1,721,074 research outputs found
PARACENTRAL ACUTE MIDDLE MACULOPATHY ASSOCIATED WITH PHOSPHODIESTERASE-5 INHIBITOR THERAPY
Full text linkPURPOSE:
To present an atypical case of paracentral acute middle maculopathy occurred upon awakening in the morning within hours after phosphodiesterase-5 (PDE-5) inhibitor consumption at bedtime.
METHODS:
Multimodal retinal imaging findings, including fluorescein angiography, spectral domain optical coherence tomography, optical coherence tomography angiography, and microperimetry of a particular case of paracentral acute middle maculopathy lesion that follow the distribution of the cilioretinal artery.
RESULTS:
A 52-year-old healthy man presented with an acute paracentral scotoma in his left eye upon awakening in the morning, after the use of a PDE-5 inhibitor pill the previous night. Spectral domain optical coherence tomography illustrated a hyperreflective band-like lesion at the level of the inner nuclear layer, consistent with a diagnosis of paracentral acute middle maculopathy, along the course of the cilioretinal artery that appeared normally perfused with fluorescein angiography. Optical coherence tomography angiography showed a perfusion deficit and capillary pruning of the retinal deep capillary plexus, with preserved intermediate capillary plexus, that colocalized with the paracentral scotoma confirmed with microperimetry.
CONCLUSION:
To our knowledge, this is the first report of paracentral acute middle maculopathy after the use of PDE-5 inhibitor. Nocturnal arterial hypotension exacerbated by the vasodilatory effect of the PDE-5 inhibitor may have caused transient cilioretinal artery hypo/nonperfusion and insufficiency. Paracentral acute middle maculopathy may represent the earliest form of ischemia in the central macular region, occurring after a milder vascular insult
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
Evaluation of the Choroid in Eyes With Retinitis Pigmentosa and Cystoid Macular Edema
Full text linkPurpose: To study the anatomical choroidal features associated with the presence of cystoid macular edema (CME) in eyes with retinitis pigmentosa (RP). Methods: A total of 159 eyes (from 159 patients) with a diagnosis of RP were enrolled in this retrospective cross-sectional case-control study and divided into two groups based on the presence (67 eyes) or absence (92 eyes) of CME. Retinal and choroidal features were evaluated on spectral domain optical coherence tomography including central macular thickness (CMT) and subfoveal choroidal thickness (CT). Total choroidal area (TCA), choroidal luminal area (LA), and choroidal stromal area (SA) were measured and the choroidal vascularity index (CVI) was calculated in all study eyes. Results: Average age was 49.2 ± 14.9 and 47.1 ± 15.5 years (P = 0.40) and logMAR Snellen visual acuity (VA) was 0.4 ± 0.6 (median 0.3, 20/40) and 0.2 ± 0.4 (median 0.1, 20/25) in the RP groups with and without CME, respectively (P = 0.05). Mean CMT was 334.1 ± 93.5 and 252.6 ± 47.6 μm in the RP groups with and without CME, respectively (P < 0.001). The subfoveal CT was significantly increased in the RP group with versus without CME (294.2 ± 110.9 μm vs. 198.1 ± 75.5 μm, respectively, P < 0.001). In patients with CME, the CVI was lower (P < 0.001) and the TCA, LA, and SA were all significantly higher (P < 0.001). Conclusions: In patients with CME associated with RP, the choroid exhibited significantly greater subfoveal thickening and decreased CVI. The choroid may be an important factor to consider in the etiology of CME in patients with RP
Is Pachychoroid Serous Retinopathy a Better Name to Describe the Features of Central Serous Chorioretinopathy?
Full text linkCentral serous chorioretinopathy (CSC) is a common retinal disease characterized by serous detachment
of the neurosensory retina. Although studies in recent years have provided a better understanding of the characteristics of the disorder, its pathogenesis is still not fully elucidated.1,2 With greater knowledge and understanding of the mechanisms of disease of CSC because of progressive investigation and study of this disorder over many years, there has been a constant change in the nomenclature. Central serous chorioretinopathy was first named “recurrent central retinitis” by von Graefe3 (in 1866)
who suggested that inflammation was a component of the underlying pathogenesis, possibly related to syphilis a common infectious disorder at the time. “Central” referred to serous retinal detachment of the
macula. In 1927, Horniker4 renamed the disease “capillarospastic central retinitis” and observed the disorder in angioneurotic patients without syphilis.The proposed mechanism was angioneuresis causing
retinal vasospasm and subsequent macular exudation. In 1939, Gifford and Marquardt5 suggested that an
angiopathy caused by abnormal vessel tone was the underlying etiology and called the condition “central
angiospastic retinopathy.
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
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