1,720,960 research outputs found
Reproducibility of rotating Scheimpflug camera imaging system in patients with keratoconus
No full textPurpose:To determine the reproducibility of indices for diagnosis and follow-up of keratoconus measured with Rotating Scheimpflug Camera imaging system (Pentacam).
Methods:Three consecutive scans, taken by the same operator, at a 5 minute interval each, were randomly taken on one eye of 14 patients with keratoconus using Pentacam. The parameters taken into evaluation were: corneal volume (CV), maximal keratometry value (K max), radii of curvature (Rh, Rv) and mean keratometry (Rm) of front (CF) and back (CB) cornea, thinnest location (TL), x (X) and y (Y) position of TL, anterior (ACE) and posterior corneal elevation (PCE) of TL.Reproducibility was assessed by calculating percentage coefficient of variation (%CoV) for all parameters except X and Y for which standard deviation (SD) was considered. The effect of mean value on %CoV was tested by regression analysis and their association with R2.
Results:Results are shown in Table 1. %CoVs were <2% in all parameters except ACE and PCE (about 5% each). SD was 0.05 for X and 0.31 for Y. Regression analysis was negative and R2 negligible for all parameters except for RmCF (y= -0,2811x +2,3185, P=0.007, R2=0.47)
Conclusions:Pentacam %CoVs in patients with keratoconus were low and independent from mean values (except RmCF). Values outside these ranges should be considered suspect for progression of the disease
Corneal Involvement In Primary Biliary Cirrhosis : An In Vivo Confocal Microscopy Study
No full textPurpose:To investigate the corneal involvement in Primary Biliary Cirrhosis (PBC), a slowly progressive cholestatic liver disease of autoimmune etiology.
Methods:Seven female patients affected by PBC underwent a slit-lamp biomicroscopy of the anterior segment with and without Goldmann's three-mirror contact lens, and laser scanning confocal microscopy (LSCM, Heidelberg Engineering Germany). LSCM images were acquired and analyzed for all layers of central and peripheral cornea (four quadrants).
Results:All patients had normal findings both at slit-lamp biomicroscopy and at gonioscopy. Peculiar findings were shown at LSCM: all patients showed keratocytes activation (Figure 1); sub-basal nerve fibers with beadlike structure (Figure 2) were found in six patients (86%); four subjects (57%) had hyper-reflective stromal macro-deposits (Figure 2). No deposits suggestive for copper deposition were detected at the level of Descemet’s membrane.
Conclusions:To the best of our knowledge this is the first confocal microscopy study on PBC patients. LSCM could show that subclinical corneal inflammation is a very common finding also in ophthalmoscopically normal patients affected by this autoimmune disease
Oct changes after idiopathic macular epiretinal membrane removal with internal limiting membrane peeling : 1 year follow up
No full textPurpose:To analyze long term anatomical outcomes after idiopathic macular epiretinal membrane (ERM) removal with internal limiting membrane (ILM) peeling.
Methods:A retrospective, observational case series of 24 eyes that underwent three-port pars plana vitrectomy for ERM was conducted. In all the eyes ERM removal and Brilliant Blue G assisted ILM peeling were performed by the same surgeon (SDC). Visual acuity examination (ETDRS chart) and OCT assessment of the macular profile were performed preoperatively and postoperatively on day 1, 7 and 14 and at 1, 3, 6 and 12 months after surgery. We divided all patients in 2 groups considering visual acuity. The correlation between the postoperative BCVA and foveal microstructural findings was evaluated
Results:Visual acuity stayed the same or with 1 line improvement in 7 patients (29.16%, Group A)and improved by two or more lines of vision in 17 patients (70.84%, Group B) at twelve months. Central retinal thickness decreased significantly after surgery: the mean thickness was 453.7+/-115.4 micron before surgery and 295.4+/-73.2 micron twelve months after surgery. None of the subjects had increasing foveal thickness twelve months after surgery. Inner hyper-reflective structure, attributable to the internal limiting membrane, could not be detected in 100% of eyes on day 1 and 7 after surgery in both group. In 71.4% of patients of group A and 75% of patients in group B a new inner hyper-reflective structure could be detected at 30+/-14 days after surgery. No recurrence of ERM was observed.
Conclusions:ERM removal with ILM peeling is nowadays a safe and successful surgery for vitreoretinal interface syndrome. Many authors described a correlation between postoperative visual acuity and final foveal thickness. We observed that inner hyper-reflective structure, attributable to the internal limiting membrane, becomes newly detectable after 30+/-14 days after surgery in 70.9% of the patients and this doesn’t seem to have any influence on final visual outcome
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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