1,721,090 research outputs found
Antiangiogenic therapy with anti-vascular endothelial growth factor modalities for diabetic macular oedema
No full textBackground Diabetic macular oedema (DMO) is a common complication of diabetic retinopathy. The retina at the macula thickens and this can cause gradual loss of central vision. Although grid or focal laser photocoagulation has been shown to reduce the risk of visual loss in DMO or clinically significant macular oedema (CSMO), vision is rarely improved. Antiangiogenic therapy with anti-vascular endothelial growth factor (anti-VEGF) modalities has recently been proposed for improving vision in people with DMO. Anti-VEGF drugs are delivered by an injection in the vitreous cavity of the eye. Objectives This review aims to assess the effectiveness of anti-VEGF therapy for preserving or improving vision in people with DMO. Search strategy We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE and Caribbean Literature on Health Sciences (LILACS). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 16 April 2009. Selection criteria We included randomised controlled trials (RCTs) comparing any antiangiogenic drugs with an anti-VEGF mechanism of action compared to another treatment, sham treatment, or no treatment. Data collection and analysis Two authors independently extracted the data. The risk ratio (RR) of visual loss and visual gain of 3 or more lines was estimated at least six months after treatment. Main results We found four small studies that collected only short-term outcomes (24 to 36 weeks); three of which had more than two randomisation groups generating five types of comparisons overall. Only one comparison included more than one trial in the analysis. The short-term outcome was the mean change in LogMAR visual acuity. One study on 172 patients compared three doses of pegaptanib versus sham (about 5 injections on average) and another compared bevacizumab or bevacizumab plus triamcinolone with sham (multiple bevacizumab injections and a single triamcinolone injection in 101 patients, 115 eyes overall) in patients with CSMO that was refractory to photocoagulation. Bevacizumab or bevacizumab plus triamcinolone were also compared to photocoagulation in 129 patients with untreated CSMO(150 eyes, multiple injections needed in 24 patients). Although comparisons tended to favour antiangiogenic therapy, estimates did not reach statistical significance or, if they did, they were not robust to sensitivity analysis regarding missing data and potential bias related to single trial estimates. No difference could be demonstrated in one study on 26 patients comparing bevacizumab to triamcinolone (both administered with a single injection) and between bevacizumab and bevacizumab plus triamcinolone in two studies on 182 patients. All the studies in this review, except for the study on pegaptanib, were at risk of bias based on the assessment of six methodological quality items. There were no serious adverse effects in these short-term studies, except for one case of severe anterior uveitis in one eye treated with bevacizumab. No included study examined long-term adverse effects of antiangiogenic therapy. Authors' conclusions There is not sufficient high quality evidence from large RCTs supporting the use of either single or multiple anti-VEGF intravitreal injections to treat DMO. Results from ongoing studies on several compounds should assess not only treatment efficacy but also, if a benefit is found, the number of injections needed for maintenance and long-term safety
Prognostic relevance of optical coherence tomography angiography biomarkers in diabetic macular edema
Full text linkAbstract was not mandatory. The review article was devoted to describe optical coherence tomography angiography (OCTA) biomarkers with a prognostic significance in predicting the evolution of diabetic macular edema (DME). OCTA features are crucial to the early prediction of DME but also to evaluate the response to treatment, identifying potential poor responders
Interleukin-1beta tear concentration in glaucomatous and ocular hypertensive patients treated with preservative-free nonselective beta-blockers
Full text linkPURPOSE: To evaluate the ocular surface inflammatory response to the presence of preservatives in nonselective
beta-blocker eyedrops.
