÉTODOS: Se realizó un estudio descriptivo, de corte transversal en el Servicio de Cirugía Refractiva Corneal del Instituto Cubano de Oftalmología "Ramón Pando Ferrer" en el último trimestre del año 2008. La muestra quedó conformada por 16 ojos a los que se les realizó la queratomileusis in situ con láser como técnica quirúrgica para corregir ametropía y que presentaron complicaciones con esta cirugía. Se analizaron variables como la agudeza visual sin corrección; los ojos con esta complicación fueron analizados según la clasificación de Linebarger. RESULTADOS: La frecuencia de queratitis lamelar difusa fue de 3,0 por cada 100. La agudeza visual no corregida se comportó entre 0,8 y 1,0 en 12 ojos de 16 afectados, el estadio 1 se presentó en 12 ojos. CONCLUSIONES: La queratitis lamelar difusa es una complicación poco frecuente, los casos que la padecieron alcanzaron una buena agudeza visual final sin corrección. Predominó la forma leve de este cuadro.OBJECTIVE: To describe the situation of Diffuse lamellar keratitis as a complication after in situ keratomileusis with laser. METHODS: A descriptive cross-sectional study was carried out in the Refractive Corneal Service of "Ramón Pando Ferrer" Cuban Institute of Ophthalmology during the last quarter of 2008. The sample embraced 16 eyes that underwent in situ keratomileusis plus laser as the refractive procedure to correct ametropy and presented with some complications. Visual acuity without correction was one the analyzed variables and the eyes with this type of complication were classified according to Linebarger´s classification. RESULTS: The diffuse lamellar keratitis frequency was 3.0 per one hundred cases, the visual acuity without correction was 0.8 to 1.0 in 12 out of 16 eyes whereas stage 1 was

  17. The observation of post-LASIK cornea using confocal microscopy%共聚焦显微镜在LASIK术后角膜检查中的应用

    Institute of Scientific and Technical Information of China (English)

    余晨颖; 李莹

    2013-01-01

    Objective To evaluate the role that confocal microscopy could play in post-laser in situ keratomileusis (LASIK) examinations.Methods Twenty-seven patients (54 eyes) who had LASIK surgery in Peking Union Medical College Hospital were included in this cross-sectional study.Patients were divided into 2 groups (6-month group and 1-year group) based on the post-LASIK follow-up.Confocal microscopy was used to observe the regeneration of corneal nerves that could then be analyzed by ACCMetrics software using quantitative parameters (e.g.,corneal nerve fiber length,density,nerve branch density,tortuosity and reflectivity of nerve fiber) before undergoing comparisons between the 2 groups.Confocal microscopy could also provide a general idea about the healing of the corneal flap and changes in keratocytes.The quantitative data of the 2 groups was compared using an independent samples t test.Results The values of corneal nerve fiber length,density,nerve branch density,and grading scores of nerve fiber tortuosity and reflectivity in patients from the 1-year group were all higher than those from the 6-month group (t=7.246,5.335,3.789,3.808,2.825,P<0.01),and confocal microscopy revealed a clear-cut corneal flap edge in patients who had FS-LASIK surgery.For the 2 patients whose post-LASIK visual acuity did not reach 1.0,confocal microscopy also help to identify some abnormalities in corneal structure that might have contributed to the condition.Conclusion The use of confocal microscopy revealed that central corneal nerves were in a regenerative state within 1 year post-LASIK,with their density and morphological features undergoing significant changes.Besides,confocal microscopy could also assess corneal micro-structural changes at a cellular level,thus promoting the diagnosis and treatment of post-LASIK complications.%目的 评估共聚焦显微镜在准分子激光原位角膜磨镶术(LASIK)术后角膜检查的应用价值.方法 横断面研究.选择在北京

  18. Estudo comparativo entre duas plataformas para realização de Lasik personalizado para correção de miopia e astigmatismo: Alcon CustomCornea® versus Bausch & Lomb Zyoptix® Wavefront-Guided Lasik for low to moderate myopia: CustomCornea® versus Zyoptix®

    Directory of Open Access Journals (Sweden)

    Telma Pereira Barreiro

    2009-08-01

    Full Text Available OBJETIVO: Comparar os resultados obtidos após o Lasik personalizado utilizando duas plataformas diferentes. MÉTODOS: Estudo prospectivo, randomizado com 50 pacientes míopes submetidos a cirurgia refrativa em ambos os olhos. Foram selecionados para o estudo, pacientes com equivalente esférico semelhante entre os olhos. Todos foram submetidos a Lasik bilateral e simultâneo, sendo que um olho foi operado pela plataforma CustomCornea® e o outro pela Zyoptix®. Acuidade visual sem e com correção, refração dinâmica e estática, medida das aberrações oculares, teste de sensibilidade ao contraste foram realizados no período pré-operatório e pós-operatório de 1, 3 e 6 meses. RESULTADOS: No período pré-operatório a média do equivalente esférico era de -3,29 ± 1,56 D no grupo CustomCornea® e de -3,22 ± 1,50 D no Zyoptix® (p=0,267. No sexto mês de pós-operatório, a média do equivalente esférico no grupo CustomCornea® era de -0,077 ± 0,23 D e -0,282 ± 0,30 D no Zyoptix® (p 20/20 foi alcançada em 86% dos olhos no grupo CustomCornea® e 70% no grupo Zyoptix® (p=0,094. Nenhum paciente perdeu duas ou mais linhas da melhor acuidade visual corrigida. Cem por cento dos olhos CustomCornea® e 88% dos Zyoptix® ficaram entre ± 0,50 D da emetropia (p=0,014*. Melhora da sensibilidade ao contraste em todas as frequências espaciais testadas foi observada em ambos os grupos. A aberração esférica apresentou aumento em ambos os grupos, porém este foi estatisticamente maior na plataforma Zyoptix® (pPURPOSE: To compare the visual and clinical outcomes of Wavefront-guided laser in situ keratomileusis (Lasik with Alcon CustomCornea® and Zyoptix® systems. METHODS: A prospective, randomized, masked and bilateral study was conducted. Fifty patients with preoperative spherical equivalent ranging from -1.00 to -6.50 D were enrolled for customized ablation in both eyes. All of them were submitted to Lasik CustomCornea® treatment in one

  19. Prospective evaluation of myopic keratomileusis.

    Science.gov (United States)

    Swinger, C A; Barker, B A

    1984-07-01

    The initial results of a prospective evaluation of myopic keratomileusis are reported. The procedure was attempted on 42 eyes, with an average follow-up of 10 months. The average reductions of myopia were 7.05 D and 11.59 D when measured by keratometry and refraction, respectively. Regular astigmatism increased by 0.50 D on keratometry, but there was no change in the refractive cylinder. The majority of patients had some irregular astigmatism on corneoscopy. The average percent correction, based on refraction, was 94.1 +/- 24%, and the correlation coefficient was 0.43. Visual rehabilitation was rapid. No patient followed for 1 year or more had a decrease in the best-corrected acuity, and 63% of this group had an average improvement of 1.5 lines with as much as five lines. The final refraction may take up to 6 months to stabilize. Complications consisted of epithelium and debris in the interface and focal necrosis of Bowman's membrane. The technique is difficult but may have application in the visual rehabilitation of the high myope.

  20. NEI-RQL-42量表中文版对LASIK手术患者生存质量的评价研究%Evaluation of quality of life after LASIK by Chinese version of NEI-RQL-42 instrument

    Institute of Scientific and Technical Information of China (English)

    李华; 吕莎; 张永烨; 宋胜仿

    2013-01-01

    Objective To set up a Chinese questionnaire for quality of life in vision-related patients with refractive error,and to investigate the changes of the quality of life after laser assisted in situ keratomileusis (LASIK).Methods After the 42-item National Eye Institute Refractive Error Quality of Life Questionnaire (NEI-RQL-42) was translated into Chinese,and its validity and reliability were investigated by surveying 126 patients undergoing LASIK in our department from November 2010 to May 2011.Except for assessing vision and refraction,such as uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),before and after surgery,the quality of life of these patients were applied with the Chinese version of NEI-RQL-42 instrument.Results The systematic protocols were set as forward translations,backward translation and cultural adaptations.And the Cronbach α coefficient was defined as > 0.7,while the intra-class correlation coefficient was 0.83 to 0.87 as estimated by test-retest reliability.The Chinese version of the NEI-RQL-42 was confirmed with sound content validity,structure validity and discriminant validity.LASIK resulted in great improvement in BCVA,which was restored and superior to that before surgery (P < 0.05).Among the items of the questionnaire,except for the items of glare and symptoms,the scores of all items were increased after operation.The most obvious changed items were activity limitations,diurnal fluctuations,dependence on correction,suboptimal correction,appearance and satisfaction with correction (P < 0.05).The integrated score was 62.27 ±30.76 before operation,and was 81.64 ±25.38 and 82.14 ±23.27 respectively in 1 and 3 month after operation.The quality of life was greatly improved in 1 and 3 month after operation when compared with that before operation (P < 0.05).Conclusion The Chinese version of the NEI-RQL-42 is a reliable and valid instrument to evaluate the quality of life after LASIK.LASIK improves quality of life

  1. A study on the effect of different residual stroma thicknesses on the rabbit cornea after laser in situ keratomileusis%不同角膜切削深度的准分子激光原位角膜磨镶术对兔角膜的影响

    Institute of Scientific and Technical Information of China (English)

    贺瑞; 周迎霞; 陈维毅; 王晓君; 冯熠; 渠敏; 刘斌; 赵炬伟

    2010-01-01

    目的 比较不同切削量的准分子激光原位角膜磨镶术(LASIK)术后眼角膜生物力学特性及角膜变形的情况.方法 选取成年新西兰白兔16只(32眼)随机分成A、B、C、D四个组.A、B、C组均行LASIK手术,使残留的基质床厚度分别为全层角膜厚度的30%、50%、70%;D组不行切削手术,作为对照组.术后6个月对兔眼行角膜地形图检查;对条状角膜在Instron试验机上进行单向拉伸和拉伸蠕变实验,用最小二乘法拟合得出不同切削量的角膜在蠕变实验中的弹性系数.结果 术后6个月,角膜地形图检测结果显示,A组角膜切削区的中央部较周边膨隆;B、C组均未发现角膜膨隆和圆锥角膜.与对照组比较,A、B组LASIK术后角膜的弹性模量有统计学意义(P0.05). Conclusion Stiffness coefficients diminished with an increase in the depth of the incision and the anti-tensile ability of the corneas is also reduced after LASIK. Further study needs to be done on keratoconus after LASIK with a residual stroma thickness of 50% of the cornea.

  2. Changes in the multifocal electroretinogram before and after LASIK in eyes with different degrees of myopia%不同程度近视眼LASIK术前及术后多焦ERG的变化

    Institute of Scientific and Technical Information of China (English)

    高瑞新; 赵俊华; 范玉香; 李朝霞

    2015-01-01

    目的 对行准分子激光原位角膜磨镶术(LASIK)的不同程度近视患者术前及术后3个月均测定黄斑区不同部位的视网膜功能,然后评价其差异.方法 前瞻性对照研究.2012-2013年期间收集沧州市中心医院屈光门诊18~32岁的近视患者91例(169眼),分为低度近视组30例(58眼),中度近视组32例(57眼)和高度近视组29例(54眼).所有患者均经过严格的术前检查,具备手术条件,术前及术后均应用德国Roland公司的多焦视网膜电流图(mERG)仪RETI-SCANK系统记录近视患者黄斑区mERG的一阶反应,分别测定各环N1、P1波的潜伏期和振幅密度.采用单因素方差分析和配对t检验比较3组术前及术后3个月各检查结果之间的差别.结果 各组术前及术后mERG的振幅密度在第1环最大,随离心度的增加均逐渐降低.潜伏期在第1环最小,随离心度增加均逐渐延长.不同程度的近视组术前及术后的mERG相比较发现;3组mERG各环的振幅密度及潜伏期在术前及术后比较,差异均无统计学意义.结论 LASIK对于近视眼眼底黄斑区视网膜功能没有影响.%Objective To evaluate the changes in the function of the macular region in patients with different degrees of myopia at different sites on the retina before laser in situ keratomileusis (LASIK) and 3 months after LASIK.Methods Ninety-one patients (169 eyes)with myopia ranging in age from 18-32 years were enrolled from 2012 to 2013 for this prospective controlled study.Patients were divided into 3 groups:58 eyes,low myopia; 57 eyes,moderate myopia and 54 eyes,high myopia.All patients underwent strict examinations before the surgery was performed.All patients underwent multifocal electroretinogram (mERG) examinations using RETI-SCANK (Roland,Germany) to determine the function of the macular region before and after LASIK.The latencies and the amplitude densities of the P1 and N1 waves were measured at each ring.All exams were performed by the

  3. LASIK

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  10. Intrastromal corneal ring segments for post-LASIK ectasia complicated by persistent pain.

    Science.gov (United States)

    Neuffer, Marcus C; Panday, Vasudha; Reilly, Charles

    2010-02-01

    A 33-year-old man who was 2 years post laser in situ keratomileusis was found to have corneal ectasia. He was intolerant of rigid gas-permeable contact lenses and eventually chose to have placement of intrastromal corneal ring segments (ICRS) (Intacs) in the right eye. Two ICRS were implanted without complication, and postoperative examination showed improved visual acuity and decreased corneal elevation on scanning-slit tomography imaging. However, over the following 2 months, he complained of persistent pain in the right eye. Confocal microscopy showed a corneal nerve touching the superonasal ICRS. The ICRS was removed, and shortly thereafter the patient's pain resolved. Published by Elsevier Inc.

  11. Biomechanical changes in keratoconus and post-LASIK%圆锥角膜与LASIK术后角膜生物力学变化

    Institute of Scientific and Technical Information of China (English)

    吴东芳; 邓应平; 张小兰; 邱乐梅; 王顺清; 孙成淑

    2014-01-01

    Objective To analyze corneal biomechanical changes post laser in situ keratomileusis (LASIK).Methods This was a prospective case-control study.The study included a stratified sample of 50 LASIK eyes and 50 keratoconus eyes.Corneal hysteresis (CH) and the corneal resistance factor (CRF) were measured before surgery and 1 week and 6 months after surgery.The results were compared to the keratoconus group.A normal distribution test and homogeneity test of variance were used to analyze the data.Repeated measures ANOVA was used to compare the groups.Results The average CH and CRF before LASIK were 10.25±2.44 and 10.97±2.33 mmHg.These values were much higher than values 1 week after the surgery (7.84±1.25 and 7.47±1.13mmHg) and 6 months after surgery (8.33±1.16 and 8.18±1.33 mmHg).Corneal biomechanics at 6 months after the surgery were higher than those 1 week after surgery.There were no differences between the keratoconus and LASIK groups 1 week after surgery (7.19±1.35 and 7.15±1.46 mmHg),but there were significant differences 6 months after surgery (t=-3.60,-3.05,P<0.01).Conclusion After LASIK,the CH and CRF initially declined and then increased,indicating the importance of early protection of the cornea.%目的 了解LASIK术后角膜生物力学变化的规律.方法 前瞻性病例对照研究.采用分层随机法选择圆锥角膜50眼和年龄相匹配的预行LASIK手术的50眼;测量LASIK术前、术后1周、术后6个月角膜滞后量(CH)、角膜阻力因子(CRF)值,并与圆锥角膜患者相应的角膜参数进行比较.对LASIK术前、术后1周、术后6个月及圆锥角膜的生物力学数据行正态性检验及方差齐性检验,各时间点差异行重复测量的方差分析,2组之间的差异行u检验.结果 LASIK术前CH[(10.25±2.44)mmHg]及CRF[(10.97±2.33)mmHg]明显高于术后1周[(7.84±1.25)mmHg、(7.47±1.13) mmHg]及术后6个月[(8.33±1.16)mmHg、(8.18±1.33)mmHg],差异具有统计学意义;术后6个月

  12. 微型角膜刀准分子激光角膜上皮瓣下磨镶术矫治薄角膜近视的疗效观察%Results after epipolis laser in situ keratomileusis for miopia with thin cornea

    Institute of Scientific and Technical Information of China (English)

    陈静; 韩苏宁; 吴昕; 龚小雪; 吴军丽; 唐谋玉

    2007-01-01

    目的:探讨微型角膜刀准分子激光角膜上皮瓣下磨镶术(Epi-LASIK)矫治薄角膜近视的疗效、安全性、稳定性.方法:对10例(20眼)无法行准分子激光原位角膜磨镶术(LASIK)的相对薄角膜近视患者行Epi-LASIK手术.术前近视球镜为-4.00~-10.25 D,平均(-7.32±1.66)D,柱镜0~-2.50 D,平均(-0.71±0.72)D.术前角膜厚度463~519 μm,平均(491±20)μm.观察术中术后并发症,并对术后1~6 mo裸眼视力、屈光度及上皮下雾状浑浊(Haze)进行随访.结果:术中无严重并发症,术后最佳矫正视力与术前相比无1例下降,术后6mo球镜平均(-0.04±0.18)D,柱镜平均(-0.20±0.44)D.20眼等效球镜均在-0.75~+0.75D之间,其中17眼(85%)等效球镜在-0.50~+0.50D之间.角膜厚度平均(412±14)μm.Ⅰ级Haze者为1眼.结论:Epi-LASIK对于薄角膜近视治疗安全有效,可作为薄角膜中高度近视的首选术式.

  13. Clinical effect of rotein-free calf blood extract eye gel and sodium hyaluronate eye drops in the prevention and treatment of dry eye after laser-assisted in situ keratomileusis%小牛血去蛋白提取物眼用凝胶与玻璃酸钠滴眼液防治LASIK术后干眼疗效分析

    Institute of Scientific and Technical Information of China (English)

    符郁; 岑育健

    2015-01-01

    目的:比较小牛血去蛋白提取物眼用凝胶与玻璃酸钠滴眼液防治准分子激光原位角膜磨镶术(LASIK)后干眼的临床疗效。方法选取2011年6月至2014年6月于我院就诊的拟行LASIK的近视患者160例(320眼),将其随机分为A组与B组各80例(160眼),其中A组术后使用小牛血去蛋白提取物眼用凝胶治疗,B组使用玻璃酸钠滴眼液治疗。用药前与用药后4周进行干眼主观症状评分、泪膜破裂时间(BUT)、泪液分泌试验(SchirmerⅠ)及角膜荧光素染色检查,评价两组治疗效果。结果治疗4周后,A组临床治疗总有效率为91.25%,较B组的73.75%明显提高,两组间比较差异具有统计学意义(P0.05)外,A组症状评分明显低于B组,泪腺破裂时间明显长于B组,角膜荧光素染色评分明显低于B组,经比较差异均具有统计学意义(P0.05), but the subjective dry eye symptom scores of group A was sig-nificantly lower, with the BUT significantly longer and the score of corneal fluorescein staining significantly lower (P<0.05). Conclusion In the prevention and treatment of dry eye after LASIK, the clinical effect of protein-free calf blood extract eye gel is better than sodium hyaluronate eye drops, which is worthy of further clinical application.

  14. Laser in situ keratomileusis for residual myopia after photorefractive keratectomy%准分子激光角膜原位磨镶术矫治高度近视准分子激光屈光性角膜切削术后屈光回退的临床观察

    Institute of Scientific and Technical Information of China (English)

    赵金荣; 张金英; 李雪非; 于金国

    2010-01-01

    目的 评价准分子激光角膜原位磨镶术(LASIK)矫治高度近视准分子激光屈光性角膜切削术(PRK)后屈光回退的疗效.方法 回顾性临床研究.对PRK术后2年以上、屈光回退且屈光度稳定的患者8例14眼行LASIK,对LASIK术后术眼进行评价.患眼PRK术前屈光度为-6.25~-12.50 D,PRK术后屈光度为-1.50~-6.25 D.随访观察LASIK矫正1年后术眼的裸眼视力、最佳矫正视力、屈光度、上皮下雾状混浊(haze)形成和角膜厚度的变化.结果 所有患眼术后主观症状较轻.LASIK术后1年平均球镜度数为(-0.62±0.94)D.LASIK术后0.5≤裸眼视力<0.8者4眼,≥0.8者9眼,1眼(7.1%)最佳矫正视力下降2行.4眼术后出现不同程度的haze,包括2级haze 3眼、3级haze 1眼.应用氟米龙滴眼液1个月后,haze及屈光回退减轻;术后1年,1级haze 2眼,2级haze 2眼,3级haze 1眼.LASIK术前角膜厚度为(467±38)μm,术后为(422±21)μm.结论 高度近视PRK术后屈光回退行LASIK矫治是一种可行的方法,但少数患者术后可出现haze,仍需治疗.

  15. Intrastromal crosslinking in post-LASIK ectasia.

    Science.gov (United States)

    Moscovici, Bernardo Kaplan; Campos, Mauro

    2014-01-01

    We describe a case of early post-LASIK ectasia detected in the first 6 months after surgery. The patient was treated by means of intrastromal corneal crosslinking under the flap, without de-epithelialization, which resulted in a positive outcome. At the time of writing, 2 years after the procedure, the patient remained free of progression.

  16. LASIK for correcting irregular astigmatism and asymmetrical astigmatism guided by corneal topography%角膜地形图引导下准分子激光矫正角膜不规则散光及不对称性散光

    Institute of Scientific and Technical Information of China (English)

    吴震; 荆翠红; 韩九娥; 蔡娟娟; 李水仙; 王运红; 吴化宇

    2012-01-01

    目的 探讨角膜地形图引导下准分子激光个性化切削手术矫正角膜不规则散光及不对称性散光的效果和优缺点.方法 应用MEL - 70准分子激光仪及配套TOMEY -Ⅲ角膜地形图引导个性化切削系统进行准分子激光原位角膜磨镶术(LASIK)矫正不对称性或不规则角膜散光复性近视散光58例108眼.其中49例97眼为初次手术;另9例11眼为二次手术,系由不均匀切削、偏心切削或中央岛而形成的不规则散光.术前最佳矫正视力均值0.98±0.32;屈光度:球镜平均(-4.59±1.68)D,柱镜平均(-1.62±0.78)D.结果 108眼手术均顺利完成,无术中或术后并发症.术后角膜地形图显示:角膜中央3 mm切削深度平整、均匀,术后1周平均裸眼视力1.03 ±0.29.屈光度:球镜-0.50~+0.75D,平均(-0.35 ±0.29)D,柱镜0~- 0.75D,平均(-0.38 ±0.24)D.结论 TOMEY -Ⅲ角膜地形图捕捉角膜曲率信息准确,引导准分子激光个性化切削程序设计合理,系统安全可靠.用它来进行个性化LASIK可较为精确地矫正角膜不规则及不对称散光.%Objective To discuss the effect of laser in situ keratomileusis (LASIK) for correcting irregular astigmatism and asymmetrical astigmatism guided by corneal topographic map.Methods There were 58 cases( 108 eyes) with compound myopic astigmatism,asymmetric or irregular corneal astigmatism accepted LASIK under MEL- 70 excimer laser that guided by TOMEY-Ⅲ corneal topography.49 patients (97 eyes) received their first operation on the eye.9 patients ( 11 eyes) with irregular astigmatism due to uneven cutting,eccentric cutting or central island received the second operation on the same eye.The preoperative best corrected visual acuity was on average of 0.98 ± 0.32,Sphere ( - 4.59 ± 1.68 ) D,Cylinder ( - 1.62 ± 0.78) D.Results 108 operations were successfully finished without intraoperative or postoperative complications.Corneal topography showed the centra 3 mm cutting was depth uniform

  17. Analysis of corneal topography after Q-value adjusted customize laser in situ keratomileusis for myopia%Q值引导的个体化准分子激光原位角膜磨镶术后角膜地形图分析

    Institute of Scientific and Technical Information of China (English)

    赵向阳; 刘军; 李卫平; 刘晓芳

    2010-01-01

    目的 分析Q值引导的个体化准分子激光原位角膜磨镶术后角膜地形图的动态变化.方法 将94例188只眼接受准分子激光原位角膜磨镶术治疗的近视患者分为两组,47例94只眼行非球面个体化切削作为Ⅰ组;另47例94只眼行标准切削作为Ⅱ组,采用Orbscan Ⅱ角膜地形图仪随访6个月.结果 术后各时间点切削区形态、平均偏中心距离和SimK的变化,两组比较差异无统计学意义(P>0.05),各时间点Q值差异两组比较有统计学意义(P0.05). The significant difference was seen in Q-value between two groups in different time points in post-operation (P<0.05). Q-value was lower in the aspheric group than the standard group. Postoperative average corneal thickness and ablated depth were statistically significant differences (P<0.05). Conclusions Q-value adjusted customize LASIK is safety, efficacy, stable and the physiology of the corneal surface is better maintained than standard treatment. Corneal topography provides a objective method to evaluate the result of operation.

  18. Qualidade visual após retratamento de LASIK personalizado versus convencional Visual quality after custom versus standard LASIK retreatment

    Directory of Open Access Journals (Sweden)

    Andréia Peltier Urbano

    2008-12-01

    Full Text Available OBJETIVO: Avaliar a qualidade visual após retratamento personalizado e retratamento convencional em olhos submetidos a LASIK primário convencional. MÉTODOS: Foi realizado estudo prospectivo de 74 olhos submetidos ao retratamento de LASIK para correção de miopia e astigmatismo. Cada paciente foi submetido ao retratamento de LASIK com ablação personalizada (Zyoptix, Bausch & Lomb em um olho e ablação convencional (Planoscan, Bausch & Lomb no olho contralateral. Foram comparados os resultados do teste de ofuscamento e da sensibilidade ao contraste durante o acompanhamento de seis meses. RESULTADOS: Os olhos do grupo Zyoptix apresentaram melhores resultados no teste de ofuscamento e na sensibilidade ao contraste do que o olho contralateral, quando se compararam os resultados. CONCLUSÕES: O retratamento personalizado resultou em melhor qualidade visual pós-operatória do que o retratamento convencional de LASIK primário convencional.PURPOSE: To evaluate visual quality after wavefront-guided LASIK versus standard LASIK in retreatment of primary LASIK for myopia and myopic astigmatism. METHODS: A prospective study was performed with paired eye control of 74 eyes with LASIK retreatment. Each patient underwent retreatment using custom ablation (Zyoptix, Bausch & Lomb in 1 eye and standard ablation LASIK (PlanoScan, Bausch & Lomb in the contralateral eye. A complete ophthalmologic examination was performed, including evaluation of glare test and contrast sensitivity test, with a follow-up of 6 months. RESULTS: Zyoptix eyes showed better results of glare test and contrast sensitivity test than the contralateral eyes. CONCLUSIONS: Wavefront-guided LASIK produces better visual quality than standard LASIK in the retreatment of refractive errors after primary LASIK.

  19. Tomographic corneal profile analysis of central toxic keratopathy after LASIK.

    Science.gov (United States)

    Sikder, Shameema; Khalifa, Yousuf M; Neuffer, Marcus C; Moshirfar, Majid

    2012-01-01

    To describe a case of bilateral central toxic keratopathy (CTK) in a post-laser in situ keratomileusis-treated patient using tomographic methods for more than a 1-year follow-up. Case report and literature review. Tomographic analysis of a patient with bilateral CTK revealed flattening of the anterior cornea curvature and thinning at the level of anterior stromal bed, with minimal changes of the posterior curvature. A thin central flap was also noted on optical coherence tomography (OCT). Over the course of a year, the patient's hyperopic shift resolved with steepening of the anterior curvature and concomitant thickening of the flap and stromal bed. Using Scheimpflug imaging and Visante OCT, we demonstrated that the hyperopia that accompanies CTK is related to anterior corneal curvature changes. We also found that the majority of corneal tissue loss occurs at the anterior stromal bed mainly in the first postoperative week and is followed by a regeneration of tissue. A thin central flap was noted, and it is not clear whether this was created intraoperatively or resulted from the presence of CTK, requiring further study.

  20. Effects of 3% trehalose as an adjuvant treatment after LASIK

    Science.gov (United States)

    Mateo Orobia, Antonio J; Casas Pascual, Paula; Cristóbal Bescós, José Á; Perez García, Diana; Peiro Embid, Carlos; del Buey Sayas, M Ángeles; Korobko Kulikova, Valentyna; Lafuente Ojeda, Noelia

    2017-01-01

    Purpose To evaluate the effect of 3% trehalose as an adjuvant in the standard treatment after laser-assisted in situ keratomileusis. Design Interventional prospective comparative single-blind study. Setting Department of Ophthalmology, Hospital Quirón Zaragoza, Spain. Methods A total of 26 eyes (13 patients) were included, of which 12 eyes (group 1) received conventional treatment with lubricant drops of hyaluronic acid (0.15%) and 14 eyes (group 2) received, additionally, an ophthalmic solution of 3% trehalose. Pre- and postoperative quality-of-life tests and vital stains, tear breakup time, and osmolarity measurements were made. Results We obtained statistically significant differences between the groups in the Symptom Assessment in Dry Eye test in all visits with respect to severity, and in the postoperative day 1 visit with respect to frequency, in all cases favoring the trehalose treatment. The values of osmolarity were not significantly different between groups. However, we did find significant differences in the Oxford scale in day 90 for the trehalose treatment (P<0.001), and in the National Eye Institute scale in day 30 (P=0.02). Conclusion The results of this exploratory study indicate that the adjuvant treatment with 3% trehalose could be superior with respect to the standard treatment, with improvements in the objective and subjective parameters of tear quality. PMID:28243058

  1. Intrastromal crosslinking in post-LASIK ectasia

    Directory of Open Access Journals (Sweden)

    Bernardo Kaplan Moscovici

    2014-06-01

    Full Text Available Descrevemos um caso de ectasia de córnea precoce após cirurgia de LASIK, detectado no primeiro semestre pós-operatório. Nós optamos tratar este paciente com "crosslinking" embaixo do "flap" , sem desepitelização com bons resultados. A paciente permaneceu sem progressão da ectasia até o momento atual, dois anos após o procedimento.

  2. Clinical analysis of corneal flap corrugation and displcement after LASIK%LASIK后角膜辦皱褶和移位临床分析

    Institute of Scientific and Technical Information of China (English)

    陈立新; 吴华; 甘苏豫; 徐晶晶

    2011-01-01

    Objective To evaluate clinical manifestation and treatment of corneal flap corrugation and displacement after laser in situ keratomileusis (LASIK). Methods In recent years,there were 13 cases (13 eyes) with corneal flap corrugation and displacement in our hospital, whom were taken reposition treatment under operative microscopy immediately. For patients with shorter time of corrugation and displacement, corneal flaps were opened up and replaced after washing carefully; For patients with longer time of corrugation and displacement, corneal flaps were washed with low permeability brine and water for injection to make it edema, and took replacement after corrugation becoming flat. All patients with replacement should take soft corneal contact lens for 1 day to 3 days. Visual acuity, examination of slit lamp microscopy and corneal topography were observed after replacement. Results In 13 cases (13 eyes) ,10 cases (10 eyes) occurred corneal flap corrugation and displacement less than 24 hours, the naked vision was 0. 06 to 0. 6 before replacement and could not be corrected. Soft corneal contact lens was taken out within 24 hours after replacement;Visual acuity was0. 8 to 1.0 at the time for removing lens,and 1.0 in all 10 cases at 1 week for rechecking. Three patients (3 eyes) occurred corneal flap corrugation and displacement more than 24 hours. Naked vision was 0. 06 to 0. 3 before replacement, and soft corneal contact lens was removed at 72 hours for serious edema of cornal flap after replacement. Visual acuity was 0. 6 to 0. 8 at the time for removing lens,and 1.0 in all 3 cases at 1 week for rechecking. Infection and epithelium transplantation were not found. Corneal topography showed no abnormality. Conclusions Corneal flap corrugation and displacement are common after LASIK, which can have various effect on visual quality. Satisfactory clinical efficacy can be achieved with timely finding and correct treatment.%目的 探讨准分子

  3. Influence of Tobradex on Three Cytokines in Tears and the Restoration of Cornea after LASIK%典必殊对 LASIK 术后角膜修复及泪液中3种细胞因子的影响

    Institute of Scientific and Technical Information of China (English)

    张玉生; 冯有为

    2014-01-01

    -ceiving Laser in situ keratomileusis ( LASIK) , to observe the rules of their change after receiving additional Tobradex treat-ment and analyze the relations between cytokines and daily dosage and treatment course .Also, to discuss the influence of this treatment on the healing of cornea , eyesight and eye pressure for guiding reasonable postoperative drug administration . Method All 96 patients with myopia ( 189 eyes ) who received LASIK treatment , were randomly divided into three test groups of different postoperative Tobradex treatment course .All groups began to receive Tobradex treatment 24h after surger-y, the first group was treated for one week the second two weeks and the third four weeks .The tear samples of each group were collected before and 24h after surgery, one week, two weeks and four weeks after treatment to determine the concentra-tion of 3 cytokines IL-1a, IL-2 and TNF-αand analyze the influence of different daily dosage and treatment course on the ef -ficacy, healing of cornea , eyesight and eye pressure .All data were processed statistically with SAS 6.12 statistic software package.Results The content of IL-1a, IL-2 and TNF-αin tears of patients in three groups 24 hours after surgery in-creased substantially and had significant difference ( P0.05).In examination for 3 groups 24h after surgery, the wounds of cornea had all been covered by epi-thelial cells , the restoration of corneal flap was good and the wounds healed one week after surgery .Two weeks and four weeks after surgery, their eyesight improved and restored , without obvious difference ( P>0.05 ) .The occurrence rate of corticosteroid induced ocular hypertension was different in three groups two weeks after surgery , which was of statistical sig-nificance ( P<0.05 ) .Four weeks after surgery , ocular hypertension disappeared in test groups one and two , however the occurrence rate of corticosteroid induced ocular hypertension in test group three was still as high as 13.16%, the difference

  4. Intraoperative flap complications in lasik surgery performed by ophthalmology residents

    Directory of Open Access Journals (Sweden)

    Lorena Romero-Diaz-de-Leon

    2016-01-01

    Conclusion: Flap-related complications are common intraoperative event during LASIK surgery performed by in-training ophthalmologists. Keratometries and surgeon's first procedure represent a higher probability for flap related complications than some other biometric parameters of patient's eye.

  5. Night vision of the post-LASIK myope

    Directory of Open Access Journals (Sweden)

    R. Hansraj

    2007-01-01

    Full Text Available Purpose: Poor night vision has been reported as one of the side-effects of LASIK,  however, this area has not been widely studied.  This study therefore set out to assess and quantify the visual status of the post-LASIK patient in dim illumination as an indication of visual performance at night.  This was achieved by assessing the night vision threshold, glare vision threshold and glare recovery time.Setting: The study was carried out in Durban, Kwazulu-Natal in South Africa.Method: This study used the Night Sight Meter for assessment of the night vision thresholds, glare vision thresholds and glare  recovery times of individuals who had had LASIK at least one year before commencement of the study.  The inclusion criteria were post-surgical interval following LASIK of at least one year and willingness to participate in the study.  The exclusion criteria included previous ocular surgery other than LASIK, current ocular disease and any systemic illnesses.   One hundred subjects were selected from participating ophthalmologists’ records, using convenience sampling, at different post-operative periods that ranged from 12 to 57 months.  Other refractive findings taken included post-LASIK visual acuity measured using the Snellen Visual Acuity chart and post-LASIK refractive error, measured with the standard subjective refraction tests which included duochrome, Jackson crossed-cylinder and Humphrey’s Immediate Contrast test, which are used for comparison in this study.Results: Post-operatively, the majority of the eyes (89.2% were classified as having ‘poor’ night vision thresholds.  A similar trend was observed in the case of the glare vision thresholds as 84.7% of the eyes fell into the classification of below average.  The degree of pre-operative myopia appears to have an effect on the post-LASIK night vision and glare  thresholds.  Only glare recovery  time was not affected as 51.2% of the subjects displayed good recovery

  6. Comparative study of visual acuity and aberrations after intralase femtosecond LASIK: small corneal flap versus big corneal flap

    Institute of Scientific and Technical Information of China (English)

    Ya-Li; Zhang; Lei; Liu; Chang-Xia; Cui; Ming; Hu; Zhao-Na; Li; Li-Jun; Cao; Xiu-Hua; Jing; Guo-Ying; Mu

    2014-01-01

    AIM:To study the effects of different flap sizes on visual acuity, refractive outcomes, and aberrations after femtosecond laser for laser keratomileusis (LASIK). ·METHODS: In each of the forty patients enrolled, 1 eye was randomly assigned to receive treatment with a 8.1mm diameter corneal flap, defined as the small flap, while the other eye was treated with a 8.6mm diameter corneal flap, defined as the big flap. Refractive errors, visual acuity, and higher -order aberrations were compared between the two groups at week 1, month 1 and 3 postoperatively. · RESULTS: The postoperative refractive errors and visual acuity all conformed to the intended goal. Postoperative higher -order aberrations were increased, especially in spherical aberration (Z12) and vertical coma (Z7). There were no statistically significant differences between the two groups in terms of postoperative refractive errors, visual acuity, root mean square of total HOAs (HO -RMS), trefoil 30° (Z6), vertical coma (Z7), horizontal coma (Z8), trefoil 0° (Z9), and spherical aberration (Z12) at any point during the postoperative follow-up. ·CONCLUSION: Both the small and big flaps are safe and effective procedures to correct myopia, provided the exposure stroma meets the excimer laser ablations. The personalized size corneal flap is feasible, as we can design the size of corneal flap based on the principle that the corneal flap diameter should be equal to or greater than the sum of the maximum ablation diameter and apparatus error.

  7. Estudio topoaberrométrico en Lasik después de queratotomía radial Topoaberrometric study in Lasik after radial keratotomy

    Directory of Open Access Journals (Sweden)

    Yamila Díaz Parra

    2007-12-01

    Full Text Available La cirugía refractiva personalizada consiste en adecuar el tratamiento de cada paciente según las características de la córnea y corregir defectos que afectan la calidad de la visión; por ejemplo, las aberraciones ópticas. Se seleccionaron 21 ojos de 13 pacientes con miopía residual después de queratotomía radial. Se realizó agudeza visual sin corrección y con ella, queratometría, refracción dinámica, refracción ciclopléjica; topografía corneal, taquimetría, tonometría, biomicroscopia, estudio de la lágrima y fondoscopia. A todos se les aplicó el software de análisis de frente de onda corneal y se realizó Lasik (Queratomileusis in situ con láser y queratectomía refractiva optimizada. La agudeza visual sin corrección varió de 0,17 a 0,75. El equivalente esférico promedio se modificó de -4,81 D a -0,67 D. Las aberraciones de alto orden (HORMS prequirúrgicas y posquirúrgicas variaron de 0,970 um hasta 1,130 um. La agudeza visual sin corrección fue superior a 0,8 en todos los casos después de la cirugía de Lasik. Disminuyó el equivalente esférico y el componente cilíndrico en todos los ojos. Las aberraciones totales disminuyeron también en todos los casos.Customized refractive surgery means adapting treatment to the patient according to the corneal characteristics and correcting defects that affect the quality of vision, for example, optical aberrations. Twenty one eyes from 13 patients with residual myopia after undergoing radial keratotomy were selected. Visual acuity without correction and also, keratometry, dynamic refraction, cycloplegic refraction, corneal topography, tachymetry, tonometry, biomicroscopy, study of the tear and funduscopy were performed. All the eyes were applied the sofware for analysis of corneal wavefront and Lasik (Queratomileusis in situ with laser and optimized refractive keratectomy were performed. Visual acuity without correction changed from 0.17 to 0.75. Average sphere equivalent

  8. Wound healing after excimer laser keratomileusis (photorefractive keratectomy) in monkeys.

    Science.gov (United States)

    Fantes, F E; Hanna, K D; Waring, G O; Pouliquen, Y; Thompson, K P; Savoldelli, M

    1990-05-01

    Laser myopic keratomileusis (photorefractive keratectomy) was performed on 29 rhesus monkey corneas with an argon fluoride (193-nm) excimer laser and a computer-controlled, moving slit delivery system. The 4-mm-diameter central ablation zone ranged in depth from 11 microns (-2 diopters effect) to 46 microns (-8 diopters effect). Corneas were studied for the 9 months postoperatively by clinical slit-lamp microscopy, and periodically with light and transmission electron microscopy. By 6 weeks, mild to moderate subepithelial haze was apparent in 93% of the corneas, with considerable variability in density. Progressive clearing occurred so that by 6 to 9 months 12 of 13 surviving corneas (92%) were either completely clear (4 corneas) or trace hazy (8 corneas). The epithelium was thickened at 21 days after ablation and returned to normal thickness by 3 months. At 3 weeks, subepithelial fibroblasts were three times the density of normal keratocytes and returned to nearly normal numbers by 9 months. We concluded that the anterior monkey cornea demonstrated a mild, typical wound healing response after excimer laser keratomileusis.

