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Distribusjon av gonioskopiske funn på goniofotografier av unge voksne. En pilotstudie utført med Nidek GS-1 Gonioscop
Full text linkPurpose: The primary objective was to investigate the visibility of angle structures and gonioscopic findings in four quadrants in young eyes by means of 360-degree goniophotography acquired by the Nidek GS-1 Gonioscope (GS-1).
Background: The anterior chambre angle is where the majority of the aqueous, produced in the ciliary body, is drained through the trabecular meshwork. Despite being dependent on the skill of the examiner, indirect gonioscopy remains the reference standard for a qualitative examination of the anterior chambre angle. This dependence on the skill of the examiner may be a limiting factor when performing qualitative studies on the ACA. The knowledge of normal variations such as trabecular pigmentations, iris processes, blood vessels and goniosynechiae is limited. Launched in September 2018, the Nidek GS-1 Gonioscope (Nidek, Japan) is a dedicated camera for goniophotography. It provides a 360-degree photograph of the anterior chambre angle.
Methods: The study had a cross-sectional design. Subjects was recruited from the students at the University of South-east Norway, campus Krona. Goniophotography was performed using the Nidek GS-1 automated gonioscope. Image quality and normal variations was registered and graded by an optometrist trained in the use of the gonio camera. Descriptive values included was central values (mean, mode) and spread of values (standard deviations, quantiles). Inferential statistics included correlation, and comparison between groups (Two-sample Wilcoxon, Friedman rank-sum).
Results: In total, 51 eyes of 27 subjects, 10 males and 17 females, were photographed. Mean age was 25,4 years. The percentage for best grade of image quality for the superior, inferior, temporal and nasal quadrant was 70%, 90%, 84% and 82% respectively, the difference was significant. There was no significant bilateral asymmetry. The most common grade for angle opening was 4 with the inferior quadrant having a significantly lower graded angle opening. Trabecular meshwork pigmentation was found in 96% of the eyes with the inferior quadrant being significantly the most pigmented. Iris processes was found in 86% of eyes. Here the superior quadrant, with significance, had the lowest grading. Blood vessels was found in 23% of the ACA while no goniosynechiae was observed.
Conclusion: The GS-1 provided images where the ACA structures was at least partially or fully focused for identification in 99% of the eyes. This makes it a highly suitable instrument for both scientific studies and for clinical use. The ciliary body was visible in 94% of the eyes, the inferior quadrant had the narrowest angle opening. Found in 96% of the eyes, trabecular meshwork pigmentation was the most common normal variation with the inferior quadrant being the most pigmented. Iris processes was found in 86% of the eyes with the superior quadrant having the lowest amount. BVs was found in 23% of the eyes without any quadrant differing and no goniosynechiae was found. There was no significant difference between the eyes.
Keywords: Anterior chambre angle, Nidek GS-1, trabecular pigmentation, gonioscop
Occurrence of exfoliation syndrome in an optometric practice in Norway
No full textFormål: Hovedformålet med dette studie var å undersøke forekomsten og fordelingen av mistenkt eksfoliasjons syndrom (XFS) i personer fra 40 år og eldre som besøkte en optometrisk praksis i Norge for en optometrisk rutineundersøkelse. Sekundærformålet var å undersøke om det var en assosiasjon mellom bekreftet XFS og funn relatert til glaukom.
Metoder: Dette var et tverrsnittsstudie med en studiepopulasjon bestående av Norske kvinner og menn over 40 år som tok en frivilling optometrisk undersøkelse hos Krogh Optikk Majorstuen mellom januar 2022 og februar 2022. Pasienter var rekruttert fortløpende. Det var to deler til dette studie: 1. Rutine optometrisk undersøkelse med utvidet spaltelampe mikroskopi (SLM). 2: Bekreftelse av XFS hos pasienter med et eller flere XFS suspekte funn i minst ett øye ved bruk av utvidet SLM undersøkelse av linsen i øyet og diagnostiske øyedråper (Tropikamid 0.5%) utført på en etterkontroll. Statistiske analyser ble utført på personnivå (XFS i minst 1 øye) for studiepopulasjonen, prevalens og frekvens. Korrelasjons analyser mellom XFS og funn relatert til glaukom var basert på høyre øye. Beskrivende analyser besto av spredning av verdier (standard deviasjon, prosent, frekvens), sentrale verdier (gjennomsnitt, konfidens intervall). Inferensielle analyser besto av sammenligninger mellom gjennomsnitt ved bruk av «independent t-test» og «chi square test». Statistisk signifikans var satt til α= 0.05 (tosidig).
