1,720,960 research outputs found
Evaluation of the Effectiveness of Treatment with Dexamethasone Intravitreal Implant in Cystoid Macular Edema Secondary to Retinal Vein Occlusion
Get PDFPurpose. To evaluate retinal functional improvement by means of visual acuity and retinal sensibility examination after intravitreal dexamethasone implant in patients affected by cystoid macular edema secondary to retinal vein occlusion. Methods. Twenty-six consecutive patients affected by retinal vein occlusion complicated by cystoid macular edema were enrolled in this prospective interventional study. All patients underwent a baseline complete ophthalmological evaluation as well as retinal angiography, OCT examination, and microperimetry evaluation. Each patient was treated with intravitreal injection of a long-term steroid implant (Ozurdex, Allergan). Follow-up evaluations were performed at months 1, 3, and 6 and completed by OCT and MP1 examination. Clinical data underwent statistical analysis. Results. Baseline functional evaluation showed mean visual acuity of 0,63±0,42 LogMAR and retinal sensitivity of 7,93±4,73 dB (mean±standard deviation); after treatment, at day 30 we found, respectively, 0,43±0,38 LogMAR (p<0.05, compared to baseline) and 10,15±4,410 dB (p<0.05); at day 90, we found 0,44±0,32 (p<0.05) and 9.61±4,29 dB (p<0.05); at day 180, we found 0,41±0,31 (p<0.05) and 9,95±3,79 dB (p<0.05). Fixation pattern improved significantly (p<0.05), showing a stable fixation in 30% of patients at baseline, increasing to 77% of patients at day 180. Baseline morphological evaluation showed a central retinal thickness (CRT) of 398,21±181,65 μm after treatment; we found a CRT of 222,64±95,21 μm at day 30 (p<0.05, compared to baseline), 307,50±120,25 μm (p<0.05) at day 90, and 294,93±135,86 μm (p<0.05) at day 180. About 15,3% patients showed already at month 3 a recurrence of macular edema. They underwent a retreatment before month 6 as for treatment guidelines. Conclusion. Our detailed analysis showed the significative increase in retinal function in the early phases of the follow-up. Retinal sensibility showed a stronger correlation than VA in macular edema reabsorption, better underlying the progressive functional recovery and increase in quality of vision and life for the patients. This trial is registered with ClinicalTrials.gov NCT03559491
Optical coherence tomography angiography and arterial hypertension: A role in identifying subclinical microvascular damage?
No full textTo evaluate retinal microvasculature modifications by means of optical coherence tomography angiography in human subjects diagnosed with arterial hypertension and to assess potential clinical relevance for early diagnosis
Optical coherence tomography angiography and arterial hypertension: A role in identifying subclinical microvascular damage?
No full textTo evaluate retinal microvasculature modifications by means of optical coherence tomography angiography in human subjects diagnosed with arterial hypertension and to assess potential clinical relevance for early diagnosis
Early effects of intravitreal steroid on severe diabetic macular edema: morphological and functional features
No full textPurpose : To evaluate the early effects of intravitreal steroid therapy for diabetic macular edema (DME) on intraretinal structure and function.
Methods : This prospective study included 12 eyes of 10 consecutive patients who underwent intravitreal injection of a slow release steroid implant (Ozurdex, Allergan, USA) for severe DME. We defined as severe DME a central retinal thickness (CRT) > 450mm, presenting intraretinal cysts, subretinal (SRF) and intraretinal fluid (IRF); fluorescein angiography was performed at baseline to complete the diagnosis and classification of retinal pathology. We included patients naïve and patients previously treated with antiVEGF (from more than 6 months). We excluded patients affected by tractional DME and edema secondary to other vascular and inflammatory diseases. Baseline and follow up evaluations included complete ophthalmological evaluation and instrumental examination. Follow up visit were performed at day 7, 14 and 30 and then at month 1, 2 and 3. Functional evaluation was performed by ETDRS visual acuity; morphological evaluation was performed by CRT and retinal layers analysis on B-scan with SD OCT (Topcon 3D-OCT, USA). Statistical analysis was performed on collected data.
Results : Mean CRT decreased from 567,8 ± 120,6 mm at baseline to 242,4 ± 56,8 mm at month 3 (p<0.05). The SRF was the first pathological feature reducing on early follow up visits with a mean reduction of 109,6mm at month 1, followed by the reduction of IRF. The position and extension of intraretinal hard exudates changed with a migration within the foveal region and a deposition on outer retinal layers in 60% of patients.
Mean visual acuity significantly increased from 1,06 ± 0,2LogMAR at baseline to 0,53 ± 0,1 LogMAR at month 3 (p<0.05). All patients reported a reduction in visual blurring, metamorphopsia and colour disturbancies.
Conclusions : Steroid therapy demostrated its early effectiveness to reduce the effects of diabetic maculopathy on retinal morphology and function. At month 3 we showed significative results in function and morphology. Beware of the presence of hard exsudates that could influence a long-term results as they lay on foveal photoreceptor
Vitreous Substitutes: The Present and the Future
Get PDFVitreoretinal surgery has advanced in numerous directions during recent years. The removal of the vitreous body is one of the main characteristics of this surgical procedure. Several molecules have been tested in the past to fill the vitreous cavity and to mimic its functions. We here review the currently available vitreous substitutes, focusing on their molecular properties and functions, together with their adverse effects. Afterwards we describe the characteristics of the ideal vitreous substitute. The challenges facing every ophthalmology researcher are to reach a long-term intraocular permanence of vitreous substitute with total inertness of the molecule injected and the control of inflammatory reactions. We report new polymers with gelification characteristics and smart hydrogels representing the future of vitreoretinal surgery. Finally, we describe the current studies on vitreous regeneration and cell cultures to create new intraocular gels with optimal biocompatibility and rheological properties. © 2014 Simone Donati et al
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
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