  9. 飞秒激光制瓣LASIK术后眼前节参数的变化%Changes of the parameters of anterior segment of eyes after femtosecond laser LASIK

    Institute of Scientific and Technical Information of China (English)

    胡正再; 张薇; 王志军

    2016-01-01

    Objective To analyze the changes of the parameters of anterior segment of eyes after femtosecond laser LASIK.Methods In this prospective clinic study,50 eyes of 25 patients who underwent femtosecond laser laser in situ keratomileusis (LASIK) were included.The corneal endothelium density,anterior chamber depth,anterior chamber angle width,posterior corneal surface height (4 mm diameter),distance between pupil center and corneal vertex,pupil diameter under light and dark environment were compared before and 6 months or more after surgery.Distance between pupil center and corneal vertex using absolute value.Data were analyzed using paired t test.Results After surgery,comeal endothelium density (2 829.7±227.2 cells/mm2 vs.2 716.4±255.2 cells/mm2),anterior chamber depth(3.18±0.19 mm vs.3.08±0.21 mm),anterior chamber angle width (39.39°±3.90°,37.92° ±3.76°) decreased (t=3.077,11.079,5.241,P<0.01).The differences of posterior corneal surface height (4 mm diameter),pupil diameter under light and dark environment before and after surgery were insignificant.The distance between pupil center and corneal vertex on X axis increased (0.11±0.10 mm vs.0.14±0.12 mm,t=-3.318,P<0.01).The distance between pupil center and corneal vertex on Y axis increase (0.11±0.08 mm vs.0.15±0.11 mm,t=-4.157,P<0.01).Conclusion The parameters of anterior segment of eyes after femtosecond laser LASIK changed obviously,especially for the distance between pupil center and corneal vertex.Maybe this change is important in guiding the following surgery.%目的 分析飞秒激光制瓣LASIK术后眼前节各参数(前房深度、前房角宽度、4 mm范围角膜后表面最高值、瞳孔中心与角膜顶点距离)的变化.方法 前瞻性临床研究.接受飞秒制瓣LASIK手术的患者25例(50眼),记录并分析术前和术后6个月以上中央角膜内皮细胞计数、前房深度、前房角宽度、4 mm范围角膜后表面最高值、瞳孔中心与角膜顶点距离、明

  10. Assessment of the effects of LASIK on astigmatism of-2.0D or above by corneal topography%LASIK手术治疗-2.0D以上散光的角膜地形图分析

    Institute of Scientific and Technical Information of China (English)

    周少博; 路晓明; 洪海烽; 苏小波; 黎健菁; 胡群英

    2010-01-01

    目的 利用角膜地形图评价LASIK治疗-2.0D以上散光疗效的准确性.方法 对25例(36只眼)散光度在-2.0D以上的近视散光患者于LASIK手术前后行角膜地形图和主觉验光检查,并将主觉验光测得的散光值换算成角膜平面的散光值,随访6月以上,比较手术前后角膜地形图测得的角膜散光的改变情况以及主觉验光所得的散光改变.结果 手术前后平均角膜地形图散光大小分别为(-2.29±0.61)D和(-1.91±0.68)D,主觉验光手术前后平均角膜平面的散光大小分别为(-2.22±0.61)D和(-0.46±0.43)D,两者手术前后差异均有统计学意义(P0.05),散光轴位平均差异为(6.53±14.19)度,而术后角膜地形图散光和术后显然验光角膜平面的散光大小差异有统计学意义(P=0.00).结论 角膜地形图测量术前-2.0D以上散光与主觉验光结果基本一致,但LASIK术后,角膜地形图往往高估术后的散光值.%Objective To investigate the accuracy of the effects of laser in situ keratomileusis (LASIK) on astigmatism of -2.0D or above assessed by corneal topography.Methods Thirty-six eyes of 25 patients with astigmatism of-2.0D or above who underwent LASIK were included in this retrospective study. Corneal topography and subjective refraction examination were performed before and at least 6 months after surgery.The astigmatism of subjective refraction was translated to cylinder diopter of corneal plane.Astigmatism measured with corneal topography and that of subjective refraction was compared before and after the surgery. Results The mean astigmatism measured by corneal topography was (-2.29±0.61) D and (-1.91±0.68) D pre- and postoperative respectively.The meaa astigmatism in corneal plane measured by manifest refraction was (-2.22±0.61) D and (-0.46±0.43) D pro- and postoperative respectively.The differences between pre- and post-operation were both statistically significant (P<0.05).The mean difference between pre- and post

  11. Posterior Corneal Surface Stability after Femtosecond Laser-Assisted Keratomileusis

    Directory of Open Access Journals (Sweden)

    Carlo Cagini

    2015-01-01

    Full Text Available The purpose of this study was to evaluate posterior corneal surface variation after femtosecond laser-assisted keratomileusis in patients with myopia and myopic astigmatism. Patients were evaluated by corneal tomography preoperatively and at 1, 6, and 12 months. We analyzed changes in the posterior corneal curvature, posterior corneal elevation, and anterior chamber depth. Moreover, we explored correlation between corneal ablation depth, residual corneal thickness, percentage of ablated corneal tissue, and preoperative corneal thickness. During follow-up, the posterior corneal surface did not have a significant forward corneal shift: no significant linear relationships emerged between the anterior displacement of the posterior corneal surface and corneal ablation depth, residual corneal thickness, or percentage of ablated corneal tissue.

  12. Epithelial ion transport in rabbit corneas following myopic keratomileusis.

    Science.gov (United States)

    Swinger, C A; Candia, O A; Marcus, S; Barker, B A; Kornmehl, E W

    1986-08-01

    In isolated rabbit corneas that had undergone lamellar keratectomy or myopic keratomileusis, the stimulation of chloride transport by 10(-5) M epinephrine was completely inhibited at 1 week following surgery. At 28 days following surgery, both groups responded to 10(-7) M epinephrine. The response to 10(-5) M amphotericin B was normal both at 1 week and at 28 days following surgery. We conclude that, although the Na-K pump was not affected by the lamellar keratectomy and cryolathing, that either the epithelial beta receptors and/or the cAMP pathway were temporarily inhibited for at least 1 week following surgery. A lamellar keratectomy, therefore, can have an adverse effect on the epithelial transport system of the corneal epithelium even though the epithelium may appear normal clinically.

  13. Comparison of corneal aberrations after femtosecond laser LASIK and SBK%飞秒LASIK与SBK术后角膜像差的对比分析

    Institute of Scientific and Technical Information of China (English)

    张静; 张士胜; 吴江秀; 于青; 董世奇; 廉井财

    2014-01-01

    Objective To compare changes in wavefront aberrations on the cornea after femtosecond laser LASIK (FS-LASIK) and sub-Bowman's keratomileusis (SBK),especially for total higher order aberrations (HOA),corneal spherical aberrations (C40),corneal horizontal coma (C31),corneal vertical coma (C3-1),corneal horizontal trefoil (C33) and corneal oblique trefoil (C3-3).Methods A prospective study was designed for 2 groups based on the procedure used.The groups were composed of 68 eyes of 34 patients who had undergone FS-LASIK and 90 eyes of 45 patients who had been treated with SBK.A Pentacam was used under dark room conditions to measure corneal aberrations before surgery and 1 and 3 months after surgery.Data were analyzed using ANOVA,an independent samples t test and Pearson correlation.Results The preoperative and postoperative differences for the total corneal HOA,corneal C40,and corneal C31in the FS-LASIK group were significant (F=8.511,12.356,11.843,P<0.01).The corresponding differences and in addition corneal C31 were also significant for the SBK group (F=46.601,38.627,10.874,11.727,P<0.01).One month after surgery,HOAs were higher in the SBK group than in the FS group (t=-3.063,P<0.05),and the same tendency was found 3 months after surgery (t=2.998,P<0.05).The differences for C40 at 1 month were not significant between the two groups (t=-1.990,P>0.05) but the differences were statistically significant at 3 months (t=-2.666,P<0.05).One and 3 months after surgery,the trefoil aberrations (C33,C3-3) of the cornea in the two groups were higher than before surgery; only the difference for C3-3 was significant.However,the difference in the trefoil aberrations of the cornea between the two groups was not statistically significant.Conclusion Both FS-LASIK and SBK can increase corneal HOA,corneal spherical aberrations and vertical coma,but the degree of increase after FS-LASIK is smaller than that after SBK.FS-LASIK improves visual quality more than SBK.%目的

  14. Intraoperative Flap Complications in LASIK Surgery Performed by Ophthalmology Residents

    Science.gov (United States)

    Romero-Diaz-de-Leon, Lorena; Serna-Ojeda, Juan Carlos; Navas, Alejandro; Graue-Hernández, Enrique O.; Ramirez-Miranda, Arturo

    2016-01-01

    Purpose: To report the rate of flap-related complications in LASIK surgery performed by in-training ophthalmology residents and to analyze the risk factors for these complications. Methods: We analyzed 273 flap dissections in 145 patients from March 2013 to February 2014. We included all LASIK surgeries performed by 32 ophthalmology residents using a Moria M2 microkeratome. All the flap-related complications were noted. Comparison between both groups with and without complications was performed with an independent Student's t-test and relative risks were calculated. Results: There were 19 flap-related complications out of the 273 flap dissections (6.95%). The most common complication was incomplete flap dissection (n = 10; 3.66%), followed by free-cap (n = 5; 1.83%), and flap-buttonhole (n = 2; 0.73%). There was no significant difference between the complicated and uncomplicated cases in terms of the right versus the left eye, pachymetry results, white-to-white diameter, and spherical equivalent. But this difference was significant for mean keratometry (P = 0.008), K-min (P = 0.01), and K-max (P = 0.03) between these groups. Final visual acuity after rescheduling laser treatment was similar in both groups. Relative risks for flap-related complications were 2.03 for the first LASIK surgery (CI 95% 0.64 to 6.48; P = 0.22) and 1.26 (CI 95% 0.43 to 3.69; P = 0.66) for the surgeon's flap-related complications. Female gender presented an odds ratio of 2.48 (CI 95% 0.68 to 9.00; P = 0.16) for complications. Conclusion: Flap-related complications are common intraoperative event during LASIK surgery performed by in-training ophthalmologists. Keratometries and surgeon's first procedure represent a higher probability for flap related complications than some other biometric parameters of patient's eye. PMID:27621782

  15. Effect of iris registration on outcomes of LASIK for myopia with the VISX CustomVue platform

    DEFF Research Database (Denmark)

    Moshirfar, Majid; Chen, Michael C; Espandar, Ladan

    2009-01-01

    PURPOSE: To compare visual outcomes after LASIK using the VISX STAR S4 CustomVue, with and without Iris Registration technology. METHODS: In this retrospective study, LASIK was performed on 239 myopic eyes, with or without astigmatism, of 142 patients. Iris registration LASIK was performed on 121...

  16. Shewanella putrefaciens keratitis in the lamellar bed 6 years after LASIK.

    Science.gov (United States)

    Park, Hee-Jung S; Tuli, Sonal S; Downer, Donald M; Gohari, A Reza; Shah, Milan

    2007-10-01

    To present a case of infectious keratitis occurring 6 years after LASIK due to the rare human pathogen Shewanella putrefaciens. A 58-year-old man presented with redness and pain in the right eye 6 years following LASIK retreatment. Examination revealed a corneal infiltrate at the flap interface. Corneal scraping of stroma beneath the flap was submitted for histopathologic and microbiologic evaluation. An infiltrate located at the LASIK flap interface originated from an epithelial defect at the flap-corneal junction. Corneal stroma cultures demonstrated Shewanella putrefaciens. The infection resolved with antibiotic treatment. LASIK-related complications, such as infections, can occur many years following the procedure. The potential space created under the LASIK flap may predispose patients to infection by opportunistic organisms.

  17. Correção das aberrações oculares nos retratamentos de LASIK personalizado e convencional Correction of ocular aberrations in custom and standard LASIK retreatments

    Directory of Open Access Journals (Sweden)

    Andréia Peltier Urbano

    2009-10-01

    Full Text Available OBJETIVO: Comparar a correção das aberrações oculares nos retratamentos de LASIK personalizado e convencional. MÉTODOS: Foi realizado um estudo prospectivo, randomizado, de 74 olhos de 37 pacientes submetidos ao retratamento de LASIK para correção de miopia e astigmatismo. Cada paciente foi submetido ao retratamento de LASIK personalizado Zyoptix (Bausch & Lomb em um olho e convencional Planoscan (Bausch & Lomb no olho contralateral. Foi comparada a correção das aberrações oculares nos retratamentos personalizado e convencional. RESULTADOS: No sexto mês pós-operatório, os olhos submetidos ao retratamento Zyoptix apresentaram diminuição estatisticamente significativa do defocus, astigmatismo, coma, aberração esférica, segunda ordem, terceira ordem, alta ordem e aberrações totais. Os olhos submetidos ao retratamento Planoscan apresentaram diminuição estatisticamente significativa do defocus, segunda ordem e aberrações totais. CONCLUSÕES: O retratamento personalizado foi superior ao retratamento convencional para a correção das aberrações oculares de baixa e alta ordens.PURPOSE: To compare the correction of ocular aberrations between custom and standard LASIK retreatment. METHODS: Prospective, randomized trial with paired eye control of 74 eyes from 37 patients who underwent LASIK retreatment. Each patient underwent retreatment using Zyoptix LASIK (Bausch & Lomb in 1 eye and Planoscan LASIK (Bausch & Lomb in the fellow eye. Correction of ocular aberrations was compared between custom and standard LASIK retreatments. RESULTS: At 6 months, there was a statistically significant reduction in defocus, astigmatism, coma, spherical aberration, second, third, higher-order and total aberration in Zyoptix eyes. There was a statistically significant reduction in defocus, second-order and total aberration in Planoscan eyes. CONCLUSIONS: Custom retreatment was statistically superior than standard retreatment for correction of lower

  18. Comparación del LASIK convencional y el LASIK asférico en el tratamiento de la ametropía Comparison of conventional LASIK and aspheric LASIK in the treatment of ametropia

    OpenAIRE

    Yanaisa Riverón Ruiz; Sorania Rodríguez Hernández; Enrique Machado Hernández; Lorelei Ortega Díaz

    2012-01-01

    Objetivo: comparar los resultados del LASIK con patrón de ablación convencional y el asférico en la corrección de ametropías y evaluar la sensibilidad al contraste en ambos procedimientos. Métodos: se realizó un estudio comparativo y prospectivo en 64 pacientes de la consulta externa del Servicio de Cirugía Refractiva del Instituto Cubano de Oftalmología "Ramón Pando Ferrer". Estos fueron distribuidos aleatoriamente en dos grupos iguales para ambas técnicas. Las variables estudiadas fueron ag...

  19. Paquimetria esperada X obtida após LASIK para miopia Achieved X expected pachymetry after LASIK for myopia

    Directory of Open Access Journals (Sweden)

    Juliane de Freitas Santos Paranhos

    2001-06-01

    Full Text Available Objetivo: Comparar a paquimetria corneana encontrada (PEn com a esperada (PEs 3 meses após a cirurgia de LASIK para correção de miopia. Métodos: 77 olhos de 39 pacientes míopes foram incluídos neste estudo. A cirurgia foi realizada utilizando-se o excimer laser Technolas 217 e o microcerátomo automático da Chiron. Paquimetria foi realizada em todos os olhos antes e 3 meses após o LASIK. PEs foi obtida subtraindo-se a profundidade de ablação realizada pelo laser, da paquimetria pré-operatória. Os pacientes foram divididos em 3 grupos: grupo A (55 olhos com miopia variando de -1,00D a -5,75D; grupo B (14 olhos, de -6,00D a -10,00D e grupo C (8 olhos acima de -10,00D. Resultados: Houve uma diminuição da média do equivalente esférico de -2,71D para 0,00 no grupo A, -8,18D para 0,00 no grupo B e de -11,4D para -1,06D no grupo C. As médias das PEs foram 468 mim, 370 mim e 382 mim para os grupos A,B e C, respectivamente. As médias das PEn foram de 491 mim, 431 mim e 427 mim nos grupos A, B e C, respectivamente. Em 70 olhos (90,9 % a PEn foi superior a PEs, sendo esta diferença estatisticamente significativa (p=0,001. Conclusão: Apesar dos resultados mostrarem que a córnea encontrava-se mais espessa do que o esperado após a cirurgia de LASIK, não foi observada hipocorreção significativa. Após 3 meses a refração da maioria dos pacientes estava próxima da emetropia.Purpose: To compare the achieved corneal pachymetry (AP with the expected one (EP after 3 months of LASIK for myopia. Methods: 77 myopic eyes of 39 patients were included in this study. Surgery was performed with the Technolas 217 excimer laser and the Chiron automated corneal shaper microkeratome. Screening pachymetry was performed in all corneas before and 3 months after LASIK. EP was obtained by subtracting the ablation depth from the preoperative pachymetry. Patients were divided into 3 groups as follows: Group A (55 eyes, from -1.00 diopter (D to -5.75D; group

  20. Q值调整个体化准分子激光原位角膜磨镶术术后角膜非球面变化%Q-Factor Customized Aspheric Ablation Profile after LASIK for Myopia

    Institute of Scientific and Technical Information of China (English)

    姚春艳; 翟芳; 刘超; 郑玲; 孙守彬; 温泉; 孙伟英; 盛毅; 朱佳

    2012-01-01

    standard ablation (standard group). Preoperative and 1-month post-operative visual acuity, aberrometry and asphericity of the cornea, were compared between the 2 groups. All eyes received laser in situ keratomileusis surgery, and the laser treatment was accomplished with the Wavelight Eye-Q 400 Hz excimer laser. Results: There were no statistically significant differences between the 2 groups regarding any visual or optical parameter. The Q-factor optimized treated eyes has significantly smaller shift toward oblate. △Q109 △Q15 was considered statistically significant. Conclusion: Regarding safety and refractive efficacy, custom-Q ablation profiles were clinic equivalent to Standard ablation group profiles in corrections of myopia. Comeal asphericity was less impaired by the custom-Q treatment.

  1. Degenerações periféricas da retina do olho míope X LASIK Peripheral retinal degenerations in myopic eye X LASIK

    Directory of Open Access Journals (Sweden)

    João J. Nassaralla Jr.

    2004-04-01

    Full Text Available O objetivo deste artigo é apresentar as degenerações periféricas mais comuns na retina dos olhos míopes, discutindo aquelas que oferecem maiores riscos para o descolamento regmatogênico da retina, seu relacionamento com a cirurgia de LASIK e a indicação para o tratamento profilático.The purpose of this paper is to present the most frequent peripheral retinal degenerations in myopic eyes and discuss those degenerations which are a great risk for the retina and to point out the features associated with retinal detachment, its relation to LASIK and the indication for prophylactic treatment.

  2. Comparación del LASIK convencional y el LASIK asférico en el tratamiento de la ametropía Comparison of conventional LASIK and aspheric LASIK in the treatment of ametropia

    Directory of Open Access Journals (Sweden)

    Yanaisa Riverón Ruiz

    2012-12-01

    Full Text Available Objetivo: comparar los resultados del LASIK con patrón de ablación convencional y el asférico en la corrección de ametropías y evaluar la sensibilidad al contraste en ambos procedimientos. Métodos: se realizó un estudio comparativo y prospectivo en 64 pacientes de la consulta externa del Servicio de Cirugía Refractiva del Instituto Cubano de Oftalmología "Ramón Pando Ferrer". Estos fueron distribuidos aleatoriamente en dos grupos iguales para ambas técnicas. Las variables estudiadas fueron agudeza visual sin corrección y mejor corregida, aberración y sensibilidad al contraste en condiciones fotópicas. Resultados: la agudeza visual sin corrección mejoró ocho líneas en la cartilla de Snellen, sin diferencias entre ambos procedimientos. La aberración esférica presentó un valor medio inferior en el tratamiento asférico (0,30. Se encontró una disminución de la sensibilidad al contraste después del tratamiento convencional. Conclusiones: ambas técnicas quirúrgicas mantienen una buena agudeza visual con corrección y sin esta, después de la cirugía en ambientes fotópicos. La calidad visual del tratamiento asférico es superior, al inducir menor aberración esférica y mejor sensibilidad al contraste después de cirugía.Objective: to compare the results obtained with the LASIK using both conventional and aspheric patterns to correct ametropies and to evaluate the contrast sensitivity after these two procedures. Methods: a comparative and prospective study was conducted in 64 patients who attended the refractive surgery outpatient service of “Ramon Pando Ferrer” Cuban Institute of Ophthalmology. They were randomly distributed in two groups for both procedures. Several variables were studied such as: uncorrected visual acuity, best corrected visual acuity, aberration and contrast sensitivity at photopic conditions. Results: uncorrected visual acuity improved 8 lines in the Snellen’s chart, without significant

  3. In-Situ Simulation

    DEFF Research Database (Denmark)

    Bjerregaard, Anders Thais; Slot, Susanne; Paltved, Charlotte

    2015-01-01

    Introduction: In situ simulation offers on-site training to healthcare professionals. It refers to a training strategy where simulation technology is integrated into the clinical encounter. Training in the simulation laboratory does not easily tap into situational resources, e.g. individual, team......, and organisational characteristic. Therefore, it might fail to fully mimic real clinical team processes. Though research on in situ simulation in healthcare is in its infancy, literature is abundant on patient safety and team training1. Patient safety reporting systems that identify risks to patients can improve...... offered in situ simulation faculty with a model for integrating reported critical incidents and adverse events with contextual needs analysis and short-term observations. Furthermore the research group is working on detailing the barriers of in situ simulation such as resources for team training despite...

  4. Efficacy and safety of LASIK in 10,052 eyes of 5081 myopic Chinese patients.

    Science.gov (United States)

    Sun, Lanping; Liu, Guifen; Ren, Yanjun; Li, Ji; Hao, Junhua; Liu, Xia; Zhang, Yajuan

    2005-01-01

    To analyze the outcomes and incidence of postoperative complications in a large series of patients undergoing LASIK for myopia. All 5081 patients (10,052 eyes) diagnosed with myopia at The Third Hospital of Handan, China, from September 2003 through March 2005 were studied. All study eyes underwent LASIK with 1-month follow-up. Spherical equivalent refraction, best spectacle-corrected visual acuity (BSCVA), and uncorrected visual acuity (UCVA) were measured before and after surgery and intra- and postoperative complications were recorded. Uncorrected visual acuity at 1-month follow-up of 9555 (95.1%) eyes reached or exceeded the preoperative BSCVA. Hemorrhage of corneal limbus during surgery occurred in 1060 (10.5%) eyes, Sands of Sahara syndrome occurred in 232 (2.3%) eyes, interface infection responsive to treatment occurred in 4 (0.04%) eyes, and epithelial ingrowth occurred in 1 (0.01%) eye. LASIK is a safe and effective method for the treatment of myopia.

  5. The Evaluation of Yellow vs. Blue Color Contrast Sensitivity pre and Post LASIK

    Directory of Open Access Journals (Sweden)

    S. Heydarian

    2007-06-01

    Full Text Available Introduction: contrast sensitivity is one of the most important psychophysical tests that may be used for the evaluation of refractive state of eye and retinal image quality. Yellow vs. blue color contrast sensitivity may be more suitable in this regard. Materials and Methods: thirty myopic eyes were considered in this study. Yellow vs. blue color contrast sensitivity was evaluated under the same environment and conditions in these individuals pre and post LASIK. Results: The comparison of yellow vs. blue color contrast sensitivity with glasses pr e and post LASIK shows a significant improvement (p

  6. In situ groundwater bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry C.

    2009-02-01

    In situ groundwater bioremediation of hydrocarbons has been used for more than 40 years. Most strategies involve biostimulation; however, recently bioaugmentation have been used for dehalorespiration. Aquifer and contaminant profiles are critical to determining the feasibility and strategy for in situ groundwater bioremediation. Hydraulic conductivity and redox conditions, including concentrations of terminal electron acceptors are critical to determine the feasibility and strategy for potential bioremediation applications. Conceptual models followed by characterization and subsequent numerical models are critical for efficient and cost effective bioremediation. Critical research needs in this area include better modeling and integration of remediation strategies with natural attenuation.

  7. Regressão refrativa total pós-LASIK: relato de caso Total refractive regression post-LASIK: case report

    Directory of Open Access Journals (Sweden)

    Patrícia Ioschpe Gus

    2005-06-01

    Full Text Available Os corticoesteróides podem aumentar a pressão intra-ocular quando administrados de maneira tópica, sistêmica e até mesmo inalatória. É rotina sua utilização após cirurgias refrativas para diminuir ou prevenir reação inflamatória. No presente relato, apresentamos o caso de uma paciente de 36 anos que, após duas semanas de cirurgia de LASIK para correção de miopia leve, teve regressão total da miopia causada pela hipertensão ocular cortisônica. O objetivo desse relato é descrever como foi conduzido o caso, as hipóteses de diagnósticos que foram levantadas, e salientar a importância da mensuração da pressão intra-ocular no pós-operatório.Corticosteroids can increase intraocular pressure when administered topically, systemically and even when inhaled. They are routinely used after refractive surgeries to lower or prevent an inflammatory action. In this case history, we present a 36-year-old patient who had a total myopic regression two weeks after LASIK for low myopia, caused by steroid-induced ocular hypertension. The purpose of this report is to describe how the case was managed, the diagnostic hypothesis, and to stress the importance of intraocular pressure measurement after LASIK.

  8. Reason analysis and preventive treatment countermeasure of impaired vision after LASIK

    Directory of Open Access Journals (Sweden)

    Zhang-Bing Mu

    2015-02-01

    Full Text Available AIM: To analyze the reasons of impaired vision after LASIK and explore its preventive treatment measures preliminarily. METHODS: In this retrospective study, 175 eyes of 134 patients whose vision was decreased after LASIK were included. The constituent ratio of every reason was counted and uncorrected visual acuity(UCVAbetween pre-treatment and post-treatment were compared by paired t-test respectively. RESULTS: The overall incidence of impaired vision after LASIK was 1.86%. The constituent ratio of regression was 51.43% and UCVA increased from 0.61±0.22 to 0.90±0.38(t=8.00, Pt=20.00, Pt=8.14, Pt=6.33, Pt=2.53, P0.05after treatment. The constituent ratio of fundus lesions and diffuse lamellar keratitis(DLKwas 2.86% and UCVA all increased by different degrees after treatment. CONCLUSION: The reasons of impaired vision after LASIK are many and varied. These cases could recover their vision by discovery and treatment in time, and the appropriate preventive measures were essential.

  9. Epi-LASIK e PRK: um ano de estudo comparativo em olhos contralaterais

    Directory of Open Access Journals (Sweden)

    Francisco Penteado Crestana

    2013-08-01

    Full Text Available OBJETIVO: Comparar as técnicas de PRK e Epi-LASIK com relação à recuperação visual e sintomatologia pós-operatória. MÉTODOS: Série de casos intervencionista que incluiu 38 olhos de 19 pacientes com miopia até 5DE e astigmatismo até 1DC. Foram selecionados pacientes com erros refracionais semelhantes nos dois olhos, realizando-se, no mesmo tempo cirúrgico, PRK em um olho e Epi-LASIK no olho contralateral. Os pacientes foram acompanhados por um ano, avaliando-se a eficácia refracional e grau de desconforto pós-operatório. RESULTADOS: Durante as primeiras 12 horas, 79,9% dos pacientes (p=0,0003 referiram dor mais intensa no olho operado com a técnica Epi-LASIK. Após 24 horas, 63,2% dos pacientes (p=0,012 ainda referiam mais dor neste olho e apenas 10,5% no olho contralateral. A acuidade visual não corrigida foi melhor nos olhos do grupo PRK no primeiro dia (p=0,034. Nos demais dias não houve diferença significativa entre os grupos. Houveopacidade corneana grau 0,5 (Fantes em três olhos do grupo PRK e em dois no grupo Epi-LASIK. CONCLUSÃO: Ambos os grupos apresentaram resultado visual refracional satisfatório, porém o grupo Epi-LASIK apresentou maior desconforto no pós-operatório imediato.

  10. In Situ Mass Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The In Situ Mass Spectrometer projects focuses on a specific subsystem to leverage advanced research for laser-based in situ mass spectrometer development...

  11. Resultados refracionais do retratamento de LASIK com ablação personalizada versus ablação convencional Refractional results of LASIK retreatment with wavefront-guided ablation versus standard ablation

    Directory of Open Access Journals (Sweden)

    Andréia Peltier Urbano

    2008-10-01

    Full Text Available OBJETIVO: Avaliar os resultados do retratamento personalizado (Zyoptix, Bausch & Lomb e do retratamento convencional (Planoscan, Bausch & Lomb em olhos submetidos a LASIK primário convencional. MÉTODOS: Foi realizado estudo prospectivo, randomizado, de 74 olhos de 37 pacientes submetidos a retratamento de LASIK para correção de miopia e astigmatismo. Cada paciente foi submetido a retratamento de LASIK com ablação personalizada em um olho e ablação convencional no olho contralateral. Foram comparadas a acuidade visual de alto contraste e refração manifesta, com acompanhamento de seis meses. RESULTADOS: Os retratamentos personalizados de LASIK (Zyoptix e os retratamentos convencionais de LASIK (Planoscan apresentaram valores estatisticamente similares para a acuidade visual, ganho/perda de linhas da melhor acuidade visual corrigida, índices de segurança e eficácia e porcentagem de olhos com equivalente esférico (EE entre ± 0,50 D e 1,00 D no período pós-operatório de seis meses. Houve diferença significativa para os valores do componente esférico e do equivalente esférico nos períodos pós-operatórios de uma semana, um, três e seis meses entre os grupos Zyoptix e Planoscan. Os olhos do grupo Zyoptix apresentaram valores mais hipermétropes do que os olhos do grupo Planoscan. A previsibilidade da correção do equivalente esférico no grupo Zyoptix foi superior à do grupo Planoscan. CONCLUSÕES: A ablação personalizada proporciona melhores resultados refracionais do que a ablação convencional para os retratamentos de LASIK convencional. A medida da acuidade visual de alto contraste não é parâmetro sensível para evidenciar a melhor técnica cirúrgica.PURPOSE: To evaluate refractive outcomes of wavefront-guided LASIK (Zyoptix, Bausch & Lomb versus standard LASIK (PlanoScan, Bausch & Lomb in retreatment of primary LASIK for myopia and myopic astigmatism. METHODS: A prospective, randomized trial with paired eye control

  12. Edema cistoide de mácula pós-LASIK tratado com ranibizumabe

    Directory of Open Access Journals (Sweden)

    Luiz Guilherme Azevedo de Freitas

    2014-06-01

    Full Text Available Os autores relatam o caso de uma paciente que desenvolveu edema cistóide de mácula pós-cirurgia para correção de miopia pelo método LASIK. Foi submetida a tratamento com injeções intravítrea de ranibizumabe e apresentou resultado visual satisfatório.

  13. Measuring patient's expectation and the perception of quality in LASIK services

    Directory of Open Access Journals (Sweden)

    Bair Alex

    2009-07-01

    Full Text Available Abstract Background LASIK is the use of excimer lasers to treat therapeutic and refractive visual disorders, ranging from superficial scars to nearsightedness (myopia, and from astigmatism to farsightedness (hyperopia. The purposes of this study are to checking the applicability and psychometric properties of the SERVQUAL on Lasik surgery population. Second, use SEM methods to investigate the loyalty, perceptions and expectations relationship on LASIK surgery. Methods The method with which this study was conducted was questionnaire development. A total of 463 consecutive patients, attending LASIK surgery affiliated with Chung Shan Medical University Eye Center, enrolled in this study. All participants were asked to complete revised SERVQUAL questionnaires. Student t test, correlation test, and ANOVA and factor analyses were used to identify the characters and factors of service quality. Paired t test were used to test the gap between expectation and perception scores and structural equation modeling was used to examine relationships among satisfaction components. Results The effective response rate was 97.3%. Validity was verified by several methods and internal reliability Cronbach's alpha was > 0.958. The results from patient's scores were very high with an overall score of 6.41(0.66, expectations at 6.68(0.47, and perceptions at 6.51(0.57. The gap between expectations and perceptions was significant, however, (t = 6.08. Furthermore, there were significant differences in the expectation scores among the different jobs. Also, the results showed that the higher the education of the patient, the lower their perception score (r = -0.10. The factor loading results of factor analysis showed 5 factors of the 22 items of the SERVQUAL model. The 5 factors of perception explained 72.94% of the total variance there; and on expectations it explained 77.12% of the total variance of satisfaction scores. The goodness-of-fit summary, of structure equation

  14. [Comparison of the two methods, LASIK and ICL in mild and high hyperopia correction--part one].

    Science.gov (United States)

    Horáková, M; Vlková, E; Loukotová, V; Hlinomazová, Z

    2007-05-01

    The problems of hyperopia surgical correction are complicated. The most used methods are corneal laser treatments (PRK and LASIK), phakic intraocular lenses or clear lens extraction (CLE). The aim of the study was to evaluate and to compare long-term postoperative results of two types of refractive procedures in mild and high hyperopia correction: LASIK and ICL (phakic intraocular posterior chamber contact lens) implantation. The authors evaluated a group of 37 eyes of 20 patients; the average age was 36.3 years +/- 11.8 (SD) and the follow-up period 28.1 months +/- 10.2 (SD) after LASIK procedure, and group of 21 eyes of 13 patients; the average age was 28.6 years +/- 6.1 (SD) and the follow-up period 30.4 months +/- 20.9 (SD) after the ICL implantation. The final uncorrected (UCVA) and best-corrected visual acuity (BCVA) and postoperative refractive error (for far and near) and their development in time were compared. They found statistically significant improvement of the UCVA postoperatively comparing to the preoperative values in both methods (LASIK and ICL) (p 0.05). In hyperopic LASIK, the final BCVA worsened comparing to this before treatment (p > 0.05). The BCVA changes were not statistically significant. The authors also proved better final spherical refraction for far (p refraction was better after the ICL implantation during the whole follow up period. In the laser treatment, the continuous regression of the postoperative refraction was evident. The final cylindrical refraction value was also lower in the ICL group (p > 0.05). The stableness of the postoperative cylindrical refraction was also higher in the ICL method during the whole follow up period. Comparing the intraocular procedure (ICL) to the laser method (LASIK), the ICL implantation demonstrates better final BCVA and UCVA and the postoperative refraction is more stable.

  15. Implantable collamer lens and femtosecond laser for myopia: comparison using an adaptive optics visual simulator

    Directory of Open Access Journals (Sweden)

    Cari Pérez-Vives

    2014-04-01

    Full Text Available Purpose: To compare optical and visual quality of implantable collamer lens (ICL implantation and femtosecond laser in situ keratomileusis (F-LASIK for myopia. Methods: The CRX1 adaptive optics visual simulator (Imagine Eyes, Orsay, France was used to simulate the wavefront aberration pattern after the two surgical procedures for -3-diopter (D and -6-D myopia. Visual acuity at different contrasts and contrast sensitivities at 10, 20, and 25 cycles/degree (cpd were measured for 3-mm and 5-mm pupils. The modulation transfer function (MTF and point spread function (PSF were calculated for 5-mm pupils. Results: F-LASIK MTF was worse than ICL MTF, which was close to diffraction-limited MTF. ICL cases showed less spread out of PSF than F-LASIK cases. ICL cases showed better visual acuity values than F-LASIK cases for all pupils, contrasts, and myopic treatments (p0.05. For -6-D myopia, however, statistically significant differences in contrast sensitivities were found for both pupils for all evaluated spatial frequencies (p<0.05. Contrast sensitivities were better after ICL implantation than after F-LASIK. Conclusions: ICL implantation and F-LASIK provide good optical and visual quality, although the former provides better outcomes of MTF, PSF, visual acuity, and contrast sensitivity, especially for cases with large refractive errors and pupil sizes. These outcomes are related to the F-LASIK producing larger high-order aberrations.

  16. Dry Eye Disease following Refractive Surgery: A 12-Month Follow-Up of SMILE versus FS-LASIK in High Myopia

    Directory of Open Access Journals (Sweden)

    Bingjie Wang

    2015-01-01

    Full Text Available Purpose. To compare dry eye disease following SMILE versus FS-LASIK. Design. Prospective, nonrandomised, observational study. Patients. 90 patients undergoing refractive surgery for myopia were included. 47 eyes underwent SMILE and 43 eyes underwent FS-LASIK. Methods. Evaluation of dry eye disease was conducted preoperatively and at 1, 3, 6, and 12 months postoperatively, using the Salisbury Eye Evaluation Questionnaire (SEEQ and TBUT. Results. TBUT reduced following SMILE at 1 and 3 months (p<0.001 and at 1, 3, and 6 months following FS-LASIK (p<0.001. TBUT was greater following SMILE than FS-LASIK at 3, 6, and 12 months (p<0.001, p<0.001, and p=0.009, resp.. SEEQ scores increased (greater symptoms following SMILE at 1 month (p<0.001 and 3 months (p=0.003 and at 1, 3, and 6 months following FS-LASIK (p<0.001. SMILE produced lower SEEQ scores (fewer symptoms than FS-LASIK at 1, 3, and 6 months (p<0.001. Conclusion. SMILE produces less dry eye disease than FS-LASIK at 6 months postoperatively but demonstrates similar degrees of dry eye disease at 12 months.

  17. In Situ Aerosol Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is developing new platform systems that have the potential to benefit Earth science research activities, which include in situ instruments for atmospheric...

  18. Corneal Deposit of Ciprofloxacin after Laser Assisted Subepithelial Keratomileusis Procedure: A Case Report

    Directory of Open Access Journals (Sweden)

    Giacomo De Benedetti

    2010-01-01

    Full Text Available Purpose. To report one case of corneal antibiotic deposition after ciprofloxacin administration in Laser Assisted Subepithelial Keratomileusis (LASEK. Methods. One case of post-LASEK treatment resulted in corneal precipitates and poor wound healing. Debris was analyzed with dark field microscopy and placed on a blood-agar plate seeded with a susceptible stain of Staphylococcus aureus (ATCC 29213. Results. The alterations resolved with discontinuation of ciprofloxacin treatment, although some residual deposits persisted subepithelially for 6 months. Analysis of precipitates revealed polydisperse crystalline needles of 183 m average length (SD=54 m and the excised precipitate demonstrated a zone of inhibition. Conclusions. Fluoroquinolone antibiotic drops have been used extensively in postsurgical treatment of refractive surgery. Corneal precipitates have been previously reported in the literature, but up to now nothing has been documented after LASEK. Polypharmacy during refractive surgery may impair epithelialisation, and clinical management should reduce toxic environment and promote ocular surface stability when performing surface ablations.

  19. Clinical observation on treatment of Meibomian gland before IntraLase LASIK in patients with Meibomian gland dysfunction

    Directory of Open Access Journals (Sweden)

    He Huang

    2016-04-01

    Full Text Available AIM:To observe the changes of ocular surface inflammation and tear film state before and after the operation after preoperative targeted therapy for Meibomian gland in the patients scheduled for IntraLase-LASIK with Meibomian gland dysfunction(MGD. METHODS: Thirty-five patients(70 eyesscheduled for IntraLase-LASIK with different degrees of MGD from March to September 2014 were enrolled in this study. All patients were randomly divided into 2 groups, 17 patients(34 eyesin the observation group accepted preoperative targeted therapy for Meibomian gland; 18 patients(36 eyesin the control group did not give the treatment for Meibomian gland, the rest treatments were the same. The change of conjunctival congestion, photophobia, dry symptom score and tear break-up time(BUTwere observed at 1d and 1wk after IntraLase-LASIK. RESULTS: At 1d and 1wk postoperatively, the scores of conjunctival congestion, photophobia, dry symptom and BUT of the observation group were all lower than those of the control group, and the differences were significant(PCONCLUSION: For the patients scheduled for IntraLase-LASIK with MGD, preoperative targeted therapy for Meibomian gland can reduce the postoperative symptoms of ocular surface irritation, stabilize the tear film, improve the postoperative effect and improve the comfort of patients.

  20. Comparison of higher order aberrations after wavefront-guided LASIK and PRK: One year follow-up results

    Directory of Open Access Journals (Sweden)

    Seyed Hamid Reza Jahadi Hosseini

    2016-01-01

    Conclusion: For the 6mm pupil size, the total HOA increased following both personalized PRK and LASIK with no significant difference between the two groups. Change of the total HOA RMS was influenced by the preoperative values. The known influencing factors could predict nearly 50% of the changes in total HOA.

  1. Small-aperture corneal inlay in patients with prior radial keratotomy surgeries

    Directory of Open Access Journals (Sweden)

    Huseynova T

    2013-09-01

    Full Text Available Tukezban Huseynova,1,* Tomomi Kanamori,1 George O Waring IV,2 Minoru Tomita1,3,* 1Shinagawa LASIK Center, Chiyoda-ku, Tokyo, Japan; 2Medical University of South Carolina, Storm Eye Institute, Charleston, SC, USA; 3Department of Ophthalmology, Wenzhou Medical College, Wenzhou, People's Republic of China *These authors contributed equally to this study Abstract: This paper describes the 3-month results of two patients who underwent KAMRA™ (AcuFocus, Inc, Irvine, CA, USA inlay implantation surgery with a history of prior radial keratotomy. The refractive error just before KAMRA inlay implantation was corrected in one patient with a laser-assisted in situ keratomileusis (LASIK procedure. The post-inlay implantation surgery results showed effective uncorrected near visual acuity outcomes with no impact on uncorrected distance visual acuity in both patients. Keywords: KAMRA™, RK, LASIK, uncorrected distance visual acuity, refractive error, uncorrected near visual acuity

  2. Related research on corneal higher-order aberrations after different ways refractive surgery

    Directory of Open Access Journals (Sweden)

    Shu-Xi He

    2015-08-01

    Full Text Available AIM:To evaluate the changes of corneal high-order aberration(including Coma, Spab, RMShafter laser in situ keratomileusis(LASIKwith femtosecond laser, sub-Bowman keratomileusis(SBKand laser epithelial keratomileusis(LASEK.METHODS: Of 82 myopic patients(164 eyes, 31 patients(62 eyeswere treated by FS-LASIK, 31 patients(62 eyeswere treated by SBK, 20 patients(40 eyeswere treated by LASEK. Sirius system was used for measuring the coma aberration, spherical aberration, and high order aberration at 1, 15d,1, 3mo after surgery.RESULTS: 1Vision: The uncorrected visual acuity of the three groups had no differences(P>0.05. 2Corneal aberrations: Three kinds of surgical procedure for patients with corneal aberration had significant impact. The C7, C8, C12 and RMSh of three groups were increased significantly(P0.05. The C7, C8, C12 and RMSh were not recovered to preoperative levels after 3mo. But the increase of patients after FS-LASIK was smaller than the other two groups, with statistical significance(P0.05.CONCLUSION: Compared with SBK and LASEK,FS-LASIK has better visual acuity in the early postoperative and corneal higher-order aberrations increase is relatively small.

