1,720,958 research outputs found
Microperimetry and fundus autofluorescence in patients with early age-related macular degeneration
No full textMicroperimetry and fundus autofluorescence in patients with early age-related macular degeneration.
Midena E, Vujosevic S, Convento E, Manfre' A, Cavarzeran F, Pilotto E.
SourceDepartment of Ophthalmology, University of Padova, Via Giustiani 2, 35128 Padova, Italy. [email protected]
Abstract
BACKGROUND: Early age-related macular degeneration (AMD) has been correlated with different functional alterations, but the exact relationship between fundus lesions and overlying sensitivity is not well known. The aim of this study was to compare fundus-related sensitivity (microperimetry) and fundus autofluorescence (FAF) of the macular area with drusen and pigment abnormalities in early AMD.
METHODS: 13 consecutive patients with early AMD and visual acuity of 20/20 were studied by means of microperimetry, which automatically analyses macular light differential threshold and fixation patterns. Fundus colour photo and FAF of the macular area were recorded on the same day. Microperimetry was exactly (topographically) superimposed over FAF images.
RESULTS: Macular sensitivity significantly decreased over large drusen (11.2 +/- 5.6 dB, p<0.0001) and over pigment abnormalities (13.1 +/- 3.6 dB, p<0.0001). When both characteristics were present the reduction was greater if compared with its absence (9.6 +/- 4.3 versus 15.0 +/- 4.5 dB, p<0.0001). Sensitivitity reduction was significant in areas with altered FAF when compared with areas with normal FAF (p<0.0001).
CONCLUSIONS: Increased FAF in early AMD has a functional correlate exactly quantified by microperimetry. In retinal areas affected by early AMD retinal sensitivity deteriorates, despite good visual acuity. Microperimetry may allow the early detection of functional impairment caused by these lesions. Both microperimetry and FAF may be useful to monitor AMD progression.
PMID: 17504849 [PubMed - indexed for MEDLINE] PMCID: PMC209542
Long-term follow-up with optical coherence tomography and microperimetry in eyes with metamorphopsia after macula-off retinal detachment repair
No full textPURPOSE: to report the long-term sequential morphological and functional results in eyes with metamorphopsia after retinal detachment (RD) repair.
PATIENTS AND METHODS: in six eyes of six patients aged 58.7 ± 11.0 years with metamorphopsia after successful buckling surgery for macula-off RD, best-corrected visual acuity (BCVA), fundus biomicroscopy, Amsler grid test, time-domain optical coherence tomography (TD-OCT) and central 12° microperimetry (MP-1) were performed at months 1, 3, 6, 12, and 18. At 5 to 6 years after surgery all patients underwent also spectral domain (SD)-OCT.
RESULTS: three eyes slowly recovered pre-RD BCVA. In the remaining three eyes-with good final BCVA-the interrupted junction line between photoreceptor cell inner and outer segments (IS/OS) was progressively less evident after RD surgery; and the external limiting membrane was preserved on SD-OCT examination. In all eyes post-operative metamorphopsia faded with time, but fully disappeared in 6 years only in two eyes without photoreceptor abnormalities. One of the two eyes with subretinal fluid up to 6 months and IS/OS disruption had central dense scotoma with relatively unstable fixation on MP-1 and persistent metamorphopsia. Macular sensitivity (MS) increased from 9.7 ± 7.1 at month 1 to 13.5 ± 5.6 dB at the final check, and was weakly (r=0.33) correlated with post-operative BCVA and OCT abnormalities.
CONCLUSION: long-standing metamorphopsia can occur after successful macula-off RD repair even without detectable photoreceptor disruption on OCT. Post-operative BCVA recovery weakly correlates with increasing MS, and late restoration of the photoreceptor layer may be observed.
PMID: 20948555 [PubMed - indexed for MEDLINE
Combined 50-and 20-MHz frequency ultrasound imaging in intermediate uveitis
No full textPURPOSE:
To evaluate the information provided by multifrequency ultrasound examination in patients with intermediate uveitis.
DESIGN:
Prospective observational case series.
METHOD:
High-resolution ultrasonography with 50- and 20-MHz frequency immersion probes was performed in seven eyes of five young patients with clinical diagnosis of intermediate uveitis.
RESULTS:
Exudative material over the inferior pars plana and peripheral retina (snowbank) was found in all eyes with 50- and 20-MHz probe, although resolution of the latter was poorer. The 50-MHz imaging was superior for visualization of angle structures and details of pars planitis; the anterior vitreous involvement and cyclitic bands were better shown with the 20-MHz probe, which could also evidence cystoid macular edema.
CONCLUSIONS:
Ultrasound examination with both 50- and 20-MHz frequency probes can detect the typical snowbank in intermediate uveitis and be useful in eyes with small pupil, dense vitreitis, or both, especially before pars plana vitrectomy or cataract surgery
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
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
- …
