1,720,997 research outputs found
Peripapillary vascular density in resolved non-arteritic anterior ischemic optic neuropathy: colocalization between structural and vascular parameters
No full textIntroduction/aims: Non-arteritic anterior ischemic optic neuropathy (NAION) is an acute infarction of the prelaminar anterior optic disc, resulting from the occlusion of posterior ciliary arteries. Here, we evaluated the correlation between structural and vascular features in a case of resolved NAION. Methods: Observational case report. Results: A 50-year-old male patient was referred at an Eye clinic due to an altitudinal visual field defect in the left eye, occurred 9 months before. Fundus examination was unremarkable, while structural SD-OCT reveals retinal nerve fiber layer (RNFL), ganglion cell complex (GCC) thinning associated with reduction of peripapillary vascular density at OCT Angiography. Discussion: We found a precise spatial correlation among RNFL and GCC thinning, peripapillary vascular reduction and visual field defects. This case demonstrates that OCTA represents a new, valid and non-invasive imaging technique in the diagnosis and follow-up of NAION, even after the resolution of the acute phase, in the absence of clinical signs at fundus examination
Correlation between the optic nerve pial diameter and radial peripapillary vascular changes in primary open-angle glaucoma
No full textPurpose: To assess the optic nerve pial diameter (ONPD) in patients with primary open-angle glaucoma (POAG) using standardized A-scan ultrasound and to evaluate the correlation between the ONPD and structural, vascular optic nerve head features and visual field parameters in glaucomatous eyes. Methods: In this prospective study, we enrolled 126 eyes of 63 POAG patients and 124 eyes of 62 healthy controls. In all subjects, the ONPD was evaluated by means of A-scan ultrasound. Spectral domain (SD)-OCT was used to assess ganglion cell complex (GCC), retinal nerve fiber layer (RNFL), thicknesses, and the optic nerve head (ONH) morphology. OCTA measured the vessel density (VD) of radial peripapillary capillary (RPC) plexus. Results: The ONPD showed a statistically significant reduction in POAG group with respect to controls (p < 0.001). SD-OCT and OCTA parameters showed a significant impairment in patient group with respect to controls (p < 0.001). The ONH analysis revealed significantly lower values in rim area (p = 0.009) and an increased cup-to-disc area ratio (p = 0.013) and cup volume (p < 0.001) in patients with respect to controls. Significant correlations were shown in POAG group between ONPD and RPC plexus (p = 0.006). Moreover, significant correlation was also found between ONPD and structural SD-OCT parameters (p = 0.001) and between ONPD and visual field parameters (p = 0.001). Conclusions: The standardized A-scan ultrasound measurements of the ONPD showed a significant correlation with structural and vascular glaucomatous changes measured by means of SD-OCT and OCTA. These results confirm the diagnostic reliability of the ultrasound evaluation in glaucoma optic neuropathy. [Figure not available: see fulltext.
Optical coherence tomography angiography in contractile morning glory syndrome
Full text linkThis study describes the optical coherence tomography and optical coherence tomography angiography features of three eyes of three patients affected by contractile morning glory syndrome. Optical coherence tomography angiography scans of the peripapillary retina revealed a dense microvascular network without any vascular difference between the superficial vascular plexus and the deep vascular plexus around the optic nerve. These optical coherence tomography angiography findings confirm that the contractile movement could be due to the presence of an autonomic cholinergic muscular mechanism in the posterior part of the globe. In fact in our cases, the contractile movement seemed to be induced by massage of the eyeball. Optical coherence tomography angiography is a valid, non-invasive, dyeless, and reliable method that could shed light on the pathogenesis of this rare disease of the optic disk
Optical coherence tomography angiography in optic nerve sheath meningioma
Full text linkThis study describes Spectral Domain-Optical Coherence Tomography (SD-OCT) and Optical Coherence
Tomography Angiography (OCTA) features of Optic Nerve Sheath Meningioma (ONSM).
A 22-year-old woman, diagnosed with meningioma encircling the right optic nerve inside the intraorbital
segment optic canal at the magnetic resonance imaging, showed a normal fundus examination.
Instead, SD-OCT and OCTA revealed alterations in the neurostructure and microvascular network of the optic
nerve.
Despite fundoscopy and fluorescein angiography, SD-OCT and OCTA represent valid, non-invasive and reliable methods to evaluate neurostructural and vascular irregularities in this benign tumor of the optic nerv
Multiple sclerosis and maternity: A psychological explorative qualitative research
Full text linkConsidering women living with multiple sclerosis (MS), motherhood may represent a complicated event. Our aim in this study is to explore the personal meanings related to maternity and illness in women living with this disease. We have involved twenty women suffering from MS and we have administered an open interview introduced by a trigger question as a prompt aimed to elicit a narrative of their experience of illness, wishes, doubts, fears and life-projects with regard to motherhood. The interviews were audio-recorded and transcribed verbatim in order to carry out an analysis of the textual corpus. We have performed the textual analysis of the transcribed interviews through the T-LAB software. Performing a cluster analysis, four thematic clusters emerged: Daily Pain, Relationship with Health Care Services, Closing of a Circle and Family Role. We have interpreted the relationship between these themes using factorial mapping through 3 meaning vectors, representative of the following dynamics: From Concrete to Abstract; From Life-Project to Relapse; From Health Agencies to Family Support. All these meaning-vectors seem to describe the relationship between maternity and illness. Some aspects, as the presence of a stable partner or knowing diagnosis for more than ten years, might represent supporting factors for a project of motherhood. Starting from the results obtained, we provide some proposals for the definition of goals and strategies of psychological counselling within the Health Care Services
Radial peripapillary vessel density as early biomarker in preperimetric glaucoma and amnestic mild cognitive impairment
No full textPurpose: To investigate the vessel density (VD) of the radial peripapillary capillary (RPC) plexus in patients affected by preperimetric glaucoma (PPG), amnestic mild cognitive impairment (aMCI) and in a healthy control group using optical coherence tomography angiography (OCTA) in order to clarify the pathogenetic mechanisms of these neurodegenerative diseases. Methods: In this prospective study, we studied 54 eyes of 54 patients with PPG, 54 eyes of 54 patients with aMCI and 54 healthy controls. All subjects underwent structural spectral domain optical coherence tomography (SD)-OCT to assess the ganglion cell complex (GCC) and the retinal nerve fibre layer (RNFL). OCTA was used to evaluate the VD of the RPC in different regions (whole image, inside disc and peripapillary). Results: The PPG and aMCI groups showed a statistically significant reduction in SD-OCT and parameters with respect to controls (p 0.05). At OCTA examination, PPG and aMCI patients exhibited a statistically significant reduction in the VD of the RPC in whole image, inside and peripapillary regions compared to healthy controls (p < 0.001). When comparing the two study groups, the OCTA parameters were significantly impaired in PPG with respect to aMCI patients. Significant correlations were found between structural OCT and OCTA parameters in PPG and aMCI groups (p < 0.05). Conclusions: RPC vessel density could represent a helpful and sensible biomarker to identify early retinal microvascular changes in PPG and MCI in order to better understand the vascular pathophysiological mechanisms involved in these neurodegenerative diseases.[Figure not available: see fulltext.
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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