  3. In situ microbial filter used for bioremediation

    Science.gov (United States)

    Carman, M. Leslie; Taylor, Robert T.

    2000-01-01

    An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

  4. Long term results of no- alcohol laser epithelial keratomileusis and photorefractive keratectomy for myopia

    Institute of Scientific and Technical Information of China (English)

    Leopoldo; Spadea; Francesca; Verboschi; Vittoria; De; Rosa; Mariella; Salomone; Enzo; Maria; Vingolo

    2015-01-01

    AIM: To evaluate the long term clinical results of mechanical no-alcohol-assisted laser epithelial keratomileusis(LASEK) versus standard photorefractive keratectomy(PRK) for low-moderate myopia.METHODS: Twenty-five eyes treated with LASEK and twenty-five eyes treated with PRK were evaluated with a mean follow-up duration of 60 mo. Mechanical separation of the epithelium was performed with blunt spatula and without application of alcohol. Laser ablation was performed with the MEL-70 excimer laser. All patients were examined daily until epithelial closure; at 1, 3, 6,and 12 mo, and every year subsequently. Main outcome measures were uncorrected distance visual acuity(UDVA), corrected distance visual acuity(CDVA),manifest refraction, haze, efficacy and safety indexes.RESULTS: Twenty-one eyes and 22 eyes completed follow-up of 60 mo in LASEK and PRK group respectively. Manifest refraction at 60 mo follow-up was-0.01 and 0.26 in LASEK and PRK group respectively. In the LASEK group mean UDVA and mean CDVA after60 mo were 20/22 and 20/20 respectively(P >0.01). In the PRK group mean UDVA and mean CDVA at 60 mo follow-up were 20/20 and 20/20 after 60mo(P >0.01). The efficacy indexes were 0.87 and 0.95, and the safety indexes were1.25 and 1.4 respectively for LASEK group and PRK group.CONCLUSION: Both standard PRK and no-alcohol LASEK offer safe and effective correction of low-moderate myopia in the long term without any statistically significant difference between the two groups.

  5. In Situ Cardiovascular Tissue Engineering

    NARCIS (Netherlands)

    Talacua, H

    2016-01-01

    In this thesis, the feasibility of in situ TE for vascular and valvular purposes were tested with the use of different materials, and animal models. First, the feasibility of a decellularized biological scaffold (pSIS-ECM) as pulmonary heart valve prosthesis is examined in sheep (Chapter 2). Next,

  6. In situ bypass og diabetes

    DEFF Research Database (Denmark)

    Jensen, Leif Panduro; Schroeder, T V; Lorentzen, J E

    1993-01-01

    From 1986 through to 1990 a total of 483 in situ bypass procedures were performed in 444 patients. Preoperative risk-factors were equally distributed among diabetic (DM) and non-diabetic (NDM) patients, except for smoking habits (DM:48%, NDM:64%, p = 0.002) and cardiac disease (DM:45%, NDM:29%, p...

  7. In situ dehydration of yugawaralite

    DEFF Research Database (Denmark)

    Artioli, G.; Ståhl, Kenny; Cruciani, G.;

    2001-01-01

    The structural response of the natural zeolite yugawaralite (CaAl2Si6O16. 4H(2)O) upon thermally induced dehydration has been studied by Rietveld analysis of temperature-resolved powder diffraction data collected in situ in the temperature range 315-791 K using synchrotron radiation. The room-tem...

  8. Femtosecond (FS) laser vision correction procedure for moderate to high myopia

    DEFF Research Database (Denmark)

    Vestergaard, Anders Højslet; Ivarsen, Anders; Asp, Sven;

    2013-01-01

    with a retrospective study of FS-LASIK. ReLEx is a new keratorefractive procedure, where a stromal lenticule is cut by a femtosecond laser and manually extracted. Forty patients were treated with ReLEx on both eyes. A comparable group of 41 FS-LASIK patients were retrospectively identified. Visual acuity, spherical......Purpose:  To present our initial clinical experience with ReLEx(®) flex (ReLEx) for moderate to high myopia. We compare efficacy, safety and corneal higher-order aberrations after ReLEx with femtosecond laser in situ keratomileusis (FS-LASIK). Methods:  Prospective study of ReLEx compared...... 3 months was 100% (ReLEx) and 85% (FS-LASIK). For a 6.0-mm pupil, corneal spherical aberrations increased significantly less in ReLEx than FS-LASIK eyes. Conclusions:  ReLEx is an all-in-one femtosecond laser refractive procedure, and in this study, results were comparable to FS-LASIK. Refractive...

  9. Femtosecond (FS) laser vision correction procedure for moderate to high myopia

    DEFF Research Database (Denmark)

    Vestergaard, Anders Højslet; Ivarsen, Anders; Asp, Sven

    2013-01-01

    with a retrospective study of FS-LASIK. ReLEx is a new keratorefractive procedure, where a stromal lenticule is cut by a femtosecond laser and manually extracted. Forty patients were treated with ReLEx on both eyes. A comparable group of 41 FS-LASIK patients were retrospectively identified. Visual acuity, spherical......Purpose:  To present our initial clinical experience with ReLEx(®) flex (ReLEx) for moderate to high myopia. We compare efficacy, safety and corneal higher-order aberrations after ReLEx with femtosecond laser in situ keratomileusis (FS-LASIK). Methods:  Prospective study of ReLEx compared...... 3 months was 100% (ReLEx) and 85% (FS-LASIK). For a 6.0-mm pupil, corneal spherical aberrations increased significantly less in ReLEx than FS-LASIK eyes. Conclusions:  ReLEx is an all-in-one femtosecond laser refractive procedure, and in this study, results were comparable to FS-LASIK. Refractive...

  10. In situ vadose zone bioremediation.

    Science.gov (United States)

    Höhener, Patrick; Ponsin, Violaine

    2014-06-01

    Contamination of the vadose zone with various pollutants is a world-wide problem, and often technical or economic constraints impose remediation without excavation. In situ bioremediation in the vadose zone by bioventing has become a standard remediation technology for light spilled petroleum products. In this review, focus is given on new in situ bioremediation strategies in the vadose zone targeting a variety of other pollutants such as perchlorate, nitrate, uranium, chromium, halogenated solvents, explosives and pesticides. The techniques for biostimulation of either oxidative or reductive degradation pathways are presented, and biotransformations to immobile pollutants are discussed in cases of non-degradable pollutants. Furthermore, research on natural attenuation in the vadose zone is presented.

  11. In Situ TEM Electrical Measurements

    DEFF Research Database (Denmark)

    Canepa, Silvia; Alam, Sardar Bilal; Ngo, Duc-The

    2016-01-01

    Transmission electron microscopy (TEM) offers high spatial and temporal resolution that provides unique information for understanding the function and properties of nanostructures on their characteristic length scales. Under controlled environmental conditions and with the ability to dynamically...... influence the sample by external stimuli, e.g. through electrical connections, the TEM becomes a powerful laboratory for performing quantitative real time in situ experiments. Such TEM setups enable the characterization of nanostructures and nanodevices under working conditions, thereby providing a deeper...... materials and devices with the specimen being contacted by electrical, mechanical or other means, with emphasis on in situ electrical measurements performed in a gaseous or liquid environment. We will describe the challenges and prospects of electrical characterization of devices and processes induced...

  12. Oldest biliary endoprosthesis in situ

    Science.gov (United States)

    Consolo, Pierluigi; Scalisi, Giuseppe; Crinò, Stefano F; Tortora, Andrea; Giacobbe, Giuseppa; Cintolo, Marcello; Familiari, Luigi; Pallio, Socrate

    2013-01-01

    The advantages of endoscopic retrograde cholangiopancreatography over open surgery have made it the predominant method of treating patients with choledocholithiasis. After sphincterotomy, however, 10%-15% of common bile duct stones cannot be removed with a basket or balloon. The methods for managing “irretrievable stones” include surgery, mechanical lithotripsy, intraductal or extracorporeal shock wave lithotripsy and biliary stenting. The case presented was a referred 82-year-old Caucasian woman with a 7-year-old plastic biliary endoprosthesis in situ. To the best of our knowledge the examined endoprosthesis is the oldest endoprosthesis in situ reported in the literature. Endoscopic biliary endoprosthesis placement remains a simple and safe procedure for patients with stones that are difficult to manage by conventional endoscopic methods and for patients who are unfit for surgery or who are high surgical risks. To date no consensus has been reached regarding how long a biliary prosthesis should remain in situ. Long-term biliary stenting may have a role in selected elderly patients if stones extraction has failed because the procedure may prevent stones impaction and cholangitis. PMID:23858381

  13. Noise canceling in-situ detection

    Science.gov (United States)

    Walsh, David O.

    2014-08-26

    Technologies applicable to noise canceling in-situ NMR detection and imaging are disclosed. An example noise canceling in-situ NMR detection apparatus may comprise one or more of a static magnetic field generator, an alternating magnetic field generator, an in-situ NMR detection device, an auxiliary noise detection device, and a computer.

  14. Long-term bladeless LASIK outcomes with the FS200 Femtosecond and EX500 Excimer Laser workstation: the Refractive Suite

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ

    2013-02-01

    Full Text Available A John Kanellopoulos,1,2 George Asimellis11Laservision.gr Institute, Athens, Greece; 2NYU Medical School, NY, USAPurpose: The evaluation of the safety, efficacy, and long-term stability of LASIK procedures utilizing novel platform comprising a femtosecond and excimer laser and multiple networked diagnostics.Setting: Private clinical ophthalmology practice.Patients and methods: In consecutive cases of myopic LASIK procedure with a novel refractive platform (FS200 Femtosecond and EX500 Excimer Laser, 190 eyes (from 109 different patients were evaluated pre- and postoperatively for the following parameters: refractive error, best corrected distance visual acuity, uncorrected distance visual acuity, topography (Placido-disc based and tomography (Scheimpflug-image based, wavefront analysis, pupillometry, and contrast sensitivity. Follow-up visits were conducted for at least 12-months.Results: The change from pre- to postoperative mean refractive error was from −5.29 ± 2.39 diopters (D (range −8.0 to −0.50 D to −0.27 ± 0.09 D at the 3 month visit, −0.27 ± 0.10 D at the 6 month visit, and −0.39 ± 0.08 D at the 1-year visit. The change from pre- to postoperative refractive astigmatism was −1.07 ± 0.91 D (range −4.25 to 0 D to −0.14 ± 0.04 D at 3 months, −0.15 ± 0.04 at 6 months, and −0.16 ± 0.04 at the one-year visit. The proportion of the eyes with postoperative astigmatism within 0.5 D ranged between 95.6% and 99%. The proportion of eyes achieving uncorrected distance visual acuity of 1.0 (decimal was 93.0%.Conclusion: The myopic LASIK clinical results with the FS200 Femtosecond Laser and EX500 Excimer Laser showed outstanding efficacy, great safety, and long-term stability.Keywords: bladeless LASIK flap, femtosecond laser, myopic correction, long-term stability, regression, astigmatism correction, post-LASIK refraction

  15. Corneal biomechanical properties after femtosecond laser assisted LASIK with the corneal visualization Scheimpflug technology and ocular response analyzer

    Directory of Open Access Journals (Sweden)

    Jing Li

    2017-02-01

    Full Text Available AIM: To investigate the changes of corneal biomechanical properties before and after femtosecond laser assisted LASIK(FS-LASIKusing Corneal Visualisation Scheimpflug Technology(Corvis STand Ocular Response Analyzer(ORA, and the correlation with other myopic parameters. METHODS:Sixty three patients(63 eyeswho had myopic femtosecond laser assisted LASIK(FS-LASIKwere enrolled in the study. The right eye of each patient was analyzed in this study. The corneal biomechanical parameters pre-operative and 1mo post-operative was measured with the Corvis ST(Oculus, Wetzlar, Germanyand ORA(Reichert, Buffalo, New York, USA. Comparison of the biomechanical property values before and after surgery was peformed using Paired t-test or Mann-Whitney U. Pearson or Spearman correlations were used to evaluate the relationship between parameters.RESULTS: The postoperative 1st A-time, Vin, 2nd A length, Vout, HC time and Radius demonstrate significant decreases comparing with preoperative values(P=0.00, P=0.00, P=0.00, P=0.00, P=0.00, P=0.00 respectively. The postoperative 2nd A-time, DA and PD significantly increases(P=0.00, P=0.00, P=0.00, however, the 1st A length had no significant difference after surgery. The CH and CRF were significantly lower after FS-LASIK(P=0.00, P=0.00. A statistically significant correlation coefficient was found between preoperative central corneal thickness(CCTwith postoperative-preoperative changes of 1st A-time, 2nd A-time, DA and Radius respectively(P=0.01, P=0.04, P=0.03, P=0.01. CONCLUSION:There were significantly changes of corneal biomechanical properties after FS-LASIK surgery. The changes of corneal biomechanical properties after FS-LASIK can be reflected by some parameters of Corvis ST and ORA. The mainly influence of corneal biomechanical alteration was possibly correlation with corneal thickness.

  16. Corneal Backscatter Analysis by In Vivo Confocal Microscopy: Fellow Eye Comparison of Small Incision Lenticule Extraction and Femtosecond Laser-Assisted LASIK

    Directory of Open Access Journals (Sweden)

    Alper Agca

    2014-01-01

    Full Text Available Purpose. To evaluate and compare corneal backscatter from anterior stroma between small incision lenticule extraction (SMILE and femtosecond laser-assisted LASIK (femto-LASIK. Methods. A cohort of 60 eyes of 30 patients was randomized to receive SMILE in one eye and femto-LASIK in the fellow eye. In vivo confocal microscopy was performed at 1 week and 1, 3, and 6 months after surgery. The main outcome measurements were maximum backscattered intensity and the depth from which it was measured, the backscattered light intensity 30 μm below Bowman’s membrane at the flap interface and 150 μm below the superficial epithelium, and the number of refractive particles at the flap interface. Results. The mean backscattered light intensity (LI at all measured depths and the maximum backscattered LI were higher in the SMILE group than the femto-LASIK group at all postoperative visits. LI differences at 1 week and 1- and 3-month visits were statistically significant (P<0,05. LI differences at 6 months were not statistically significant. There was no difference in the number of refractive particles at the flap interface between the groups at any visit. Conclusions. SMILE results in increased backscattered LI in the anterior stroma when compared with femto-LASIK were evaluated.

  17. Q值引导与标准LASIK治疗近视临床疗效的Meta分析%Comparison of Q-value guide LASIK and standardized LASIK for the treatment of myopia:a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    施节亮; 冯一帆; 陈世豪; 王勤美

    2011-01-01

    Background Nowadays,customized ablation is widely used in the excimer laser corneal refractive Burgery.And the Q-value guide LASIK is one of the research hotspots. Objective Present study was to evaluate and compare the effectiveness of Q-value guide LASIK and standardized LASIK for myopia.Methods A systematic literature retrieval from 2003 through 2010 was conducted in the MEDLINE,CNKI,Cochrane Library,EMBASE.The literature examine possible difierences in uncorrected visual acuity(UCVA),Q-value,higher order aberrations(HOAs),and spherical equivalent(SE) between Q-value guide LASIK and standardized LASIK for correcting myopia.Statistical analysis was performed using a Review Manager 5.0 software.The data was extracted,and the methodological quality was evaluated by two reviewers independently.The quality of included literature was scored according to the Jadad Scale. Results A total of 14 studies involving 1617 patients(2956 eyes)was included in the meta-analysis.Of these fourteen studies,six studies were randomized trials and the other eight studies were retrospective cohort studies.According to the Jadad Scale,2 studies scored 3 points,and the other 12 studies scored 1~2 points.The results showed that the Q-value guide LASIK group had a better postoperative effectiveness in uncorrective visual acuity(UCVA)(WMD=0.04.95% CI 0.00 to 0.08,P<0.05).Q-value(SMD=-1.52,95% CI -2.23 to-0.81,P=0.00),total HOAs (SMD=-1.63,95% CI-2.57 to-0.69,P<0.05) and spherical-like aberrations ( SMD =-1.49,95% CI-2.22 to-0. 76,P<0. 00) after surgery. However, the number of eyes achieved UCVA≥20/20 ( OR= 1.16,95% CI 0. 61 to 2. 19,P=0. 65) ,coma-like aberrations (SMD=-1. 02,95% CI-0. 36to 0.11,P=0.29) and SE (WMD=0.10,95% CI-0.11 to 0.31,P=0.34) after surgery were comparable.Conclusion The effectiveness of Q-value guide LASIK is superior to standardized LASIK for treatment of myopia.High-quality clinical randomized-controlled study should be performed to further evaluate the comparable

  18. Resultados del LASIK miópico en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer" Results of myopic LASIK obtained at “Ramón Pando Ferrer” Cuban Institute of Ophthalmology

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Lantigua Maldonado

    2012-06-01

    Full Text Available Objetivos: Evaluar los resultados y la estabilidad del LASIK miópico realizado en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer". Métodos: Se realizó un estudio descriptivo, prospectivo y comparativo. El universo estuvo compuesto por los pacientes operados mediante LASIK (4 011 ojos desde el inicio en nuestro centro (2005 de la cirugía refractiva corneal con láser de excímeros. Se seleccionaron los pacientes con estudios realizados un año después de la cirugía. Las variables estudiadas fueron queratometría, mejor agudeza visual sin corrección, mejor agudeza visual con corrección, equivalente esférico, paquimetría y topografía. Se compararon las variables antes de la cirugía y al año de esta. Los resultados se analizaron mediante la prueba t de Student para datos pareados con significación estadística cuando pObjective: To evaluate the results and the stability of the myopic Lasik carried out in “Ramón Pando Ferrer” Cuban Institute of Ophthalmology. Methods: A prospective, descriptive and comparative study was conducted. The universe of study was made up of the patients operated on by LASIK (4011 eyes from the beginning of the corneal refractive surgery with excimer laser in our center in 2005. The patients were selected from those that had been studied for ametropy correction one year after the surgery. The studied variables were keratometry, better visual acuity without correction, better visual acuity with correction, spherical equivalent, pachymetry and topography, and the obtained results were compared before and at one year of the surgery. The paired T test served to analyze the results with statistical significance of p < 0.05. Results: Significant changes took place in keratometry and spherical equivalent that brought about improved visual acuity without correction for distance vision. The best visual acuity with correction remained the same before and after the surgery. Pachymetry remained within safe

  19. Training for teamwork through in situ simulations

    Science.gov (United States)

    Sorensen, Asta; Poehlman, Jon; Bollenbacher, John; Riggan, Scott; Davis, Stan; Miller, Kristi; Ivester, Thomas; Kahwati, Leila

    2015-01-01

    In situ simulations allow healthcare teams to practice teamwork and communication as well as clinical management skills in a team's usual work setting with typically available resources and equipment. The purpose of this video is to demonstrate how to plan and conduct in situ simulation training sessions, with particular emphasis on how such training can be used to improve communication and teamwork. The video features an in situ simulation conducted at a labour and delivery unit in response to postpartum hemorrhage. PMID:26294962

  20. The Tensions of In Situ Visualization.

    Science.gov (United States)

    Moreland, Kenneth

    2016-01-01

    In situ visualization is the coupling of visualization software with a simulation or other data producer to process the data "in memory" before the data are offloaded to a storage system. Although in situ visualization provides superior analysis, it has implementation tradeoffs resulting from conflicts with some traditional expected requirements. Numerous conflicting requirements create tensions that lead to difficult implementation tradeoffs. This article takes a look at the most prevailing tensions of in situ visualization.

  1. The SENSEI Generic In Situ Interface

    Energy Technology Data Exchange (ETDEWEB)

    Ayachit, Utkarsh [Kitware, Inc., Clifton Park, NY (United States); Whitlock, Brad [Intelligent Light, Rutherford, NJ (United States); Wolf, Matthew [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Loring, Burlen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Geveci, Berk [Kitware, Inc., Clifton Park, NY (United States); Lonie, David [Kitware, Inc., Clifton Park, NY (United States); Bethel, E. Wes [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-04-11

    The SENSEI generic in situ interface is an API that promotes code portability and reusability. From the simulation view, a developer can instrument their code with the SENSEI API and then make make use of any number of in situ infrastructures. From the method view, a developer can write an in situ method using the SENSEI API, then expect it to run in any number of in situ infrastructures, or be invoked directly from a simulation code, with little or no modification. This paper presents the design principles underlying the SENSEI generic interface, along with some simplified coding examples.

  2. Visco chop-a new technique for nucleus separation for soft cataracts in femtolaser assisted cataract surgery

    Institute of Scientific and Technical Information of China (English)

    Sri; Ganesh; Sheetal; Brar

    2015-01-01

    <正>INTRODUCTION Femtosecond laser technology,introduced clinically for ophthalmic surgery as a technique for creating lamellar flaps in laser in situ keratomileusis(LASIK),has recently been developed into a tool for cataract surgery.Preliminary experience for femtosecond laser-assisted cataract surgery show appropriate safety and efficacy,and possible advantage over conventional cataract surgery[1-4].The ability of the femtosecond laser to fragment the lens results in the need for less ultrasound energy to be expended inside the eye.Several studies indicate that less effective phacoemulsification time is needed to emulsify the lens

  3. Current status of accelerated corneal cross-linking

    Directory of Open Access Journals (Sweden)

    Michael Mrochen

    2013-01-01

    Full Text Available Corneal cross-linking with riboflavin is a technique to stabilize or reduce corneal ectasia, in diseases such as keratoconus and post-laser-assisted in situ keratomileusis (LASIK ectasia. There is an interest by patient as well as clinicians to reduce the overall treatment time. Especially, the introduction of corneal cross-linking in combination with corneal laser surgery demands a shorter treatment time to assure a sufficient patient flow. The principles and techniques of accelerated corneal cross-linking is discussed.

  4. FS200 femtosecond laser LASIK flap digital analysis parameter evaluation: comparing two different types of patient interface applanation cones

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ

    2013-06-01

    Full Text Available A John Kanellopoulos,1,2 George Asimellis1 1LaserVision.gr Eye Institute, Athens, Greece; 2New York University School of Medicine, NY, USA Purpose: To evaluate the safety and efficacy of a novel LASIK flap patient interface (PI cone with our reported digital analysis and compare for potential differences with the standard metal and glass PI in flap parameters when used with the Alcon/WaveLight FS200 femtosecond laser. Patients and methods: Thirty-six consecutive LASIK patients (72 eyes subjected to a bilateral femtosecond assisted LASIK procedure with the novel clear cone PI FS200 1505 were examined for flap diameter and flap thickness over the entire flap area via digital analysis performed on intraoperation image (flap diameter and anterior-segment optical coherence tomography image (flap thickness. This group was compared with an age- and procedure-matched group B from our practice, in which the standard metal and glass PI was employed. Results: Horizontal flap diameter for group A (clear cone was 7.87 mm ± 0.02 mm (range 7.89–7.84 mm for 8.00 mm programmed, whereas for group B (metal and glass cone was 7.85 mm ± 0.04 mm (range 7.93–7.80 mm. Likewise, along the vertical line, flap diameter for group A was 7.84 mm ± 0.02 mm (range 7.85–7.80 mm and for group B was 7.83 mm ± 0.03 mm (range 7.87–7.80 mm. Central flap thickness for group A was 113.29 µm (±1.19 µm for 110 µm planned, 122.1 µm (±2.10 µm for 120 µm planned, and 133.50 µm (±0.71 µm for 130 µm planned. Group B central flap thickness was, accordingly, 112.8 µm (±1.25 µm, 122.4 µm (±2.15 µm, and 132.50 µm (±0.90 µm. The data evaluated (paired group comparisons between group A and group B did not show statistically significant differences. Conclusion: This study indicates that two PIs in use with the FS200 femtosecond laser are safe and have highly reproducible and accurate flap parameter results, such as achieved diameter and flap thickness. The paired

  5. In situ vitrification: A review

    Energy Technology Data Exchange (ETDEWEB)

    Cole, L.L.; Fields, D.E.

    1989-11-01

    The in situ vitrification process (ISV) converts contaminated soils and sludges to a glass and crystalline product. The process appears to be ideally suited for on site treatment of both wet and dry wastes. Basically, the system requires four molybdenum electrodes, an electrical power system for vitrifying the soil, a hood to trap gaseous effluents, an off-gas treatment system, an off-gas cooling system, and a process control station. Mounted in three transportable trailers, the ISV process can be moved from site to site. The process has the potential for treating contaminated soils at most 13 m deep. The ISV project has won a number of outstanding achievement awards. The process has also been patented with exclusive worldwide rights being granted to Battelle Memorial Institute for nonradioactive applications. While federal applications still belong to the Department of Energy, Battelle transferred the rights of ISV for non-federal government, chemical hazardous wastes to a separate corporation in 1989 called Geosafe. This report gives a review of the process including current operational behavior and applications.

  6. Chemically enhanced in situ recovery

    Energy Technology Data Exchange (ETDEWEB)

    Sale, T. [CH2M Hill, Denver, CO (United States); Pitts, M.; Wyatt, K. [Surtek, Inc., Golden, CO (United States)] [and others

    1996-08-01

    Chemically enhanced recovery is a promising alternative to current technologies for management of subsurface releases of organic liquids. Through the inclusion of surfactants, solvents, polymers, and/or alkaline agents to a waterflood, the transport of targeted organic compounds can be increased and rates of recovery enhanced. By far, the vast majority of work done in the field of chemically enhanced recovery has been at a laboratory scale. The following text focuses on chemically enhanced recovery from a field application perspective with emphasis given to chlorinated solvents in a low permeability setting. While chlorinated solvents are emphasized, issues discussed are also relevant to organic liquids less dense than water such as petroleum products. Topics reviewed include: (1) Description of technology; (2) General technology considerations; (3) Low permeability media considerations; (4) Cost and reliability considerations; (5) Commercial availability; and (6) Case histories. Through this paper an appreciation is developed of both the potential and limitations of chemically enhanced recovery. Excluded from the scope of this paper is the in situ destruction of organic compounds through processes such as chemical or biological oxidation, chemically enhanced recovery of inorganic compounds, and ex situ soil treatment processes. 11 refs., 2 figs., 1 tab.

  7. Clinical Validation of Adjusted Corneal Power in Patients with Previous Myopic Lasik Surgery

    Directory of Open Access Journals (Sweden)

    Vicente J. Camps

    2015-01-01

    Full Text Available Purpose. To validate clinically a new method for estimating the corneal power (Pc using a variable keratometric index (nkadj in eyes with previous laser refractive surgery. Setting. University of Alicante and Medimar International Hospital (Oftalmar, Alicante, (Spain. Design. Retrospective case series. Methods. This retrospective study comprised 62 eyes of 62 patients that had undergone myopic LASIK surgery. An algorithm for the calculation of nkadj was used for the estimation of the adjusted keratometric corneal power (Pkadj. This value was compared with the classical keratometric corneal power (Pk, the True Net Power (TNP, and the Gaussian corneal power (PcGauss. Likewise, Pkadj was compared with other previously described methods. Results. Differences between PcGauss and Pc values obtained with all methods evaluated were statistically significant (p<0.01. Differences between Pkadj and PcGauss were in the limit of clinical significance (p<0.01, loA [−0.33,0.60] D. Differences between Pkadj and TNP were not statistically and clinically significant (p=0.319, loA [−0.50,0.44] D. Differences between Pkadj and previously described methods were statistically significant (p<0.01, except with PcHaigisL (p=0.09, loA [−0.37,0.29] D. Conclusion. The use of the adjusted keratometric index (nkadj is a valid method to estimate the central corneal power in corneas with previous myopic laser refractive surgery, providing results comparable to PcHaigisL.

  8. Four Models of In Situ Simulation

    DEFF Research Database (Denmark)

    Musaeus, Peter; Krogh, Kristian; Paltved, Charlotte

    2014-01-01

    that there are four fruitful approaches to in situ simulation: (1) In situ simulation informed by reported critical incidents and adverse events from emergency departments (ED) in which team training is about to be conducted to write scenarios. (2) In situ simulation through ethnographic studies at the ED. (3) Using...... prewritten scenarios from the simulation lab and transferring them to in situ simulation. (4) Action research – insider or participant action research to obtain in-depth understanding of team processes to guide scenario design. We evaluate the approach relying on Marks’ et al. taxonomy that posits...... the following processes: Transition processes, Action processes and Interpersonal processes. Design and purpose This abstract suggests four approaches to in situ simulation. A pilot study will evaluate the different approaches in two emergency departments in the Central Region of Denmark. Methods The typology...

  9. Chronic Electromagnetic Exposure at Occupational Safety Level Does Not Affect the Metabolic Profile nor Cornea Healing after LASIK Surgery

    Directory of Open Access Journals (Sweden)

    David Crouzier

    2014-01-01

    Full Text Available LASIK eye surgery has become a very common practice for myopic people, especially those in the military. Sometimes undertaken by people who need to keep a specific medical aptitude, this surgery could be performed in secret from the hierarchy and from the institute medical staff. However, even though the eyes have been previously described as one of the most sensitive organs to electromagnetic fields in the human body, no data exist on the potential deleterious effects of electromagnetic fields on the healing eye. The consequences of chronic long-lasting radar exposures at power density, in accordance with the occupational safety standards (9.71 GHz, 50 W/m2, were investigated on cornea healing. The metabolic and clinical statuses after experimental LASIK keratotomy were assessed on the different eye segments in a New Zealand rabbit model. The analysis methods were performed after 5 months of exposure (1 hour/day, 3 times/week. Neither clinical or histological examinations, nor experimental data, such as light scattering, 1H-NMR HRMAS metabolomics, 13C-NMR spectra of lipidic extracts, and antioxidant status, evidenced significant modifications. It was concluded that withdrawing the medical aptitude of people working in electromagnetic field environments (i.e., radar operators in the navy after eye surgery was not justified.

  10. Chronic Electromagnetic Exposure at Occupational Safety Level Does Not Affect the Metabolic Profile nor Cornea Healing after LASIK Surgery.

    Science.gov (United States)

    Crouzier, David; Dabouis, Vincent; Gentilhomme, Edgar; Vignal, Rodolphe; Bourbon, Fréderic; Fauvelle, Florence; Debouzy, Jean-Claude

    2014-01-01

    LASIK eye surgery has become a very common practice for myopic people, especially those in the military. Sometimes undertaken by people who need to keep a specific medical aptitude, this surgery could be performed in secret from the hierarchy and from the institute medical staff. However, even though the eyes have been previously described as one of the most sensitive organs to electromagnetic fields in the human body, no data exist on the potential deleterious effects of electromagnetic fields on the healing eye. The consequences of chronic long-lasting radar exposures at power density, in accordance with the occupational safety standards (9.71 GHz, 50 W/m(2)), were investigated on cornea healing. The metabolic and clinical statuses after experimental LASIK keratotomy were assessed on the different eye segments in a New Zealand rabbit model. The analysis methods were performed after 5 months of exposure (1 hour/day, 3 times/week). Neither clinical or histological examinations, nor experimental data, such as light scattering, (1)H-NMR HRMAS metabolomics, (13)C-NMR spectra of lipidic extracts, and antioxidant status, evidenced significant modifications. It was concluded that withdrawing the medical aptitude of people working in electromagnetic field environments (i.e., radar operators in the navy) after eye surgery was not justified.

  11. Comprehensive Evaluation of Anterior Corneal Change in Asphericity Calculated by the Tangential Radius of Curvature after LASIK

    Science.gov (United States)

    Ying, Jinglu; Cai, Jianqiu; Zhu, Leru

    2017-01-01

    To evaluate the change in the anterior corneal asphericity (ΔQ) comprehensively calculated using the tangential radius (rt) after LASIK. Forty-two right eyes were evaluated using the Orbscan II corneal topographer. The pre- and postoperative Q-values of the flat principal semimeridians calculated by the sagittal radius were compared to those by the tangential radius. The Q-value of each semimeridian in the horizontal region was calculated by rt. Fourier fitting was used to model the 360-semimeridional variation of Q-values and to fit the Q-values in the vertical region before and after surgery. There were significant differences in Q-values between the two methods before (P < 0.001) and after surgery (P = 0.003). A significant increase in postoperative Q-value was detected compared to preoperative Q-value (P < 0.001) calculated by rt. The 360-semimeridional variation of the Q-values was well fitted with a third- and fourth-degree Fourier function before and after surgery. The ΔQ-value distribution presented double valley variation, with the amount of ΔQ being lowest in the near-vertical regions and highest in the near-horizontal regions. Calculating the Q-value with rt combined with Fourier fitting, we evaluated 360 ΔQ-values' variation of semimeridians of the entire anterior corneal surface and then displayed true and complete anterior corneal shape after LASIK.

  12. Assessing ectasia susceptibility prior to LASIK: the role of age and residual stromal bed (RSB in conjunction to Belin-Ambrósio deviation index (BAD-D

    Directory of Open Access Journals (Sweden)

    Renato Ambrósio Jr

    2014-04-01

    Full Text Available Purpose: To compare the ability to detect preoperative ectasia risk among LASIK candidates using classic ERSS (Ectasia Risk Score System and Pentacam Belin-Ambrósio deviation index (BAD-D, and to test the benefit of a combined approach including BAD-D and clinical data. Methods: A retrospective nonrandomized study involved preoperative LASIK data from 23 post-LASIK ectasia cases and 266 stable-LASIK (follow up > 12 months. Preoperative clinical and Pentacam (Oculus; Wetzlar, Germany data were obtained from all cases. Mann-Whitney's test was performed to assess differences between groups. Stepwise logistic regression was used for combining parameters.The areas under the Receiver Operating Characteristic (ROC curves (AUC were calculated for all parameters and combinations, with pairwise comparisons of AUC (DeLong's method. Results: Statistically significant differences were found for age, residual stromal bed (RSB, central corneal thickness and BAD-D (p0.05. ERSS was 3 or more on 12/23 eyes from the ectasia group (sensitivity = 52.17% and 48/266 eyes from the stable LASIK group (18% false positive. BAD-D had AUC of 0.931 (95% CI: 0.895 to 0.957, with cut-off of 1.29 (sensitivity = 87%; specificity = 92.1%. Formula combining BAD-D, age and RSB provided 100% sensitivity and 94% specificity, with better AUC (0.989; 95% CI: 0.969 to 0.998 than all individual parameters (p>0.001. Conclusion: BAD-D is more accurate than ERSS. Combining clinical data and BAD-D improved ectasia susceptibility screening. Further validation is necessary. Novel combined functions using other topometric and tomographic parameters should be tested to further enhance accuracy.

  13. [Comparison of the efficiency and safety of the two methods, LASIK and ICL in mild and high hyperopia correction--part two].

    Science.gov (United States)

    Horácková, M; Vlková, E; Loukotová, V; Hlinomazová, Z

    2007-05-01

    The problems of mild and high hyperopia surgical correction are complicated and an individual approach is needed. The aim of the study was to evaluate long-term efficiency and safety of two types of refractive procedures in mild and high hyperopia correction: LASIK and ICL (phakic intraocular posterior chamber contact lens) implantation. The authors evaluated a group of 37 eyes of 20 patients; the average age was 36.3 years +/- 11.8 (SD) and the follow-up period was 28.1 months +/- 10.2 (SD) after LASIK procedure, and a group of 21 eyes of 13 patients; the average age was 28.6 years +/- 6.1 (SD) and the follow-up period 30.4 months +/- 20.9 (SD) after the ICL implantation. They compared occurrence of preoperative, intraoperative and postoperative complications in both methods. They specified the efficiency and safety of the procedure by means of so called efficiency and safety index. With a questionnaire they evaluated the patient's subjective satisfaction with the refractive procedure. In the group of hyperopic LASIK, they proved statistically significant appearance of the refractive error regression, number of performed re-operations, appearance of the peroperative decentration of the photoablation zone and induced astigmatism (p ICL group, the repeated preoperative sessions for Nd-YAG laser iridotomies were necessary. Postoperatively, the appearance of keratitis striata, syndrome of the late pigment dispersion, and glare were statistically significant (p ICL implantation method comparing to LASIK during the whole follow up period (p ICL implantation. Comparing the intraocular procedure (ICL) to the laser method (LASIK), in mild and high hyperopia correction, the higher efficiency and safety was achieved by ICL implantation.

  14. In Situ TEM Creation of Nanowire Devices

    DEFF Research Database (Denmark)

    Alam, Sardar Bilal

    Integration of silicon nanowires (SiNWs) as active components in devices requires that desired mechanical, thermal and electrical interfaces can be established between the nanoscale geometry of the SiNW and the microscale architecture of the device. In situ transmission electron microscopy (TEM...... of SiNW were also investigated in situ. SiNWs were grown on silicon microcantilever heaters using the VLS mechanism. When grown across a gap between adjacent cantilevers, contact was formed when the SiNW impinged on the sidewall of an adjacent cantilever. Using in situ TEM, SiNW contact formation...

  15. Scientific rationale of Saturn's in situ exploration

    CERN Document Server

    Mousis, O; Lebreton, J -P; Wurz, P; Cavalié, T; Coustenis, A; Courtin, R; Gautier, D; Helled, R; Irwin, P G J; Morse, A D; Nettelmann, N; Marty, B; Rousselot, P; Venot, O; Atkinson, D H; Waite, J H; Reh, K R; Simon-Miller, A; Atreya, S; André, N; Blanc, M; Daglis, I A; Fischer, G; Geppert, W D; Guillot, T; Hedman, M M; Hueso, R; Lellouch, E; Lunine, J I; Murray, C D; O'Donoghue, J; Rengel, M; Sanchez-Lavega, A; Schmider, F -X; Spiga, A; Spilker, T; Petit, J -M; Tiscareno, M S; Ali-Dib, M; Altwegg, K; Bouquet, A; Briois, C; Fouchet, T; Guerlet, S; Kostiuk, T; Lebleu, D; Moreno, R; Orton, G S; Poncy, J

    2014-01-01

    Remote sensing observations meet some limitations when used to study the bulk atmospheric composition of the giant planets of our solar system. A remarkable example of the superiority of in situ probe measurements is illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases abundances and the precise measurement of the helium mixing ratio have only been made available through in situ measurements by the Galileo probe. This paper describes the main scientific goals to be addressed by the future in situ exploration of Saturn placing the Galileo probe exploration of Jupiter in a broader context and before the future probe exploration of the more remote ice giants. In situ exploration of Saturn's atmosphere addresses two broad themes that are discussed throughout this paper: first, the formation history of our solar system and second, the processes at play in planetary atmospheres. In this context, we detail the reasons why measurements of Saturn's bulk element...

  16. Observatory Magnetometer In-Situ Calibration

    Directory of Open Access Journals (Sweden)

    A Marusenkov

    2011-07-01

    Full Text Available An experimental validation of the in-situ calibration procedure, which allows estimating parameters of observatory magnetometers (scale factors, sensor misalignment without its operation interruption, is presented. In order to control the validity of the procedure, the records provided by two magnetometers calibrated independently in a coil system have been processed. The in-situ estimations of the parameters are in very good agreement with the values provided by the coil system calibration.

  17. In-situ characterization of heterogeneous catalysts

    CERN Document Server

    Rodriguez, Jose A; Chupas, Peter J

    2013-01-01

    Helps researchers develop new catalysts for sustainable fuel and chemical production Reviewing the latest developments in the field, this book explores the in-situ characterization of heterogeneous catalysts, enabling readers to take full advantage of the sophisticated techniques used to study heterogeneous catalysts and reaction mechanisms. In using these techniques, readers can learn to improve the selectivity and the performance of catalysts and how to prepare catalysts as efficiently as possible, with minimum waste. In-situ Characterization of Heterogeneous Catalysts feat

  18. In situ microcosms in aquifer bioremediation studies.

    Science.gov (United States)

    Mandelbaum, R T; Shati, M R; Ronen, D

    1997-07-01

    The extent to which aquifer microbiota can be studied under laboratory or simulated conditions is limited by our inability to authentically duplicate natural conditions in the laboratory. Therefore, extrapolation of laboratory results to real aquifer situations is often criticized, unless validation of the data is performed in situ. Reliable data acquisition is critical for the estimation of chemical and biological reaction rates of biodegradation processes in groundwater and as input data for mathematical models. Typically, in situ geobiochemical studies relied on the injection of groundwater spiked with compounds or bacteria of interest into the aquifer, followed by monitoring the changes over time and space. In situ microcosms provide a more confined study site for measurements of microbial reactions, yet closer to natural conditions than laboratory microcosms. Two basic types of in situ aquifer microcosm have been described in recent years, and both originated from in situ instruments initially designed for geochemical measurements. Gillham et al. [Ground Water 28 (1990) 858-862] constructed an instrument that isolates a portion of an aquifer for in situ biochemical rate measurements. More recently Shati et al. [Environ. Sci. Technol. 30 (1996) 2646-2653] modified a multilayer sampler for studying the activity of inoculated bacteria in a contaminated aquifer Keeping in mind recent advances in environmental microbiology methodologies such as immunofluorescence direct counts, oligonucleotide and PCR probes, fatty acid methyl esther analysis for the detection and characterization of bacterial communities, measurement of mRNA and expression of proteins, it is evident that much new information can now be gained from in situ work. Using in situ microcosms to study bioremediation efficiencies, the fate of introduced microorganisms and general geobiochemical aquifer processes can shed more realistic light on the microbial underworld. The aim of this paper is to

  19. 人工晶状体植入治疗白内障后准分子激光上皮下角膜磨镶矫治的安全性%Laser epithelial keratomileusis for the treatment of refractive errors after cataractlens implantation:a stability evaluation

    Institute of Scientific and Technical Information of China (English)

    魏芬; 艾明

    2015-01-01

    BACKGROUND:After cataract extraction and intraocular lens implantation, some patients stil appear to suffer from refractive errors to varying degrees. In this case, excimer laser epithelial keratomileusis or excimer laser in situ keratomileusis can be used for correction of refractive errors. OBJECTIVE:To observe the therapeutic effect of excimer laser epithelial keratomileusis on the treatment of residual refractive errors after cataract extraction and intraocular lens implantation. METHODS:Thirty-eight patients with refractive errors (45 eyes) who had received cataract extraction and intraocular lens implantation were enroled, including 22 males and 16 females. Patient’s age was 24-74 years, and the central corneal thickness ranged 490-590μm. Before laser epithelial keratomileusis, the uncorrected visual acuity and corrected visual acuity were 0.1-0.3 and 0.6-1.0, respectively. The uncorrected visual acuity, best corrected visual acuity, diopter, and intraocular pressure were observed at 12 months after correction. RESULTS AND CONCLUSION:Most of the patients had foreign body sensation, pain and other symptoms of eye irritation at 3-6 postoperative hours, and then presented with eye pain, photophobia, tearing and other symptoms of corneal irritation with 2 days after surgery. The corneal epithelium healed basicaly at 7 days after surgery, and the vision recovered to top after about 20 days. After 12 months, the uncorrected visual acuity was 0.6-1.2,≥ 0.6 in al eyes,≥ 1.0 in 26 eyes (58%) and reached or exceeded the preoperative best corrected visual acuity in 35 eyes (78%). After surgery, the spherical degree was decreased from -2.5 m-1 to 0.5 m-1, and the cylinder degree was reduced from-3.85 m-1 to -0.53 m-1. High intraocular pressure occurred in 12 eyes, and 0.5-level corneal haze formed in 5 eyes. The results demonstrate that the excimer laser epithelial keratomileusis is safe and effective for treatment of refractive errors after cataract extraction

  20. Cicatrización estromal y reinervación corneal por microscopia confocal en LASIK posterior a queratotomía radial de 15 años de evolución Stromal scaring and corneal re-inervation by using confocal microscopy in Lasik after radial postkeratotomy of 15 years of evolution

    National Research Council Canada - National Science Library

    María del Carmen Benítez Merino; Yanet González Sotero; Armando Capote Cabrera; Taimí Cárdenas Díaz; Justo Noriega Martínez

    2012-01-01

    Objetivo: Describir las alteraciones morfológicas de la cicatrización estromal y la reinervación por microscopia confocal en pacientes operados de LASIK posterior a queratotomía radial de 15 años de evolución. Métodos: Se realizó...

