1,720,975 research outputs found
Treatment Outcomes Using the PAUL Glaucoma Implant to Control Intraocular Pressure in Eyes with Refractory Glaucoma
No full textPurpose: To investigate efficacy 1 year after implantation of a novel glaucoma tube shunt, the PAUL Glaucoma Implant (PGI; Advanced Ophthalmic Innovations, Singapore, Republic of Singapore), in the treatment of eyes with refractory glaucoma. Design: Clinical trial. Participants: Glaucoma patients who are recalcitrant to maximum tolerated medical therapy and require tube shunt surgery. Methods: Interventional cohort study involving consecutive PGIs implanted at 6 international centers between December 1, 2017, and December 1, 2018. All the participants were followed up for 1 year after surgery. Main Outcome Measures: The primary outcome measure was failure, defined prospectively as intraocular pressure (IOP) of more than 21 mmHg or less than 20% reduction from the preoperative baseline on 2 consecutive visits, 3 months or more after surgery; persistent late hypotony, defined as IOP of less than 6 mmHg on 2 consecutive visits after 3 months; additional glaucoma surgery; loss of light perception vision; or removal of the implant for any reason. Results: Of 82 patients enrolled, 74 (74 eyes) completed 12 months of follow-up. The mean age ± standard deviation at enrollment was 62.3±14.7 years, 73.0% were men, and 36.5% had secondary glaucoma. One year after surgery, 4 patients (5.4%) fulfilled the surgical criteria for failure, 68.9% (51/74 eyes) were deemed complete successes, and 93.2% (69/74 eyes) were considered qualified successes. Compared with the medicated preoperative IOP (23.1±8.2 mmHg), the postoperative IOPs at 6 and 12 months were 13.8±4.0 mmHg and 13.2±3.3 mmHg, respectively (P < 0.001). The mean number of IOP-lowering drugs used before surgery and after 12 months of follow-up were 3.3±0.9 and 0.3±0.6, respectively (P < 0.001). Significant postoperative complications included self-limiting shallow anterior chamber (n = 11; 14.9%), hypotony requiring intervention (n = 7; 9.5%), tube shunt occlusion (n = 5; 6.8%), tube exposure (n = 3; 4.1%), and endophthalmitis with resultant loss of vision (n = 1; 1.4%). Conclusions: The PGI demonstrated comparable efficacy with other currently available implants, with almost three quarters of the enrolled patients with refractory glaucoma achieving complete surgical success after 1 year of follow-up
The effect of race and selective laser trabeculoplasty on the aqueous humor dynamics in patients with glaucoma
Get PDFPremi Extraordinari de Doctorat concedit pels programes de doctorat de la UAB per curs acadèmic 2016-2017Aquesta tesi doctoral titulada "L'efecte de la raça i trabeculoplastia làser selectiva sobre la dinàmica de l' humor aquós en pacients amb glaucoma" és el resultat de dos estudis prospectius. El primer estudi compara la dinàmica de l'humor aquós basal entre 32 pacients blanc-caucàsics i 37 pacients d'origen africà amb hipertensió ocular o glaucoma primari d'angle obert. La pressió intraocular (PIO) es va mesurar mitjançant un pneumotonòmetre; la producció d' humor aquós es va mesurar mitjançant la fluorofotometria i la facilitat de sortida de l'humor aquós a través de la malla trabecular per tonografia electrònica de Schiøtz. El flux de sortida uveoscleral es calculà utilitzant l'equació de Goldmann assumint una pressió venosa episcleral de 8, 9, 10 i 11 mmHg. Es van analitzar les diferències entre grups amb proves paramètriques i no paramètriques, i la relació entre paràmetres de la dinàmica de l'humor aquós amb una anàlisi de regressió lineal. No es van trobar diferències en la dinàmica de l' humor aquós entre els pacients blancs i els pacients d'origen africà. No obstant això, els pacients negres tenien còrnies significativament més primes que podrien haver emmascarat diferències potencials en la sortida trabecular de l' humor aquós i la PIO entre els diferents grups. Un grup d'aquests pacients van ser tractats amb trabeculoplastia laser selective (SLT) per reduir la seva PIO. El segon estudi va investigar l'efecte de la SLT sobre la dinàmica de l' humor aquós en 18 ulls. Es va observer una reducció del 21% en la PIO amb un augment del 55% en la facilitat de sortida trabecular 3 mesos després del tractament amb làser. No es van trobar diferències en la producció de l'humor aquós. Així doncs, els resultats van demostrar que la SLT redueix la PIO augmentant la sortida de l'humor aquós a través de la malla trabecular.This PhD titled "The effect of race and selective laser trabeculoplasty on the aqueous humor dynamics in patients with glaucoma" is the result of two prospective studies. The first study compared the baseline aqueous humor dynamics between 32 white-Caucasian and 37 African descent subjects with treatment-naïve ocular hypertension (OHT) or primary open angle glaucoma (POAG). Intraocular pressure (IOP) was measured using a pneumatonometer; morning aqueous humor flow rate was measured by fluorophotometry and trabecular outflow facility by electronic Schiøtz tonography. Uveoscleral outflow was calculated using Goldmann's equation with assumed episcleral venous pressure of 8, 9, 10, and 11 mmHg. Differences among groups were analyzed with parametric and nonparametric tests and the relationship between aqueous dynamics parameters were evaluated with linear regression analyses. No differences in aqueous humor dynamics between black African and white Caucasian patients were found. However, black patients were found to have significantly thinner corneas that could have been masking potential differences in outflow facility and IOP measurements between the racial groups. A group of these patients were treated with selective laser trabeculoplasty (SLT) to reduce their IOP. The second study investigated the effect of SLT on the aqueous humor dynamics in 18 eyes. A 21% reduction in IOP with a 55% increase in trabecular outflow facility was observed 3 months after laser treatment. No differences in aqueous humor production were found. Thus, our results showed that SLT reduces the IOP by increasing the trabecular outflow facility
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Development of a new glaucoma drainage device
Get PDFGlaucoma filtration surgery has been shown to be more effective at preventing disease progression than other primary treatment modalities in open angle glaucoma. If it were possible to avoid complications associated with poor flow control, primary glaucoma filtration surgery would probably be offered more widely. Trabeculectomy, the procedure of choice in conventional glaucoma filtration surgery, has remained essentially unchanged tor over a quarter of a century. Local control over wound healing with antimetabolite agents such as 5-tluorouracil and mitomycin C has improved the prognosis for cases with high risk of filtration failure; but flow control remains imprecise despite the introduction of a variety of suture adjustment techniques. Glaucoma drainage devices have the potential to regulate flow consistently, eliminating hypotony after surgery. Design, material, and manufacturing deficiencies have left this potential unfulfilled in existing glaucoma drainage devices, all of which exhibit problems with poor flow control and suboptimal tissue compatibility. This thesis will examine whether a new flow resistor produced by excimer laser ablation in a polymer substrate and a new external glaucoma drainage device design could prevent hypotony in a series of in vitro experiments and a limited in vivo study. It will also investigate whether phosphorylcholine coating of polymethyl methacrylate can reduce the adhesion of cells and proteins compared to current biomaterials used in the construction of glaucoma drainage devices
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