1,243 research outputs found

    Evaluating Refractive Outcomes after Cataract Surgery

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    Purpose To compare methods for evaluating refractive outcomes after cataract surgery to detect outliers. Design Case series database study of the evaluation of diagnostic technology. Participants Consecutive patients who had uneventful cataract operations over a 5-year period. Methods The intended and postoperative refractive outcome and differences between these were analyzed as a spherical equivalent, cylinder, and spherocylinder. The average keratometry and differences between steep and flat keratometric meridians were used to calculate the intended refractive error. Main Outcome Measures Outliers were defined as patients for whom the difference between the intended and postoperative refractive errors was more than 3 standard deviations (SDs) away from the mean. Results A total of 9000 patients were included. Twelve patients had missing data and were excluded. The mean intended refractive outcome was −0.12+0.12×2 (95% lower confidence limit [LCL], −1.94+1.06×44; 95% upper confidence limit [UCL], +0.77+1.05×140). The actual postoperative refractive error was −0.30+0.47×6 (95% LCL, −2.36+1.31×36; 95% UCL, +1.00+1.18×148) with a difference from the intended of −0.18+0.35×7 (95% LCL, −1.91+1.22×38; 95% UCL, +0.75+1.09×145). Treating the components of the refractive error independently, outliers were observed in 82 eyes (0.91%) based on the sphere, 46 eyes (0.51%) based on the spherical equivalent, 115 eyes (1.28%) based on treating the cylinder as a scalar, and 76 eyes (0.85%) based on treating the cylinder as a vector. When the differences between the intended and postoperative refractive errors were calculated as a compound spherocylinder, outliers were observed for 233 eyes (2.59%). Conclusions Treating the intended refractive outcome as a spherocylinder improves the precision for detecting clinically significant refractive outliers

    Limited contribution of ancient methane to surface waters of the U.S. Beaufort Sea shelf

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    © The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Science Advances 4 (2018): eaao4842, doi:10.1126/sciadv.aao4842.In response to warming climate, methane can be released to Arctic Ocean sediment and waters from thawing subsea permafrost and decomposing methane hydrates. However, it is unknown whether methane derived from this sediment storehouse of frozen ancient carbon reaches the atmosphere. We quantified the fraction of methane derived from ancient sources in shelf waters of the U.S. Beaufort Sea, a region that has both permafrost and methane hydrates and is experiencing significant warming. Although the radiocarbon-methane analyses indicate that ancient carbon is being mobilized and emitted as methane into shelf bottom waters, surprisingly, we find that methane in surface waters is principally derived from modern-aged carbon. We report that at and beyond approximately the 30-m isobath, ancient sources that dominate in deep waters contribute, at most, 10 ± 3% of the surface water methane. These results suggest that even if there is a heightened liberation of ancient carbon–sourced methane as climate change proceeds, oceanic oxidation and dispersion processes can strongly limit its emission to the atmosphere.The National Science Foundation (PLR-1417149; awarded to J.D.K.) primarily supported this work with additional support provided by the U.S. Department of Energy (DE-FE0028980; awarded to J.D.K.). Atmospheric 14C-CH4 measurements were funded by NASA via the Jet Propulsion Laboratory (Earth Ventures project “Carbon in Arctic Reservoirs Vulnerability Experiment”) to the University of Colorado under contract 1424124. K.M.S. acknowledges support from the University of Minnesota Grant-in-Aid program

    The Royal College of Ophthalmologists' National Ophthalmology Database study of cataract surgery: Report 7, immediate sequential bilateral cataract surgery in the UK: Current practice and patient selection.