  1. Refractive lenticule extraction (ReLEx through a small incision (SMILE for correction of myopia and myopic astigmatism: current perspectives

    Directory of Open Access Journals (Sweden)

    Ağca A

    2016-10-01

    Full Text Available Alper Ağca,1 Ahmet Demirok,2 Yusuf Yıldırım,1 Ali Demircan,1 Dilek Yaşa,1 Ceren Yeşilkaya,1 İrfan Perente,1 Muhittin Taşkapılı1 1Beyoğlu Eye Research and Training Hospital, 2Department of Ophthalmology, Istanbul Medeniyet University, Istanbul, Turkey Abstract: Small-incision lenticule extraction (SMILE is an alternative to laser-assisted in situ keratomileusis (LASIK and photorefractive keratectomy (PRK for the correction of myopia and myopic astigmatism. SMILE can be performed for the treatment of myopia ≤-12 D and astigmatism ≤5 D. The technology is currently only available in the VisuMax femtosecond laser platform. It offers several advantages over LASIK and PRK; however, hyperopia treatment, topography-guided treatment, and cyclotorsion control are not available in the current platform. The working principles, potential advantages, and disadvantages are discussed in this review. Keywords: SMILE, small-incision lenticule extraction, femtosecond laser, laser in situ keratomileusis, corneal biomechanics

  2. Design Games for In-Situ Design

    DEFF Research Database (Denmark)

    Kristiansen, Erik

    2013-01-01

    on a design problem where an in-situ design practice may further the early design process: the case of designing a pervasive game. Pervasive games are computer games, played using the city as a game board and often using mobile phones with GPS. Some contextual design methods exist, but we propose an approach...... that calls for the designer to conceptualise and perform ideas in-situ, that is on the site, where the game is supposed to be played. The problem was to design a creativity method that incorporated in-situ design work and which generated game concepts for pervasive games. The proposed design method, called...... sitestorming, is based on a game using Situationistic individual exploration of the site and different types of game cards, followed by a joint evaluation of the generated ideas. A series of evaluations showed that the designers found the method enjoyable to use, that the method motivated idea generation...

  3. In situ macromolecular crystallography using microbeams.

    Science.gov (United States)

    Axford, Danny; Owen, Robin L; Aishima, Jun; Foadi, James; Morgan, Ann W; Robinson, James I; Nettleship, Joanne E; Owens, Raymond J; Moraes, Isabel; Fry, Elizabeth E; Grimes, Jonathan M; Harlos, Karl; Kotecha, Abhay; Ren, Jingshan; Sutton, Geoff; Walter, Thomas S; Stuart, David I; Evans, Gwyndaf

    2012-05-01

    Despite significant progress in high-throughput methods in macromolecular crystallography, the production of diffraction-quality crystals remains a major bottleneck. By recording diffraction in situ from crystals in their crystallization plates at room temperature, a number of problems associated with crystal handling and cryoprotection can be side-stepped. Using a dedicated goniometer installed on the microfocus macromolecular crystallography beamline I24 at Diamond Light Source, crystals have been studied in situ with an intense and flexible microfocus beam, allowing weakly diffracting samples to be assessed without a manual crystal-handling step but with good signal to noise, despite the background scatter from the plate. A number of case studies are reported: the structure solution of bovine enterovirus 2, crystallization screening of membrane proteins and complexes, and structure solution from crystallization hits produced via a high-throughput pipeline. These demonstrate the potential for in situ data collection and structure solution with microbeams.

  4. In situ viscometry by optical trapping interferometry

    DEFF Research Database (Denmark)

    Guzmán, C.; Flyvbjerg, Henrik; Köszali, R.

    2008-01-01

    We demonstrate quantitative in situ viscosity measurements by tracking the thermal fluctuations of an optically trapped microsphere subjected to a small oscillatory flow. The measured power spectral density of the sphere's positions displays a characteristic peak at the driving frequency of the f......We demonstrate quantitative in situ viscosity measurements by tracking the thermal fluctuations of an optically trapped microsphere subjected to a small oscillatory flow. The measured power spectral density of the sphere's positions displays a characteristic peak at the driving frequency...

  5. Calidad de visión y satisfacción del paciente usuario de pantallas de visualización de datos tras cirugía refractiva

    Directory of Open Access Journals (Sweden)

    Mª Isabel Rubio Cuevas

    2007-03-01

    Full Text Available Objetivo: Evaluar la influencia en la calidad de vida y satisfacción de los trabajadores usuarios de pantallas de visualización de datos (PVD que se asocia a la mejora de la función visual tras queratomileusis in situ con láser excimer (LASIK. Métodos: Estudio observacional y longitudinal en una población de 96 pacientes intervenidos de cirugía refractiva con láser excimer según técnica LASIK mediante aplicación de un cuestionario construído al efecto aplicado antes y después de cirugía por un observador independiente. Resultados: Agudeza visual y refracción ocular han mejorado tras LASIK, siendo el índice de eficacia de 1.1. La sensibilidad al contraste tras cirugía mejora en todas las frecuencias (6 c/g, 3 c/g y 1 c/g en el ojo derecho. Mientras que en el ojo izquierdo no hay diferencias significativas. La calidad de visión con y sin corrección es mejor tras LASIK (significativa p Purpose: To evaluate the influence in quality of vision and satisfaction of video display terminal (VDT users related to improvement of visual functions following excimer laser in situ keratomileusis (LASIK. Methods: Longitudinal and observational study in a population of 96 patients that underwent LASIK using a questionnaire made for that, applied before and after surgery by an independent observer. Results: Visual acuity and ocular refraction have improved after LASIK, being the efficiency index 1.1. Contrast sensitivity postoperative improved at all spatial frequencies in the right eye (6 c/g, 3 c/g and 1 c/. While in the left eye there were no significant differences. Quality of vision with and without correction is also better after LASIK (p < 0.05. And 84.38 % of patients would repeat themselves and recommend this surgery to other patients. Conclusions: The results show that LASIK improves visual function and quality of life of patients.

  6. Reasons For Not Performing Keratorefractive Surgery in Patients Seeking Refractive Surgery in a Hospital-Based Cohort in “Yemen”

    Science.gov (United States)

    Bamashmus, Mahfouth A.; Saleh, Mahmoud F.; Awadalla, Mohamed A.

    2010-01-01

    Background: To determine and analyze the reasons why keratorefractive surgery, laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) were not performed in patients who presented for refractive surgery consultation. Materials and Methods: A retrospective observational study was performed between January 2006 and December 2007 in the Yemen Magrabi Hospital. The case records of 2,091 consecutive new patients who presented for refractive surgery were reviewed. Information from the pre-operative ophthalmic examination, such as refractive error, corneal topography and visual acuity, were analyzed. The reasons for not performing LASIK and PRK in the cases that were rejected were recorded and analyzed. Results: In this cohort, 1,660 (79.4%) patients were advised to have LASIK or PRK from the 2,091 patients examined. LASIK and PRK were not advised in 431 (21%) patients. The most common reasons for not performing the surgery were high myopia >-11.00 Diopters (19%), keratoconus (18%), suboptimal central corneal thickness (15%), cataract (12%) and keratoconus suspect (forme fruste keratoconus) (10%). Conclusion: Patients who requested keratorefractive surgery have a variety of problems and warrant comprehensive attention to selection criteria on the part of the surgeon. Corneal topographies and pachymetry of refractive surgery candidates need to be read cautiously. High-refractive error, keratoconus and insufficient corneal thickness were found to be the leading reasons for not performing keratorefractive surgery in this study. PMID:21180437

  7. Analysis of correlation between corneal topographical data and visual performance

    Science.gov (United States)

    Zhou, Chuanqing; Yu, Lei; Ren, Qiushi

    2007-02-01

    Purpose: To study correlation among corneal asphericity, higher-order aberrations and visual performance for eyes of virgin myopia and postoperative laser in situ keratomileusis (LASIK). Methods: There were 320 candidates 590 eyes for LASIK treatment included in this study. The mean preoperative spherical equivalence was -4.35+/-1.51D (-1.25 to -9.75), with astigmatism less than 2.5 D. Corneal topography maps and contrast sensitivity were measured and analyzed for every eye before and one year after LASIK for the analysis of corneal asphericity and wavefront aberrations. Results: Preoperatively, only 4th and 6th order aberration had significant correlation with corneal asphericity and apical radius of curvature (pcorneal asphericity (pcorneal aberrations had no significant correlation with visual acuity and area under the log contrast sensitivity (AULCSF) (P>0.05). Postoperatively, corneal aberrations still didn't have significant correlation with visual acuity (P>0.05), but had significantly negative correlation with AULCSF (PCorneal asphericity had no significant correlation with AULCSF before and after the treatment (P>0.05). Conclusions: Corneal aberrations had different correlation with corneal profile and visual performance for eyes of virgin myopia and postoperative LASIK, which may be due to changed corneal profile and limitation of metrics of corneal aberrations.

  8. Carcinoma in situ in the testis

    DEFF Research Database (Denmark)

    Rørth, M; Rajpert-De Meyts, E; Andersson, L

    2000-01-01

    Carcinoma in situ (CIS) of the testis is a common precursor of germ-cell tumours in adults and adolescents, with the exception of spermatocytic seminoma. This article reviews existing knowledge on the pathobiology, genetic aspects and epidemiology of CIS, discusses current hypotheses concerning...

  9. In Situ Flash Pyrolysis of Straw

    DEFF Research Database (Denmark)

    Bech, Niels

    In-Situ Flash Pyrolysis of Straw Ph.D. dissertation by Niels Bech Submitted: April 2007. Supervisors: Professor Kim Dam-Johansen, Associate Professor Peter Arendt Jensen Erfaringerne med forbrænding af halm opnået gennem et årti har vist, at en proces der kan koncentrere energien på marken, fjerne...

  10. Treatment options for carcinoma in situ testis

    DEFF Research Database (Denmark)

    Mortensen, M S; Gundgaard, M.G.; Daugaard, G

    2011-01-01

    Carcinoma in situ testis (CIS) is known as the precursor of germ cell cancer of the testis. International guidelines on diagnosis and treatment are inconsistent. Some countries offer routine biopsies of the contralateral testicle in relation to orchidectomy for testicular cancer, whereas other...

  11. Recent Advances in Fluorescence in situ Hybridization

    OpenAIRE

    吉田, 廸弘; Michihiro C., Yoshida; 北海道大学理学部附属動物染色体研究施設; Chromosome Research Unit, Faculty of Science, Hokkaido University

    1992-01-01

    Fluorescence in situ hybridization (FISH) procedures that directly couple molecular and cytological information allow precise visualization of DNA sequences on metaphase chromosomes and interphase nuclei. These techniques can be used to identify chromosomes, detect chromosomal aberrations, and analyze linear and spetial genome organization. FISH procedures are also used to clinical fields for diagnosis of disease-related chromosome changes and tumor biology.

  12. Contemporary management of ductal carcinoma in situ and lobular carcinoma in situ.

    Science.gov (United States)

    Obeng-Gyasi, Samilia; Ong, Cecilia; Hwang, E Shelley

    2016-06-01

    The management of in situ lesions ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS) continues to evolve. These diagnoses now comprise a large burden of mammographically diagnosed cancers, and with a global trend towards more population-based screening, the incidence of these lesions will continue to rise. Because outcomes following treatment for DCIS and LCIS are excellent, there is emerging controversy about what extent of treatment is optimal for both diseases. Here we review the current approaches to the diagnosis and treatment of both DCIS and LCIS. In addition, we will consider potential directions for future management of these lesions.

  13. Comparison of laser epithelial keratomileusis and photorefractive keratectomy for the correction of myopia:a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    CUI Min; CHEN Xiao-ming; L(U) Peng

    2008-01-01

    Background It is unclear whether a laser epithelial keratomileusis (LASEK) has any significant advantage over a photorefractive keratectomy (PRK) for correcting myopia.We undertook this meta-analysis of randomized controlled trials to examine possible differences in efficacy,accuracy,safety and side-effects between two methods,LASEK and PRK,for correcting myopia.Methods A systematic literature retrieval was conducted in the PubMed,EMBASE,Chinese Bio-medicine Database,and Cochrane Controlled Trials Register to identify potentially relevant randomized controlled trials.The statistical analysis was performed using a RevMan 4.2 software.The results included efficacy outcomes (proportion of eyes with uncorrected visual acuity (UCVA)≥ 20/20 at 1 month and 12 months post-treatment),accuracy outcomes (proportion of eyes within ±0.50 diopters (D) of target refraction at 1 month and 12 months post-treatment),safety outcomes (loss of ≥2 lines of best spectacle-corrected visual acuity (BSCVA) at ≥ 6 months post-treatment),mean pain scores on day 1 post-treatment,and mean corneal haze scores at 6 and 12 months post-treatment.Results Seven articles describing a total of 604 eyes with myopia from 0 to -9.0 D were identified in this meta-analysis.The combined results showed that the efficacy and accuracy outcomes between the two groups at 1 month and 12 months post-treatment were comparable.No patient lost ≥ 2 lines of BSCVA at ≥ 6 months post-treatment in four relevant trials.Compared with PRK,LASEK did not relieve discomfort on day 1 post-treatment or reduce corneal haze intensity at 6 and 12 months post-treatment.Conclusions According to the available data,LASEK does not appear to have any advantage over PRK for correcting myopia from 0 to -9.0 D.This meta-analysis focuses mainly on the comparison of the early,mid-term and mid-long term results of the two methods.Additional studies to compare the long-term (>one year) results should be considered.

  14. In Situ Remediation Integrated Program: Technology summary

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    The In Situ Remediation Integrated Program (ISR IP) was instituted out of recognition that in situ remediation could fulfill three important criteria: significant cost reduction of cleanup by eliminating or minimizing excavation, transportation, and disposal of wastes; reduced health impacts on workers and the public by minimizing exposure to wastes during excavation and processing; and remediation of inaccessible sites, including: deep subsurfaces, in, under, and around buildings. Buried waste, contaminated soils and groundwater, and containerized wastes are all candidates for in situ remediation. Contaminants include radioactive wastes, volatile and non-volatile organics, heavy metals, nitrates, and explosive materials. The ISR IP intends to facilitate development of in situ remediation technologies for hazardous, radioactive, and mixed wastes in soils, groundwater, and storage tanks. Near-term focus is on containment of the wastes, with treatment receiving greater effort in future years. ISR IP is an applied research and development program broadly addressing known DOE environmental restoration needs. Analysis of a sample of 334 representative sites by the Office of Environmental Restoration has shown how many sites are amenable to in situ remediation: containment--243 sites; manipulation--244 sites; bioremediation--154 sites; and physical/chemical methods--236 sites. This needs assessment is focused on near-term restoration problems (FY93--FY99). Many other remediations will be required in the next century. The major focus of the ISR EP is on the long term development of permanent solutions to these problems. Current needs for interim actions to protect human health and the environment are also being addressed.

  15. Topography-modified refraction (TMR: adjustment of treated cylinder amount and axis to the topography versus standard clinical refraction in myopic topography-guided LASIK

    Directory of Open Access Journals (Sweden)

    Kanellopoulos AJ

    2016-11-01

    Full Text Available Anastasios John Kanellopoulos1,2 1LaserVision Clinical and Research Institute, Athens, Greece; 2Department of Ophthalmology, NYU Medical School, New York, NY, USA Purpose: To evaluate the safety, efficacy, and contralateral eye comparison of topography-guided myopic LASIK with two different refraction treatment strategies. Setting: Private clinical ophthalmology practice. Patients and methods: A total of 100 eyes (50 patients in consecutive cases of myopic topography-guided LASIK procedures with the same refractive platform (FS200 femtosecond and EX500 excimer lasers were randomized for treatment as follows: one eye with the standard clinical refraction (group A and the contralateral eye with the topographic astigmatic power and axis (topography-modified treatment refraction; group B. All cases were evaluated pre- and post-operatively for the following parameters: refractive error, best corrected distance visual acuity (CDVA, uncorrected distance visual acuity (UDVA, topography (Placido-disk based and tomography (Scheimpflug-image based, wavefront analysis, pupillometry, and contrast sensitivity. Follow-up visits were conducted for at least 12 months. Results: Mean refractive error was -5.5 D of myopia and -1.75 D of astigmatism. In group A versus group B, respectively, the average UDVA improved from 20/200 to 20/20 versus 20/16; post-operative CDVA was 20/20 and 20/13.5; 1 line of vision gained was 27.8% and 55.6%; and 2 lines of vision gained was 5.6% and 11.1%. In group A, 27.8% of eyes had over -0.50 diopters of residual refractive astigmatism, in comparison to 11.7% in group B (P<0.01. The residual percentages in both groups were measured with refractive astigmatism of more than –0.5 diopters. Conclusion: Topography-modified refraction (TMR: topographic adjustment of the amount and axis of astigmatism treated, when different from the clinical refraction, may offer superior outcomes in topography-guided myopic LASIK. These findings

  16. EarIy changes of anterior chamber parameters after FS-LASIK%飞秒 LASlK 术后早期前房参数的变化研究

    Institute of Scientific and Technical Information of China (English)

    程蕾; 朱冉; 王丹梅; 魏梅

    2015-01-01

      结论:飞秒LASIK术后早期引起前房参数变化,包括ACD变浅,ACV变小,但对周边前房角无明显影响,对屈光手术后行内眼手术患者有进一步指导作用。%· AlM: To investigate the changes of early anterior chamber parameters after femtosecond laser in -situ keratomileusis ( FS-LASlK) . ·METHODS:A total of 90 patients (90 eyes) in routine operation indications received FS-LASlK operation from January to June 2014 in our hospital were collected, including 47 males (47 eyes) , 43 females (43 eyes) , aged 18-33 years old (mean age 22.38±3.96 years).According to the diopter, the patients were divided into three groups:30 cases ( 30 eyes ) were in mild myopia group (group A) with diopter≤3D;30 cases (30 eyes) were in moderate myopia group ( group B) with diopter >3D and≤6D; 30 cases ( 30 eyes) were in high myopia group (group C) with diopter >6D.Pentacam measurements were used to measure the anterior chamber parameters including the changes of anterior chamber depth ( ACD) , anterior chamber volume ( ACV) , anterior chamber angle ( ACA ) before surgery and at 1, 3mo after surgery respectively. · RESULTS: All surgical procedures were performed successfully without complications. Compared with the value of ACD and ACV at pre-operation and 1, 3mo post-operation among groups A, B, C, there was statistically significant difference ( P0.05).However, in groups A, B and C, the value of ACA had no statistically significant difference ( P>0.05).Diopter had no obvious relevance with the changes of ACD, ACV, ACA values. · CONCLUSlON:The early changes of anterior chamber parameters after FS-LASlK, including that ACD become shallow, ACV become smaller, but there was no obvious effect on the peripheral anterior chamber angle.There will be a further instruction for those people who want to perform intraocular surgery after ocular refractive surgery.

  17. Corrección de ametropías con cirugía refractiva: lasik y lasek.

    Directory of Open Access Journals (Sweden)

    Jenny García Milián

    2009-06-01

    Full Text Available En el Hospital General Universitario “Camilo Cienfuegos” de Sancti Spíritus aplicamos el Láser Excimer para corregir defectos refractivos desde el 3 de abril del año 2008, para ello contamos con un láser de última generación de la casa comercial Schwind, modelo Esiris, que nos permite realizar ablación a la medida guiada por topografía corneal. Se realizó un estudio prospectivo de corte transversal en el período comprendido del 3 de abril de 2008 al 3 de abril de 2009 con el objetivo de conocer los resultados de la cirugía refractiva en Sancti Spíritus desde su puesta en marcha. El grupo seleccionado estuvo conformado por 314 ojos, correspondientes a 164 pacientes operados de los diferentes tipos de ametropías con excimer láser, independientemente de la técnica quirúrgica que utilizamos (Lasik o Lasek. Se analizó el comportamiento de diferentes variables clínico-epidemiológicas y quedó identificada la descripción del defecto refractivo más frecuente, la técnica quirúrgica más utilizada, la agudeza visual de los pacientes antes y después de la cirugía, así como las complicaciones postoperatorias. Los resultados mostraron que predominó el sexo femenino, el defecto refractivo más comúnmente encontrado fue el astigmatismo miópico compuesto, la mayoría de los pacientes alcanzaron una visión por encima de 0.7, la técnica quirúrgica más utilizada fue el Lasik, aquejaron mayores molestias los operados con técnica Lasek, y con ambas técnicas quirúrgicas se logró una buena agudeza visual sin corrección óptica de manera que en el total de los pacientes se logró la no dependencia del cristal.

  18. New in situ crosslinking chemistries for hydrogelation

    Science.gov (United States)

    Roberts, Meredith Colleen

    Over the last half century, hydrogels have found immense value as biomaterials in a vast number of biomedical and pharmaceutical applications. One subset of hydrogels receiving increased attention is in situ forming gels. Gelling by either bioresponsive self-assembly or mixing of binary crosslinking systems, these technologies are useful in minimally invasive applications as well as drug delivery systems in which the sol-to-gel transition aids the formulation's performance. Thus far, the field of in situ crosslinking hydrogels has received limited attention in the development of new crosslinking chemistries. Moreover, not only does the chemical nature of the crosslinking moieties allow these systems to perform in situ, but they contribute dramatically to the mechanical properties of the hydrogel networks. For example, reversible crosslinks with finite lifetimes generate dynamic viscoelastic gels with time-dependent properties, whereas irreversible crosslinks form highly elastic networks. The aim of this dissertation is to explore two new covalent chemistries for their ability to crosslink hydrogels in situ under physiological conditions. First, reversible phenylboronate-salicylhydroxamate crosslinking was implemented in a binary, multivalent polymeric system. These gels formed rapidly and generated hydrogel networks with frequency-dependent dynamic rheological properties. Analysis of the composition-structure-property relationships of these hydrogels---specifically considering the effects of pH, degree of polymer functionality, charge of the polymer backbone and polymer concentration on dynamic theological properties---was performed. These gels demonstrate diverse mechanical properties, due to adjustments in the binding equilibrium of the pH-sensitive crosslinks, and thus have the potential to perform in a range of dynamic or bioresponsive applications. Second, irreversible catalyst-free "click" chemistry was employed in the hydrogelation of multivalent azide

  19. Motivación y satisfacción de los pacientes miopes sometidos a cirugía LASIK Motivation and satisfaction of myopic patients undergoing LASIK surgery

    Directory of Open Access Journals (Sweden)

    Tania Aimeé Díaz Martínez

    2009-06-01

    Full Text Available OBJETIVO: Analizar la motivación y los niveles de satisfacción de los pacientes miopes sometidos a la cirugía refractiva con excímer láser. MÉTODOS: Se realizó una encuesta a 126 pacientes miopes (241 ojos, que asistieron a la consulta de cirugía refractiva en el Hospital Militar "Dr. Carlos Juan Finlay", los cuales fueron intervenidos con cirugía refractiva LASIK, con el propósito de analizar sus principales motivaciones y el grado de satisfacción obtenido después de transcurridos 3 meses de realizada la cirugía. Se estudiaron las siguientes variables: datos personales, motivación por la cirugía, refracción, agudeza visual, efectos secundarios y grado de satisfacción en general, así como su relación con las demás variables analizadas. RESULTADOS: La edad media de los encuestados fue de 30 años (de 20 a 54 años. Se encontró una mayor frecuencia de miopes en el sexo femenino (68,2 %. La graduación previa fue de un rango de -1,50 D a -12 D de equivalente esférico, y en el momento de la encuesta en más del 90 % de los pacientes era inferior a ± 1D. La motivación principal en el 82,9 % de los pacientes fue mejorar la agudeza visual, en el 9,9 %, la comodidad, en el 2,4 % la intolerancia a lentes de contacto, en el 1,2 % mejorar la imagen, y en el 1,6 % por acceso a puestos de trabajo, así como la diferencia de la visión entre un ojo y otro. El grado de satisfacción de los encuestados fue: 96,3 % muy contento, 2,8 % bastante contento, 0,4 % algo descontento y 0,4 % muy descontento. El grado de satisfacción estuvo relacionado con la graduación previa del paciente. Los pacientes más contentos fueron los que se operaron para mejorar la agudeza visual. De forma general el grado de satisfacción (más del 98 % fue elevado. CONCLUSIONES: El grado de satisfacción de los pacientes intervenidos con LASIK fue aceptable o alto en la mayoría de los casos.OBJECTIVE: To analyze motivation and levels of satisfaction of myopic

  20. Ceratectomia fotorrefrativa associada à ceratotomia lamelar pediculada (LASIK para correção de miopias, com ou sem secagem do estroma Photorefractive keratectomy associated with lamellar keratotomy (LASIK for correction of myopia, with or without drying the stroma

    Directory of Open Access Journals (Sweden)

    Cesar K. Suzuki

    2000-12-01

    Full Text Available Objetivo: Avaliar os resultados clínicos da ceratectomia fotorrefrativa associada à ceratotomia lamelar pediculada (LASIK, para miopia moderada e alta, com ou sem secagem do leito estromal durante a foto-ablação. Pacientes e Métodos: Estudo retrospectivo de 39 olhos de 30 pacientes submetidos a LASIK sem secagem do leito estromal durante a foto-ablação no período de abril de 1996 a abril de 1997 (Grupo I e 42 olhos de 28 pacientes com secagem do leito estromal durante a foto-ablação a cada 80 pulsos, no período de abril de 1997 a setembro de 1997 (Grupo II. Após a ceratotomia lamelar pediculada corneana com um microcerátomo automatizado (Chiron Corneal Shaper ®, foi realizada a foto-ablação com excimer laser de fluoreto de argônio de 193 nm da Summit modelo Apex Plus®. Em 2 olhos do Grupo I, a foto-ablação não foi realizada, devido a complicações durante a ceratotomia lamelar. Resultados: O tempo médio de seguimento pós-operatório foi de 8,7 meses no Grupo I e 7,7 meses no Grupo II. A média de tratamento foi de -10,81D (±2,38 no grupo I e -8,73D (±2,82 no grupo II. As médias das variações dos equivalentes esféricos obtidos em relação ao tratamento desejado nos meses 1, 3, 6 e 12 foram respectivamente, -0,96D (±1,19, -1,19D (±1,37, -1,06D (±1,41 e -1,10D (±0,66 no Grupo I e -0,23D (±1,02, -0,41D (±1,34, -0,75D (±1,16 e -1,03D (±1,31 no Grupo II. Três olhos do total (3,7%, todos do Grupo I, perderam 2 ou mais linhas de visão. Na visita mais recente, 17 olhos (45,9% do Grupo I e 31 olhos (73,8% do Grupo II apresentaram Acuidade Visual sem correção de 20/40 ou melhor. Ocorreram 4 complicações intra-operatórias no grupo I, sendo que 2 casos tiveram a foto-ablação não-efetuada e uma complicação intra-operatória no Grupo II. Conclusão: A secagem do leito estromal possibilitou recuperação visual mais rápida, devido a menor hipocorreção primária. O seguimento a longo prazo não evidenciou

  1. In situ hydrogen loading on zirconium powder

    Energy Technology Data Exchange (ETDEWEB)

    Maimaitiyili, Tuerdi, E-mail: tuerdi.maimaitiyili@mah.se; Blomqvist, Jakob [Malmö University, Östra Varvsgatan 11 A, Malmö, Skane 20506 (Sweden); Steuwer, Axel [Lund University, Ole Römers väg, Lund, Skane 22100 (Sweden); Nelson Mandela Metropolitan University, Gardham Avenue, Port Elizabeth 6031 (South Africa); Bjerkén, Christina [Malmö University, Östra Varvsgatan 11 A, Malmö, Skane 20506 (Sweden); Zanellato, Olivier [Ensam - Cnam - CNRS, 151 Boulevard de l’Hôpital, Paris 75013 (France); Blackmur, Matthew S. [Materials Performance Centre, School of Materials, The University of Manchester, Manchester M1 7HS (United Kingdom); Andrieux, Jérôme [European Synchrotron Radiation Facility, 6 rue J Horowitz, Grenoble 38043 (France); Université de Lyon, 43 Bd du 11 novembre 1918, Lyon 69100 (France); Ribeiro, Fabienne [Institut de Radioprotection et Sûreté Nucléaire, IRSN, BP 3, 13115 Saint-Paul Lez Durance (France)

    2015-06-26

    Commercial-grade Zr powder loaded with hydrogen in situ and phase transformations between various Zr and ZrH{sub x} phases have been monitored in real time. For the first time, various hydride phases in a zirconium–hydrogen system have been prepared in a high-energy synchrotron X-ray radiation beamline and their transformation behaviour has been studied in situ. First, the formation and dissolution of hydrides in commercially pure zirconium powder were monitored in real time during hydrogenation and dehydrogenation, then whole pattern crystal structure analysis such as Rietveld and Pawley refinements were performed. All commonly reported low-pressure phases presented in the Zr–H phase diagram are obtained from a single experimental arrangement.

  2. In situ SU-8 silver nanocomposites

    DEFF Research Database (Denmark)

    Fischer, Søren Vang; Uthuppu, Basil; Jakobsen, Mogens Havsteen

    2015-01-01

    to this problem, an easy new method of fabricating silver nanocomposites by an in situ reduction of precursors within the epoxy-based photoresist SU-8 has been developed. AgNO3 dissolved in acetonitrile and mixed with the epoxy-based photoresist SU-8 forms silver nanoparticles primarily during the pre- and post......Nanocomposite materials containing metal nanoparticles are of considerable interest in photonics and optoelectronics applications. However, device fabrication of such materials always encounters the challenge of incorporation of preformed nanoparticles into photoresist materials. As a solution......-exposure soft bake steps at 95 degrees C. A further high-temperature treatment at 300 degrees C resulted in the formation of densely homogeneously distributed silver nanoparticles in the photoresist matrix. No particle growth or agglomeration of nanoparticles is observed at this point. The reported new in situ...

  3. Inherently safe in situ uranium recovery

    Science.gov (United States)

    Krumhansl, James L; Brady, Patrick V

    2014-04-29

    An in situ recovery of uranium operation involves circulating reactive fluids through an underground uranium deposit. These fluids contain chemicals that dissolve the uranium ore. Uranium is recovered from the fluids after they are pumped back to the surface. Chemicals used to accomplish this include complexing agents that are organic, readily degradable, and/or have a predictable lifetime in an aquifer. Efficiency is increased through development of organic agents targeted to complexing tetravalent uranium rather than hexavalent uranium. The operation provides for in situ immobilization of some oxy-anion pollutants under oxidizing conditions as well as reducing conditions. The operation also artificially reestablishes reducing conditions on the aquifer after uranium recovery is completed. With the ability to have the impacted aquifer reliably remediated, the uranium recovery operation can be considered inherently safe.

  4. In situ models, physico-chemical aspects.

    Science.gov (United States)

    ten Cate, J M

    1994-07-01

    In situ (intra-oral) caries models are used for two purposes. First, they provide information about oral physiological processes. Such information helps to detail our knowledge of the oral ecosystem and to verify conclusions from in vitro experiments. Second, in situ models are utilized to test preventive agents in the phase between laboratory testing and clinical trials. Most investigations involving enamel inserts have been aimed at testing new dentifrices. The experimental designs of such studies usually do not allow one to draw conclusions on physico-chemical processes, e.g., because of single point measurements. Studies of model parameters (lesion type, lesion severity, and de/remineralization in time) constitute only a minority of the research reports. The most striking observation obtained with in situ models has been the significant differences in de/remineralization observed among individuals and, more importantly, within one individual during different time periods and between different sites in the same mouth (for review, see ten Cate et al., 1992). Regardless of this, some general findings can be inferred: During in situ demineralization, up to 62 vol% microns/day may be removed from enamel. For dentin specimens, this value may be as high as 89 vol% microns/day. For remineralization, during fluoride dentifrice treatment, a median deposition rate of 0.7%/day (for lesions with integrated mineral loss values between 2000 and 4000 vol% microns) is found. The rate of deposition seems to be correlated with the extent of the pre-formed lesion. This suggests that the number of sites (crystallite surface) available for calcium phosphate precipitation is an important parameter.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. In situ hybridization-theory and practice.

    Science.gov (United States)

    Kadkol, S S; Gage, W R; Pasternack, G R

    1999-09-01

    In situ hybridization is a technique to determine and localize target nucleic acids in morphologically preserved tissue sections. Recent advances in methods have greatly increased the sensitivity of the technique, and it is currently possible to detect extremely few copies of any given target sequence with nonisotopic methods. In this teaching review, we integrate theoretical background, technical considerations, and guidelines for usage for this important component of molecular diagnosis.

  6. In situ health monitoring of piezoelectric sensors

    Science.gov (United States)

    Jensen, Scott L. (Inventor); Drouant, George J. (Inventor)

    2013-01-01

    An in situ health monitoring apparatus may include an exciter circuit that applies a pulse to a piezoelectric transducer and a data processing system that determines the piezoelectric transducer's dynamic response to the first pulse. The dynamic response can be used to evaluate the operating range, health, and as-mounted resonance frequency of the transducer, as well as the strength of a coupling between the transducer and a structure and the health of the structure.

  7. Squamous cell carcinoma in situ after irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kambara, Takeshi; Nishiyama, Takafumi; Yamada, Rie; Nagatani, Tetsuo; Nakajima, Hiroshi [Yokohama City Univ. (Japan). School of Medicine; Sugiyama, Asami

    1997-12-31

    We report two cases with Squamous Cell Carcinoma (SCC) in situ caused by irradiation to hand eczemas, resistant to any topical therapies. Both of our cases clinically show palmer sclerosis and flexor restriction of the fingers, compatible to chronic radiation dermatitis. Although SCC arising in chronic radiation dermatitis is usually developed ten to twenty years after irradiation, in our cases SCC were found more than forty years after irradiation. (author)

  8. In situ ion irradiation of zirconium carbide

    Science.gov (United States)

    Ulmer, Christopher J.; Motta, Arthur T.; Kirk, Mark A.

    2015-11-01

    Zirconium carbide (ZrC) is a candidate material for use in one of the layers of TRISO coated fuel particles to be used in the Generation IV high-temperature, gas-cooled reactor, and thus it is necessary to study the effects of radiation damage on its structure. The microstructural evolution of ZrCx under irradiation was studied in situ using the Intermediate Voltage Electron Microscope (IVEM) at Argonne National Laboratory. Samples of nominal stoichiometries ZrC0.8 and ZrC0.9 were irradiated in situ using 1 MeV Kr2+ ions at various irradiation temperatures (T = 20 K-1073 K). In situ experiments made it possible to continuously follow the evolution of the microstructure during irradiation using diffraction contrast imaging. Images and diffraction patterns were systematically recorded at selected dose points. After a threshold dose during irradiations conducted at room temperature and below, black-dot defects were observed which accumulated until saturation. Once created, the defect clusters did not move or get destroyed during irradiation so that at the final dose the low temperature microstructure consisted only of a saturation density of small defect clusters. No long-range migration of the visible defects or dynamic defect creation and elimination were observed during irradiation, but some coarsening of the microstructure with the formation of dislocation loops was observed at higher temperatures. The irradiated microstructure was found to be only weakly dependent on the stoichiometry.

  9. In situ Raman mapping of art objects

    Science.gov (United States)

    Lauwers, D.; Brondeel, Ph.; Moens, L.; Vandenabeele, P.

    2016-12-01

    Raman spectroscopy has grown to be one of the techniques of interest for the investigation of art objects. The approach has several advantageous properties, and the non-destructive character of the technique allowed it to be used for in situ investigations. However, compared with laboratory approaches, it would be useful to take advantage of the small spectral footprint of the technique, and use Raman spectroscopy to study the spatial distribution of different compounds. In this work, an in situ Raman mapping system is developed to be able to relate chemical information with its spatial distribution. Challenges for the development are discussed, including the need for stable positioning and proper data treatment. To avoid focusing problems, nineteenth century porcelain cards are used to test the system. This work focuses mainly on the post-processing of the large dataset which consists of four steps: (i) importing the data into the software; (ii) visualization of the dataset; (iii) extraction of the variables; and (iv) creation of a Raman image. It is shown that despite the challenging task of the development of the full in situ Raman mapping system, the first steps are very promising. This article is part of the themed issue "Raman spectroscopy in art and archaeology".

  10. In situ Management and Domestication of Plants in Mesoamerica

    National Research Council Canada - National Science Library

    ALEJANDRO CASAS; ADRIANA OTERO-ARNAIZ; EDGAR PÉREZ-NEGRÓN; ALFONSO VALIENTE-BANUET

    2007-01-01

    ... in plant populations under in situ management in the region. • Methods Information on wild and in situ managed populations of the herbaceous weedy plants Anoda cristata and Crotalaria puntila, the tree Leucaena esculenta...

  11. Intrathecal Delivery of Ketorolac Loaded In Situ Gels for Prolonged ...

    African Journals Online (AJOL)

    in situ gel near the fractured vertebra in a rat model). ... The formulated in situ gels can potentially be used as implants for the treatment of .... xanthan gum orally in an appropriate volume. ..... polyelectrolyte alginate-chitosan complex based.

  12. Application of fluorescence in situ hybridization (FISH) to the ...

    African Journals Online (AJOL)

    Application of fluorescence in situ hybridization (FISH) to the analysis of ... In this study, fluorescent in situ hybridization (FISH) as a culture-independent molecular ... a high percentage and took place in an oily biological system under aerobic ...

  13. In situ synthesis studies of silicon clathrates

    Science.gov (United States)

    Hutchins, Peter Thomas

    Solid state clathrates have shown considerable potential as a new class of materials over the past 30 years. Experimental and theoretical studies have shown that precise tuning and synthetic control of these materials, may lead to desirable properties. Very little is known about the mechanism of formation of the clathrates and so the desire to have accurate synthetic control was, until now, unrealistic. This thesis address the problem using in situ synchrotron x-ray techniques. In this study, experiments were designed to utilise time-resolved in situ diffraction techniques and high temperature 23Na NMR, in efforts to understand the mechanism of formation for this class of expanded framework materials. A complex high vacuum capillary synthesis cell was designed for loading under inert conditions and operation under high vacuum at station 6.2 of the SRS Daresbury. The cell was designed to operate in conjunction with a custom made furnace capable of temperatures in excess of 1000 C, as well as a vacuum system capable of 10"5 bar. The clathrate system was studied in situ, using rapid data collection to elucidate the mechanism of formation. The data were analysed using Rietveld methods and showed a structural link between the monoclinic, C2/c, Zintl precursors and the cubic, Pm3n, clathrate I phase. The phases were found to be linked by relation of the sodium planes in the silicide and the sodium atoms resident at cages centres in the clathrate system. This evidence suggests the guest species is instrumental in formation of the clathrate structure by templating the formation of the cages in the structure. Solid state 23Na NMR was utilised to complete specially design experiments, similar to those complete in situ using synchrotron x-ray techniques. The experiments showed increased spherical symmetry of the alkali metal sites and suggested increased mobility of the guest atoms during heating. In addition, cyclic heating experiments using in situ diffraction showed

  14. 30 CFR 828.12 - In situ processing: Monitoring.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false In situ processing: Monitoring. 828.12 Section 828.12 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE... PROCESSING § 828.12 In situ processing: Monitoring. (a) Each person who conducts in situ...

  15. 30 CFR 828.11 - In situ processing: Performance standards.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false In situ processing: Performance standards. 828.11 Section 828.11 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT... STANDARDS-IN SITU PROCESSING § 828.11 In situ processing: Performance standards. (a) The person who...

