1,720,965 research outputs found
Spectral domain optical coherence tomography as an effective screening test for hydroxychloroquine retinopathy (the “flying saucer” sign)
No full textEric Chen, David M Brown, Matthew S Benz, Richard H Fish, Tien P Wong, Rosa Y Kim, James C MajorRetina Consultants of Houston, The Methodist Hospital, Houston, Texas, USAPurpose: While the long-term incidence of hydroxychloroquine (HCQ) retinopathy is low, there remains no definitive clinical screening test to recognize HCQ toxicity before ophthalmoscopic fundus changes or visual symptoms. Patients receiving HCQ were evaluated with spectral domain optical coherence tomography (SD OCT) to assess the feasibility of identifying HCQ retinopathy at an early stage.Methods: Twenty-five patients referred for the evaluation of hydroxychloroquine toxicity underwent a comprehensive ocular examination, Humphrey visual field (HVF) perimetry, time domain OCT, and SD OCT. Some patients with screening abnormalities also underwent further diagnostic testing at the discretion of the treating providers.Results: Five patients were found to have SD OCT findings corresponding to HCQ toxicity and retinal damage as seen by clinical exam and/or HVF perimetry. Two patients with advanced toxicity were found to have significant outer retina disruption in the macula on SD OCT. Three patients with early HCQ toxicity and HVF 10-2 perifoveal defects were found to have loss of the perifoveal photoreceptor inner segment/outer segment (IS/OS) junction with intact outer retina directly under the fovea, creating the “flying saucer” sign. While two of these three patients had early ophthalmoscopic fundus changes, one had none.Conclusion: Outer retinal abnormalities including perifoveal photoreceptor IS/OS junction disruption can be identified by SD OCT in early HCQ toxicity, sometimes even before ophthalmoscopic fundus changes are apparent. SD OCT may have a potential complementary role in screening for HCQ retinopathy due to its quick acquisition and because it is more objective than automated perimetry.Keywords: drug toxicity, hydroxychloroquine, photoreceptors, screening test, spectral domain optical coherence tomography&nbsp
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
Use of nepafenac (Nevanac®) in combination with intravitreal anti-VEGF agents in the treatment of recalcitrant exudative macular degeneration requiring monthly injections
No full textEric Chen, Matthew S Benz, Richard H Fish, David M Brown, Tien P Wong, Rosa Y Kim, James C MajorRetina Consultants of Houston, The Methodist Hospital, Houston, TX, USAPurpose: The purpose of this study is to determine the efficacy of combining topical nepafenac with monthly intravitreal injections of ranibizumab or bevacizumab in the treatment of recalcitrant exudative macular degeneration.Methods: This was a retrospective, consecutive case series of patients with exudative macular degeneration requiring maintenance therapy of antivascular endothelial growth factor (anti-VEGF) injections at least every 6 weeks, who were started on topical nepafenac. Despite frequent anti-VEGF dosing, all patients included in the study had persistence of any combination of the following: intraretinal cysts, subretinal fluid, and/or pigment epithelial detachment. Patients underwent pinhole visual acuity, clinical exam, and optical coherence tomography (OCT) at baseline and every follow-up visit. Response to therapy was graded by reviewing quantitative and qualitative OCT data, and statistical analysis was done with paired Student’s t-test.Results: Twenty-five patients (average age 77; 14 male and 11 female) were reviewed; the mean number of previous injections was 17.4 (range 3–31). Baseline mean visual acuity was 20/55, and final mean visual acuity after 3 months of treatment was 20/51 (P = 0.13). Monthly mean central foveal thickness measurements were 248, 250, 257, and 247 µm (P = 0.53) at baseline, 1, 2, and 3 months, respectively. By the end of the 3-month time point, qualitative OCT findings on 13 patients treated with nepafenac were classified as stable, 10 as better, and 2 as worse.Conclusions: There was no significant change in visual acuity or quantitative OCT measurements, but there appeared to be a mild trend toward improved anatomy and qualitative OCT findings when topical nepafenac was added to monthly anti-VEGF injections in patients with persistent intraretinal cysts, subretinal fluid, and/or pigment epithelial detachment. Further prospective studies with longer follow-up may be warranted.Keywords: anti-VEGF, combination therapy, exudative macular degeneration, nonsteroidal anti-inflammatory, optical coherence tomography&nbsp
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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