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    BACKGROUND: Cataract extraction is the most frequently performed surgical intervention in the world and demand is rising due to an ageing demography. One option to address this challenge is to offer selected patients immediate sequential bilateral cataract surgery (ISBCS). This study aims to investigate patient and operative characteristics for ISBCS and delayed bilateral cataract surgery (DSCS) in the UK. METHODS: Data were analysed from the Royal College of Ophthalmologists' National Ophthalmology Database Audit (NOD) of cataract surgery. Eligible patients were those undergoing bilateral cataract extraction from centres with a record of at least one ISBCS operation between 01/04/2010 and 31/08/2018. Variable frequency comparison was undertaken with chi-square tests. RESULTS: During the study period, 1073 patients had ISBCS and 248,341 DSCS from 73 centres. A higher proportion of ISBCS patients were unable to lie flat (11.3% vs. 1.8%; p < 0.001), unable to cooperate (9.7% vs. 2.7%; p < 0.001); underwent general anaesthesia (58.7% vs. 6.6% (p < 0.001)); had brunescent/white/mature cataracts (odds ratio (OR) 5.118); no fundal view/vitreous opacities (OR 8.381); had worse pre-operative acuity 0.60 LogMAR ISBCS vs. 0.50 (first) and 0.40 (second eye) DSCS and were younger (mean ages, 71.5 vs. 75.6 years; p < 0.001). Posterior capsular rupture (PCR) rates adjusted for case complexity were comparable (0.98% ISBCS and 0.78% DSCS). CONCLUSIONS: ISBCS was performed on younger patients, with difficulty cooperating and lying flat, worse pre-operative vision, higher rates of known PCR risk factors and more frequent use of general anaesthesia than DSCS in centres recorded on NOD

    Simple guide to starting a research group

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    Conducting cutting-edge research and scholarship becomes more complicated with each passing year; forming a collaborative research group offers a way to navigate this increasing complexity. Yet many individuals whose work might benefit from the formation of a collaborative team may feel overwhelmed by the prospect of attempting to build and maintain a research group. We propose this simple guide for starting and maintaining such an enterprise

    Sonic Booms in Atmospheric Turbulence (SonicBAT): The Influence of Turbulence on Shaped Sonic Booms

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    The objectives of the Sonic Booms in Atmospheric Turbulence (SonicBAT) Program were to develop and validate, via research flight experiments under a range of realistic atmospheric conditions, one numeric turbulence model research code and one classic turbulence model research code using traditional N-wave booms in the presence of atmospheric turbulence, and to apply these models to assess the effects of turbulence on the levels of shaped sonic booms predicted from low boom aircraft designs. The SonicBAT program has successfully investigated sonic boom turbulence effects through the execution of flight experiments at two NASA centers, Armstrong Flight Research Center (AFRC) and Kennedy Space Center (KSC), collecting a comprehensive set of acoustic and atmospheric turbulence data that were used to validate the numeric and classic turbulence models developed. The validated codes were incorporated into the PCBoom sonic boom prediction software and used to estimate the effect of turbulence on the levels of shaped sonic booms associated with several low boom aircraft designs. The SonicBAT program was a four year effort that consisted of turbulence model development and refinement throughout the entire period as well as extensive flight test planning that culminated with the two research flight tests being conducted in the second and third years of the program. The SonicBAT team, led by Wyle, includes partners from the Pennsylvania State University, Lockheed Martin, Gulfstream Aerospace, Boeing, Eagle Aeronautics, Technical & Business Systems, and the Laboratory of Fluid Mechanics and Acoustics (France). A number of collaborators, including the Japan Aerospace Exploration Agency, also participated by supporting the experiments with human and equipment resources at their own expense. Three NASA centers, AFRC, Langley Research Center (LaRC), and KSC were essential to the planning and conduct of the experiments. The experiments involved precision flight of either an F-18A or F-18B executing steady, level passes at supersonic airspeeds in a turbulent atmosphere to create sonic boom signatures that had been distorted by turbulence. The flights spanned a range of atmospheric turbulence conditions at NASA Armstrong and Kennedy in order to provide a variety of conditions for code validations. The SonicBAT experiments at both sites were designed to capture simultaneous F-18A or F-18B onboard flight instrumentation data, high fidelity ground based and airborne acoustic data, surface and upper air meteorological data, and additional meteorological data from ultrasonic anemometers and SODARs to determine the local atmospheric turbulence and boundary layer height

    Primary trabeculectomy versus primary glaucoma eye drops for newly diagnosed advanced glaucoma:TAGS RCT