DESIGN: Prospective, crossover, single-masked, randomized
clinical study. METHODS: STUDY POPULATION: Twenty primary open angle glaucoma or ocular hypertensive patients were divided in two groups, one treated with preservative-free timolol 0.5% (group 1) and the other with preserved timolol 0.5% (group 2) eyedrops. After 60 days of therapy and 3 more weeks of washout, the two groups switched to the other therapy. PROCEDURE: At each visit,basal tear samples were collected from the inferior conjunctival fornix for the determination of interleukin (IL)-1 tear concentrations by an enzyme-linked immunosorbent assay. Intraocular pressure measurement, conjunctival
hyperemia, superficial punctate keratitis, and tear film breakup time were evaluated. MAIN OUTCOME MEASURE: IL-1 concentration in tears following the use of preserved eyedrops.
RESULTS: IL-1 tear concentrations increased significantly in both groups, compared with baseline values,during preserved timolol therapy. There were no statistically significant changes in hyperemia and superficial punctate keratitis throughout the study in either group.A statistically significant breakup time reduction was observed in both groups after 30 days and after 60 days of preserved therapy.
CONCLUSION: The use of preservatives in timolol 0.5% eyedrops leads to tear film instability and ocular surface inflammatory changes documented by a reduction of breakup time and an increase of IL-1 tear concentrations.Preservative-free beta-blockers are preferable for long-term hypotensive therapy to prevent ocular surface inflammation
Large choroidal excavation in retinitis pigmentosa: A case report
No full textPurpose: To report the morphological and clinical features of a case of retinitis pigmentosa with large choroidal excavation. Methods: The patient underwent a complete ophthalmologic examination including best-corrected visual acuity assessment, anterior segment and dilated fundus examination and spectral-domain optical coherence tomography. Results: A 41-year-old woman affected by retinitis pigmentosa with genetic confirmation with mutation in RDH12 gene had a best-corrected visual acuity of 20/50 in both eyes. Dilated fundus examination revealed waxy pallor of the optic disc, diffuse narrowing of the retinal arterioles and a generalized retinal pigment epithelium mottling with bony spicule associated with diffuse retinal atrophy. At the posterior pole, an extended bilateral chorioretinal atrophy was evident with a partial sparing of the macular area. On spectral-domain optical coherence tomography, a bilateral large choroidal excavation could be clearly detected and it was associated with a diffuse retinal thinning at the posterior pole and a partial sparing of the fovea. Conclusion: Large choroidal excavation has been rarely reported. Although the pathogenetic mechanisms leading to the formation of large choroidal excavation are still a matter of debate, a combination of primary degenerative-inflammatory factors could be retained responsible for the large choroidal excavation development
Management of diabetic macular edema with intravitreal dexamethasone implants: Expert recommendations using a Delphi-based approach
No full textObjectives: Despite being approved and effective, steroids, and especially dexamethasone intravitreal implants, still have a poorly-defined role in management of diabetic macular edema. In order to overcome some of the limitations in current recommendations, a group of experts met to define consensus on some of the most controversial issues on the use of dexamethasone intravitreal implants in daily management of diabetic macular edema. Methods: A Delphi-based approach was utilized to develop clinically relevant statements applicable to routine treatment settings. A Steering Committee composed of four experts formulated 30 relevant statements, which were voted upon by a panel of 40 ophthalmologists/retinal specialists from across Italy. Results: Dexamethasone intravitreal implants were considered to be a valid first-line alternative to treatment with an anti-vascular endothelial growth factor agent and should be the first choice in pseudophakic and vitrectomized patients. A Pro Re Nata regimen was felt to be appropriate for retreatment with dexamethasone intravitreal implants while a 6-month waiting period was not considered suitable. Among steroid treatments, dexamethasone intravitreal implants were considered to have the best ocular tolerability. In patients with persistent macular edema after the loading-phase treatment with an anti-vascular endothelial growth factor, consensus was reached that clinicians should consider switching therapy to dexamethasone intravitreal implants. Moreover, dexamethasone intravitreal implants can reduce the treatment burden for individuals who are not able to cope with the more intensive treatment regimen required by anti-vascular endothelial growth factor therapy. Conclusions: While further studies are needed, this survey provides some key recommendations for clinicians treating diabetic macular edema that may be useful when choosing dexamethasone intravitreal implants in daily practice
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
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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