  16. Coleção fluídica na interface do LASIK causada por glaucoma secundário à ceratouveíte herpética: relato de caso LASIK interface fluid accumulation caused by glaucoma associated with herpetic keratouveitis: case report

    Directory of Open Access Journals (Sweden)

    Eliane Mayumi Nakano

    2007-02-01

    Full Text Available A infecção por Herpes simplex vírus (HSV é causa freqüente de inflamação intra-ocular ou uveíte anterior. A hipertensão ocular é característica comumente observada nas ceratouveítes herpéticas. Neste relato descrevemos o acúmulo de fluido e descolamento do "flap" corneano da ceratomileusis, no pós-operatório tardio de LASIK (28 meses, associado a quadro hipertensivo ocular secundário a ceratouveíte herpética. Este achado corrobora a suposição que a cicatrização corneana após LASIK seja apenas parcial e o espaço virtual produzido pela ceratomileuisis permaneça indefinidamente. Condições de aumento excessivo da pressão intra-ocular podem causar edema corneano com acúmulo de fluido da interface.Herpes simplex virus infection is a frequent cause of intraocular inflammation or anterior uveitis. Ocular hypertension is a common feature in herpetic keratouveitis. We describe a fluid accumulation and flap displacement in late postoperative period (28 months of LASIK associated with ocular hypertension caused by herpetic keratouveitis. This finding supports the theory that flap attachment after LASIK is only partial and the virtual space remains indefinitely. The presence of ocular hypertension may lead to corneal edema and fluid accumulation in the interface.

  17. In situ upgrading : coupled enhanced oil recovery with in situ upgrading : ultra dispersed catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Almao, P.P. [Calgary Univ., AB (Canada). Schulich School of Engineering]|[Alberta Ingenuity Centre for In Situ Energy, Edmonton, AB (Canada)

    2007-07-01

    This paper presented a research program that demonstrates the use of ultra dispersed (UD) catalysts as a means of improving the economics of oil sands processing. An outline of current processing techniques was provided. In situ upgrading options included the use of solvents, thermal methods, radiation methods, bio-upgrading, and thermo-catalytic methods. Enhanced oil recovery (EOR) is often combined with in situ upgrading to increase the efficiency of energy use in reservoirs where thermal methods are used. The use of diluents often reduces water usage as well as problems related to contamination and emissions. Recent studies have suggested that vis-breaking (VB) is the lowest investment residual conversion process currently available for in situ processing. UD catalyst formulations can be commercially prepared using nano-particle techniques, and can be used in portable configurations. UD catalysts are known to outperform conventional fixed bed types for both hydrogenation, hydrotreating, and hydrocracking. Research is currently being conducted at the Alberta Ingenuity Centre for In Situ Energy to examine issues related to particles recycling, deactivation and losses. Permeability studies are also being conducted to examine permeability rates of emulsions and nanoparticles through oil sands porous media. The short term financial rewards of various in situ upgrading technologies were also considered. refs., tabs, figs.

  18. Topography-modified refraction (TMR): adjustment of treated cylinder amount and axis to the topography versus standard clinical refraction in myopic topography-guided LASIK.

    Science.gov (United States)

    Kanellopoulos, Anastasios John

    2016-01-01

    To evaluate the safety, efficacy, and contralateral eye comparison of topography-guided myopic LASIK with two different refraction treatment strategies. Private clinical ophthalmology practice. A total of 100 eyes (50 patients) in consecutive cases of myopic topography-guided LASIK procedures with the same refractive platform (FS200 femtosecond and EX500 excimer lasers) were randomized for treatment as follows: one eye with the standard clinical refraction (group A) and the contralateral eye with the topographic astigmatic power and axis (topography-modified treatment refraction; group B). All cases were evaluated pre- and post-operatively for the following parameters: refractive error, best corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), topography (Placido-disk based) and tomography (Scheimpflug-image based), wavefront analysis, pupillometry, and contrast sensitivity. Follow-up visits were conducted for at least 12 months. Mean refractive error was -5.5 D of myopia and -1.75 D of astigmatism. In group A versus group B, respectively, the average UDVA improved from 20/200 to 20/20 versus 20/16; post-operative CDVA was 20/20 and 20/13.5; 1 line of vision gained was 27.8% and 55.6%; and 2 lines of vision gained was 5.6% and 11.1%. In group A, 27.8% of eyes had over -0.50 diopters of residual refractive astigmatism, in comparison to 11.7% in group B (Prefractive astigmatism of more than -0.5 diopters. Topography-modified refraction (TMR): topographic adjustment of the amount and axis of astigmatism treated, when different from the clinical refraction, may offer superior outcomes in topography-guided myopic LASIK. These findings may change the current clinical paradigm of the optimal subjective refraction utilized in laser vision correction.

  19. Calibrating feedwater flow nozzles in-situ

    Energy Technology Data Exchange (ETDEWEB)

    Caudill, M. [Tri-State Generation and Transmission, Inc., Montrose, CA (United States); Diaz-Tous, I.; Murphy, S.; Leggett, M.; Crandall, C. [ENCOR-AMERICA, Inc., Mountain View, CA (United States)

    1996-05-01

    This paper presents a new method for in-situ calibration of feedwater flow nozzles wherein feedwater flow is determined indirectly by performing a high accuracy heat balance around the highest-pressure feedwater heater. It is often difficult to reliably measure feedwater flow. Over the life of a power plant, the feedwater nozzle can accumulate deposits, erode, or suffer other damage that can render the original nozzle calibration inaccurate. Recalibration of installed feedwater flow nozzles is expensive and time consuming. Traditionally, the nozzle is cut out of the piping and sent to a laboratory for recalibration, which can be an especially difficult, expensive, and time-consuming task when involving high pressure feedwater lines. ENCOR-AMERICA, INC. has developed an accurate and cost-effective method of calibrating feedwater nozzles in-situ as previously reported at the 1994 EPRI Heat Rate Improvement Conference. In this method, feedwater flow and differential pressure across the nozzle are measured concurrently. The feedwater flow is determined indirectly by performing a heat balance around the highest-pressure feedwater heater. Extraction steam to the feedwater heater is measured by use of a high accuracy turbine flowmeter. The meters used have been calibrated at an independent laboratory with a primary or secondary device traceable to the NIST. In this paper, a new variation on the above method is reported. The new approach measures the heater drains and vent flows instead of the extraction steam flow. Test theory and instrumentation will be discussed. Results of in-situ feedwater nozzle calibration tests performed at two units owned by Tri-State Generation and Transmission Association will be presented.

  20. In-situ thermal testing program strategy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    In the past year the Yucca Mountain Site Characterization Project has implemented a new Program Approach to the licensing process. The Program Approach suggests a step-wise approach to licensing in which the early phases will require less site information than previously planned and necessitate a lesser degree of confidence in the longer-term performance of the repository. Under the Program Approach, the thermal test program is divided into two principal phases: (1) short-term in situ tests (in the 1996 to 2000 time period) and laboratory thermal tests to obtain preclosure information, parameters, and data along with bounding information for postclosure performance; and (2) longer-term in situ tests to obtain additional data regarding postclosure performance. This effort necessitates a rethinking of the testing program because the amount of information needed for the initial licensing phase is less than previously planned. This document proposes a revised and consolidated in situ thermal test program (including supporting laboratory tests) that is structured to meet the needs of the Program Approach. A customer-supplier model is used to define the Project data needs. These data needs, along with other requirements, were then used to define a set of conceptual experiments that will provide the required data within the constraints of the Program Approach schedule. The conceptual thermal tests presented in this document represent a consolidation and update of previously defined tests that should result in a more efficient use of Project resources. This document focuses on defining the requirements and tests needed to satisfy the goal of a successful license application in 2001, should the site be found suitable.

  1. In situ rheology of yeast biofilms.

    Science.gov (United States)

    Brugnoni, Lorena I; Tarifa, María C; Lozano, Jorge E; Genovese, Diego

    2014-01-01

    The aim of the present work was to investigate the in situ rheological behavior of yeast biofilms growing on stainless steel under static and turbulent flow. The species used (Rhodototula mucilaginosa, Candida krusei, Candida kefyr and Candida tropicalis) were isolated from a clarified apple juice industry. The flow conditions impacted biofilm composition over time, with a predominance of C. krusei under static and turbulent flow. Likewise, structural variations occurred, with a tighter appearance under dynamic flow. Under turbulent flow there was an increase of 112 μm in biofilm thickness at 11 weeks (p rheology and contribute to a thin body of knowledge about fungal biofilm formation.

  2. Computer Aided in situ Cognitive Behavioral Therapy

    DEFF Research Database (Denmark)

    Chongtay, Rocio A.; Hansen, John Paulin; Decker, Lone

    2006-01-01

    . One of the most common and successfully used treatments for phobic conditions has been Cognitive Behavioral Therapy (CBT), which helps people learn to detect thinking patterns that trigger the irrational fear and to replace them with more realistic ideas. The health and financial impacts in society...... presented here is being designed in a modular and scalable fashion. The web-based module can be accessed anywhere any time from a PC connected to the internet and can be used alone or as supplement for a location-based module for in situ gradual exposure therapy....

  3. In Situ Preservation of Historic Spacecraft

    Science.gov (United States)

    Barclay, R.; Brooks, R.

    The loss of the Mir space station is shown to symbolize a new consciousness of the value of space artefacts. The reasons why such artefacts as Mir become historic objects worthy of preservation are examined. Preservation of space vehicles in situ is discussed, with particular reference to safety, monitoring and long term costs. An argument is made for a wider definition for World Heritage designations to include material beyond the surface of the Earth, and for international bodies to assess, monitor and oversee these projects. Such heritage sites are seen as an economic driver for the development of space tourism in the 21st century.

  4. In situ viscometry by optical trapping interferometry

    Science.gov (United States)

    Guzmán, Camilo; Flyvbjerg, Henrik; Köszali, Roland; Ecoffet, Carole; Forró, László; Jeney, Sylvia

    2008-11-01

    We demonstrate quantitative in situ viscosity measurements by tracking the thermal fluctuations of an optically trapped microsphere subjected to a small oscillatory flow. The measured power spectral density of the sphere's positions displays a characteristic peak at the driving frequency of the flow, which is simply proportional to the viscosity, when measured in units of the thermal power spectral density at the same frequency. Measurements are validated on different water-glycerol mixtures, as well as in a glycerol gradient, where no a priori knowledge of the solution is used to determine the glycerol concentration.

  5. In situ characterization of undulator magnetic fields.

    Science.gov (United States)

    Moreno, Thierry; Otero, Edwige; Ohresser, Philippe

    2012-03-01

    A new in situ method is proposed to characterize the peak magnetic fields of undulator sources. The X-ray beam emitted by the HU52 Apple-2 undulator of the DEIMOS beamline of the SOLEIL synchrotron is analyzed using the Bragg diffraction of a Si(111) crystal. Measurements over the undulator gap range in linear horizontal polarization are compared with simulations in order to rebuild the Halbach function linking the undulator gaps to their peak magnetic fields. The method presented also allows information about the electron beam to be obtained.

  6. Polypropylene/graphite nanocomposites by in situ polymerization; Nanocompositos polipropileno/grafite via polimerizacao in situ

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Marceo A.; Galland, Giselda B., E-mail: griselda@iq.ufrgs.br [Instituto de Quimica, UFRGS, Porto Alegre, RS (Brazil); Quijada, Raul [Universidade de Chile, Santiago (Chile). Centro de Ciencias de los Materiales; Basso, Nara R.S. [Fac. de Quimica, PUCRS, Porto Alegre, RS (Brazil)

    2011-07-01

    This work presents the synthesis of nanocomposites of polypropylene/graphite by in situ polymerization using metallocene catalyst and graphene nanosheets. Initially was analyzed which of the metallocene catalysts rac-Et(Ind){sub 2}ZrCl{sub 2} or rac-Me{sub 2}Si(Ind){sub 2}ZrCl{sub 2} produces polypropylene with mechanical properties more relevant. Then it were performed the in situ polymerization reactions to obtain the nanocomposites. The polymeric materials were characterized by XRD, DSC, GPC and DMTA. (author)

  7. Laser-assited subepithelial keratomileusis combined with mitomycin C for special myopia%LASEK联合丝裂霉素C矫正特殊近视眼的临床研究

    Institute of Scientific and Technical Information of China (English)

    李卫涛; 李虎; 王小芳; 魏静; 王芳; 乔鹏; 唐雨姿

    2012-01-01

    Objective To investigate the clinical value of laser-assisited sub-epithelial keratomilcusis(LASEK) combined with mitomycin C for special myopia.Methods Sixty-four eyes of special myopia(small eye,thin comea,special corneal currature,et al) were treated by LASEK combined with mitomycin C and followed for 6 months.Periodic follow-up was done to observe postoperative symptoms,uncorrected visual acuity,refraction,corneal topography and haze occurrence.Results For 64 eyes of 32 cases,60 eyes (93.75%) uncorrected visual acuity (UAVA) reached or exceed their preoperative corrected visual acuity,the postoperative refraction of 57 eyes (89.06%) were within ± 1.O0 D.According to the corneal topography examination,graphic symmetry was good without obvious bias cutting.Haze occurred in 5 eyes(7.81%) after operation,they were all ≤1 grade according the Fantes(1990) grading standards.There was no serious complication in the operation course or postoperation.Conclusions For special myopia,LASEK combined with mitomycin C is safe,effective and expands the application of laser-assisted in situ keratomileusis.%目的 研究准分子激光上皮瓣下磨镶术(LASEK)联合丝裂霉素C治疗特殊近视眼群体的临床效果.方法 应用美国VISX STAR S4IR型准分子激光对64眼特殊的近视群体(眼球较小、眼窝较深、角膜偏薄、曲率相对异常等)行LASEK手术,术中联合使用0.02%丝裂霉素C,术后随诊6个月,定期随诊术后症状、裸眼视力、屈光度、角膜地形图、角膜上皮下混浊(haze)发生情况.结果 32例64眼中,60眼(93.75%)术后裸眼视力达到或超过术前最佳矫正视力;57眼(89.06%)术后屈光度在±1.00 D之间;所有病例角膜地形图检查对称性良好,无偏心切削;术后6个月有5眼(7.8 1%)出现haze,按照Fantes(1990)分级标准≤l级;术中、术后无严重并发症.结论 LASEK联合丝裂霉素C治疗特殊近视眼类型安全有效,并且拓宽了准分子激光手术的治疗范围.

  8. In situ combustion field experiences in Venezuela

    Energy Technology Data Exchange (ETDEWEB)

    Villalba, M.; Estrada, M.; Bolivar, J. [INTEVEP, Caracas (Venezuela)

    1995-02-01

    A literature review of four in situ combustion projects: in Miga, Tia Juana, Melones and Morichal fields in Venezuela was made, and a summary of these projects is presented. Reservoir description and project performance data were analyzed. The behavior of the four in situ combustion field tests can be summarized as follows: The problems most often encountered were corrosion and high temperature producing wells. The direction in which the burning front moved was guided essentially by reservoir characteristics. The produced oil was upgraded by about 4{degrees} API, and viscosity was substantially reduced. For Mirochal and Miga fields, the analyses of available information from the combustion projects indicated that the process has been successful in the affected region. Conclusions from this review indicate that the two most frequent problems encountered were operational problems in producing wells and the direction of the burning front. The heterogeneous nature of the sands probably resulted in the burning front moving in a preferential direction, hence reducing areal sweep efficiency.

  9. GAS TURBINE REHEAT USING IN SITU COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    D.M. Bachovchin; T.E. Lippert; R.A. Newby P.G.A. Cizmas

    2004-05-17

    In situ reheat is an alternative to traditional gas turbine reheat design in which fuel is fed through airfoils rather than in a bulky discrete combustor separating HP and LP turbines. The goals are to achieve increased power output and/or efficiency without higher emissions. In this program the scientific basis for achieving burnout with low emissions has been explored. In Task 1, Blade Path Aerodynamics, design options were evaluated using CFD in terms of burnout, increase of power output, and possible hot streaking. It was concluded that Vane 1 injection in a conventional 4-stage turbine was preferred. Vane 2 injection after vane 1 injection was possible, but of marginal benefit. In Task 2, Combustion and Emissions, detailed chemical kinetics modeling, validated by Task 3, Sub-Scale Testing, experiments, resulted in the same conclusions, with the added conclusion that some increase in emissions was expected. In Task 4, Conceptual Design and Development Plan, Siemens Westinghouse power cycle analysis software was used to evaluate alternative in situ reheat design options. Only single stage reheat, via vane 1, was found to have merit, consistent with prior Tasks. Unifying the results of all the tasks, a conceptual design for single stage reheat utilizing 24 holes, 1.8 mm diameter, at the trailing edge of vane 1 is presented. A development plan is presented.

  10. Molecular cytogenetics using fluorescence in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.

    1990-12-07

    Fluorescence in situ hybridization (FISH) with chromosome-specific probes enables several new areas of cytogenetic investigation by allowing visual determination of the presence and normality of specific genetic sequences in single metaphase or interphase cells. in this approach, termed molecular cytogenetics, the genetic loci to be analyzed are made microscopically visible in single cells using in situ hybridization with nucleic acid probes specific to these loci. To accomplish this, the DNA in the target cells is made single stranded by thermal denaturation and incubated with single-stranded, chemically modified probe under conditions where the probe will anneal only with DNA sequences to which it has high DNA sequence homology. The bound probe is then made visible by treatment with a fluorescent reagent such as fluorescein that binds to the chemical modification carried by the probe. The DNA to which the probe does not bind is made visible by staining with a dye such as propidium iodide that fluoresces at a wavelength different from that of the reagent used for probe visualization. We show in this report that probes are now available that make this technique useful for biological dosimetry, prenatal diagnosis and cancer biology. 31 refs., 3 figs.

  11. Inherently safe in situ uranium recovery.

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, James Lee; Beauheim, Richard Louis; Brady, Patrick Vane; Arnold, Bill Walter; Kanney, Joseph F.; McKenna, Sean Andrew

    2009-05-01

    Expansion of uranium mining in the United States is a concern to some environmental groups and sovereign Native American Nations. An approach which may alleviate some problems is to develop inherently safe in situ uranium recovery ('ISR') technologies. Current ISR technology relies on chemical extraction of trace levels of uranium from aquifers that, once mined, can still contain dissolved uranium and other trace metals that are a health concern. Existing ISR operations are few in number; however, high uranium prices are driving the industry to consider expanding operations nation-wide. Environmental concerns and enforcement of the new 30 ppb uranium drinking water standard may make opening new mining operations more difficult and costly. Here we propose a technological fix: the development of inherently safe in situ recovery (ISISR) methods. The four central features of an ISISR approach are: (1) New 'green' leachants that break down predictably in the subsurface, leaving uranium, and associated trace metals, in an immobile form; (2) Post-leachant uranium/metals-immobilizing washes that provide a backup decontamination process; (3) An optimized well-field design that increases uranium recovery efficiency and minimizes excursions of contaminated water; and (4) A combined hydrologic/geochemical protocol for designing low-cost post-extraction long-term monitoring. ISISR would bring larger amounts of uranium to the surface, leave fewer toxic metals in the aquifer, and cost less to monitor safely - thus providing a 'win-win-win' solution to all stakeholders.

  12. In situ SU-8 silver nanocomposites

    Directory of Open Access Journals (Sweden)

    Søren V. Fischer

    2015-07-01

    Full Text Available Nanocomposite materials containing metal nanoparticles are of considerable interest in photonics and optoelectronics applications. However, device fabrication of such materials always encounters the challenge of incorporation of preformed nanoparticles into photoresist materials. As a solution to this problem, an easy new method of fabricating silver nanocomposites by an in situ reduction of precursors within the epoxy-based photoresist SU-8 has been developed. AgNO3 dissolved in acetonitrile and mixed with the epoxy-based photoresist SU-8 forms silver nanoparticles primarily during the pre- and post-exposure soft bake steps at 95 °C. A further high-temperature treatment at 300 °C resulted in the formation of densely homogeneously distributed silver nanoparticles in the photoresist matrix. No particle growth or agglomeration of nanoparticles is observed at this point. The reported new in situ silver nanocomposite materials can be spin coated as homogeneous thin films and structured by using UV lithography. A resolution of 5 µm is achieved in the lithographic process. The UV exposure time is found to be independent of the nanoparticle concentration. The fabricated silver nanocomposites exhibit high plasmonic responses suitable for the development of new optoelectronic and optical sensing devices.

  13. Mitigating in situ oil sands carbon costs

    Energy Technology Data Exchange (ETDEWEB)

    Theriault, D.J.; Peterson, J. [Laricina Energy Ltd., Calgary, AB (Canada); Heinrichs, H. [Canadian Chemical Technology Inc., Calgary, AB (Canada)

    2008-10-15

    Carbon capture and sequestration is a complex problem with a variety of dimensions that need to be considered. The political, social, and regulatory pressures are forcing carbon costs on the oil sands industry in an effort to reduce the carbon footprint of oil sands operations. This paper reviewed the political, social, and regulatory pressures and obligations for the in-situ oil sands industry. It presented the views and insights of Laricina Energy on the carbon challenge. It also described the initiatives that Laricina Energy is taking to manage these imperatives and outlined the challenges the industry is facing. The purpose of the paper was to encourage dialogue and collaboration by the oil sands industry. The paper also described the dimensions of the carbon problem and how the industry can contribute to a solution. Last, the paper reviewed the parameters of carbon dioxide or greenhouse gas containment and storage issues. It was concluded that the regulatory and policy requirements need to be clarified so that industry understands the new business landscape as well as the requirements that influence the economics of in-situ oil sands development. 7 refs., 7 figs.

  14. Changes of corneal wavefront aberrations and topography after laser in situ keratomileusis for myopia%近视眼LASIK手术前后角膜波阵面像差和地形图的变化

    Institute of Scientific and Technical Information of China (English)

    周炜; 彭子春; 黄蕊; 郑洁

    2005-01-01

    目的:探讨LASIK矫治近视眼前后角膜前表面波阵面像差与地形图的变化及影响因素.方法:术后裸眼视力1.O以上,接受LASIK矫治的近视者100例200眼.回顾术前和术后1mo时使用Optikon-2000角膜地形图仪测得的角膜地形图和角膜波阵面像差数据.记录角膜测量区为3.0,4.5,6.0mm时术前和术后Zernike多项式系数的变化,分析切除区大小对角膜波阵面像差测量结果的影响,以及角膜地形图与角膜波阵面像差的相关性.结果:角膜测量区直径为3.0,4.5,6.0mm时,分别有4,8,9项Zernike系数手术前后的差别具有显著性或非常显著性.当测量区的直径在4.5mm和6.0mm时,RMS的增大均有显著的意义(P<0.05,P<0.01).角膜切除区直径小于测量直径时,术后RMS的增大有非常显著性(P<O.01).角膜地形图参数BFC和BFIT分别与角膜波阵面像差的散光和RMS成正相关(r=0.6756,P<0.001;r=0.6076,P<0.001).结论:LASIK矫治近视眼术后角膜前表面波阵面像差的增大与角膜测量直径有关,角膜地形图参数BFC和BFIT变化能反映角膜波阵面像差散光和RMS的变化.

  15. 虹膜定位波前引导的LASIK与标准LASIK比较治疗近视散光疗效的Meta分析%Iris-Registration in Wavefront-Guided LASIK versus Conventional LASIK for Correction of Myopia and Myopic Astigmatism: A Meta-Analysis

    Institute of Scientific and Technical Information of China (English)

    李岩; 成拾明; 周霞; 许玲

    2013-01-01

    Objective To systematically evaluate the efficacy and safety of iris-registration in wavefront-guided LASIK (IR+WG LASIK) versus conventional LASIK for correction of myopia accompanied with astigmatism. Methods Such databases as PubMed, EMbase, The Cochrane library (Issue 2, 2012), CBM, CNKI, VIP, and WangFang Data were searched to collect the randomized controlled trials (RCTs) and quasi-RCTs about IR+WG LASIK versus conventional LASIK for correction of myopia accompanied with astigmatism. The retrieval time was from inception to February 2012, and the language was in both Chinese and English. Two reviewers independently screened the literature, extracted the data and assessed the quality of the included studies. Then the meta-analysis was performed by using RevMan 5.1 software. Results A total of 9 studies involving 3 903 eyes were included. The results of meta-analysis showed that, compared with the conventional LASIK group, the IR+WG LASIK group had a higher ratio in patients with postoperative un-corrected visual acuity no less than 1.0 (RR=1.03, 95%CI 1.01 to 1.05, P=0.002), as well as in patients with best-corrected visual acuity gained over 1 line (RR=1.75, 95%CI 1.49 to 2.16, P<0.000 01); it was smaller in the postoperative high order aberration RMS (WMD=-0.16, 95%CI -0.21 to -0.11, P<0.000 01), coma-like RMS (WMD=-0.05, 95%CI -0.11 to 0.00, P=0.07), spherical-like RMS (WMD=-0.15, 95%CI -0.23 to -0.07, P=0.000 2), and residual astigmatism (WMD=0.14, 95%CI 0.10 to 0.18, P<0.000 01); moreover, it was lower in the incidence of postoperative glare (RR=0.27, 95%CI 0.15 to 0.50, P<0.000 1), and it was higher in the subjective satisfaction of patients (RR=1.08, 95%CI 1.04 to 1.13, P=0.000 3). Conclusion Compared with conventional LASIK, IR+WG LASIK can more effectively reduce astigmatism, postoperative high order aberration RMS and spherical-like RMS. It can also get visual function including uncorrected visual acuity and best-corrected visual acuity

  16. 兔Epi-LASIK与Flap-free Epi-LASIK术后TGF-β 2和b-FGF的表达及其对Haze形成的影响研究%Research of TGF- β 2 and b-FGF's expression after Epi-LASIK and Flap-free Epi-LASIK on rabbit and discuss the influence on Haze

    Institute of Scientific and Technical Information of China (English)

    向一旻; 杜之渝; 刘玺; 黄正; 赵武校

    2009-01-01

    目的 观察比较Haze形成过程中的两个主要调控因子TGF-β和b-FGF,在兔Epi-LASIK与Flap-free Epi-LASIK术后表达有否差异,并探讨其对术后Haze形成的影响.方法 选用18只实验兔,建立兔Flap-free Epi-LASIK、Epi-LASIK模型,用VISX20/20B准分子激光仪作-10D切削,在无任何药物干预的情况下观察术后1、2、3月角膜Haze情况及检测比较角膜TGF-β2和b-FGF的表达水平,并探讨其对Haze形成的影响.结果 裂隙灯下观察Haze分级水平在术后1月、2月、3月差异均无统计学意义.Flap-free Epi-LASIK和Epi-LASIK术后1、2、3月TGF-β2表达差异没有统计学意义,且表现出逐渐降低的趋势.术后各时间点b-FGF表达组间比较差异无统计学意义,组内比较,b-FGF表达水平均呈现出持续升高的特点.结论 Epi-LASIK与Flap-free Epi-LASIK术后各时间点TGF-β2和b-FGF的表达情况及Haze发生程度均未见明显差异.%Objective To observe and compare the main control factor TGF-β 2 and b-FGF's expres-sion after the operation Epi-LASIK and Flap-free Epi-LASIK on rabbit during the process of Haze forming and discuss the influence on Haze forming after the operation. Methods 18 rabbits are established as Flap-free Epi-LASIK、Epi-LASIK models.Do-10D artherectomy with VISX20/20B.Then observe the Haze of 1、2、3m cornea under the situation without any drug intervention niter operation.Test and compare cornea TGF-β 2 and b-FGF expression and discuss its influence on Haze forming. Results It shows that there is no statistic mean-ing of the discrepancy of Haze after 1 month, 2 months and 3 months observing with slit lamp.The expression discrepancy of 1、2、3mTGF-β 2 niter Flap-free Epi-LASIK & Epi-LASIK is also no statistic meaning,and it presents falling trend.On each time point niter operation, comparing of each b-FGF, the discrepancy is no statis-tic meaning.Comparing in group,the expression of b-FGF presents rising trend. Conclusion There is no obvi

  17. Alternatieve in situ bodemsaneringstechnieken; literatuuronderzoek bij het project "In Situ Biorestauratie" Asten

    NARCIS (Netherlands)

    Scheuter AJ; LBG

    1997-01-01

    In developing in situ remediation most of the focus used to be on techniques using infiltration water to supply oxygen to the location. Later, techniques were developed in which soil was flushed with air to enhance the oxygen availability to microorganisms. The aim of the study reported here was to

  18. Alternatieve in situ bodemsaneringstechnieken; literatuuronderzoek bij het project "In Situ Biorestauratie" Asten

    NARCIS (Netherlands)

    Scheuter AJ; LBG

    1997-01-01

    In developing in situ remediation most of the focus used to be on techniques using infiltration water to supply oxygen to the location. Later, techniques were developed in which soil was flushed with air to enhance the oxygen availability to microorganisms. The aim of the study reported here was to

  19. The effect of humidity and temperature on visual outcomes after myopic corneal laser refractive surgery

    Directory of Open Access Journals (Sweden)

    Hood CT

    2016-11-01

    Full Text Available Christopher T Hood,1 Roni M Shtein,1 Daniel Veldheer,1,2 Munira Hussain,1 Leslie M Niziol,1 David C Musch,1,3 Shahzad I Mian1 1Department of Ophthalmology and Visual Sciences, University of Michigan W.K. Kellogg Eye Center, Ann Arbor, MI, 2Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, 3Department of Epidemiology, University of Michigan, Ann Arbor, MI, USA Objective: To determine whether procedure room environmental conditions are associated with outcomes after myopic laser in situ keratomileusis (LASIK or laser-assisted keratomileusis (LASEK. Design: Retrospective chart review. Participants: Eight hundred sixty-three eyes of 458 consecutive patients at a university-based academic practice. Methods: We reviewed the medical records of consecutive patients who underwent LASIK or LASEK over a 3-year period. Linear mixed regression models were used to investigate the association of laser room temperature and humidity with the outcomes of visual acuity and postoperative manifest spherical equivalent refraction. Repeated measures logistic regression models were used for the outcomes of diffuse lamellar keratitis (DLK and need for enhancement surgery. Results: Subjects were on an average 38.6 years old at the time of surgery (standard deviation [SD] =10.3 and the average spherical equivalent refraction of eyes was 3.8 diopters (SD =2.03. Regression models did not reveal a significant association between temperature and uncorrected distance visual acuity (UDVA or corrected distance visual acuity (CDVA, or between humidity and UDVA (P>0.05 for all. However, increased humidity was associated with a small but statistically significant improvement in CDVA after LASIK at 1 day, 1 month, 3 months, and 1 year postoperatively (P<0.05 for all. There was no significant association between temperature and humidity and the need for enhancement, the incidence of DLK, or postoperative manifest refraction. Conclusion: While increased laser

  20. Refractive surgery: Is the new small-incision lenticule extraction (SMILE) technique equal to or better than the standard flap-and-ablation (FS-LASIK) technique for treating high-degree myopia?

    DEFF Research Database (Denmark)

    Hansen, Rasmus Søgaard; Lyhne, Niels; Grauslund, Jakob

    treated with SMILE or FS-LASIK for high-degree myopia from 2011-2013 at the Department of Ophthalmology, Odense University Hospital, Denmark. Inclusion criteria: Best spectacle-corrected visual acuity (BSCVA) of 20/25 or better on Snellen chart, and no other ocular condition than high-degree myopia...

  1. Refractive surgery: Is the new small-incision lenticule extraction (SMILE) technique equal to or better than the standard flap-and-ablation (FS-LASIK) technique for treating high-degree myopia?

    DEFF Research Database (Denmark)

    Hansen, Rasmus Søgaard; Lyhne, Niels; Grauslund, Jakob

    2014-01-01

    treated with SMILE or FS-LASIK for high-degree myopia from 2011-2013 at the Department of Ophthalmology, Odense University Hospital, Denmark. Inclusion criteria: Best spectacle-corrected visual acuity (BSCVA) of 20/25 or better on Snellen chart, and no other ocular condition than high-degree myopia...

  2. In-situ trainable intrusion detection system

    Energy Technology Data Exchange (ETDEWEB)

    Symons, Christopher T.; Beaver, Justin M.; Gillen, Rob; Potok, Thomas E.

    2016-11-15

    A computer implemented method detects intrusions using a computer by analyzing network traffic. The method includes a semi-supervised learning module connected to a network node. The learning module uses labeled and unlabeled data to train a semi-supervised machine learning sensor. The method records events that include a feature set made up of unauthorized intrusions and benign computer requests. The method identifies at least some of the benign computer requests that occur during the recording of the events while treating the remainder of the data as unlabeled. The method trains the semi-supervised learning module at the network node in-situ, such that the semi-supervised learning modules may identify malicious traffic without relying on specific rules, signatures, or anomaly detection.

  3. IN SITU URANIUM STABILIZATION BY MICROBIAL METABOLITES

    Energy Technology Data Exchange (ETDEWEB)

    Turick, C; Anna Knox, A; Chad L Leverette,C; Yianne Kritzas, Y

    2006-11-29

    Soil contaminated with U was the focus of this study in order to develop in-situ, U bio-immobilization technology. We have demonstrated microbial production of a metal chelating biopolymer, pyomelanin, in U contaminated soil from the Tims Branch area of the Department of Energy (DOE) Savannah River Site (SRS) as a result of tyrosine amendments. Bacterial densities of pyomelanin producers were >106 cells/g wet soil. Pyomelanin demonstrated U chelating and mineral binding capacities at pH 4 and 7. In laboratory studies, in the presence of goethite or illite, pyomelanin enhanced U sequestration by these minerals. Tyrosine amended soils in field tests demonstrated increased U sequestration capacity following pyomelanin production up to 13 months after tyrosine treatments.

  4. Unannounced in situ simulation of obstetric emergencies

    DEFF Research Database (Denmark)

    Sorensen, Jette Led; Lottrup, Pernille; van der Vleuten, Cees

    2014-01-01

    AIM: To describe how unannounced in situ simulation (ISS) was perceived by healthcare professionals before and after its implementation, and to describe the organisational impact of ISS. STUDY DESIGN: Ten unannounced ISS involving all staff were scheduled March-August 2007. Questionnaire surveys...... on staff perceptions were conducted before (2003-2006) and after (2007-2008) implementation of unannounced ISS. Information from the debriefing sessions following each ISS constituted a proxy measure of the organisational impact of the ISS. RESULTS: Five out of ten of the unannounced ISS scheduled were...... conducted. Twenty-three members of the staff at work on a scheduled day for ISS were randomly selected to participate. Questionnaires before implementation revealed that 137/196 (70%) of staff members agreed or strongly agreed that ISS was a good idea and 52/199 (26%) thought it likely to be stressful...

  5. Overview of In - Situ Biodegradation and Enhancement

    Institute of Scientific and Technical Information of China (English)

    DONG Jun; Anthony ADZOMANI; ZHAO Yongsheng

    2002-01-01

    Microbial degradation technologies have been developed to restore ground water quality in aquifers polluted by organic contaminants effectively in recent years. However, in course of the degradation, the formation of biofilms in ground water remediation technology can be detrimental to the effectiveness of a ground water remediation project. Several alternatives are available to a remedial design engineer, such as Permeable Reactive Barriers (PRBs) and in -situ bioremediation, Hydrogen Releasing Compounds (HRCs) barrier, Oxygen Releasing Compounds (ORCs) barrier etc. which are efficient and cost- effective technologies. Excessive biomass formation renders a barrier ineffective in degrading the contaminants, Efforts are made to develop kinetics models which accurately determine bio - fouling and bio - filn formation and to control excessive biomass formation.

  6. In-situ SEM electrochemistry and radiolysis

    DEFF Research Database (Denmark)

    Møller-Nilsen, Rolf Erling Robberstad; Norby, Poul

    Electron microscopy is a ubiquitous technique to see effects which are too small to see with traditional optical microscopes. Recently it has become possible to also image liquid samples by encapsulating them from the vacuum of the microscope and a natural evolution from that has been to include...... microelectrodes on the windows to enable studies of electrohcemical processes. In this way it is possible to perform in-situ electrochemical experiments such as electroplating and charge and discharge analysis of battery electrodes. In a typical liquid cell, electrons are accelerated to sufficiently high energies...... to traverse a thin window made by a silicon nitride membrane, and interact with the sample immersed in liquid. In transmission electron microscopy (TEM) the majority of the electrons continue through the sample to form an image. In scanning electron microscopy (SEM) a fraction of the electrons...

  7. High resolution in situ ultrasonic corrosion monitor

    Science.gov (United States)

    Grossman, R.J.

    1984-01-10

    An ultrasonic corrosion monitor is provided which produces an in situ measurement of the amount of corrosion of a monitoring zone or zones of an elongate probe placed in the corrosive environment. A monitoring zone is preferably formed between the end of the probe and the junction of the zone with a lead-in portion of the probe. Ultrasonic pulses are applied to the probe and a determination made of the time interval between pulses reflected from the end of the probe and the junction referred to, both when the probe is uncorroded and while it is corroding. Corresponding electrical signals are produced and a value for the normalized transit time delay derived from these time interval measurements is used to calculate the amount of corrosion.

  8. Support Routines for In Situ Image Processing

    Science.gov (United States)

    Deen, Robert G.; Pariser, Oleg; Yeates, Matthew C.; Lee, Hyun H.; Lorre, Jean

    2013-01-01

    This software consists of a set of application programs that support ground-based image processing for in situ missions. These programs represent a collection of utility routines that perform miscellaneous functions in the context of the ground data system. Each one fulfills some specific need as determined via operational experience. The most unique aspect to these programs is that they are integrated into the large, in situ image processing system via the PIG (Planetary Image Geometry) library. They work directly with space in situ data, understanding the appropriate image meta-data fields and updating them properly. The programs themselves are completely multimission; all mission dependencies are handled by PIG. This suite of programs consists of: (1)marscahv: Generates a linearized, epi-polar aligned image given a stereo pair of images. These images are optimized for 1-D stereo correlations, (2) marscheckcm: Compares the camera model in an image label with one derived via kinematics modeling on the ground, (3) marschkovl: Checks the overlaps between a list of images in order to determine which might be stereo pairs. This is useful for non-traditional stereo images like long-baseline or those from an articulating arm camera, (4) marscoordtrans: Translates mosaic coordinates from one form into another, (5) marsdispcompare: Checks a Left Right stereo disparity image against a Right Left disparity image to ensure they are consistent with each other, (6) marsdispwarp: Takes one image of a stereo pair and warps it through a disparity map to create a synthetic opposite- eye image. For example, a right eye image could be transformed to look like it was taken from the left eye via this program, (7) marsfidfinder: Finds fiducial markers in an image by projecting their approximate location and then using correlation to locate the markers to subpixel accuracy. These fiducial markets are small targets attached to the spacecraft surface. This helps verify, or improve, the

  9. DUCTAL CARCINOMA IN SITU OF THE BREAST

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To investigate the clinical characteristics, treatment and prognosis of ductal carcinoma in situ (DCIS) of the breast. Methods: Clinicopathological and follow-up data were collected in 52 patients with DCIS. Results: The clinic data showed that 50 patients had signs of breast lumps or/and nipple discharges, 2 patients presented abnormal mammography; 2 patients had lymph node involved; and 14 patients were accompanied with intraductal papillomatosis. All patients were Received surgical therapy. The follow-up data showed 1 patient locally recurred after lumpectomy, and was underwent mastectomy again, then cured. There were no patients died of DCIS. Conclusion: Mastectomy should be a standard surgical mode, and the prognosis of DCIS was favorable, but mammography for screening of asymptomatic women should be strengthened to find DCIS.

  10. In situ Fabrication of Monolithic Copper Azide

    Science.gov (United States)

    Li, Bing; Li, Mingyu; Zeng, Qingxuan; Wu, Xingyu

    2016-04-01

    Fabrication and characterization of monolithic copper azide were performed. The monolithic nanoporous copper (NPC) with interconnected pores and nanoparticles was prepared by decomposition and sintering of the ultrafine copper oxalate. The preferable monolithic NPC can be obtained through decomposition and sintering at 400°C for 30 min. Then, the available monolithic NPC was in situ reacted with the gaseous HN3 for 24 h and the monolithic NPC was transformed into monolithic copper azide. Additionally, the copper particles prepared by electrodeposition were also reacted with the gaseous HN3 under uniform conditions as a comparison. The fabricated monolithic copper azide was characterized by Fourier transform infrared (FTIR), inductively coupled plasma-optical emission spectrometry (ICP-OES), and differential scanning calorimetry (DSC).

  11. Fungal biodegradation of phthalate plasticizer in situ.

    Science.gov (United States)

    Pradeep, S; Faseela, P; Josh, M K Sarath; Balachandran, S; Devi, R Sudha; Benjamin, Sailas

    2013-04-01

    This unique study describes how Aspergillus japonicus, Penicillium brocae and Purpureocillium lilacinum, three novel isolates of our laboratory from heavily plastics-contaminated soil completely utilized the plasticizer di(2-ethylhexyl)phthalate (DEHP) bound to PVC blood storage bags (BB) in simple basal salt medium (BSM) by static submerged growth (28 °C). Initial quantification as well as percentage utilization of DEHP blended to BB were estimated periodically by extracting it into n-hexane. A two-stage cultivation strategy was employed for the complete mycoremediation of DEHP from BB in situ. During the first growth stage, about two-third parts of total (33.5% w/w) DEHP bound to BB were utilized in two weeks, accompanied by increased fungal biomass (~0.15-0.32 g per g BB) and sharp declining (to ~3) of initial pH (7.2). At this stagnant growth state (low pH), spent medium was replaced by fresh BSM (pH, 7.2), and thus in the second stage the remaining DEHP (one-third) in BB was utilized completely. The ditches and furrows seen from the topology of the BB as seen by the 3D AFM image further confirmed the bioremediation of DEHP physically bound to BB in situ. Of the three mycelial fungi employed, P. lilacinum independently showed highest efficiency for the complete utilization of DEHP bound to BB, whose activity was comparable to that of the consortium comprising all the three fungi described herein. To sum up, the two-stage cultivation strategy demonstrated in this study shows that a batch process would efficiently remediate the phthalic acid esters blended in plastics on a large scale, and thus it offers potentials for the management of plastics wastes.