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    Funding Information: Declared competing interests of authors: Anthony J King declares receiving honoraria payments from Thea Pharmaceutical (Keele, UK) and Allergan Pharmaceutical (Dublin, Ireland) for speaking at educational meetings. Augusto Azuara-Blanco declares membership of the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Prioritisation Committee B (2020–present). Jennifer Burr declares membership of the NIHR HTA Clinical Evaluations and Trials Committee (2010–14). David Garway-Heath reports grants from NIHR for the HTA programme 12/35/38 during the conduct of the study; personal fees from Aerie Pharmaceuticals (Bedminster, NJ, USA), Allergan Pharmaceuticals, Bausch & Lomb (Rochester, NY, USA), Omikron (Beirut, Lebanon) and OptoVue (Fremont, CA, USA); personal fees and non-financial support from Carl Zeiss Meditec (Jena, Germany) and CenterVue (Padova, Italy); grants from Pfizer Inc. (New York, NY, USA) and Alcon Research Institute (Geneva, Switzerland); grants and personal fees from Santen Pharmaceutical (Osaka, Japan); and research equipment from Heidelberg Engineering (Heidelberg, Germany) and Topcon (Tokyo, Japan) outside the submitted work. David Garway-Heath also declared membership of the NIHR HTA Clinical Evaluations and Trials Committee (2014–17). John Norrie reports grants from University of Aberdeen and University of Edinburgh during the conduct of the study; and reports being a past and present member of the following: HTA Commissioning Sub-Board (EOI), NIHR Clinical Trials Unit Standing Advisory Committee, NIHR HTA and Efficacy and Mechanism Evaluation (EME) Editorial Board, Pre-Exposure Prophylaxis Impact Review Panel, EME Strategy Advisory Committee, EME Funding Committee Members, EME Funding Committee Sub-Group Remit and Comp Check, HTA General Committee, HTA Funding Committee Policy Group (formerly CSG) and the HTA Commissioning Committee. John Norrie also reports the HTA Post-funding Committee Teleconference (2016–19) and Covid Reviewing 2020. Luke Vale reports grants from NIHR HTA programme 12/35/38 during the conduct of the study. Luke Vale was also a member of the NIHR HTA Clinical Trials and Evaluation Panel from 2014 to 2018. John M Sparrow reports grants from NIHR HTA programme 12/35/38 during the conduct of the study, and was the previous chairperson of the National Institute for Health and Care Excellence Glaucoma Guideline Committee guideline published in 2017. Keith Barton reports personal fees from Allergan Pharmaceuticals, Alcon Pharmaceuticals, Laboratoires Thea (Clermont-Ferrand, France), EyeTechCare (Rillieux-la-Pape, France), Glaukos (San Clemente, CA, USA), Kowa Pharmaceuticals (Montgomery, AL, USA), Ivantis Inc. (Irvine, CA, USA), pH Pharma (South San Francisco, CA, USA), iStar Medical (Wavre, Belgium), Radiance Therapeutics (Tucson, AZ, USA) and EyeD Pharma (Liège, Belgium), grants from Allergan and Laboratoires Thea, stock from Vision Medical Events Ltd (London, UK), International Glaucoma Surgery Registry (London, UK) and MedEther Ophthalmology (London, UK), and a patent from Advanced Ophthalmic Implants outside the submitted work. This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 72. See the NIHR Journals Library website for further project information. The research reported in this issue of the journal was funded by the HTA programme as project number 12/35/38. The contractual start date was in January 2014. The draft report began editorial review in February 2020 and was accepted for publication in December 2020. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The HTA editors and publisher have tried to ensure the accuracy of the authors’ report and would like to thank the reviewers for their constructive comments on the draft document. However, they do not accept liability for damages or losses arising from material published in this report.Peer reviewedPublisher PD

    Primary trabeculectomy for advanced glaucoma : pragmatic multicentre randomised controlled trial (TAGS)

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    Funding: The project was funded by the National Institute of Health Research (NIHR) Health Technology Assessment (HTA) Programme (project number 12/35/38). The Health Services Research Unit is funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorates. The funders had no role in considering the study design or in the collection, analysis, or interpretation of data; writing the report; or the decision to submit the article for publication. The views expressed herein are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care. Acknowledgments Sponsor representative: Pauline Hyman-Taylor (from February 2019), Natalie McGregor (March 2015 to February 2019), Audrey Athlan (from July 2014 to March 2015), Joanne Thornhill (from 2013 to July 2014). Patient and public involvement representative: Rick Walsh, Russel Young. CHaRT Trial Office: Mark Forrest (from 2015), Gladys McPherson (until 2015). CHaRT Trial Office data coordinator: Pauline Garden. Health economists: Eoin Maloney (until 2015), Mehdi Javanbakht (until June 2019).All participants in the trial, staff, and members of the TAGS Investigator Group responsible for recruitment in the clinical centres.Peer reviewedPublisher PD
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