1,721,086 research outputs found
Acute macular neuroretinopathy: pathogenetic insights from optical coherence tomography angiography.
No full textAIM
To describe the optical coherence tomography angiography (OCT-A) features of patients affected by acute macular neuroretinopathy (AMN).
METHODS
This is a prospective, observational, cross-sectional study. Multimodal imaging, including spectral domain OCT (Spectralis HRA+OCT; Heidelberg Engineering, Heidelberg, Germany) and 6×6 mm swept source OCT-A (ZEISS PLEX Elite 9000; ZEISS, Dublin, California), was performed on all patients. The primary outcome measure was assessment of the vascular alterations of the superficial (SCP) and deep (DCP) capillary plexuses and choriocapillaris (CC). A segmentation of the AMN lesions using enface OCT images of photoreceptors-retinal pigment epithelium complex was used to discriminate intralesional and extralesional regions on the OCT-A enface slabs of the DCP and CC reconstructions. Each OCT-A slab was imported into ImageJ V.1.50 and digitally binarised for quantitative analyses.
RESULTS
Overall, seven patients (mean age 19.4±3.2 years, six women) affected by AMN were included. The mean best-corrected visual acuity was 0.00±0.00 logarithm of the minimum angle of resolution. Twelve healthy age-matched subjects (mean age 22±3.4 years, 10 women) represented the control group. The quantitative analysis of global vessel densities showed that the CC vessel density was significantly lower in patients with AMN (0.495±0.03) compared with the age-matched controls (0.545±0.02) (corrected p=0.0003). The intralesional vessel density of the DCP was 0.349±0.04 in AMN and vs 0.497±0.02 in the controls (corrected p=0.0002).
CONCLUSIONS
Our study confirmed inner choroidal vascular flow void as a possible pathogenetic mechanism of AMN. We also found a focal impairment of the DCP within the AMN lesions. Future studies are needed to clarify which is the primary location of the vascular insult in this condition
Treatment options for the wet form of age-related macular degeneration—a perspective
No full textTreatment of the wet form of age-related macular degeneration (wet AMD) has been
revolutionized a decade ago with the introduction of vascular endothelial growth factor (VEGF) blockers
that reduce neovascularization and macular edema. Two approved drugs are marketed for the treatment of
wet AMD—ranibizumab and aflibercept, but there is a third drug, bevacizumab, which is widely used offlabel;
a cancer drug that also blocks VEGF but was never tested in pivotal trials and never approved for
ophthalmic indications including wet AMD. Similarity of bevacizumab to ranibizumab led to off-label use
and even to government-sponsored studies comparison the approved ranibizumab head-to-head to the offlabel
cancer drug bevacizumab in wet AMD, like the Comparison of Age-related Macular Degeneration
Treatments Trials (CATT) study, discussed in this perspective paper. Recent publication of 5-year follow-up
from the initial 2-year CATT study provided the occasion to discuss the similarities and differences between
these two drugs and the lessons learned from the last decade of anti-VEGF therapy for wet AMD. Clinical
efficacy is comparable, with an advantage for ranibizumab. Likewise, safety finding favor ranibizumab over
bevacizumab in some aspects. The latest addition of approved anti-VEGF drugs for wet AMD, aflibercept,
may provide even more benefit to patients. In this perspective we discuss results of CATT and other longterm
follow-up and comparative studies. While all demonstrate clinical benefit of anti-VEGF, all reveal that
most patients’ loose visual acuity (VA) in real-life situations over 5–7 years. This loss is based on—what we
believe—significant under-treatment of wet AMD patients, due to economic or practical limitations and
overestimation of perceived risks as geographic atrophy. We compare own data that showed more intensive
treatment (more than twice the CATT-follow-up injections) with ranibizumab or aflibercept can maintain a
sustained gain in VA in wet AMD patients after 6 years. We encourage retina specialists to treat wet AMD
patients more aggressively and frequently in order to provide the maximum benefit for their patients
Modern Imaging Techniques for Visualising Choroidal Morphology and Function.
No full textThe choroid is directly adjacent to the retina and consists of a dense vascular network that supplies the outer retina. Pathologies in the choroid can lead to changes in the retinal pigment epithelium (RPE) and photoreceptors. Thus, the choroid plays a crucial role in the development of retinal diseases such as age-related macular degeneration (AMD), central serous chorioretinopathy (CSCR), pathologic myopia, and inflammatory diseases such as Vogt-Koyanagi-Harada syndrome (VKH). Basic knowledge of the structure and physiology of the choroid, as well as diagnostic options for visualizing choroidal changes, provides a better understanding of the physiology and pathology of choroidal processes. This review provides an overview of the anatomy and function of the choroid, and describes the diagnostic techniques currently available to characterize and visualize the choroid. It also includes an overview of various retinal conditions, which are associated with choroidal changes
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
Multiple Evanescent White Dot Syndrome (MEWDS) from a Patient's Perspective.
No full textPURPOSE
Multiple evanescent white dot syndrome (MEWDS) is a self-limiting inflammatory condition of the outer retina.Only little information is available how patients experience their symptoms.
METHOD
We report a case of a 28-year-old male graphic designer with MEWDS, who precisely illustrated the development and course of the characteristic symptoms while looking at the ceiling, at a face and on his phone.
RESULT
At onset, the scotoma was sparking/ shiny and appeared on the temporal field of view, consistent with an enlarged blind spot. Over the course of the disease, the scotoma decreased in intensity and moved superiorly and nasally until it completely faded.
CONCLUSION
Illustrations from a patient's perspective over the course of the disease can be beneficial for physicians and other MEWDS patients for a better understanding and monitoring of their disease
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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