  12. In Situ Field Testing of Processes

    Energy Technology Data Exchange (ETDEWEB)

    J. Wang

    2001-12-14

    The purpose of this Analysis/Model Report (AMR) is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts of the Yucca Mountain Site Characterization Project (YMP). This revision updates data and analyses presented in the initial issue of this AMR. This AMR was developed in accordance with the ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' and ''Technical Work Plan for UZ Flow, Transport, and Coupled Processes Process Model Report. These activities were performed to investigate in situ flow and transport processes. The evaluations provide the necessary framework to: (1) refine and confirm the conceptual model of matrix and fracture processes in the unsaturated zone (UZ) and (2) analyze the impact of excavation (including use of construction water and effect of ventilation) on the UZ flow and transport processes. This AMR is intended to support revisions to ''Conceptual and Numerical Models for UZ Flow and Transport'' and ''Unsaturated Zone Flow and Transport Model Process Model Report''. In general, the results discussed in this AMR are from studies conducted using a combination or a subset of the following three approaches: (1) air-injection tests, (2) liquid-release tests, and (3) moisture monitoring using in-drift sensors or in-borehole sensors, to evaluate the impact of excavation, ventilation, and construction-water usage on the surrounding rocks. The liquid-release tests and air-injection tests provide an evaluation of in situ fracture flow and the competing processes of matrix imbibition. Only the findings from testing and data not covered in the ''Seepage Calibration Model and Seepage Testing Data'' are analyzed in detail in the AMR.

  13. The study on the posterior corneal surface topography after LASIK%LASIK后角膜后表面形态的研究

    Institute of Scientific and Technical Information of China (English)

    许琛琛; 王勤美; 余野

    2001-01-01

    Objective:To investigate the changes in the posterior corneal surface topography after LASIK and the factors that influence the results.Methods:This study comprised 41 eyes of middle and high myopia(2 patients) that had undergone LASIK. Diopter and radius of curvature of posterior corneal surface were measured by Orbscan before operation, and at 3rd day, 3rd month post-operatiion. Eyes were divided into two groups(3mm area and 5mm area) according to the optical diameter of cornea.Results:Significant difference in posterior corneal surface topography existed between pre-operation and post-operation(P<0.05) in corneal center and peripheral(P<0.05). There is significant difference in 3 months and 3 days post operation in 3mm area(P<0.05). The change in radius of curvature of posterior corneal surface was correlated with corneal thickness after LASIK(r=-0.6,P<0.05), but irrelevant to IOP. The change of posterior corneal surface topography was more significant in the corneal thickness less than 350μm(P<0.01).Conclusion:LASIK can decrease the radius of curvature of the posterior corneal surface. The corneal thickness after LASIK is a major contributing factor.%目的:研究激光角膜原位磨镶术(LASIK)前后,角膜后表面屈光度及曲率半径的改变以及影响因素。 方法:随机选择停戴隐形眼镜一月以上的中高度近视41眼进行LASIK治疗,依角膜光学区直径的不同,分3mm区及5mm区两组,应用Orbscan分别观察分析其术前及术后3天、3月角膜后表面屈光度和曲率半径。 结果:各组术前与术后各期相比,角膜后表面屈光度和曲率半径的改变均有显著性意义(P<0.05),角膜中央变化较周边明显(P<0.05),角膜3mm区术后3月与3天相比差异有显著性意义(P<0.05),角膜后表面曲率半径的改变与患眼正常眼压无关,与术后角膜厚度存在统计学相关性(r=-0.6,P<0.05),厚度小于350μm时角膜后表

  14. In-situ gelling polymers for biomedical applications

    CERN Document Server

    2015-01-01

    This book presents the research involving in situ gelling polymers and can be used as a guidebook for academics, industrialists and postgraduates interested in this area. This work summaries the academic contributions from the top authorities in the field and explore the fundamental principles of in situ gelling polymeric networks, along with examples of their major applications. This book aims to provide an up-to-date resource of in situ gelling polymer research.

  15. A review of in-situ EBSD experiments

    Institute of Scientific and Technical Information of China (English)

    Stuart I. WRIGHT; Matthew M. NOWELL

    2005-01-01

    Automated EBSD or Orientation Imaging Microscopy (OIM) systems are being used in combination with other equipment within the scanning electron microscope (SEM) to perform in-situ measurements. This paper briefly reviews OIM studies of in-situ experiments performed using tensile and heating stages as well as in-situ serial sectioning. In particular, in-situ OIM scan results on an aluminum alloy sample deformed in tension; phase transformations in a cobalt sample, recrystallization and grain growth in a copper sample and serial sectioning of a nickel super-alloy sample are reviewed.

  16. Melanoma "in situ" tratado con Imiquimod Melanoma in situ treated with Imiquimod

    Directory of Open Access Journals (Sweden)

    RE Achenbach

    Full Text Available Comunicamos un caso con dos melanomas "in situ", en un varón de 86 años, localizados en ambos lados de la cara con alto riesgo quirúrgico, quien fuera tratado con imiquimod al 5% una vez al día durante dos meses; los resultados hasta el momento, clínicos e histológicos han sido satisfactorios.A 86 years-old man with two melanomas "in situ" at both sides of his face, treated with imiquimod 5% are presented. The patient has a cardiovascular high risk due to isquemic heart disease, for that reason we start the treatment with imiquimod once a day for two months. The clinical and histological response was good and a follow up will be as long as we can.

  17. Detection of denitrification genes by in situ rolling circle amplification - fluorescence in situ hybridization (in situ RCA-FISH) to link metabolic potential with identity inside bacterial cells

    DEFF Research Database (Denmark)

    Hoshino, Tatsuhiko; Schramm, Andreas

    2010-01-01

    A target-primed in situ rolling circle amplification (in situ RCA) protocol was developed for detection of single-copy genes inside bacterial cells and optimized with Pseudomonas stutzeri, targeting nitrite and nitrous oxide reductase genes (nirS and nosZ). Two padlock probes were designed per gene......). Nevertheless, multiple genes (nirS and nosZ; nirS and the 16S rRNA gene) could be detected simultaneously in P. stutzeri. Environmental application of in situ RCA-FISH was demonstrated on activated sludge by the differential detection of two types of nirS-defined denitrifiers; one of them was identified...

  18. Chromogenic in situ hybridization: a multicenter study comparing silver in situ hybridization with FISH.

    Science.gov (United States)

    Bartlett, J M S; Campbell, Fiona M; Ibrahim, Merdol; Wencyk, Peter; Ellis, Ian; Kay, Elaine; Connolly, Yvonne; O'Grady, Anthony; Di Palma, Silvana; Starczynski, Jane; Morgan, John M; Jasani, Bharat; Miller, Keith

    2009-10-01

    Our purposes were to perform a robust assessment of a new HER2 chromogenic in situ hybridization test and report on concordance of silver in situ hybridization (SISH) data with fluorescence in situ hybridization (FISH) data and on intraobserver and interlaboratory scoring consistency. HER2 results were scored from 45 breast cancers in 7 laboratories using the Ventana (Tucson, AZ) INFORM HER-2 SISH assay and in 1 central laboratory using a standard FISH assay. Overall, 94.8% of cases were successfully analyzed by SISH across the 6 participating laboratories that reported data. Concordance for diagnosis of HER2 amplification by SISH compared with FISH was high (96.0% overall). Intraobserver variability (8.0%) and intersite variability (12.66%) of absolute HER2/chromosome 17 ratios appear to be tightly controlled across all 6 participating laboratories. The Ventana INFORM HER-2 SISH assay is robust and reproducible, shows good concordance with a standard FISH assay, and complies with requirements in national guidelines for performance of diagnostic tests.

  19. IN-SITU TRITIUM BETA DETECTOR

    Energy Technology Data Exchange (ETDEWEB)

    J.W. Berthold; L.A. Jeffers

    1998-04-15

    The objectives of this three-phase project were to design, develop, and demonstrate a monitoring system capable of detecting and quantifying tritium in situ in ground and surface waters, and in water from effluent lines prior to discharge into public waterways. The tritium detection system design is based on measurement of the low energy beta radiation from the radioactive decay of tritium using a special form of scintillating optical fiber directly in contact with the water to be measured. The system consists of the immersible sensor module containing the optical fiber, and an electronics package, connected by an umbilical cable. The system can be permanently installed for routine water monitoring in wells or process or effluent lines, or can be moved from one location to another for survey use. The electronics will read out tritium activity directly in units of pico Curies per liter, with straightforward calibration. In Phase 1 of the project, we characterized the sensitivity of fluor-doped plastic optical fiber to tritium beta radiation. In addition, we characterized the performance of photomultiplier tubes needed for the system. In parallel with this work, we defined the functional requirements, target specifications, and system configuration for an in situ tritium beta detector that would use the fluor-doped fibers as primary sensors of tritium concentration in water. The major conclusions from the characterization work are: A polystyrene optical fiber with fluor dopant concentration of 2% gave best performance. This fiber had the highest dopant concentration of any fibers tested. Stability may be a problem. The fibers exposed to a 22-day soak in 120 F water experienced a 10x reduction in sensitivity. It is not known whether this was due to the build up of a deposit (a potentially reversible effect) or an irreversible process such as leaching of the scintillating dye. Based on the results achieved, it is premature to initiate Phase 2 and commit to a prototype

  20. Experimental Measurement of In Situ Stress

    Science.gov (United States)

    Tibbo, Maria; Milkereit, Bernd; Nasseri, Farzine; Schmitt, Douglas; Young, Paul

    2016-04-01

    The World Stress Map data is determined by stress indicators including earthquake focal mechanisms, in situ measurement in mining, oil and gas boreholes as well as the borehole cores, and geologic data. Unfortunately, these measurements are not only infrequent but sometimes infeasible, and do not provide nearly enough data points with high accuracy to correctly infer stress fields in deep mines around the world. Improvements in stress measurements of Earth's crust is fundamental to several industries such as oil and gas, mining, nuclear waste management, and enhanced geothermal systems. Quantifying the state of stress and the geophysical properties of different rock types is a major complication in geophysical monitoring of deep mines. Most stress measurement techniques involve either the boreholes or their cores, however these measurements usually only give stress along one axis, not the complete stress tensor. The goal of this project is to investigate a new method of acquiring a complete stress tensor of the in situ stress in the Earth's crust. This project is part of a comprehensive, exploration geophysical study in a deep, highly stressed mine located in Sudbury, Ontario, Canada, and focuses on two boreholes located in this mine. These boreholes are approximately 400 m long with NQ diameters and are located at depths of about 1300 - 1600 m and 1700 - 2000 m. Two borehole logging surveys were performed on both boreholes, October 2013 and July 2015, in order to perform a time-lapse analysis of the geophysical changes in the mine. These multi-parameter surveys include caliper, full waveform sonic, televiewer, chargeability (IP), and resistivity. Laboratory experiments have been performed on borehole core samples of varying geologies from each borehole. These experiments have measured the geophysical properties including elastic modulus, bulk modulus, P- and S-wave velocities, and density. The apparatus' used for this project are geophysical imaging cells capable

  1. CGS and In Situ Measurements in Gävle 1999

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C; Bargholz, Kim

    1999-01-01

    Calibration of CGS-equipment.In situ measuremts with HPGe-detector (and dose rate meter)in Gävle Sweden as part of the Nordic exercise RESUME99.......Calibration of CGS-equipment.In situ measuremts with HPGe-detector (and dose rate meter)in Gävle Sweden as part of the Nordic exercise RESUME99....

  2. In-situ remediation of contaminated sediments : conceivable and feasible?!

    NARCIS (Netherlands)

    Joziasse, J.; Gun, J. van der

    2000-01-01

    In-situ remediation has assumed large proportions in dealing with terrestrial soil pollution. Although implementation of in-situ remediation for contaminated sediments is restricted by the fact that dredging is necessary for nautical or water management reasons, it should not be discarded

  3. In-situ tensile testing of propellant samples within SEM

    NARCIS (Netherlands)

    Benedetto, G.L. di; Ramshorst, M.C.J. van; Duvalois, W.; Hooijmeijer, P.A.; Heijden, A.E.D.M. van der; Klerk, W.P.C. de

    2015-01-01

    A tensile module system placed within a FEI NovaNanoSEM 650 Scanning Electron Microscope (SEM) was utilized in this work to conduct in-situ tensile testing of propellant material samples. This tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mec

  4. In situ silica-EPDM nanocomposites obtained via reactive processing

    NARCIS (Netherlands)

    Miloskovska, Elena; Hristova-Bogaerds, Denka; van Duin, Martin; de With, Gijsbertus

    2015-01-01

    In situ rubber nanocomposites prepared via reactive batch mixing and via reactive extrusion were studied. Materials produced via reactive batch mixing showed a significantly higher silica content for a similar reaction time as compared to previously prepared in situ nanocomposites using a diffusion

  5. Oxidative stress inhibits calpain activity in situ.

    Science.gov (United States)

    Guttmann, R P; Johnson, G V

    1998-05-22

    In this study, the effects of oxidative stress on calpain-mediated proteolysis and calpain I autolysis in situ were examined. Calpain activity was stimulated in SH-SY5Y human neuroblastoma cells with the calcium ionophore, ionomycin. Calpain-mediated proteolysis of the membrane-permeable fluorescent substrate N-succinyl-L-leucyl-L-leucyl-L-valyl-L-tyrosine-7-amido-4-methylcouma rin, as well as the endogenous protein substrates microtubule-associated protein 2, tau and spectrin, was measured. Oxidative stress, induced by addition of either doxorubicin or 2-mercaptopyridine N-oxide, resulted in a significant decrease in the extent of ionophore-stimulated calpain activity of both the fluorescent compound and the endogenous substrates compared with control, normoxic conditions. Addition of glutathione ethyl ester, as well as other antioxidants, resulted in the retention/recovery of calpain activity, indicating that oxidation-induced calpain inactivation was preventable/reversible. The rate of autolytic conversion of the large subunit of calpain I from 80 to 78 to 76 kDa was decreased during oxidative stress; however, the extent of calpain autolysis was not altered. These data indicate that oxidative stress may reversibly inactivate calpain I in vivo.

  6. Visualizing T cell migration in-situ

    Directory of Open Access Journals (Sweden)

    Alexandre P Benechet

    2014-07-01

    Full Text Available Mounting a protective immune response is critically dependent on the orchestrated movement of cells within lymphoid tissues. The structure of secondary lymphoid organs regulates immune responses by promoting optimal cell-cell and cell-extracellular matrix interactions. Naïve T cells are initially activated by antigen presenting cells in secondary lymphoid organs. Following priming, effector T cells migrate to the site of infection to exert their functions. Majority of the effector cells die while a small population of antigen specific T cells persist as memory cells in distinct anatomical locations. The persistence and location of memory cells in lymphoid and non-lymphoid tissues is critical to protect the host from re-infection. The localization of memory T cells is carefully regulated by several factors including the highly organized secondary lymphoid structure, the cellular expression of chemokine receptors and compartmentalized secretion of their cognate ligands. This balance between the anatomy and the ordered expression of cell surface and soluble proteins regulates the subtle choreography of T cell migration. In recent years, our understanding of cellular dynamics of T cells has been advanced by the development of new imaging techniques allowing in-situ visualization of T cell responses. Here we review the past and more recent studies that have utilized sophisticated imaging technologies to investigate the migration dynamics of naive, effector and memory T cells.

  7. Cubesat in-situ degradation detector (CIDD)

    Science.gov (United States)

    Rievers, Benny; Milke, Alexander; Salden, Daniel

    2015-07-01

    The design of the thermal control and management system (TCS) is a central task in satellite design. In order to evaluate and dimensionize the properties of the TCS, material parameters specifying the conductive and radiative properties of the different TCS components have to be known including their respective variations within the mission lifetime. In particular the thermo-optical properties of the outer surfaces including critical TCS components such as radiators and thermal insulation are subject to degradation caused by interaction with the space environment. The evaluation of these material parameters by means of ground testing is a time-consuming and expensive endeavor. Long-term in-situ measurements on board the ISS or large satellites not only realize a better implementation of the influence of the space environment but also imply high costs. Motivated by this we propose the utilization of low-cost nano-satellite systems to realize material tests within space at a considerably reduced cost. We present a nanosat-scale degradation sensor concept which realizes low power consumption and data rates compatible with nanosat boundaries at UHF radio. By means of a predefined measurement and messaging cycle temperature curves are measured and evaluated on ground to extract the change of absorptivity and emissivity over mission lifetime.

  8. In-situ combustion with solvent injection

    Energy Technology Data Exchange (ETDEWEB)

    D' Silva, J.; Kakade, G. [Society of Petroleum Engineers, Kuala Lumpur (Malaysia)]|[Maharashtra Inst. of Technology, Pune (India)

    2008-10-15

    The effects of combining in situ combustion and heavy hydrocarbon naphtha vapor injection techniques in a heavy oil reservoir were investigated. Oil production rates and steam injection efficiencies were considered. The technique was also combined with toe-to-heel air injection (THAI) processes. The study showed that the modified THAI process achieved high rates of recovery for both primary production and as a follow-up technique in partially depleted reservoirs after cyclic steam and cold production. Oil produced using the modified THAI technique was also partially upgraded by the process. Results of the vapour chamber pressure calculations showed that the volume of oil produced by naphtha assisted gravity drainage was between 1 to 3 times higher than amounts of oil produced by SAGD processes during the same amount of time. The naphtha injection process produced more oil than the steam only process. However, high amounts of naphtha were needed to produce oil. Injection and production rates during the naphtha injection process were higher. Naphtha vapor was injected near the heel of a horizontal producer well. The vapor acted as a thermal and diluent mechanism in order to reduce the viscosity of the heavy oil . 9 refs., 4 tabs., 6 figs.

  9. Photonic MEMS for NIR in-situ

    Energy Technology Data Exchange (ETDEWEB)

    Bond, T C; Cole, G D; Goddard, L L; Behymer, E

    2007-07-03

    We report on a novel sensing technique combining photonics and microelectromechanical systems (MEMS) for the detection and monitoring of gas emissions for critical environmental, medical, and industrial applications. We discuss how MEMS-tunable vertical-cavity surface-emitting lasers (VCSELs) can be exploited for in-situ detection and NIR spectroscopy of several gases, such as O{sub 2}, N{sub 2}O, CO{sub x}, CH{sub 4}, HF, HCl, etc., with estimated sensitivities between 0.1 and 20 ppm on footprints {approx}10{sup -3} mm{sup 3}. The VCSELs can be electrostatically tuned with a continuous wavelength shift up to 20 nm, allowing for unambiguous NIR signature determination. Selective concentration analysis in heterogeneous gas compositions is enabled, thus paving the way to an integrated optical platform for multiplexed gas identification by bandgap and device engineering. We will discuss here, in particular, our efforts on the development of a 760 nm AlGaAs based tunable VCSEL for O{sub 2} detection.

  10. In Situ Immobilization of Selenium in Sediment

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Robert C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stewart, Thomas Austin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    This project focused on the use of a sorbent, carbonated apatite, to immobilize selenium in the environment. It is know that apatite will sorb selenium and based on the mechanism of sorption it is theorized that carbonated apatite will be more effective that pure apatite. Immobilization of selenium in the environment is through the use of a sorbent in a permeable reactive barrier (PRB). A PRB can be constructed by trenching and backfill with the sorbent or in the case of apatite as the sorbent formed in situ using the apatite forming solution of Moore (2003, 2004). There is very little data on selenium sorption by carbonated apatite in the literature. Therefore, in this work, the basic sorptive properties of carbonated apatite were investigated. Carbonated apatite was synthesized by a precipitation method and characterized. Batch selenium kinetic and equilibrium experiments were performed. The results indicate the carbonated apatite contained 9.4% carbonate and uptake of selenium as selenite was rapid; 5 hours for complete uptake of selenium vs. more than 100 hours for pure hydroxyapatite reported in the literature. Additionally, the carbonated apatite exhibited significantly higher distribution coefficients in equilibrium experiments than pure apatite under similar experimental conditions. The next phase of this work will be to seek additional funds to continue the research with the goal of eventually demonstrating the technology in a field application.

  11. Comparison of corneal topography after topography-guided FS-LASIK and wavefront-optimized FS-LASIK%角膜地形图引导与波前像差优化的飞秒LASIK术后角膜地形图比较

    Institute of Scientific and Technical Information of China (English)

    张丽; 周跃华; 徐雯; 李颖; 王玥; 张秋露; 柳静; 胡雅斌

    2016-01-01

    Objective To compare the outcomes of topography-guided LASIK and wavefront-optimized LASIK in eyes of patients undergoing femtosecond laser LASIK (FS-LASIK) for myopia with astigmatism.Methods In this prospective clinical study,44 eyes of 22 patients underwent topography-guided LASIK (topography group) and 43 eyes of 22 patients underwent wavefront-optimized LASIK (wavefront group).The topography treatment was based on data generated by a networked diagnostic device:Wavelight Topolyzer.Visual acuity,refractive error,the index of corneal surface variance (ISV),corneal wavefront aberrations and ablation decentration were evaluated 6 months postoperatively.Data were analyzed using independent t test.Results Six months postoperatively,there were no significant differences in UCVA or BCVA (t=-1.553,-1.570,P>0.05) between the groups.No eyes lost a line of BCVA in either group.There were no statistically significant differences in postoperative average sphere,cylinder refraction or spherical equivalent (SE) between the groups.The postoperative value of ISV increased compared to baseline for both groups (t=5.216,7.870,P<0.05).The mean postoperative ISV in the topography group (39.9±13.0) was significantly lower than that in the wavefront group (44.9±12.2) (t=-2.296,P<0.05).The postoperative mean decentration in the topography group (0.24± 0.29 mm) was less than that in the wavefront group (0.29±±0.31 mm),but the difference was not statistically significant (t=-1.005,P>0.05).There were significant differences in postoperative coma aberrations (Z31) [-0.166 ±0.357 m vs.-0.362±±0.353 m,t=2.325,P<0.05] and spherical aberrations (Z40) [0.390± 0.263 μm vs.0.486±±0.164 μm,t=-2.096,P<0.05] between the two groups.Conclusion Both topography-guided ablation and wavefront-optimized ablation provide good visual acuity and refractive results,but the former treatment results in a better index of corneal surface variance and induces fewer corneal aberrations

  12. Cliuical effecfive of LASIK for hyperopic ~anisometropia in adoleacent%青少年远视屈光参差性弱视LASIK效果观察

    Institute of Scientific and Technical Information of China (English)

    张芬萍; 马红霞; 李晓林

    2011-01-01

    Objective To investigate efficacy and safety of LASIK for hyperopic anisometropic amblyopia in adolescent. Methods 56 Cases (9 - 17 years old) of hyperopic anisometropic amblyopia were involved in the clinical study. The mean corrected visual acuity was 0. 38 ± 0. 09 ; routine perioperative examination was performed. All the patients were accepted birocular vision training and treatment of amblyopia. Results The poatoperative uncorrected visual acuity in 3 months was 0. 65 ± 0. 15 compared 0. 07 ±0.03 preoperatively,and was 0. 68 ±0. 14 in 6 months postoperatively. Postoperative refractionsignificantly decreased ( P <0.05 ). 52 patients improved binocular vision, and 36 patients establish complete stereopsis. Conclusion LASIK for hyperopic anisometropic amblyopia is safe and effective in adolescent. It could improve binocular vision.%目的 探讨准分子激光原位角膜磨镶术( LASIK)矫治青少年重度远视屈光参差性弱视的效果与安全性。方法 56例(56眼)平均矫正视力为0.38±0.09的9~17岁远视屈光参差性弱视纳入观察,常规行围手术期检查。术后进行双眼训练和弱视治疗。结果 术后3个月弱视眼平均裸眼视力由术前的0.07±0.03提高到0.65 ±0.15;术后6个月平均裸眼视力为0.68±0.14。术后矫正视力较术前明显提高;术后屈光度较术前明显降低(P<0.05);52例(92.86%)同时视和融合功能改善,其中36例(64.29%)建立完整立体视功能。结论 青少年远视屈光参差性弱视的LASIK安全有效,有助于改善双眼单视功能。

  13. In situ containment and stabilization of buried waste

    Energy Technology Data Exchange (ETDEWEB)

    Allan, M.L.; Kukacka, L.E.; Heiser, J.H.

    1992-11-01

    The objective of the project was to develop, demonstrate and implement advanced grouting materials for the in-situ installation of impermeable, durable subsurface barriers and caps around waste sites and for the in-situ stabilization of contaminated soils. Specifically, the work was aimed at remediation of the Chemical Waste (CWL) and Mixed Waste Landfills (MWL) at Sandia National Laboratories (SNL) as part of the Mixed Waste Landfill Integrated Demonstration (MWLID). This report documents this project, which was conducted in two subtasks. These were (1) Capping and Barrier Grouts, and (2) In-situ Stabilization of Contaminated Soils. Subtask 1 examined materials and placement methods for in-situ containment of contaminated sites by subsurface barriers and surface caps. In Subtask 2 materials and techniques were evaluated for in-situ chemical stabilization of chromium in soil.

  14. in situ Calcite Precipitation for Contaminant Immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiko Fujita; Robert W. Smith

    2009-08-01

    in situ Calcite Precipitation for Contaminant Immobilization Yoshiko Fujita (Yoshiko.fujita@inl.gov) (Idaho National Laboratory, Idaho Falls, Idaho, USA) Robert W. Smith (University of Idaho-Idaho Falls, Idaho Falls, Idaho, USA) Subsurface radionuclide and trace metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOE’s greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent trace ions, such as the short-lived radionuclide strontium-90, is co-precipitation in calcite. Calcite, a common mineral in the arid western U.S., can form solid solutions with trace metals. The rate of trace metal incorporation is susceptible to manipulation using either abiotic or biotic means. We have previously demonstrated that increasing the calcite precipitation rate by stimulating the activity of urea hydrolyzing microorganisms can result in significantly enhanced Sr uptake. Urea hydrolysis causes the acceleration of calcium carbonate precipitation (and trace metal co-precipitation) by increasing pH and alkalinity, and also by liberating the reactive cations from the aquifer matrix via exchange reactions involving the ammonium ion derived from urea: H2NCONH2 + 3H2O ? 2NH4+ + HCO3- + OH- urea hydrolysis >X:2Ca + 2NH4+ ? 2>X:NH4 + Ca2+ ion exchange Ca2+ + HCO3- + OH- ? CaCO3(s) + H2O calcite precipitation where >X: is a cation exchange site on the aquifer matrix. This contaminant immobilization approach has several attractive features. Urea hydrolysis is catalyzed by the urease enzyme, which is produced by many indigenous subsurface microorganisms. Addition of foreign microbes is unnecessary. In turn the involvement of the native microbes and the consequent in situ generation of reactive components in the aqueous phase (e.g., carbonate and Ca or Sr) can allow dissemination of the reaction over a larger volume and/or farther away from an amendment injection point, as compared to direct addition of the reactants at

  15. MENDING THE IN SITU MANIPULATION BARRIER

    Energy Technology Data Exchange (ETDEWEB)

    PETERSEN, S.W.

    2006-02-06

    In early 2004, the U.S. Department of Energy (DOE) Richland and Fluor Hanford requested technical assistance from the DOE Headquarters EM-23 Technical Assistance Program to provide a team of technical experts to develop recommendations for mending the In Situ Redox Manipulation (ISRM) Barrier in the 100-D Area of the Hanford Site in Washington State. To accommodate this request, EM-23 provided support to convene a group of technical experts from industry, a national laboratory, and a DOE site to participate in a 2 1/2-day workshop with the objective of identifying and recommending options to enhance the performance of the 100-D Area reactive barrier and of a planned extension to the northeast. This report provides written documentation of the team's findings and recommendations. In 1995, a plume of dissolved hexavalent chromium [Cr(VI)], which resulted from operation of the D/DR Reactors at the Hanford site, was discovered along the Columbia River shoreline and in the 100-D Area. Between 1999 and 2003, a reactive barrier using the In Situ Redox Manipulation (ISRM) technology, was installed a distance of 680 meters along the river to reduce the Cr(VI) in the groundwater. The ISRM technology creates a treatment zone within the aquifer by injection of sodium dithionite, a strong reducing agent that scavenges dissolved oxygen (DO) from the aquifer and reduces ferric iron [Fe(III)], related metals, and oxy-ions. The reduction of Fe(III) to ferrous [Fe(II)] iron provides the primary reduction capacity to reduce Cr(VI) to the +3 state, which is less mobile and less toxic. Bench-scale and field-scale treatability tests were initially conducted to demonstrate proof-of principle and to provide data for estimation of barrier longevity. These calculations estimated barrier longevity in excess of twenty years. However, several years after initial and secondary treatment, groundwater in a number of wells has been found to contain elevated chromium (Cr) concentrations

  16. MENDING THE IN SITU MANIPULATION BARRIER

    Energy Technology Data Exchange (ETDEWEB)

    PETERSEN, S.W.

    2006-02-06

    In early 2004, the U.S. Department of Energy (DOE) Richland and Fluor Hanford requested technical assistance from the DOE Headquarters EM-23 Technical Assistance Program to provide a team of technical experts to develop recommendations for mending the In Situ Redox Manipulation (ISRM) Barrier in the 100-D Area of the Hanford Site in Washington State. To accommodate this request, EM-23 provided support to convene a group of technical experts from industry, a national laboratory, and a DOE site to participate in a 2 1/2-day workshop with the objective of identifying and recommending options to enhance the performance of the 100-D Area reactive barrier and of a planned extension to the northeast. This report provides written documentation of the team's findings and recommendations. In 1995, a plume of dissolved hexavalent chromium [Cr(VI)], which resulted from operation of the D/DR Reactors at the Hanford site, was discovered along the Columbia River shoreline and in the 100-D Area. Between 1999 and 2003, a reactive barrier using the In Situ Redox Manipulation (ISRM) technology, was installed a distance of 680 meters along the river to reduce the Cr(VI) in the groundwater. The ISRM technology creates a treatment zone within the aquifer by injection of sodium dithionite, a strong reducing agent that scavenges dissolved oxygen (DO) from the aquifer and reduces ferric iron [Fe(III)], related metals, and oxy-ions. The reduction of Fe(III) to ferrous [Fe(II)] iron provides the primary reduction capacity to reduce Cr(VI) to the +3 state, which is less mobile and less toxic. Bench-scale and field-scale treatability tests were initially conducted to demonstrate proof-of principle and to provide data for estimation of barrier longevity. These calculations estimated barrier longevity in excess of twenty years. However, several years after initial and secondary treatment, groundwater in a number of wells has been found to contain elevated chromium (Cr) concentrations

  17. Ductal carcinoma in situ: a challenging disease

    Directory of Open Access Journals (Sweden)

    Sevilay Altintas

    2011-12-01

    Full Text Available Ductal carcinoma in situ (DCIS represents a heterogenous group of lesions with variable malignant potential. Although it is clearly pre-invasive, not all lesions progress to an invasive malignant disease. The significant increase in the frequency of diagnosis is the result of both widespread use of screening mammography and better recognition among pathologists. Treatment is controversial, but for several decades total mastectomy has been considered as the appropriate treatment. The tendency to be less aggressive in terms of surgery has followed the pattern of events observed in the treatment of invasive breast carcinomas. More recently, it has become clear that breastconserving procedures could be applied and selected on the basis of diagnostics and risk factors. When all patients with DCIS are considered, the overall mortality is extremely low, only about 1–2%. On the other hand, breast-conserving surgery is only curative in 75–85%; 50% of the local recurrences have proven to be invasive with a mortality rate of 12–15%. There is no place for axillary node dissection, adjuvant hormonal treatment or chemotherapy in the treatment. Important factors in predicting local recurrence are age, family history, nuclear grade, comedo-type necrosis, tumor size and margin width. With the addition of radiation therapy to excisional surgery, there is a 50% reduction in the overall local recurrence rate. The Van Nuys Prognostic Index (VNPI, recently updated, is a tool that quantifies measurable prognostic factors that can be used in the decision-making process of treatment. Recent data from large cohort studies and randomized trials have emerged to guide treatment. DCIS is now understood to have diverse malignant potential and it is unlikely that there will be a single treatment for this wide range of lesions. Advances in molecular biology and gene expression profiling of human breast tumors have been providing important insights into the relationship

  18. Microbial Repopulation Following In Situ STAR Remediation

    Science.gov (United States)

    Gerhard, J.; Overbeeke, G.; Edwards, E.; Lomheim, L.; Grant, G.

    2016-12-01

    STAR (Self-sustaining Treatment for Active Remediation) is an emerging remediation technology that employs a self-sustaining smouldering reaction to destroy nonaqueous phase liquids (NAPLs) in the subsurface. The reaction front travels outwards from an ignition well at approximately 0.5 per day and subjects the soil to temperatures of 400°C-1000°C. The objectives of this work were to monitor re-saturation of the soil over time and quantify the microbial repopulation of the treated zone. STAR is currently being applied as a full scale, in situ remedy for coal tar beneath a former creosol manufacturing facility in New Jersey, USA. This study analyzed soil cores taken at regular intervals following STAR treatment, allowing time for groundwater to re-infiltrate and for microbial populations to potentially reestablish. Soil and groundwater were analyzed for total number of microorganisms via quantitative Polymerase Chain Reaction (qPCR), as well as microbial diversity via amplicon sequencing. Results demonstrate that microbes rapidly repopulated over a 2 month period to 106 gene copies/g of soil. However, concentrations in the treated zone did not rise above this concentration over 6 months post-STAR, indicating a low carrying capacity of the treated soil. To examine the system in more detail and consider the effects of bio-stimulation, a bench top column study using site soil and artificial groundwater explored the rate at which STAR-treated soil is repopulated with naturally occurring microorganisms in the presence and absence of lactate and a terminal electron acceptor. Results demonstrated that biostimulation did not increase the carrying capacity of the STAR treated sol, but rather shifted the microbial community to reflect the TEA provided, in this case, promoting sulfate reducers. Overall, the work illustrates that microbial populations in STAR treated soil do recover via groundwater infiltration but robust communities will take time to naturally establish.

  19. In-situ bioassays using caged bivalves

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.H.; Salazar, S.M.

    1995-12-31

    It is important to make the distinction between chemical measurements to assess bioaccumulation potential versus biological measurements to assess potential bioeffects because bioaccumulation is not a bioeffect. Caging provides a unique opportunity to make synoptic measurements of each and facilitates making these measurements over space and time. Measuring bioaccumulation in resident and transplanted bivalves has probably been the most frequently used form of an in-situ bioassay because bivalves concentrate chemicals in their tissues. They are also easy to collect, cage, and measure. The authors have refined bivalve bioassay methods by minimizing the size range of test animals, making repetitive measurements of the same individuals, and standardizing test protocols for a variety of applications. They are now attempting to standardize criteria for accepting and interpreting data in the same way that laboratory bioassays have been standardized. Growth measurements can serve two purposes in this assessment strategy: (1) An integrated biological response endpoint that is easily quantifiable and with significance to the population, and (2) A means of calibrating bioaccumulation by assessing the relative health and physiological state of tissues that have accumulated the chemicals. In general, the authors have found the highest bioconcentration factors associated with the highest growth rates, the highest concentrations ({micro}g/g) of chemicals in juvenile mussels, and the highest chemical content ({micro}g/animal) in adult mussels. Without accounting for possible dilution of chemical concentrations by tissue growth or magnification through degrowth, contaminant concentrations can be misleading. Examples are provided for the Sudbury River in Massachusetts (Elliptio complanata), San Diego Bay (Mytilus galloprovincialis), and the Harbor Island Superfund Site in Puget Sound (Mytilus trossulus).

  20. Laser de femtosegundo versus microceratótomo mecânico na confecção do flap para LASIK

    Directory of Open Access Journals (Sweden)

    Alexander Rodrigo Hasimoto

    2013-12-01

    Full Text Available OBJETIVO: Avaliar comparativamente os resultados cirúrgicos, na técnica LASIK, realizando com laser de femtosegundo e microcerátomo mecânico. MÉTODOS: Estudo clínico, prospectivo, comparativo, randomizado e mascarado de 32 olhos (16 pacientes. Cada paciente foi submetido a diferentes técnicas para o LASIK, em um dos olhos foi utilizado o microcerátomo HansatomeTM Bausch & Lomb (grupo microcerátomo e no outro foi utilizado femtosegundo FEMTO LDV TM Ziemer (grupo femtosegundo. A triagem ocorreu no setor de Cirurgia Refrativa do Hospital de Olhos do Paraná entre 07/2010 e 09/2010. Os critérios de inclusão foram miopia menor que 6,00 D, astigmatismo menor que 3,00 D, menor que 5,00 D de hipermetropia, refração estável, diâmetro corneano menor que 11 mm, descontinuação de lente de contato sete dias antes da avaliação pré-operatória, acuidade visual de no mínimo 20/20 em ambos os olhos. As variáveis analisadas no pré-operatório entre os grupos, femtosegundo e microcerátomo foram: acuidade visual sem correção e com correção, equivalente esférico, aberrações totais de alta ordem, acuidade visual de baixo contraste, preferência do paciente e complicações. RESULTADOS: Todas as variáveis estudadas foram similares nos dois grupos. CONCLUSÃO: Não foi possível observar neste estudo, diferenças significativas entre os grupos analisados

  1. Clinal effects of LASIK on binocular vision in myopic anisometropia%近视性屈光参差患者LASIK术后双眼视功能评估

    Institute of Scientific and Technical Information of China (English)

    杨亮; 胡琦; 康杨; 黄磊; 王珂萌

    2012-01-01

    目的 观察近视性屈光参差患者接受准分子激光原位角膜磨镶术( LASIK)后双眼视功能的变化,探讨LASIK手术矫治近视性屈光参差对三级视功能的影响,从双眼视觉的变化评价其临床应用价值.设计前瞻性病例系列.研究对象36例(72眼)行LASIK手术的近视性屈光参差患者(双眼屈光参差≥2.50 D).方法 对36例行LASIK手术的近视性屈光参差患者分别于手术前和手术后3个月进行裸眼视力、最佳矫正视力、屈光状态和同视机双眼视功能的检测,并对双眼视功能的变化进行随访研究.主要指标手术前后裸眼视力、最佳矫正视力、屈光度、同时视、融合功能、远立体视和近立体视.结果 术前72眼的裸跟视力在0.01-0.2之间,术后3个月时均达到1.0.双跟屈光参差由术前的(5.01±1.96)D( 2.50~9.00 D),降低到术后3个月的( 0.28±0.22 )D(0.00~0.75 D).手术前后的屈光参差度的改变,差异均有显著统计学意义(P<0.01).26例屈光参差量≥2.50 D且≤6.00 D的高度屈光参差者术前戴框架眼镜下近立体视正常的12例,术后3个月增至22例,差异有统计学意义(P<0.05);16例屈光参差量>6.0D的重度屈光参差者手术前后均没有正常近立体视.术前戴框架眼镜下三级视功能(同时视、融合功能、远立体视)正常的分别为33例、18例、13例,LASIK术后3个月三级视功能正常的分别为34例、33例、23例,手术后获得融合功能和远立体视者较术前明显增加(P均<0.05).结论 LASIK矫治近视性屈光参差,不仅可提高患者裸眼视力,而且可通过减小患者双眼间的屈光差异,增加双眼物像的融合,改善立体视功能.%Objective To analyze the clinical effects on binocular vision after LASIK for myopic anisomelropia, and evaluate its clinical value in the view of vision quality. Design Prospective case series. Participants 36 cases (72 eyes) with myopic anisometropia who received

  2. NOVEL IN-SITU METAL AND MINERAL EXTRACTION TECHNOLOGY

    Energy Technology Data Exchange (ETDEWEB)

    Glenn O' Gorman; Hans von Michaelis; Gregory J. Olson

    2004-09-22

    This white paper summarizes the state of art of in-situ leaching of metals and minerals, and describes a new technology concept employing improved fragmentation of ores underground in order to prepare the ore for more efficient in-situ leaching, combined with technology to continuously improve solution flow patterns through the ore during the leaching process. The process parameters and economic benefits of combining the new concept with chemical and biological leaching are described. A summary is provided of the next steps required to demonstrate the technology with the goal of enabling more widespread use of in-situ leaching.

  3. satellite and in-situ measurements

    Directory of Open Access Journals (Sweden)

    José de Jesús Salas Pérez

    2005-01-01

    Full Text Available La distribución espacial y temporal de la circulación superficial de la Bahía de Banderas se obtuvo con el empleo de series temporales de rapidez de viento, temperatura superficial del mar (AVHR radiómetro y un termógrafo, nivel del mar y trazas ascendentes y descendentes del radar altimétrico ERS-2. El período que abarca dichos datos es de cuatro años, ya que comenzó en el verano de 1997 y finalizó en el invierno de 2002. La marea en la Bahía es mixta (F=0.25 con predominio del armónico M2. La bahía no muestra características de resonancia con la marea del mar abierto. Amplitudes promedio de 30 cms., resultan en corrientes de marea de pocos cms./s. Las bajas frecuencias (periodos mayores a tres días parecen ser los principales generadores de la circulación marina en esta área, en la que predomina el periodo estacional sobre los otros periodos. FEOs fueron aplicadas a las componentes de velocidad, calculadas con observaciones de altimetría medidas en la boca de la Bahía, las cuales mostraron dos principales distribuciones espaciales. El primer periodo de distribución, que se extendió desde febrero hasta julio, muestra un flujo de entrada por la porción norte/sur de la bahía, con un flujo de salida por su boca (distribución anticiclónica. El segundo periodo se extiende desde agosto hasta diciembre y es opuesto al primero (distribución ciclónica. Las características de la circulación aquí presentadas son hipotéticas y observaciones de velocidad medidas in-situ deben confirmarlas

  4. In Situ Probe Science at Saturn

    Science.gov (United States)

    Atkinson, D.H.; Lunine, J.I.; Simon-Miller, A. A.; Atreya, S. K.; Brinckerhoff, W.; Colaprete, A.; Coustenis, A.; Fletcher, L. N.; Guillot, T.; Lebreton, J.-P.; Mahaffy, P.; Mousis, O.; Orton, G. S.; Reh, K.; Spilker, L. J.; Spilker, T. R.; Webster, C.

