1,720,956 research outputs found
Choroidal Neovascularization in Pathologic Myopia
No full textWith regard to the power calculations please note the following. The population covered by the present study consists of all subjects potentially affected with myopic CNV. It is a population of modalities, and therefore, is unlimited. The sample was selected according to inclusion and exclusion criteria, mentioned in the “Methods.” From a statistical point of view, it is a simple, random, no orderly sample without replacement: it is a nonprobabilistic sample with reasoned choice, which does not allow the application of the Horvitz-Thompson estimator to estimate variance, and then errors and best sample size. We elected to enroll every eligible patient who sought treatment from February 2008 through December 2008; therefore, the sample size was left to chance. The 1-tailed paired t test we used to compare the best-corrected visual acuity (BCVA) results applies with the compound hypothesis; therefore, the test power 1 - beta cannot be determined by the Neyman-Pearson lemma. The Neyman-Pearson test, indeed, applies to the case of a simple null hypothesis against a simple alternative hypothesis; on the contrary, the 1- beta varies with an alternate hypothesis. With a sample size of 16 patients in each arm, we found a standard deviation equal to 8.413 for BCVA in the bevacizumab group. We can assume a prudential alternate hypothesis of BCVA improvement equal to 7 letters; given an alfa error of 5%, we obtain a power of 0.942, and therefore a beta error of 5.8%. As for the proportional confidence interval of a complication rate, it is absolutely arbitrary to evaluate as 25% because we could not examine the problem, not being detected over all of the 32 patients. This means that the probability of complications is less than 3%, corresponding to a maximum proportional confidence interval equal to 11.7%, with an error of 5%
Choroidal Neovascularization in Pathologic Myopia: Intravitreal Ranibizumab Versus Bevacizumab—A Randomized Controlled Trial
No full texttreating myopic choroidal neovascularization (CNV). ? DESIGN: Prospective, comparative, randomized, interventional study. ? METHODS: Thirty-two eyes from 32 patients with myopic CNV were consecutively enrolled and randomly treated, in a 1:1 ratio, with intravitreal ranibizumab (0.5 mg) or bevacizumab (1.25 mg) as needed, after the first injection. ETDRS best-corrected visual acuity (BCVA), foveal center thickness (FCT) on optical coherence tomography (OCT), and fluorescein angiographic findings were examined before and after treatment. Patients were followed up for 6 months. ? RESULTS: No statistically significant difference in the BCVA improvement, as well as in the FCT reduction, was found between groups during follow-up (P value at 1, 3, 6 months > .05). Complete resolution of fluorescein leakage was observed in all 16 bevacizumab-treated eyes and in 15 out of 16 (93.7%) ranibizumab-treated eyes. No ocular or systemic adverse effects from treatment were encountered. ? CONCLUSION: This randomized clinical study cannot determine a statistically significant difference in anti- VEGF treatment effect between ranibizumab and bevacizumab for the treatment of CNV secondary to pathologic myopia. A larger study is required to determine the relative efficacy and duration of action of these drugs. (Am J Ophthalmol 2010;149:458–464. © 2010 by Elsevier Inc. All rights reserved.
Correlation between specratl-domain optical coherence tomography findings and visual outcome after primary rhegmatogenous retinal detachment repair.
No full textPurpose: To correlate the postoperative visual outcome with the spectral-domain optical coherence tomography (SD-OCT) findings in the fovea after successful rhegmatogenous retinal detachment repair. Cross-sectional, observational study.
Methods: Thirty-five patients with preoperative macula-on rhegmatogenous retinal detachment (12 eyes) and macula-off rhegmatogenous retinal detachment (23 eyes) who underwent scleral buckling surgery for primary rhegmatogenous retinal detachment were recruited. Early Treatment Diabetic Retinopathy Study best-corrected visual acuity measurement, microperimetry, and SD-OCT examination were performed on the same day. Foveal center retinal thickness, central 1-mm subfield thickness, and outer nuclear layer thickness were measured using SD-OCT. The presence or absence of epiretinal membrane, intraretinal fluid, and subretinal fluid was assessed. The status of the external limiting membrane, inner/outer segment junction, and intermediate line was also evaluated and judged as disrupted or complete. The correlations between SD-OCT findings and either postoperative best-corrected visual acuity or retinal sensitivities for central 12 degrees were analyzed.
Results: The outer nuclear layer thickness was the only significant SD-OCT retinal measurement strongly correlated with both postoperative best-corrected visual acuity (r = 0.61; P < 0.001) and retinal sensitivities for central 12 degrees (r = 0.53; P = 0.001). Among the SD-OCT imaging findings, status of the external limiting membrane, inner/outer segment junction, and intermediate line and the presence of intraretinal fluid showed a significantly high correlation either with best-corrected visual acuity outcome (r = -0.60; P < 0.001, r = -0.63; P < 0.001, r = -0.66; P < 0.001, and r = -0.50; P = 0.002, respectively) or with postoperative retinal sensitivities (r = -0.59; P < 0.001, r = -0.61; P < 0.001, r = -0.66; P < 0.001, r = -0.50; P = 0.002, respectively). Multivariate analysis showed that the outer nuclear layer thickness and the status of the intermediate line were the most important predictors of visual outcome (P, 0.001 and P, 0.001, respectively).
Conclusion: This study showed that not only the status of the external limiting membrane and the inner/outer segment junction but also the integrity of the intermediate line and the outer nuclear layer thickness changes may be important predictors of postoperative visual outcome after anatomically successful rhegmatogenous retinal detachment repair. RETINA 32:43-53, 201
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
- …
