1,720,974 research outputs found
Visualization of vitreomacular tractions with en face optical coherence tomography.
No full textBackground In vitreomacular traction syndrome, an incomplete vitreous detachment with persistent vitreous traction on the macula is present. This condition may determine formation of epiretinal membranes, macular puckering, macular oedema, and traction macular detachment. Recently introduced en face optical coherence tomography (OCT) provides not only longitudinal B-scan but also coronal C-scan images of the retina.
Methods Fifteen eyes of 11 non-diabetic patients presenting vitreomacular traction syndrome have been evaluated with en face OCT (OTI, Toronto, Ontario, Canada).
Results In 12 eyes, cystoid macular oedema was detectable at fundus examination and was associated with a broad-based adherence of the posterior hyaloid to the macula. In three eyes, foveal detachment appeared to be associated with focal foveal vitreoretinal traction. In all eyes, the lateral extent of the hyaloidal tractions on the macula was clearly detectable at coronal C-scan. They appeared as sigmoid hyper-reflective bands in the hyporeflective vitreous chamber. Overlay of C-scans on red-free confocal images allowed the visualization of the edges of the adherences in relation to the structures of the posterior pole.
Conclusions The C-scan images allowed clear visualization of the total extension of the posterior vitreomacular adherences and their relationships with the vascular arcades, the optic disc, and the fovea
Effect of dihydroergocriptine mesylate on arterial blood pressure and intraocular pressure in healthy volunteers and glaucomatous patients
No full textEvaluation of peripapillary detachment in pathologic myopia with en face optical coherence tomography.
No full textEvaluation of peripapillary detachment in pathologic myopia with en face optical coherence tomography.
No full textBackground A newly recognized lesion in pathologic myopia is peripapillary detachment of the retinal pigment epithelium (RPE) and retina. Recently introduced en face optical coherence tomography (OCT) provides not only cross-sectional but also coronal scans of the retina, and allows lateral extent visualization and thickness measurement of lesions. Methods Three patients presenting bilateral peripapillary yellow-orange lobulated area in high myopia have been evaluated with fluorescein angiography ( FA), indocyanine green angiography (ICGA), en face OCT (OCT/SLO; Ophthalmic Technologies Inc, Toronto, Canada), and Humphrey visual field analyzer. Results In all eyes, en face OCT has shown the presence of a peripapillary sub-RPE nonreflective area. The lateral extent of this area was clearly detectable and the measurement of its thickness was obtained. We detected a cleft in the RPE at one edge of the cavitation in two eyes, vascular tractions and vitreoretinal tractions in two eyes, a macular hole with posterior retinal detachment, and small areas of RPE detachment nonconnected with the peripapillary detachment in one eye. In the four eyes presenting a proper central fixation, glaucomatous visual field defects were evident. Conclusion En face OCT has allowed to evaluate the thickness and the lateral extent of the peripapillary detachment. Therefore, its use could be important in determining the size and grading of these lesions at first visit, and to detect minimal changes of width and thickness during follow-up as an alternative to fluorescein angiography
Evaluation of peripapillary detachment in pathologic myopia with en face optical coherence tomography.
No full textBackground A newly recognized lesion in pathologic myopia is peripapillary detachment of the retinal pigment epithelium (RPE) and retina. Recently introduced en face optical coherence tomography (OCT) provides not only cross-sectional but also coronal scans of the retina, and allows lateral extent visualization and thickness measurement of lesions. Methods Three patients presenting bilateral peripapillary yellow-orange lobulated area in high myopia have been evaluated with fluorescein angiography ( FA), indocyanine green angiography (ICGA), en face OCT (OCT/SLO; Ophthalmic Technologies Inc, Toronto, Canada), and Humphrey visual field analyzer. Results In all eyes, en face OCT has shown the presence of a peripapillary sub-RPE nonreflective area. The lateral extent of this area was clearly detectable and the measurement of its thickness was obtained. We detected a cleft in the RPE at one edge of the cavitation in two eyes, vascular tractions and vitreoretinal tractions in two eyes, a macular hole with posterior retinal detachment, and small areas of RPE detachment nonconnected with the peripapillary detachment in one eye. In the four eyes presenting a proper central fixation, glaucomatous visual field defects were evident. Conclusion En face OCT has allowed to evaluate the thickness and the lateral extent of the peripapillary detachment. Therefore, its use could be important in determining the size and grading of these lesions at first visit, and to detect minimal changes of width and thickness during follow-up as an alternative to fluorescein angiography
Aberrant congenital macular vessel crossing the fovea: evaluation with optical coherence tomography.
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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
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