    2014-01-01

    A fundamental goal of solar system exploration is to understand the origin of the solar sys-tem, the initial stages, conditions, and processes by which the solar system formed, how the formation pro-cess was initiated, and the nature of the interstellar seed material from which the solar system was born. Key to understanding solar system formation and subsequent dynamical and chemical evolution is the origin and evolution of the giant planets and their atmospheres. Several theories have been put forward to explain the process of solar system formation, and the origin and evolution of the giant planets and their atmospheres. Each theory offers quantifiable predictions of the abundances of noble gases He, Ne, Ar, Kr, and Xe, and abundances of key isotopic ratios 4He3He, DH, 15N14N, 18O16O, and 13C12C. Detection of certain dis-equilibrium species, diagnostic of deeper internal pro-cesses and dynamics of the atmosphere, would also help discriminate between competing theories. Measurements of the critical abundance profiles of these key constituents into the deeper well-mixed at-mosphere must be complemented by measurements of the profiles of atmospheric structure and dynamics at high vertical resolution and also require in situ explora-tion. The atmospheres of the giant planets can also serve as laboratories to better understand the atmospheric chem-istries, dynamics, processes, and climates on all planets including Earth, and offer a context and provide a ground truth for exoplanets and exoplanetary systems. Additionally, Giant planets have long been thought to play a critical role in the development of potentially habitable planetary systems. In the context of giant planet science provided by the Galileo, Juno, and Cassini missions to Jupiter and Sat-urn, a small, relatively shallow Saturn probe capable of measuring abundances and isotopic ratios of key at-mospheric constituents, and atmospheric structure in-cluding pressures, temperatures, dynamics, and cloud

  5. Morfometría corneal in vivo versus magnitud de la ametropía en pacientes operados con láser de excímeros por la técnica LASIK

    OpenAIRE

    Eduardo Rojas Alvarez

    2012-01-01

    Objetivo: Establecer la correlación entre los cambios morfométricos corneales y la magnitud de la ametropía tratada hasta el año de cirugía corneal con láser de excímeros por la técnica LASIK.   Método: Se realizó una investigación observacional, descriptiva, longitudinal y prospectiva. La muestra quedó constituida por 78 pacientes (151 ojos) operados con LASIK con microquerátomo pendular en el  Hospital Abel Santamaría Cuadrado en Pinar del Río de noviembre de 2010 a junio de 2011. Se utili...

  6. Epoxy nanodielectrics fabricated with in situ and ex situ techniques

    Energy Technology Data Exchange (ETDEWEB)

    Tuncer, Enis [ORNL; Polyzos, Georgios [ORNL; Sauers, Isidor [ORNL; James, David Randy [ORNL; Ellis, Alvin R [ORNL; More, Karren Leslie [ORNL

    2012-01-01

    In this study, we report fabrication and characterisation of a nanocomposite system composed of a commercial resin and extremely small (several nanometres in diameter) titanium dioxide particles. Nanoparticles were synthesised in situ with particle nucleation occurring inside the resin matrix. In this nanodielectric fabrication method, the nanoparticle precursor was mixed to the resin solution, and the nanoparticles were in situ precipitated. Note that no high shear mixing equipment was needed to improve particle dispersion - nanoparticles were distributed in the polymer matrix uniformly since particle nucleation occurs uniformly throughout the matrix. The properties of in situ nanodielectrics are compared to the unfilled resin and an ex situ nanocomposite. We anticipate that the presented in situ nanocomposite would be employed in high-temperature superconductivity applications. In additions, the improvement shown in the dielectric breakdown indicates that conventional high-voltage components and systems can be reduced in size with novel nanodielectrics.

  7. Novel Instrumentation for In Situ Combustion Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Phase I is to develop, demonstrate and test a novel instrument based on laser absorption diagnostics for fast, in situ measurements of important...

  8. Novel Instrumentation for In Situ Combustion Measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Phase I is to develop, demonstrate and test a novel instrument based on laser absorption diagnostics for fast, in situ measurements of...

  9. Fathead minnow whole-mount in situ hybridization (WISH)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This study demonstrates the potential of whole-mount in situ hybridization (WISH), in conjunction with quantitative real-time polymerase chain reaction (QPCR)...

  10. In Situ Oxygen Production from Lunar and Martian Regolith Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In situ oxygen production is of immense importance to NASA in the support of the NASA initiative to sustain man's permanent presence in space. The oxygen produced...

  11. In Situ Instrument to Detect Prebiotic Compounds in Planetary Ices

    Science.gov (United States)

    Getty, Stephanie A.; Dworkin, Jason; Glavin, Daniel P.; Southard, Adrian; Balvin, Manuel; Kotecki, Carl; Ferrance, Jerome

    2013-01-01

    The development of an in situ LC-MS instrument for future planetary science missions to icy surfaces that are of high astrobiology and astrochemistry potential will advance our understanding of organics in the solar system.

  12. An Efficient Heat Exchanger for In Situ Resource Utilization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In situ resource utilization (ISRU) is essential for several of NASA's future flagship missions. Currently envisioned ISRU plants include production of oxygen from...

  13. Real-Time In Situ Landing Site Assessment

    Science.gov (United States)

    Adams, D.; Hibbard, K.; McGee, T.

    2017-02-01

    Landing spacecraft on other objects in the solar system provides a unique opportunity to make direct in situ science measurements, but extraterrestrial environments create unique challenges for the design and testing of the system.

  14. In situ quantification of genomic instability in breast cancer progression

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz de Solorzano, Carlos; Chin, Koei; Gray, Joe W.; Lockett, Stephen J.

    2003-05-15

    Genomic instability is a hallmark of breast and other solid cancers. Presumably caused by critical telomere reduction, GI is responsible for providing the genetic diversity required in the multi-step progression of the disease. We have used multicolor fluorescence in situ hybridization and 3D image analysis to quantify genomic instability cell-by-cell in thick, intact tissue sections of normal breast epithelium, preneoplastic lesions (usual ductal hyperplasia), ductal carcinona is situ or invasive carcinoma of the breast. Our in situ-cell by cell-analysis of genomic instability shows an important increase of genomic instability in the transition from hyperplasia to in situ carcinoma, followed by a reduction of instability in invasive carcinoma. This pattern suggests that the transition from hyperplasia to in situ carcinoma corresponds to telomere crisis and invasive carcinoma is a consequence of telomerase reactivation afertelomere crisis.

  15. Comparison Between Fluorescent In Situ Hybridization (FISH) and ...

    African Journals Online (AJOL)

    ... were collected, for culture method and bacteria characterized by biochemical ... for 24 hours and later preserved in 70% alcohol before in situ hybridization test. ... were observed in 47 to 75% while the bacterium was isolated on culture in 7 ...

  16. In-Situ Burning of Crude Oil on Water

    DEFF Research Database (Denmark)

    van Gelderen, Laurens

    in the small scale water basin. Boilovers were also observed during the burning of a heavy crude oil with a substantial light fraction without a water layer, however, which suggests that water is not essential for boilover occurrence. Further studies are required to determine the conditions under which......The fire dynamics and fire chemistry of in-situ burning of crude oil on water was studied in order to improve predictions on the suitability of this oil spill response method. For this purpose, several operational parameters were studied to determine the factors that control the burning efficiency...... of in-situ burning, i.e. the amount of oil (in wt%) removed from the water surface by the burning process. The burning efficiency is the main parameter for expressing the oil removal effectiveness of in-situ burning as response method and is thus relevant for suitability predictions of in-situ burning...

  17. In-situ Airborne Sampler for Advanced Guided Dropsonde Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a low-cost, retrievable and reusable, autonomously guided dropsonde capable of in-situ atmospheric measurements. The proposed effort will...

  18. Surgical options for correction of refractive error following cataract surgery.

    Science.gov (United States)

    Abdelghany, Ahmed A; Alio, Jorge L

    2014-01-01

    Refractive errors are frequently found following cataract surgery and refractive lens exchange. Accurate biometric analysis, selection and calculation of the adequate intraocular lens (IOL) and modern techniques for cataract surgery all contribute to achieving the goal of cataract surgery as a refractive procedure with no refractive error. However, in spite of all these advances, residual refractive error still occasionally occurs after cataract surgery and laser in situ keratomileusis (LASIK) can be considered the most accurate method for its correction. Lens-based procedures, such as IOL exchange or piggyback lens implantation are also possible alternatives especially in cases with extreme ametropia, corneal abnormalities, or in situations where excimer laser is unavailable. In our review, we have found that piggyback IOL is safer and more accurate than IOL exchange. Our aim is to provide a review of the recent literature regarding target refraction and residual refractive error in cataract surgery.

  19. A review of corneal diameter, curvature and thickness values and influencing factors*

    Directory of Open Access Journals (Sweden)

    K. P. Mashige

    2013-12-01

    Full Text Available The cornea is an important ocular structure involved in the mediation of visual perception. It is the principal refractive surface of the eye and vision can be significantly affected by relatively small changes in its structure and parameters. Measurement of corneal parameters is important in the diagnosis and management of ocular diseasessuch as keratoconus and glaucoma, and also in the fitting of contact lenses or with refractive surgery such as Laser-Assisted in situ Keratomileusis(LASIK and photorefractive keratectomy (PRK. The human corneal diameter, anterior curvature and centre thickness as well as factors influencing them are reviewed in this article. This review will be useful to eye care professionals who routinely measure these parameters when fitting contact lenses and assessing, diagnosing as well as managing corneal and other ocular conditions. (S Afr Optom 2013 72(4 185-194

  20. Using complex networks towards information retrieval and diagnostics in multidimensional imaging

    CERN Document Server

    Banerjee, Soumya Jyoti; Sen, Debanjan; Savale, Smruti; Datta, Himadri; Dasgupta, Anjan Kr; Roy, Soumen

    2015-01-01

    We present a fresh and general yet simple approach towards information retrieval in general and diagnostics in particular by applying the theory of complex networks on multidimensional images. We demonstrate a successful use of our method with the time series generated from high content thermal imaging videos of patients suffering from aqueous deficient dry eye (ADDE) disease. The approach is scalable to a device where fluctuation derived network parameters serve as diagnostic markers. Remarkably, network analysis of thermal imaging time series of contact lens users and patients upon whom Laser-Assisted in situ Keratomileusis (Lasik) surgery has been conducted, exhibits pronounced similarities with results obtained from ADDE patients. We also propose a general framework for transformation of multidimensional images to networks for futuristic biometry.

  1. The therapeutic effects analysis on LASIK surgical correction of myopic and hyperopic anisometropia of visual function in patients%LASIK手术矫治屈光参差患者视功能的疗效分析

    Institute of Scientific and Technical Information of China (English)

    陈利; 杨红; 汪辉; 王科; 宋利兵

    2012-01-01

    目的 探讨LASIK手术治疗儿童屈光参差的疗效.方法 通过回顾性分析30例屈光参差患儿实施LASIK手术前与手术后不同时间视力、屈光度、眼轴、双眼视觉、VEP等视功能参数的变化,了解LASIK手术的疗效.结果 近视组手术后裸眼视力有明显提高(P0.05).两组手术前后眼轴无明显增长(P>0.05).结论 LASIK手术矫治儿童屈光参差,能降低高屈光度眼的屈光力、缩小双眼屈光度的差别,利于双眼融像.%Objective To investigate the efficacy of two sets of anisometropic in patients with LASIK surgery. Methods A retrospectively comparative analysis of the LASIK surgery correcting myopia and anisometropic in patients with postoperative visual function changes. Observe high diopter eyes of 15 cases with myopic anisometropia and 15 cases with hyperopic anisometropia after LASIK surgery preoperative and postoperative 1 year, 2 years, 3 years of visual acuity, and check the diopter ,axial length,binocular vision,and VEP. Results Myopia unconnected visual acuity was significantly improved( P 0. 05 ). The axial length of two groups did not significantly increase( P >0. 05 ). Conclusion LASIK surgery correction of children anisometropia can reduce the refractive power of the high-diopter eye, narrowed eyes diopter difference, which will help the eyes melt.

  2. Single-step transepithelial ASLA (SCHWIND with mitomycin-C for the correction of high myopia: long term follow-up

    Directory of Open Access Journals (Sweden)

    Aslanides IM

    2014-12-01

    Full Text Available Ioannis M Aslanides, Panagiotis N Georgoudis, Vasilis D Selimis, Achyut N Mukherjee Emmetropia Mediterranean Eye Institute, Heraklion, Crete, Greece Purpose: We wanted to compare the outcomes of single-step modified transepithelial photorefractive keratectomy (tPRK termed a SCHWIND all surface laser ablation (ASLA versus conventional alcohol-assisted photorefractive keratectomy (PRK and laser-assisted in situ keratomileusis (LASIK for the correction of higher myopia of 6.00 diopters (D or more, in an area with high risk of haze due to high intensity of sunlight.Methods: We used a prospective interventional cohort with matched retrospective control groups. Patients with >6 D myopia and <3.5 D of astigmatism were included. All treatments were performed with the SCHWIND Amaris system using aspheric ablation profiles. Mitomycin C was used in all PRK and ASLA cases. Outcomes were postoperative refraction, visual acuity, stability, and complications. The follow-up period was up to 12 months.Results: In total, 101 eyes were included after exclusions. Mean preoperative spherical equivalent refraction was −7.9 D, −8.2 D, and −7.4 D in the ASLA (n=41, PRK (n=29, and LASIK (n=31 groups. Mean postoperative spherical equivalent at 12 months postoperatively was −0.1 (standard deviation [SD]: 0.34, −0.2 (SD: 0.59, and −0.08 (SD: 0.36 in the ASLA, PRK, and LASIK groups, with 91.4%, 85.7%, and 83.9% within 0.5 D of target, respectively. Refractive outcomes and regression at 12 months did not vary among groups (P>0.05. Mean logMAR (logarithm of the minimum angle of resolution uncorrected distance visual acuity at 12 months was 0.00 (SD: 0.05, 0.06 (SD: 0.1, and 0.05 (SD: 0.09 in the ASLA, PRK, and LASIK groups, with significantly better vision in the tPRK group versus LASIK (P=0.01 and PRK (P=0.01 groups.Conclusion: ASLA (SCHWIND tPRK with mitomycin C for high myopia demonstrates comparable refractive outcomes to LASIK and PRK, with relatively

  3. In situ guided tissue regeneration in musculoskeletal diseases and aging

    OpenAIRE

    Jakob, Franz; Ebert, Regina; Rudert, Maximilian; Nöth, Ulrich; Walles, Heike; Docheva, Denitsa; Schieker, Matthias; Meinel, Lorenz; Groll, Jürgen

    2016-01-01

    In situ guided tissue regeneration, also addressed as in situ tissue engineering or endogenous regeneration, has a great potential for population-wide “minimal invasive” applications. During the last two decades, tissue engineering has been developed with remarkable in vitro and preclinical success but still the number of applications in clinical routine is extremely small. Moreover, the vision of population-wide applications of ex vivo tissue engineered constructs based on cells, growth and ...

  4. In-situ resist colloidal lithography for affordable plasmonics

    Science.gov (United States)

    Bochenkov, Vladimir E.

    2017-09-01

    A recently developed extension of Sparse Colloidal Lithography, an In-situ Resist Colloidal Lithography method is presented. The technique is based on in-situ deposition of structured resist layer having low adhesion to target material to form nanoparticles of desired shape. A high potential of the method is demonstrated by the examples of fabricated plasmonic nanostructures with different shapes, including concentric and non-concentric rings, disks and chiral comma-like particles.

  5. In situ primary production in young Antarctic sea ice

    OpenAIRE

    Mock, Thomas

    2002-01-01

    An in situ incubation technique used successfully to measure the photosynthetic carbon assimilation of internal algal assemblages within thick multiyear Arctic sea ice was developed and improved to measure the photosynthetic carbon assimilation within young sea ice only 50 cm thick (Eastern Weddell Sea, Antarctica). The new device enabled some of the first precise measurements of in situ photosynthetic carbon assimilation in newly formed Antarctic sea ice.

  6. BAW and SAW sensors for in-situ analysis

    Science.gov (United States)

    Bar-Cohen, Y.; Bao, X. Q.; Chang, Z.; Sherrit, S.

    2003-01-01

    In-situ analysis is a major goal in current and future NASA exploration missions. In general in-situ analysis experiments are designed to investigate chmical, biological or geological markers or properties to determine the complex history of the body being studied. In order to expand the number of applicable sensor schemes an investigation into piezoelectric bulk acoustic wave (BAW) and surface acoustic wave (SAW) resonators has been initiated.

  7. Characterization of VPO ammoxidation catalysts by in situ methods

    Energy Technology Data Exchange (ETDEWEB)

    Martin, A.; Luecke, B.; Brueckner, A.; Steinike, U. [Institut fuer Angewandte Chemie Berlin-Adlershof e.V., Berlin (Germany); Brzezinka, K.W. [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany); Meisel, M. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Chemie

    1998-12-31

    In-situ methods are well known as powerful tools in studying catalyst formation processes, their solid state properties under working conditions and the interaction with the feed, intermediates and products to reveal reaction mechanisms. This paper gives a short overview on results of intense studies using in-situ techniques to reveal VPO catalyst generation processes, interaction of educts, intermediates and products with VPO catalyst surfaces and mechanistic insights. Catalytic data of the ammoxidation of toluene on different VPOs complete these findings. The precursor-catalyst transformation processes were preferently investigated by in-situ XRD, in-situ Raman and in-situ ESR spectroscopy. The interaction of aromatic molecules and intermediates, resp., and VPO solid surfaces was followed by in-situ ESR and in-situ FTIR spectroscopy. Mechanistic information was mainly obtained using in-situ FTIR spectroscopy and the temporal-analysis-of-products (TAP) technique. Catalytic studies were carried out in a fixed-bed microreactor on pure (NH{sub 4}){sub 2}(VO){sub 3}(P{sub 2}O{sub 7}){sub 2}, generated [(NH{sub 4}){sub 2}(VO{sub 3})(P{sub 2}O{sub 7}){sub 2}+V{sub x}O{sub y}] catalysts, having different V{sub x}O{sub y} proportions by use of VOHPO{sub 4} x 1/2H{sub 2}O (V/P=1) and recently studied (VO){sub 3}(PO{sub 4}){sub 2} x 7 H{sub 2}O (V/P=1.5) precursors; the well-known (VO){sub 2}P{sub 2}O{sub 7} was used for comparison. (orig.)

  8. Advanced and In Situ Analytical Methods for Solar Fuel Materials.

    Science.gov (United States)

    Chan, Candace K; Tüysüz, Harun; Braun, Artur; Ranjan, Chinmoy; La Mantia, Fabio; Miller, Benjamin K; Zhang, Liuxian; Crozier, Peter A; Haber, Joel A; Gregoire, John M; Park, Hyun S; Batchellor, Adam S; Trotochaud, Lena; Boettcher, Shannon W

    2016-01-01

    In situ and operando techniques can play important roles in the development of better performing photoelectrodes, photocatalysts, and electrocatalysts by helping to elucidate crucial intermediates and mechanistic steps. The development of high throughput screening methods has also accelerated the evaluation of relevant photoelectrochemical and electrochemical properties for new solar fuel materials. In this chapter, several in situ and high throughput characterization tools are discussed in detail along with their impact on our understanding of solar fuel materials.

  9. Matrix diffusion model. In situ tests using natural analogues

    Energy Technology Data Exchange (ETDEWEB)

    Rasilainen, K. [VTT Energy, Espoo (Finland)

    1997-11-01

    Matrix diffusion is an important retarding and dispersing mechanism for substances carried by groundwater in fractured bedrock. Natural analogues provide, unlike laboratory or field experiments, a possibility to test the model of matrix diffusion in situ over long periods of time. This thesis documents quantitative model tests against in situ observations, done to support modelling of matrix diffusion in performance assessments of nuclear waste repositories. 98 refs. The thesis includes also eight previous publications by author.

  10. Ocular higher-order aberrations features analysis after corneal refractive surgery

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; ZHAO Kan-xing; HE Ji-chang; JIN Ying; ZUO Tong

    2007-01-01

    Background The recent studies have shown that visual performance might be affected by the ocular aberration after the corneal refractive surgery, and try to minimize it. This study was to investigate the effects of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) on the higher order of wavefront aberration and analysis of their characteristics.Method This prospective study involved 32 eyes with similar refractive powers (-5.0 D to -6.0 D preoperatively). LASIK and PRK were performed with the same parameters of 6 mm diameter optical zone and 7 mm diameter transition zone ablation. Wavefront aberrations were tested using a ray tracing technique preoperatively and 3 months postoperatively.Three measurements were obtained for each condition; the root mean squared wavefront error (RMS), values for overall wavefront aberrations and each order of the Zernike aberrations were analyzed using the Matlab software. The 2-tailed t test was used for statistical analysis.Results Overall higher order aberrations were increased from (0.55±0.26) μm preoperatively to (0.93±0.37) μm for PRK and (0.79±0.38) μm for LASIK postoperatively. This was a 1.69 fold increase in the PRK group (t=3.95, P<0.001)and a 1.43 fold increase in the LASIK group (t=2.60, P<0.05). At 3 months, the mean RMS value for higher-order (3rd to 6th) were significantly increased compared with the corresponding preoperative values (P<0.05). The fourth order aberrations, spherical like aberration, were dominant by a 2.64 fold in PRK and a 2.31 fold in LASIK. Different influences of the PRK group and LASIK group were shown in the various zernike components. The statistically significant differences were seen in C40, C4+4, C5+1, C5+3, C5+5 and C6+2 of the PRK group and C3-3, C40, C5-5, C5+5, C6-2 of the LASIK group, which represents a 7.42, 3.58, 9.21, 2.72 and 5.3 fold increases in PRK group, and 6.40, 10.80, 11.06, 3.47 and 6.09 fold increases in LASIK group, respectively. C3

  11. LASIK - Laser Eye Surgery

    Science.gov (United States)

    ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ...

  12. LASIK Eye Surgery

    Science.gov (United States)

    ... are nearsighted. You may need another refractive surgery (enhancement surgery) within a year to remove more tissue. ... may happen due to certain conditions, such as abnormal wound healing, hormonal imbalances or pregnancy. Visual loss ...

  13. IN SITU FIELD TESTING OF PROCESSES

    Energy Technology Data Exchange (ETDEWEB)

    J.S.Y. YANG

    2004-11-08

    The purpose of this scientific analysis report is to update and document the data and subsequent analyses from ambient field-testing activities performed in underground drifts and surface-based boreholes through unsaturated zone (UZ) tuff rock units. In situ testing, monitoring, and associated laboratory studies are conducted to directly assess and evaluate the waste emplacement environment and the natural barriers to radionuclide transport at Yucca Mountain. This scientific analysis report supports and provides data to UZ flow and transport model reports, which in turn contribute to the Total System Performance Assessment (TSPA) of Yucca Mountain, an important document for the license application (LA). The objectives of ambient field-testing activities are described in Section 1.1. This report is the third revision (REV 03), which supercedes REV 02. The scientific analysis of data for inputs to model calibration and validation as documented in REV 02 were developed in accordance with the Technical Work Plan (TWP) ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (BSC 2004 [DIRS 167969]). This revision was developed in accordance with the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.4) for better integrated, consistent, transparent, traceable, and more complete documentation in this scientific analysis report and associated UZ flow and transport model reports. No additional testing or analyses were performed as part of this revision. The list of relevant acceptance criteria is provided by ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654]), Table 3-1. Additional deviations from the TWP regarding the features, events, and processes (FEPs) list are discussed in Section 1.3. Documentation in this report includes descriptions of how, and under what

  14. Characterizing In Situ Uranium and Groundwater Flux

    Science.gov (United States)

    Cho, J.; Newman, M. A.; Stucker, V.; Peacock, A.; Ranville, J.; Cabaniss, S.; Hatfield, K.; Annable, M. D.; Klammler, H.; Perminova, I. V.

    2010-12-01

    The goal of this project is to develop a new sensor that incorporates the field-tested concepts of the passive flux meter to provide direct in situ measures of uranium and groundwater fluxes. The sensor uses two sorbents and resident tracers to measure uranium flux and specific discharge directly; but, sensor principles and design should also apply to fluxes of other radionuclides. Flux measurements will assist with obtaining field-scale quantification of subsurface processes affecting uranium transport (e.g., advection) and transformation (e.g., uranium attenuation) and further advance conceptual and computational models for field scale simulations. Project efforts will expand our current understanding of how field-scale spatial variations in uranium fluxes and those for salient electron donor/acceptors, and groundwater are coupled to spatial variations in measured microbial biomass/community composition, effective field-scale uranium mass balances, attenuation, and stability. The new sensor uses an anion exchange resin to measure uranium fluxes and activated carbon with resident tracers to measure water fluxes. Several anion-exchange resins including Dowex 21K and 21K XLT, Purolite A500, and Lewatit S6328 were tested as sorbents for capturing uranium on the sensor and Lewatit S6328 was determined to be the most effective over the widest pH range. Four branched alcohols proved useful as resident tracers for measuring groundwater flows using activated carbon for both laboratory and field conditions. The flux sensor was redesigned to prevent the discharge of tracers to the environment, and the new design was tested in laboratory box aquifers and the field. Geochemical modeling of equilibrium speciation using Visual Minteq and an up-to-date thermodynamic data base suggested Ca-tricarbonato-uranyl complexes predominate under field conditions, while calculated uranyl ion activities were sensitive to changes in pH, dissolved inorganic carbon (DIC) and alkaline earth

  15. 预防性视网膜激光光凝治疗LASIK术前视网膜变性的护理%Nuring care in the laser coagulation applied in retinal denaturalization before LASIK

    Institute of Scientific and Technical Information of China (English)

    赵娜; 李娇娥; 王倩; 张琳

    2011-01-01

    Objective:To study the nursing experience in the laser coagulation applied in retinal denaturalization before LASIK. Methods:Totally, 1S8 eyes with retinal denaturalization were found in the pre-examination of LASIK. Nursing care was performed before laser coagulation, during and after the treatment. Results: Chromatosis was seen by examination at 2 weeks after laser coagulation. The patients received LASIK in alternated day, and none complication happened after the operation. Conclusion:Good nursing care can guarantee good effects of laser coagulation applied in retinal de-naturalization, improve the success rate and satisfaction rate.%目的:探讨LASIK术前预防性激光治疗视网膜变性及裂孔的护理.方法:LASIK术前检查发现视网膜变性158眼,在进行预防性视网膜激光光凝术前、术中、术后进行护理.结果:光凝2周后复查可见光凝区色素沉着,择期行LASIK手术,术后随访无一例并发症出现.结论:良好的护理方法可以保证视网膜病变激光光凝治疗的疗效,提高LASIK手术的成功率和满意率.

  16. In situ management and domestication of plants in Mesoamerica.

    Science.gov (United States)

    Casas, Alejandro; Otero-Arnaiz, Adriana; Pérez-Negrón, Edgar; Valiente-Banuet, Alfonso

    2007-11-01

    Ethnobotanical studies in Mexico have documented that Mesoamerican peoples practise systems of in situ management of wild and weedy vegetation directed to control availability of useful plants. In situ management includes let standing, encouraging growing and protection of individual plants of useful species during clearance of vegetation, which in some cases may involve artificial selection. The aim of this study was to review, complement and re-analyse information from three case studies which examined patterns of morphological, physiological and genetic effects of artificial selection in plant populations under in situ management in the region. Information on wild and in situ managed populations of the herbaceous weedy plants Anoda cristata and Crotalaria pumila, the tree Leucaena esculenta subsp. esculenta and the columnar cacti Escontria chiotilla, Polaskia chichipe and Stenocereus stellatus from Central Mexico was re-analysed. Analyses compared morphology and frequency of morphological variants, germination patterns, and population genetics parameters between wild and managed in situ populations of the species studied. Species of columnar cacti are under different management intensities and their populations, including cultivated stands of P. chichipe and S. stellatus, were also compared between species. Significant differences in morphology, germination patterns and genetic variation documented between wild, in situ managed and cultivated populations of the species studied are associated with higher frequencies of phenotypes favoured by humans in managed populations. Genetic diversity in managed populations of E. chiotilla and P. chichipe is slightly lower than in wild populations but in managed populations of S. stellatus variation was higher than in the wild. However, genetic distance between populations was generally small and influenced more by geographic distance than by management. Artificial selection operating on in situ managed populations of the

  17. In situ vitrification: application analysis for stabilization of transuranic waste

    Energy Technology Data Exchange (ETDEWEB)

    Oma, K.H.; Farnsworth, R.K.; Rusin, J.M.

    1982-09-01

    The in situ vitrification process builds upon the electric melter technology previously developed for high-level waste immobilization. In situ vitrification converts buried wastes and contaminated soil to an extremely durable glass and crystalline waste form by melting the materials, in place, using joule heating. Once the waste materials have been solidified, the high integrity waste form should not cause future ground subsidence. Environmental transport of the waste due to water or wind erosion, and plant or animal intrusion, is minimized. Environmental studies are currently being conducted to determine whether additional stabilization is required for certain in-ground transuranic waste sites. An applications analysis has been performed to identify several in situ vitrification process limitations which may exist at transuranic waste sites. Based on the process limit analysis, in situ vitrification is well suited for solidification of most in-ground transuranic wastes. The process is best suited for liquid disposal sites. A site-specific performance analysis, based on safety, health, environmental, and economic assessments, will be required to determine for which sites in situ vitrification is an acceptable disposal technique. Process economics of in situ vitrification compare favorably with other in-situ solidification processes and are an order of magnitude less than the costs for exhumation and disposal in a repository. Leachability of the vitrified product compares closely with that of Pyrex glass and is significantly better than granite, marble, or bottle glass. Total release to the environment from a vitrified waste site is estimated to be less than 10/sup -5/ parts per year. 32 figures, 30 tables.

  18. Rapid in situ detection of chromosome 21 by PRINS technique

    Energy Technology Data Exchange (ETDEWEB)

    Pellestor, F.; Girardet, A.; Andreo, B. [CNRS UPR 9008, Montpellier (France)] [and others

    1995-05-08

    The {open_quotes}PRimed IN Situ labeling{close_quotes} (PRINS) method is an interesting alternative to in situ hybridization for chromosomal detection. In this procedure, chromosome labeling is performed by in situ annealing of specific oligonucleotide primers, followed by primer elongation by a Taq polymerase in the presence of labeled nucleotides. Using this process, we have developed a simple and semi-automatic method for rapid in situ detection of human chromosome 21. The reaction was performed on a programmable temperature cycler, with a chromosome 21 specific oligonucleotide primer. Different samples of normal and trisomic lymphocytes and amniotic fluid cells were used for testing the method. Specific labeling of chromosome 21 was obtained in both metaphases and interphase nuclei in a 1 hour reaction. The use of oligonucleotide primer for in situ labeling overcomes the need for complex preparations of specific DNA probes. The present results demonstrate that PRINS may be a simple and reliable technique for rapidly detecting aneuploidies. 18 refs., 1 fig.

  19. In situ Measurements of Phytoplankton Fluorescence Using Low Cost Electronics

    Directory of Open Access Journals (Sweden)

    Dana L. Wright

    2013-06-01

    Full Text Available Chlorophyll a fluorometry has long been used as a method to study phytoplankton in the ocean. In situ fluorometry is used frequently in oceanography to provide depth-resolved estimates of phytoplankton biomass. However, the high price of commercially manufactured in situ fluorometers has made them unavailable to some individuals and institutions. Presented here is an investigation into building an in situ fluorometer using low cost electronics. The goal was to construct an easily reproducible in situ fluorometer from simple and widely available electronic components. The simplicity and modest cost of the sensor makes it valuable to students and professionals alike. Open source sharing of architecture and software will allow students to reconstruct and customize the sensor on a small budget. Research applications that require numerous in situ fluorometers or expendable fluorometers can also benefit from this study. The sensor costs US$150.00 and can be constructed with little to no previous experience. The sensor uses a blue LED to excite chlorophyll a and measures fluorescence using a silicon photodiode. The sensor is controlled by an Arduino microcontroller that also serves as a data logger.

  20. Nanoparticles laden in situ gelling system for ocular drug targeting

    Directory of Open Access Journals (Sweden)

    Divya Kumar

    2013-01-01

    Full Text Available Designing an ophthalmic drug delivery system is one of the most difficult challenges for the researchers. The anatomy and physiology of eye create barriers like blinking which leads to the poor retention time and penetration of drug moiety. Some conventional ocular drug delivery systems show shortcomings such as enhanced pre-corneal elimination, high variability in efficiency, and blurred vision. To overcome these problems, several novel drug delivery systems such as liposomes, nanoparticles, hydrogels, and in situ gels have been developed. In situ-forming hydrogels are liquid upon instillation and undergo phase transition in the ocular cul-de-sac to form viscoelastic gel and this provides a response to environmental changes. In the past few years, an impressive number of novel temperature, pH, and ion-induced in situ-forming systems have been reported for sustain ophthalmic drug delivery. Each system has its own advantages and drawbacks. Thus, a combination of two drug delivery systems, i.e., nanoparticles and in situ gel, has been developed which is known as nanoparticle laden in situ gel. This review describes every aspects of this novel formulation, which present the readers an exhaustive detail and might contribute to research and development.

  1. Management of Adenocarcinoma In Situ of Cervix in Pregnancy

    Directory of Open Access Journals (Sweden)

    Alireza Abidi

    2008-03-01

    Full Text Available Adenocarcinoma in situ is one of the premalignant lesions of the cervix and its incidence is believed to be increasing while the pathogenesis of the disease is not clearly understood. Management of Adenocarcinoma in situ (AIS unlike carcinoma in situ (CIS has not been clearly described in the current literature. Here we describe conservative management and serial colposcopy of two pregnant women with adenocarcinoma in situ of the cervix. Both of the cases were diagnosed initially with abnormal Pap smears and were confirmed by colposcopic directed biopsy. None of the patients agreed with any invasive procedure during pregnancy and both of them were followed with serial colposcopy. None of the lesions showed any evidence of progression. All cases underwent cold knife cone biopsies in their postpartum period. Hysterectomy as the final treatment has been done in both cases with no evidence of progression of the disease during pregnancy. We concluded that adenocarcinoma in situ of the cervix during pregnancy could be managed conservatively with definite treatment postponed till after delivery.

  2. Feasibility of in situ beta ray measurements in underwater environment.

    Science.gov (United States)

    Park, Hye Min; Park, Ki Hyun; Kang, Sung Won; Joo, Koan Sik

    2017-09-01

    We describe an attempt at the development of an in situ detector for beta ray measurements in underwater environment. The prototype of the in situ detector is based on a CaF2: Eu scintillator using crystal light guide and Si photomultiplier. Tests were conducted using various reference sources for evaluating the linearity and stability of the detector in underwater environment. The system is simple and stable for long-term monitoring, and consumes low power. We show here an effective detection distance of 7 mm and a 2.273 MeV end-point energy spectrum of (90)Sr/(90)Y when using the system underwater. The results demonstrate the feasibility of in situ beta ray measurements in underwater environment and can be applied for designing an in situ detector for radioactivity measurement in underwater environment. The in situ detector can also have other applications such as installation on the marine monitoring platform and quantitative analysis of radionuclides. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Nanoparticles laden in situ gel for sustained ocular drug delivery

    Directory of Open Access Journals (Sweden)

    Himanshu Gupta

    2013-01-01

    Full Text Available Proper availability of drug on to corneal surface is a challenging task. However, due to ocular physiological barriers, conventional eye drops display poor ocular bioavailability of drugs (< 1%. To improve precorneal residence time and ocular penetration, earlier our group developed and evaluated in situ gel and nanoparticles for ocular delivery. In interest to evaluate the combined effect of in situ gel and nanoparticles on ocular retention, we combined them. We are the first to term this combination as "nanoparticle laden in situ gel", that is, poly lactic co glycolic acid nanoparticle incorporated in chitosan in situ gel for sparfloxacin ophthalmic delivery. The formulation was tested for various physicochemical properties. It showed gelation pH near pH 7.2. The observation of acquired gamma camera images showed good retention over the entire precorneal area for sparfloxacin nanoparticle laden in situ gel (SNG as compared to marketed formulation. SNG formulation cleared at a very slow rate and remained at corneal surface for longer duration as no radioactivity was observed in systemic circulation. The developed formulation was found to be better in combination and can go up to the clinical evaluation and application.

  4. Master of Puppets: Cooperative Multitasking for In Situ Processing

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, Dmitriy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lukic, Zarija [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-01-01

    Modern scientific and engineering simulations track the time evolution of billions of elements. For such large runs, storing most time steps for later analysis is not a viable strategy. It is far more efficient to analyze the simulation data while it is still in memory. Here, we present a novel design for running multiple codes in situ: using coroutines and position-independent executables we enable cooperative multitasking between simulation and analysis, allowing the same executables to post-process simulation output, as well as to process it on the fly, both in situ and in transit. We present Henson, an implementation of our design, and illustrate its versatility by tackling analysis tasks with different computational requirements. This design differs significantly from the existing frameworks and offers an efficient and robust approach to integrating multiple codes on modern supercomputers. The techniques we present can also be integrated into other in situ frameworks.

  5. Review on Fabrication Methods of in situ Metal Matrix Composites

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper deals with a series of novel processing techniques based on the in situ production of metal matrix composites (MMCs). In situ techniques involve a chemical reaction resulting in the formation of a very fine and thermodynamically stable reinforcing ceramic phase within a metal matrix. As a result, this provides thermodynamic compatibility at the matrix-reinforcement interface. The reinforcement surfaces are also likely to be free of contamination and, therefore, a stronger matrix-dispersion bond can be achieved. Some of these technologies including DIMOXTM, XD, PRIMEXTM, reactive gas infiltration, high-temperature self-propagating synthesis (SHS), and liquid-solid, or solid-gas-liquid reactions as well as plasma in situ MMCs are expressed in this paper.

  6. Characteristics of in situ stress field at Qingshui coal mine

    Institute of Scientific and Technical Information of China (English)

    Yang Xiaojie; Pang Jiewen; Lou Haopeng; Fan Lipeng

    2015-01-01

    In this study, the characteristics of geological structure at Qingshui coal mine were analyzed. And the hollow inclusion strain cell overcoring method was used to obtain the in situ stress. The effect of in situ stress on the stability of soft rock roadway was analyzed. The results show that the maximum principal stress is in the horizontal direction with a northeast orientation and has a value of about 1.2–1.9 times larger than gravity; the right side of roadway roof and floor is easily subject to serious deformation and failure, and the in situ stress is found to be a major factor. This paper presents important information for developing countermeasures against the large deformation of the soft rock roadway at Qingshui coal mine.

  7. Microstructure analysis of laboratory and in-situ compacted silts

    Directory of Open Access Journals (Sweden)

    Russo Giacomo

    2016-01-01

    Full Text Available The paper presents and discusses some results of an experimental research aimed at analysing the influence of compaction variables (w and energy and method on the resulting microstructure of a compacted silty soil. In particular, the experimental data here discussed allow to compare the microstructure induced by different dynamic compaction techniques, comparing that characterising specimens obtained by two laboratory methods (Proctor standard and Harvard and that of samples compacted in-situ during the construction of an embankment built for river regimentation purposes. Both undisturbed and disturbed samples have been retrieved from the embankment, the latter one with the purpose of collecting the soil subsequently used for laboratory compaction. Microstructural analyses (SEM, MIP performed on laboratory and in-situ compacted samples evidenced a substantial similarity of the texture induced by the various compaction techniques, highlighting that laboratory compaction is suitable to provide soil samples representative of earth in-situ compacted soil.

  8. Detector calibration for in-situ gamma ray spectrometry

    CERN Document Server

    Balea, G

    2002-01-01

    The power in the technique of in-situ spectrometry lies in the fact that a detector placed on ground measures gamma radiation from sources situated over an area of several hundred square meters. The 'field of view' for the detector would be larger for high energy radiation sources and for sources closer to the soil surface. In contrast, a soil sample would represent an area of a few tens of hundreds of square centimeters. In practice, an effective characterization of a site would involve in-situ gamma ray spectrometry in conjunction with soil sampling. As part of an overall program, in-situ gamma ray spectrometry provides a means to assess the degree of contamination in areas during the course of operations in the field, thus guiding the investigator on where to collect samples. It can also substantially reduce the number of samples need to be collected and subsequently analyzed. (author)

  9. In Situ Atom Probe Deintercalation of Lithium-Manganese-Oxide.

    Science.gov (United States)

    Pfeiffer, Björn; Maier, Johannes; Arlt, Jonas; Nowak, Carsten

    2017-01-30

    Atom probe tomography is routinely used for the characterization of materials microstructures, usually assuming that the microstructure is unaltered by the analysis. When analyzing ionic conductors, however, gradients in the chemical potential and the electric field penetrating dielectric atom probe specimens can cause significant ionic mobility. Although ionic mobility is undesirable when aiming for materials characterization, it offers a strategy to manipulate materials directly in situ in the atom probe. Here, we present experimental results on the analysis of the ionic conductor lithium-manganese-oxide with different atom probe techniques. We demonstrate that, at a temperature of 30 K, characterization of the materials microstructure is possible without measurable Li mobility. Also, we show that at 298 K the material can be deintercalated, in situ in the atom probe, without changing the manganese-oxide host structure. Combining in situ atom probe deintercalation and subsequent conventional characterization, we demonstrate a new methodological approach to study ionic conductors even in early stages of deintercalation.

  10. Development of portable HPGe spectrometer for in situ measurements

    Directory of Open Access Journals (Sweden)

    Kail Artjoms

    2015-01-01

    Full Text Available In situ applications require a very high level of portability of high-resolution spectrometric equipment. Usage of HPGe detectors for radioactivity measurements in the environment or for nuclear safeguard applications, to combat illicit trafficking of nuclear materials or uranium and plutonium monitoring in nuclear wastes, has become a norm in the recent years. Portable HPGe-based radionuclide spectrometer with electrical cooling has lately appeared on the market for in situ applications. At the same time deterioration of energy resolution associated with vibrations produced by cryocooler or high weight of the instrument, short time of autonomous operation and high price of these spectrometers are limiting their usage in many cases. In this paper we present development results of ultra compact hand held all-in-one spectrometer for in situ measurements based on HPGe detector cooled by liquid nitrogen without listing the above disadvantages.

  11. 武警某部新兵准分子激光角膜屈光手术后干眼症调查%Clinical investigation of dry eye disease among recruits of armed police forces following excimer laser keratomileusis

    Institute of Scientific and Technical Information of China (English)

    芦胜芝; 范敏; 张川敏; 黄汉英

    2012-01-01

    目的 对驻京某部准分子激光角膜屈光手术后的新兵进行干眼症调查.方法 在2012年度新兵入伍体检时,选择283例准分子激光角膜屈光手术的新兵(手术组)并随机抽取其他273例新兵(非手术组)纳入研究,首先排除结角膜炎等其他疾患,然后两组分别进行问卷调查及干眼症的特异性检查,之后进行统计分析.结果 有干眼症状的(包括:干涩、异物感、疲劳感、不适感等),手术组:79例,占28%,非手术组:17例,占6%;诊断为干眼症的,手术组:53例,占18.72%,非手术组:12例,占6.23%.两组患病率差异有统计学意义(χ2=27.65,P<0.01).结论 准分子激光角膜屈光手术后的新兵干眼症的发病率明显高于非手术者.%To investigate the dry - eye disease in recruits who have received excimer laser keratomileusis. Methods During the physical examination of recruits for 2012, 283 recruits who had undergone excimer laser keratomileusis were randomly selected ( surgery group) while other 273 non - surgery recruits ( non - surgical group) served as control. After keratoconjunctivitis and other disorders were excluded, a survey and a dry eye specificity examination were conducted in the two groups for statistical analysis. Result Seventy - nine recruits (28%) suffered from dry eyes( including dry eyes、foreign body sensaLion、feeling of fatigue and discomfort) in surgical group while in non - surgical group there were only seventeen cases (6% ) . Fifty - three cases ( 18. 72% ) were diagnosed with dry eyes in surgical group compared to twelve cases (6.23% ) in the other group. The difference was statistically signifi-cant. Conclusion Dry eyes are much more prevalent among recruits who underwent excimer laser keratomileusis.

  12. Extreme Spectroscopy: In situ nuclear materials behavior from optical data

    Energy Technology Data Exchange (ETDEWEB)

    Guimbretiere, G.; Canizares, A.; Raimboux, N.; Omnee, R.; Duval, F.; Ammar, M.R.; Simon, P. [CNRS - UPR3079 CEMHTI, Universite d' Orleans, 45071Orleans cedex 2 (France); Desgranges, L.; Mohun, R. [CEA, DEN, DEC, F-13108 Saint-Paul-Lez-Durance (France); Jegou, C.; Magnin, M. [CEA/DTCD/SECM/LMPA, Marcoule 30207 Bagnols Sur Ceze (France); Clavier, N.; Dacheux, N. [ICSM-UMR5257 CEA/CNRS/UM2/ENSCM, Marcoule, BP17171, 30207 Bagnols sur Ceze (France)

    2015-07-01

    In the nuclear industry, materials are regularly exposed to high temperature or/and irradiation and a better knowledge and understanding of their behavior under such extreme conditions is a key-point for improvements and further developments. Nowadays, Raman spectroscopy begins to be well known as a promising technique in the post mortem and remote characterization of nuclear materials exposed to extreme conditions. On this topic, at ANIMMA 2013 conference, we have presented some results about its implementation in the study of model or real nuclear fuel. However, the strength of Raman spectroscopy as in situ characterization tool is mainly its ability to be implemented remotely through optical fibers. Aware of this, implementation of other optical techniques can be considered in order to gain information not only on the structural dynamics of materials but also on the electronic charge carrier populations. In this paper, we propose to present our last advances in Raman characterization of nuclear materials and enlarge to the in situ use of complementary optical spectroscopies. Emphasis will be made on the information that can be gained to the behavior of the model fuel depleted UO{sub 2} under extreme conditions of high temperature and ionic irradiation: - In Situ Raman identification of the radiolysis alteration products of UO{sub 2} in contact with water under ionic irradiation. - In Situ Raman recording of the damaged dynamic of UO{sub 2} under inert atmosphere. - In Situ Raman and photo-luminescence study of virgin and damaged UO2 at high temperature. - In Situ study of electronic charge carriers' behavior in U{sub x}Th{sub 1-x}O{sub 2} solid solutions by mean of Iono- and Thermo- luminescence under and post- ionic irradiation. (authors)

  13. In situ measurement of conductivity during nanocomposite film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Blattmann, Christoph O.; Pratsinis, Sotiris E., E-mail: sotiris.pratsinis@ptl.mavt.ethz.ch

    2016-05-15

    Highlights: • Flame-made nanosilver dynamics are elucidated in the gas-phase & on substrates. • The resistance of freshly depositing nanosilver layers is monitored. • Low T{sub g} polymers facilitate rapid synthesis of conductive films. • Conductive nanosilver films form on top of or within the polymer depending on MW. - Abstract: Flexible and electrically conductive nanocomposite films are essential for small, portable and even implantable electronic devices. Typically, such film synthesis and conductivity measurement are carried out sequentially. As a result, optimization of filler loading and size/morphology characteristics with respect to film conductivity is rather tedious and costly. Here, freshly-made Ag nanoparticles (nanosilver) are made by scalable flame aerosol technology and directly deposited onto polymeric (polystyrene and poly(methyl methacrylate)) films during which the resistance of the resulting nanocomposite is measured in situ. The formation and gas-phase growth of such flame-made nanosilver, just before incorporation onto the polymer film, is measured by thermophoretic sampling and microscopy. Monitoring the nanocomposite resistance in situ reveals the onset of conductive network formation by the deposited nanosilver growth and sinternecking. The in situ measurement is much faster and more accurate than conventional ex situ four-point resistance measurements since an electrically percolating network is detected upon its formation by the in situ technique. Nevertheless, general resistance trends with respect to filler loading and host polymer composition are consistent for both in situ and ex situ measurements. The time lag for the onset of a conductive network (i.e., percolation) depends linearly on the glass transition temperature (T{sub g}) of the host polymer. This is attributed to the increased nanoparticle-polymer interaction with decreasing T{sub g}. Proper selection of the host polymer in combination with in situ resistance

  14. In situ and operando transmission electron microscopy of catalytic materials

    DEFF Research Database (Denmark)

    Crozier, Peter A.; Hansen, Thomas Willum

    2015-01-01

    Catalytic nanomaterials play a major role in chemical conversions and energy transformations. Understanding how materials control and regulate surface reactions is a major objective for fundamental research on heterogeneous catalysts. In situ environmental transmission electron microscopy (ETEM......) is a powerful technique for revealing the atomic structures of materials at elevated temperatures in the presence of reactive gases. This approach can allow the structure-reactivity relations underlying catalyst functionality to be investigated. Thus far, ETEM has been limited by the absence of in situ...

  15. In Situ burning of Arctic marine oil spills

    DEFF Research Database (Denmark)

    Fritt-Rasmussen, Janne

    Oil spills in ice filled and Arctic waters pose other challenges for oil spill response compared to open and temperate waters. In situ burning has been proven to be an effective oil spill response method for oil spills in ice filled waters. This thesis presents results from laboratory and field...... experiments where the ignitability of oil spill as a function of oil type and weathering conditions (time/ice) was tested. The results show that the composition of the oil and the ice cover is important for the in situ burning time-window. The results were used to develop an algorithm that was implemented...

  16. In-situ bioremediation drilling and characterization work plan

    Energy Technology Data Exchange (ETDEWEB)

    Koegler, K.J.

    1994-04-26

    This work plan describes the design and construction of proposed wells and outlines the characterization activities to be performed in support of the In Situ Bioremediation Task for FY 1994. The purpose of the well-design is to facilitate implementation and monitoring of in situ biodegradation of CCl{sub 4} in ground water. However, the wells will also be used to characterize the geology, hydrology, microbiology, and contaminant distribution, which will all feed into the design of the technology. Implementation and design of this remediation demonstration technology will be described separately in an integrated test plan.

  17. Continued Development of in Situ Geochronology for Planetary Missions

    Science.gov (United States)

    Devismes, D.; Cohen, B. A.

    2015-01-01

    The instrument 'Potassium (K) Argon Laser Experiment' (KArLE) is developed and designed for in situ absolute dating of rocks on planetary surfaces. It is based on the K-Ar dating method and uses the Laser Induced Breakdown Spectroscopy - Laser Ablation - Quadrupole Mass Spectrometry (LIBSLA- QMS) technique. We use a dedicated interface to combine two instruments similar to SAM of Mars Science Laboratory (for the QMS) and ChemCam (for the LA and LIBS). The prototype has demonstrated that KArLE is a suitable and promising instrument for in situ absolute dating.

  18. In-Situ Investigation of Advanced Structural Coatings and Composites

    Science.gov (United States)

    Ustundag, Ersan

    2003-01-01

    The premise of this project is a comprehensive study that involves the in-situ characterization of advanced coatings and composites by employing both neutron and x-ray diffraction techniques in a complementary manner. The diffraction data would then be interpreted and used in developing or validating advanced micromechanics models with life prediction capability. In the period covered by this report, basic work was conducted to establish the experimental conditions for various specimens and techniques. In addition, equipment was developed that will allow the in-situ studies under a range of conditions (stress, temperature, atmosphere, etc.).

  19. Future directions for in-situ product removal (ISPR)

    DEFF Research Database (Denmark)

    Woodley, John; Bisschops, Marc; Straathof, Adrie J J

    2008-01-01

    This paper summarizes the main findings of a round-table discussion held to examine the key bottlenecks in the further application and industrial implementation of in-situ product removal (ISPR) techniques. It is well established that ISPR can yield great benefits for processes limited by inhibit......This paper summarizes the main findings of a round-table discussion held to examine the key bottlenecks in the further application and industrial implementation of in-situ product removal (ISPR) techniques. It is well established that ISPR can yield great benefits for processes limited...

  20. In-situ ALD growth of hafnium oxide films

    Energy Technology Data Exchange (ETDEWEB)

    Karavaev, Konstantin; Tallarida, Massimo; Schmeisser, Dieter [Brandenburgische Technische Universitaet Cottbus (Germany). Angewandte Physik - Sensorik; Zschech, Ehrenfried [AMD Saxony LLC and Co. KG, Center for Complex Analysis, Dresden (Germany)

    2008-07-01

    We report on a novel system for in-situ atomic layer growth (ALD) of high-k dielectric films. First results were obtained for Hf-oxide samples by using Hf-tetrachloride as precursor and water as oxidizer. We compare the photoelectron spectra of Si 2p, O 1s and Hf 4f of our in-situ prepared films with samples (ex-situ) prepared by industrial ALD reactors and discuss similarities and differences observed in the core level spectra of the various samples by considering the different growth conditions.

  1. In-situ strain observation in high power laser cladding

    OpenAIRE

    Ocelik, V.; Bosgra, J.; De Hosson, J. Th. M.

    2009-01-01

    The modern experimental technique - so called Digital Image Correlation - is applied during high power laser surface treatments for in-situ observation of displacements and strains near the processing area during and a short time after laser processing. An experimental setup has been designed and tested to measure in-situ the strain during treatment with a high power 2 kW CW Nd:YAG laser, i.e. laser hardening, surface remelting, and laser cladding with Nanosteel, Eutroloy 16012 and MicroMelt ...

  2. DEBIE - first standard in-situ debris monitoring instrument

    Science.gov (United States)

    Kuitunen, J.; Drolshagen, G.; McDonnell, J. A. M.; Svedhem, H.; Leese, M.; Mannermaa, H.; Kaipiainen, M.; Sipinen, V.

    2001-10-01

    Objects larger than a few centimetres can be tracked with radar or with optical telescopes. The population of smaller particles can only be investigated by the analysis of retrieved spacecraft and passive detectors or by in-situ monitors in orbit. Patria Finavitec together with UniSpace Kent have developed the DEBIE (DEBris In-orbit Evaluator) instrument to determine the parameters of sub-millimetre sized space debris and micrometeoroids in-situ by their impact with a detecting surface. The main goal has been to develop an economical and low-resource instrument, easy to integrate into any spacecraft, while providing reliable real-time data for space debris modelling.

  3. Electrochemical atomic force microscopy: In situ monitoring of electrochemical processes

    Science.gov (United States)

    Reggente, Melania; Passeri, Daniele; Rossi, Marco; Tamburri, Emanuela; Terranova, Maria Letizia

    2017-08-01

    The in-situ electrodeposition of polyaniline (PANI), one of the most attractive conducting polymers (CP), has been monitored performing electrochemical atomic force microscopy (EC-AFM) experiments. The electropolymerization of PANI on a Pt working electrode has been observed performing cyclic voltammetry experiments and controlling the evolution of current flowing through the electrode surface, together with a standard AFM image. The working principle and the potentialities of this emerging technique are briefly reviewed and factors limiting the studying of the in-situ electrosynthesis of organic compounds discussed.

  4. Meta-analysis of corneal sensitivity after femtosecond LASIK and SMILE surgery%飞秒激光制瓣的LASIK与SMILE术后角膜敏感性变化的Meta分析

    Institute of Scientific and Technical Information of China (English)

    金男; 方一明; 李晓霞; 姚鹏翔; 王振亮; 蒋建伟

    2014-01-01

    目的 系统评价飞秒激光制瓣的LASIK(FS-LASIK)和SMILE治疗近视术后角膜敏感性的差异.方法 Meta分析.采用严密设计的检索策略检索Medline、Cochrane图书馆、中国生物医学文献数据库(CBM disc)、中国期刊全文数据库(CNKI),对比较FS-LASIK和SMILE术后角膜敏感性的文献进行Meta分析.分析内容主要包括术前,术后1周、1个月、3个月及6个月的中央角膜敏感性.采用RevMan 5.0进行统计分析,计量资料以加权均数差(WMD) (95%CI)为疗效分析统计量.对检索文献的证据等级按照Jadad量表进行评价.结果 共有4篇文献符合本研究的纳入标准,共198例(316眼).Meta分析结果显示:术前FS-LASIK和SMILE中央角膜敏感性差异无明显统计学意义(WMD=0.28,95%CI:-0.73~1.29,P>0.05);然而,术后1周、1个月、3个月及6个月两者差异均有明显统计学意义(WMD=-14.56,95%CI:-23.79~-5.34,P<0.01;WMD=-15.29,95%CI:-22.46~-8.11,P<0.01;WMD=-13.12,95%CI:-18.77~-7.46,P<0.01;WMD=-3.45,95%CI:-5.72~-1.18,P<0.01).结论 与FS-LASIK相比,SMILE术后角膜敏感性下降幅度可能更小,恢复更快;术后6个月时,SMILE术后角膜敏感性仍高于FS-LASIK.%Objective To evaluate and compare corneal sensitivity after Femtosecond LASIK (FS-LASIK) and small incision lenticule extraction (SMILE) from a systematic review of literature.Methods This was a meta-analysis study.A systematic literature retrieval was conducted in Medline,the Cochrane Library,CBM disc,and CNKI.Central corneal sensitivity after FS-LASIK and SMILE was compared by meta-analysis,including pre-operation,1 week,1 month,3 months and 6 months post-operation.A statistical analysis was performed using RevMan 5.0 software.Weighted mean difference (WMD) (95%CI) was used to analyze continuous variables.The quality of the included literature was scored according to the Jadad scale.Results A total of 4 studies with a total of 198 patients (316 eyes) in the

  5. Eyelid hygiene as a tool for prevention and treatment of complications due to ocular surface diseases in early post-LASIK period

    Directory of Open Access Journals (Sweden)

    V. V. Kurenkov

    2014-07-01

    Full Text Available Purpose: to analyze the effect of eyelid hygiene and therapy on early post-op period following excimer laser refractive surgery.Methods: 144 patients (288 eyes aged 18-57 yrs who underwent excimer laser vision correction (LASIK were followed. All patients were divided into two groups depending on therapy. In treatment group (70 patients/140 eyes, eyelid hygiene was prescribed 7 days before and 7 days again following refractive surgery for 1 or 2 months. In control group (74 patients/148 eyes, no eyelid hygiene was prescribed.Results: Complex method of eyelid hygiene and therapy was developed that consisted in eyelid margins self-massage using Blepharogel 1 or Blepharogel 2 and warm compresses using Blepharopads impregnated with Blepharolotion. When using in combina- tion with antibacterial and tear replacement therapy, this method provides significant decrease in infectious complications rate and effective recovery of tear production in early post-op period following excimer laser surgery. these observations are confirmed by the dynamics of clinical, functional and subjective parameters.Conclusion: 7-days eyelid hygiene and therapy course that is prescribed immediately before and following laser vision correctionprovides multi-factorial effect, i.e., reduces post-op inflammatory complications rate and increases tear film stability.

  6. Eyelid hygiene as a tool for prevention and treatment of complications due to ocular surface diseases in early post-LASIK period

    Directory of Open Access Journals (Sweden)

    V. V. Kurenkov

    2012-01-01

    Full Text Available Purpose: to analyze the effect of eyelid hygiene and therapy on early post-op period following excimer laser refractive surgery.Methods: 144 patients (288 eyes aged 18-57 yrs who underwent excimer laser vision correction (LASIK were followed. All patients were divided into two groups depending on therapy. In treatment group (70 patients/140 eyes, eyelid hygiene was prescribed 7 days before and 7 days again following refractive surgery for 1 or 2 months. In control group (74 patients/148 eyes, no eyelid hygiene was prescribed.Results: Complex method of eyelid hygiene and therapy was developed that consisted in eyelid margins self-massage using Blepharogel 1 or Blepharogel 2 and warm compresses using Blepharopads impregnated with Blepharolotion. When using in combina- tion with antibacterial and tear replacement therapy, this method provides significant decrease in infectious complications rate and effective recovery of tear production in early post-op period following excimer laser surgery. these observations are confirmed by the dynamics of clinical, functional and subjective parameters.Conclusion: 7-days eyelid hygiene and therapy course that is prescribed immediately before and following laser vision correctionprovides multi-factorial effect, i.e., reduces post-op inflammatory complications rate and increases tear film stability.

  7. Diagnosis of In Situ Metabolic State and Rates of Microbial Metabolism During In Situ Uranium Bioremediation with Molecular Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lovley, Derek R. [University of Massachusetts, Amherst

    2012-11-28

    The goal of these projects was to develop molecule tools to tract the metabolic activity and physiological status of microorganisms during in situ uranium bioremediation. Such information is important in able to design improved bioremediation strategies. As summarized below, the research was highly successful with new strategies developed for estimating in situ rates of metabolism and diagnosing the physiological status of the predominant subsurface microorganisms. This is a first not only for groundwater bioremediation studies, but also for subsurface microbiology in general. The tools and approaches developed in these studies should be applicable to the study of microbial communities in a diversity of soils and sediments.

  8. Mixing and In situ product removal in micro-bioreactors

    NARCIS (Netherlands)

    Li, X.

    2009-01-01

    Summary Of the thesis :’ Mixing and In-situ product removal in micro bioreactors’ by Xiaonan Li The work presented in this thesis is a part of a large cluster project, which was formed between DSM, Organon, Applikon and two university groups (TU Delft and University of Twente), under the ACTS and

  9. Repurposing CRISPR/Cas9 for in situ functional assays

    NARCIS (Netherlands)

    Malina, Abba; Mills, John R; Cencic, Regina; Yan, Yifei; Fraser, James; Schippers, Laura M; Paquet, Marilène; Dostie, Josée; Pelletier, Jerry

    2013-01-01

    RNAi combined with next-generation sequencing has proven to be a powerful and cost-effective genetic screening platform in mammalian cells. Still, this technology has its limitations and is incompatible with in situ mutagenesis screens on a genome-wide scale. Using p53 as a proof-of-principle

  10. In situ nanoindentation in a transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Minor, Andrew M. [Univ. of California, Berkeley, CA (United States)

    2002-01-01

    This dissertation presents the development of the novel mechanical testing technique of in situ nanoindentation in a transmission electron microscope (TEM). This technique makes it possible to simultaneously observe and quantify the mechanical behavior of nano-scale volumes of solids.

  11. Applied in situ product recovery in ABE fermentation

    Science.gov (United States)

    Lalander, Carl‐Axel; Lee, Jonathan G. M.; Davies, E. Timothy; Harvey, Adam P.

    2017-01-01

    The production of biobutanol is hindered by the product's toxicity to the bacteria, which limits the productivity of the process. In situ product recovery of butanol can improve the productivity by removing the source of inhibition. This paper reviews in situ product recovery techniques applied to the acetone butanol ethanol fermentation in a stirred tank reactor. Methods of in situ recovery include gas stripping, vacuum fermentation, pervaporation, liquid–liquid extraction, perstraction, and adsorption, all of which have been investigated for the acetone, butanol, and ethanol fermentation. All techniques have shown an improvement in substrate utilization, yield, productivity or both. Different fermentation modes favored different techniques. For batch processing gas stripping and pervaporation were most favorable, but in fed‐batch fermentations gas stripping and adsorption were most promising. During continuous processing perstraction appeared to offer the best improvement. The use of hybrid techniques can increase the final product concentration beyond that of single‐stage techniques. Therefore, the selection of an in situ product recovery technique would require comparable information on the energy demand and economics of the process. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:563–579, 2017 PMID:28188696

  12. In situ measurements of Merensky pillar behaviour at Impala Platinum

    CSIR Research Space (South Africa)

    Watson, BP

    2009-12-01

    Full Text Available to stabilize the stoping excavations. This paper describes the in situ measurement, of stress within a Merensky pillar from Impala Platinum. These measurements were used to derive a stress-strain curve that includes pre and post failure behaviour. 2D FLAC...

  13. Light-emission from in-situ grown organic nanostructures

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Kjelstrup-Hansen, Jakob; Rubahn, Horst-Günter

    2011-01-01

    Organic crystalline nanofibers made from phenylene-based molecules exhibit a wide range of extraordinary optical properties such as intense, anisotropic and polarized luminescence that can be stimulated either optically or electrically, waveguiding and random lasing. For lighting and display...... of morphological characterization and demonstrate how appropriate biasing with an AC gate voltage enables electroluminescence from these in-situ grown organic nanostructures....

  14. Testicular carcinoma in situ in subfertile Danish men

    DEFF Research Database (Denmark)

    Olesen, Inge A; Hoei-Hansen, Christina E; Skakkebaek, Niels E

    2007-01-01

    Carcinoma in situ (CIS) testis is the precursor stage for the majority of testicular germ cell tumours (TGCT). Infertility is one of the conditions known to predispose to TGCT, but based on scarce existing data, the prevalence of CIS in this risk group was estimated at only approximately 1...

  15. In situ spectrophotometric measurement of dissolved inorganic carbon in seawater.

    Science.gov (United States)

    Liu, Xuewu; Byrne, Robert H; Adornato, Lori; Yates, Kimberly K; Kaltenbacher, Eric; Ding, Xiaoling; Yang, Bo

    2013-10-01

    Autonomous in situ sensors are needed to document the effects of today's rapid ocean uptake of atmospheric carbon dioxide (e.g., ocean acidification). General environmental conditions (e.g., biofouling, turbidity) and carbon-specific conditions (e.g., wide diel variations) present significant challenges to acquiring long-term measurements of dissolved inorganic carbon (DIC) with satisfactory accuracy and resolution. SEAS-DIC is a new in situ instrument designed to provide calibrated, high-frequency, long-term measurements of DIC in marine and fresh waters. Sample water is first acidified to convert all DIC to carbon dioxide (CO2). The sample and a known reagent solution are then equilibrated across a gas-permeable membrane. Spectrophotometric measurement of reagent pH can thereby determine the sample DIC over a wide dynamic range, with inherent calibration provided by the pH indicator's molecular characteristics. Field trials indicate that SEAS-DIC performs well in biofouling and turbid waters, with a DIC accuracy and precision of ∼2 μmol kg(-1) and a measurement rate of approximately once per minute. The acidic reagent protects the sensor cell from biofouling, and the gas-permeable membrane excludes particulates from the optical path. This instrument, the first spectrophotometric system capable of automated in situ DIC measurements, positions DIC to become a key parameter for in situ CO2-system characterizations.

  16. NASAL IN SITU GEL: A NOVEL DRUG DELIVERY SYSTEM

    Directory of Open Access Journals (Sweden)

    Dhrupesh panchal

    2012-06-01

    Full Text Available Over the past few decades, advances in the in situ gel technologies have spurred development in manymedical and biomedical applications including controlled drug delivery. Many novel in situ gel baseddelivery matrices have been designed and fabricated to fulfill the ever increasing needs of thepharmaceutical and medical fields. In situ gelling systems are liquid at room temperature but undergogelation when in contact with body fluids or change in pH. In situ gel forming drug delivery is a type ofmucoadhesive drug delivery system. The formation of gel depends on factors like temperaturemodulation, pH change, presence of ions and ultraviolet irradiation from which the drug gets released ina sustained and controlled manner. Nasal delivery is a promising drug delivery option where commondrug administrations such as intravenous, intramuscular or oral are inapplicable. Recently, it has beenshown that many drugs have better bioavailability by nasal route than the oral route. This has beenattributed to rich vasculature and a highly permeable structure of the nasal mucosa coupled withavoidance of hepatic first-pass elimination, gut wall metabolism and/or destruction in thegastrointestinal tract. The physiology of the nose presents obstacles but offers a promising route for noninvasivesystemic delivery of numerous therapies and debatably drug delivery route to the brain. Thusthis review focuses on nasal drug delivery, various aspects of nasal anatomy and physiology, nasal drugabsorption mechanisms, various nasal drug delivery systems and their applications in drug delivery.

  17. Supernumerary ring chromosome 20 characterized by fluorescence in situ hybridization

    NARCIS (Netherlands)

    Van Langen, Irene M.; Otter, Mariëlle A.; Aronson, Daniël C.; Overweg-Plandsoen, W.C.G.; Hennekam, Raoul C.M.; Leschot, Nico J.; Hoovers, Jan M.N.

    1996-01-01

    We report on a boy with mild dysmorphic features and developmental delay, in whom karyotyping showed an additional minute ring chromosome in 60% of metaphases. Fluorescence in situ hybridization (FISH) with a centromere specific probe demonstrated that the ring chromosome contained the centromeric r

  18. In situ polarization of polymer films in microsensors

    Science.gov (United States)

    Kranz, M.; Allen, M. G.; Hudson, T.

    2012-04-01

    Electret and polymer piezoelectric films have been previously integrated into Micro Electro Mechanical System (MEMS) acoustic sensors and energy harvesters. Common techniques employed in MEMS polymer integration include corona discharge [1] and backlighted thyratron [2], followed by macro-scale assembly of the polymer into the micro device. In contrast, this paper reports a method for post-fabrication in-situ polarization of polymer films embedded within the MEMS device itself. The method utilizes microplasma discharges with self-aligned charging grids integrated within the device to charge fluoropolymer films in a fashion similar to the common corona discharge technique. This in-situ approach enables the integration of uncharged polymer films into MEMS and subsequent post-fabrication and post-packaging polarization, simultaneously enabling the formation of buried or encapsulated electrets as well as eliminating the need to restrict fabrication and packaging processes that might otherwise discharge pre-charged materials. Using the in situ approach, a microscale charging grid structure is fabricated and suspended a short distance above the polymer film. After fabrication of the charging grid, standard microfabrication steps are performed to build MEMS sensors. After completing the entire fabrication and packaging flow, the polarization process is performed. When energized by a high voltage, the sharp metal edges of the charging grid lead to high dielectric fields that ionize the air in the gap and force electric charge onto the polymer surface. This paper presents modeling and results for this in situ polarization process.

  19. Crystal Transformation of Nylon 11 Using in situ WAXD

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    a Form Nylon 11 films were found to exist a non-linear transformation at 70oC during the heating process using in situ WAXD. The a Form disappeared but d form appeared when the temperature was higher 70℃.

  20. In Situ Magnetic Separation for Extracellular Protein Production

    DEFF Research Database (Denmark)

    Kappler, T.; Cerff, Martin; Ottow, Kim Ekelund

    2009-01-01

    employed directly in the broth during the fermentation, followed by in situ magnetic separation, Proof of the concept was first demonstrated in shake flask culture, then scaled up and applied during a fed batch cultivation ill a 3.7 L bioreactor. It could be demonstrated that growth of B. licheniformis...

  1. In situ XAS of the solvothermal decomposition of dithiocarbamate complexes

    NARCIS (Netherlands)

    Islam, H.-U.; Roffey, A.; Hollingsworth, N.; Catlow, R.; Wolthers, M.; de Leeuw, N.H.; Bras, W.; Sankar, G.; Hogarth, G.

    2012-01-01

    An in situ XAS study of the solvothermal decomposition of iron and nickel dithiocarbamate complexes was performed in order to gain understanding of the decomposition mechanisms. This work has given insight into the steps involved in the decomposition, showing variation in reaction pathways between t

  2. ENGINEERING ISSUE: IN SITU BIOREMEDIATION OF CONTAMINATED UNSATURATED SUBSURFACE SOILS

    Science.gov (United States)

    An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of th...

  3. In-situ strain observation in high power laser cladding

    NARCIS (Netherlands)

    Ocelik, V.; Bosgra, J.; de Hosson, J. Th. M.

    2009-01-01

    The modern experimental technique - so called Digital Image Correlation - is applied during high power laser surface treatments for in-situ observation of displacements and strains near the processing area during and a short time after laser processing. An experimental setup has been designed and

  4. In situ quantification of membrane foulant accumulation by reflectometry

    NARCIS (Netherlands)

    Schroen, C. G. P. H.; Roosjen, A.; Norde, W.; Boom, R. M.; Tang, K.

    2010-01-01

    In this paper, we present laser light reflectometry [1] (not to be mistaken with ultrasound reflectometry [2] that uses ultrasound waves) as a tool for quantitative investigation of (the initial stages of) fouling on membrane-like surfaces. Reflectometry allows in situ investigation of adsorption an

  5. In-Situ Catalytic Fast Pyrolysis Technology Pathway

    Energy Technology Data Exchange (ETDEWEB)

    Biddy, M.; Dutta, A.; Jones, S.; Meyer, A.

    2013-03-01

    This technology pathway case investigates converting woody biomass using in-situ catalytic fast pyrolysis followed by upgrading to gasoline-, diesel-, and jet-range hydrocarbon blendstocks. Technical barriers and key research needs that should be pursued for this pathway to be competitive with petroleum-derived blendstocks have been identified.

  6. Ultrasensitive in situ visualization of active glucocerebrosidase molecules

    NARCIS (Netherlands)

    Witte, Martin D.; Kallemeijn, Wouter W.; Aten, Jan; Li, Kah-Yee; Strijland, Anneke; Donker-Koopman, Wilma E.; Nieuwendijk, Adrianus M.C.H. van den; Bleijlevens, Boris; Kramer, Gertjan; Florea, Bogdan I.; Hooibrink, Berend; Hollak, Carla E.M.; Ottenhoff, Roelof; Boot, Rolf G.; Marel, Gijsbert A. van der; Overkleeft, Herman S.; Aerts, Johannes M.F.G.

    2010-01-01

    Deficiency of glucocerebrosidase (GBA) underlies Gaucher disease, a common lysosomal storage disorder. Carriership for Gaucher disease has recently been identified as major risk for parkinsonism. Presently, no method exists to visualize active GBA molecules in situ. We here report the design, synthe

  7. AFM cantilever with in situ renewable mercury microelectrode

    NARCIS (Netherlands)

    Schön, Peter Manfred; Geerlings, J.; Tas, Niels Roelof; Sarajlic, Edin

    2013-01-01

    We report here first results obtained on a novel, in situ renewable mercury microelectrode integrated into an atomic force microscopy (AFM) cantilever. Our approach is based on a fountain pen probe with appropriate dimensions enabling reversible filling with(nonwetting) mercury under changing the

  8. Supernumerary ring chromosome 17 identified by fluorescent in situ hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Fagan, K. [Hunter Area Pathology Service, New South Wales (Australia); Edwards, M. [Western Suburbs Hospital, New South Wales (Australia)

    1997-04-14

    We present a patient with multiple anomalies and severe developmental delay. A small supernumerary ring chromosome was found in 40% of her lymphocyte cells at birth. The origin of the marker chromosome could not be determined by GTG banding, but fluorescent in situ hybridization (FISH) later identified the marker as deriving from chromosome 17. 20 refs., 2 figs., 1 tab.

  9. In situ nonlinear elastic behavior of soil observed by DAET

    Energy Technology Data Exchange (ETDEWEB)

    Larmat, Carene [Los Alamos National Laboratory; Renaud, Guillaume [Eramus Medical Center, Rotterdam, The Netherlands; Rutledge, James T. [EES-17: GEOPHYSICS; Lee, Richard C. [Los Alamos National Laboratory; Guyer, Robert A. [Los Alamos National Laboratory; Johnson, Paul A. [Los Alamos National Laboratory

    2012-07-05

    The key to safe design of critical facilities (strong ground motion in low velocity materials such as soils). Current approaches are predictions from measurements of the elastic non-linear properties of boreholes samples. Need for in-situ, local and complete determination of non-linear properties of soil, rock in response to high-strain motion.

  10. In-situ strain observation in high power laser cladding

    NARCIS (Netherlands)

    Ocelik, V.; Bosgra, J.; de Hosson, J. Th. M.

    2009-01-01

    The modern experimental technique - so called Digital Image Correlation - is applied during high power laser surface treatments for in-situ observation of displacements and strains near the processing area during and a short time after laser processing. An experimental setup has been designed and te

  11. Simulating realistic imaging conditions for in situ liquid microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Welch, David A., E-mail: dawelch@ucdavis.edu [Department of Chemical Engineering and Materials Science, University of California, Davis, CA (United States); Faller, Roland [Department of Chemical Engineering and Materials Science, University of California, Davis, CA (United States); Evans, James E. [Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, WA (United States); Browning, Nigel D. [Pacific Northwest National Laboratory, Fundamental Computational Sciences Directorate, Richland, WA (United States)

    2013-12-15

    In situ transmission electron microscopy enables the imaging of biological cells, macromolecular protein complexes, nanoparticles, and other systems in a near-native environment. In order to improve interpretation of image contrast features and also predict ideal imaging conditions ahead of time, new virtual electron microscopic techniques are needed. A technique for virtual fluid-stage high-angle annular dark-field scanning transmission electron microscopy with the multislice method is presented that enables the virtual imaging of model fluid-stage systems composed of millions of atoms. The virtual technique is exemplified by simulating images of PbS nanoparticles under different imaging conditions and the results agree with previous experimental findings. General insight is obtained on the influence of the effects of fluid path length, membrane thickness, nanoparticle position, defocus and other microscope parameters on attainable image quality. - Highlights: • Image simulation has been performed to understand in situ electron microscopy experiments. • Experimentally observed resolution of in situ grown PbS nanoparticles has been virtually reproduced. • General relationships between image resolution and in situ holder design, defocus, and particle size have been determined. • The presented image simulation technique can predict the obtainable resolution of future experiments.

  12. Acral Lentiginous Melanoma in Situ: A Diagnostic and Management Challenge

    Directory of Open Access Journals (Sweden)

    Hyun Sun Park

    2010-04-01

    Full Text Available Early stage recognition of acral lentiginous melanoma (ALM is important for a better prognosis, but in-depth understanding and proper management of ALM in situ is complicated, because there are only a few reports, probably due to its rarity and diagnostic difficulty. We have reviewed our experience with seven patients who were diagnosed as having ALM in situ and discuss how to accurately diagnose and properly manage these rare lesions. Clinically the lesions showed black to brown discoloration of the nail with Hutchinson’s sign and hyperpigmented macules on the heel with color variegation. All the lesions showed a diffuse lentiginous pattern of melanocytic proliferation with variable level of atypism along the dermoepidermal junction. Dermoscopic findings were available in three and revealed parallel ridge patterns. Confrontation of clinical and histopathologic findings was observed in three, and the lesions were not recognized or diagnosed as ALM in situ in the first place. Excision of the primary lesion with variable operative margin was done as an initial treatment. Recurrence was observed in three patients and one developed invasive ALM and lymph node metastasis. Integration of all available information concerning the clinical presentation, histopathology, and dermoscopic findings is very important and can lead to the best classification for correct diagnosis. Lack of knowledge upon clinical course and optimal margin to control ALM in situ provokes the need for further studies with longer follow up and larger number of cases.

  13. Mixing and In situ product removal in micro-bioreactors

    NARCIS (Netherlands)

    Li, X.

    2009-01-01

    Summary Of the thesis :’ Mixing and In-situ product removal in micro bioreactors’ by Xiaonan Li The work presented in this thesis is a part of a large cluster project, which was formed between DSM, Organon, Applikon and two university groups (TU Delft and University of Twente), under the ACTS and

  14. Genetic predisposition to ductal carcinoma in situ of the breast

    NARCIS (Netherlands)

    C. Petridis (Christos); R.H. Brook; V. Shah (Vandna); K. Kohut (Kelly); P. Gorman (Patricia); M. Caneppele (Michele); D. Levi (Dina); E. Papouli (Efterpi); N. Orr (Nick); A. Cox (Angela); S.S. Cross (Simon); I. dos Santos Silva (Isabel); J. Peto (Julian); A.J. Swerdlow (Anthony ); M. Schoemaker (Minouk); M.K. Bolla (Manjeet); Q. Wang (Qing); J. Dennis (Joe); K. Michailidou (Kyriaki); J. Benítez (Javier); A. González-Neira (Anna); D.C. Tessier (Daniel C.); D. Vincent (Daniel); J. Li (Jingmei); J.D. Figueroa (Jonine); V. Kristensen (Vessela); A.-L. Borresen-Dale (Anne-Lise); P. Soucy (Penny); J. Simard (Jacques); R.L. Milne (Roger); G.G. Giles (Graham); S. Margolin (Sara); A. Lindblom (Annika); T. Brüning (Thomas); H. Brauch (Hiltrud); M.C. Southey (Melissa); J.L. Hopper (John); T. Dörk (Thilo); N.V. Bogdanova (Natalia); M. Kabisch (Maria); U. Hamann (Ute); R.K. Schmutzler (Rita); A. Meindl (Alfons); H. Brenner (Hermann); V. Arndt (Volker); R. Winqvist (Robert); K. Pykäs (Katri); P.A. Fasching (Peter); M.W. Beckmann (Matthias); J. Lubinski (Jan); A. Jakubowska (Anna); A.M. Mulligan (Anna Marie); I.L. Andrulis (Irene); R.A.E.M. Tollenaar (Rob); P. Devilee (Peter); L. Le Marchand (Loic); C.A. Haiman (Christopher); A. Mannermaa (Arto); V-M. Kosma (Veli-Matti); P. Radice (Paolo); P. Peterlongo (Paolo); F. Marme (Federick); B. Burwinkel (Barbara); C.H.M. van Deurzen (Carolien); A. Hollestelle (Antoinette); N. Miller (Nicola); M. Kerin (Michael); D. Lambrechts (Diether); O.A.M. Floris; J. Wesseling (Jelle); H. Flyger (Henrik); S.E. Bojesen (Stig); S. Yao (Song); C.B. Ambrosone (Christine); G. Chenevix-Trench (Georgia); T. Truong (Thérèse); P. Guénel (Pascal); A. Rudolph (Anja); J. Chang-Claude (Jenny); H. Nevanlinna (Heli); C. Blomqvist (Carl); K. Czene (Kamila); J.S. Brand (Judith S.); J.E. Olson (Janet); F.J. Couch (Fergus); A.M. Dunning (Alison); P. Hall (Per); D.F. Easton (Douglas); P.D.P. Pharoah (Paul); S. Pinder (Sarah); M.K. Schmidt (Marjanka); I.P. Tomlinson (Ian); R. Roylance (Rebecca); M. García-Closas (Montserrat); E.J. Sawyer (Elinor)

    2016-01-01

    textabstractBackground: Ductal carcinoma in situ (DCIS) is a non-invasive form of breast cancer. It is often associated with invasive ductal carcinoma (IDC), and is considered to be a non-obligate precursor of IDC. It is not clear to what extent these two forms of cancer share low-risk

  15. Repurposing CRISPR/Cas9 for in situ functional assays

    NARCIS (Netherlands)

    Malina, Abba; Mills, John R; Cencic, Regina; Yan, Yifei; Fraser, James; Schippers, Laura M; Paquet, Marilène; Dostie, Josée; Pelletier, Jerry

    2013-01-01

    RNAi combined with next-generation sequencing has proven to be a powerful and cost-effective genetic screening platform in mammalian cells. Still, this technology has its limitations and is incompatible with in situ mutagenesis screens on a genome-wide scale. Using p53 as a proof-of-principle target