Resultater: 91 personer deltok i studie med et aldersspenn fra 40-79 år og gjennomsnittsalder på 57 (±10.1 SD) år, hvor 55% var kvinner. 17 deltakere hadde suspekte funn for XFS. Prevalensen for suspekt XFS over 40 år kom på 18.7% (n=17/91) og i aldersgruppene; 40-49 år 9.1% (n=2/22), 50-59 år 13.9% (n=5/36), 60-69 år 23.5% (n=4/17) og 70-79 år 37.5% (n=6/16). Ni av disse deltok på del 2 for å bekrefte/avkrefte XFS. Syv deltakere fikk bekreftet XFS hvor 6 var identifisert bilateralt og 1 unilateralt. Korrelasjons analysene fant en statistisk signifikans (α=0.05, tosidig) i gjennomsnitt mellom målene av global parapapillær nervefibertykkelse med en p-verdi på 0.002 mellom bekreftet XFS og de uten XFS. Ingen andre signifikante korrelasjoner ble funnet.
Konklusjon: Dette studie viser at XFS er tilstede i optometrisk praksis i Norge. Prevalensen funnet ser ut til å være høyere enn andre studier med lignende populasjoner, men grunnet dette studies mindre utvalg av deltakere, er det vanskelig å overføre resultatene til en større populasjon. Prevalensen øker med alder, noe som støtter forståelsen av at XFS er en alders relatert tilstand. Det er kun ett funn assosiert med glaukom som det ble funnet en korrelasjon med bekreftet XFS. XFS er forstått en kjent risikofaktor for å utvikle glaukom, derfor bør diagnostisering av XFS vurderes som klinisk viktig. Studie demonstrerer også bruken av diagnostiske øyedråper er klinisk nyttig for å bekrefte XFS. Videre forskning er nødvendig for å finne prevalensen av XFS i optometrisk praksis i Norge.
Nøkkelord: Prevalens, Eksfoliasjons syndrom, glaukom, dilaterende øyedråperPurpose: The primary aim of this study was to investigate the occurrence and distribution of suspected exfoliation syndrome (XFS) in persons aged 40 and older who attended an optometric practice in Norway for a routine optometric examination. Secondary objective was to investigate if there was an association between confirmed XFS and findings associated with glaucoma.
Methods: This is a cross sectional study where the study population were all Norwegian women and men over the age of 40 years who underwent a voluntary optometric examination at the practice Krogh Optikk Majorstuen between January 2022 and February 2022. Patients was recruited consecutively. There were two parts of this study. 1: Screening for findings of XFS during a standard optometric examination by means of an extended slit lamp biomicroscope (SLM) examination. 2: Confirmation of XFS in participants with one or more suspect findings of XFS in at least one eye by the means of an extended SLM investigation of the intraocular lens with the use of diagnostic eyedrops (tropicamide 0.5%) at a separate appointment. Statistical analyses were performed on person level (XFS in at least one eye) for the study population, prevalence and frequencies. Correlation analyses between XFS and findings associated with glaucoma was based on the right eye. Descriptive analyses consisted of spread of values (standard deviation, percentages, frequencies), central values (mean, confidence intervals). Inferential statistics consisted of comparisons of means with independent t-test and chi square test. Statistical significance set to α = 0.05 two-sided.
Results: 91 people participated in this study from age 40-79 years with a mean age of 57 (±10.1 SD) years where 55% were woman. 17 participants had suspect findings of XFS. The prevalence of suspect XFS over the age of 40 years of was found to be 18.7% (n=17/91) and in the age groups; 40-49 years 9.1% (n=2/22), 50-59 years 13.9% (n=5/36), 60-69 years 23.5% (n=4/17) and 70-79 years 37.5% (n=6/16). Nine of these underwent the second investigation to confirm/disconfirm the condition. 7 participants were confirmed with XFS where 6 was identified as bilateral and 1 as unilateral. Correlation analyses found a statistically significant difference (α=0.05, two-sided) in mean (independent t-test) with the measurements of average global parapapillary nerve fibre thickness with a p value of 0.002 between confirmed XFS (mean 71.75µm ±18.39) and no XFS (mean 92.79µm ±9.95). No other correlations were found.
Conclusion: This study shows that XFS is present in optometric practice in Norway. The prevalence found seem to be higher than other studies with similar populations, but because of the small sample size of this study, it is difficult to transfer the results to a bigger population. The increase of prevalence by age supports the understanding that XFS is an age-related condition. Only one finding associated with glaucoma was found to be associated with confirmed XFS, even so, XFS is a known risk for glaucoma, therefore diagnosing XFS should be considered clinically important. The study demonstrates that diagnostic eyedrops is clinically useful in diagnosing XFS. More research is needed to establish the prevalence of XFS in optometric practice in Norway.
Keywords: Prevalence, Exfoliation syndrome, glaucoma, dilating eyedrop
Vurdering av synsnervehodet - Sammenligning av todimensjonale og tredimensjonale diskgraderinger utført av erfarne optometrister
No full textHensikt: Hovedmålet med oppgaven var å skaffe kunnskap om konformiteten av graderinger av synsnervehodet basert på ikke-stereoskopisk (2D) og stereoskopisk (3D) vurdering av fundusfotografier utført av erfarne optometrister.
Bakgrunn: Evaluering av det bakre segmentet av øyet er en del av rutinemessig øyeundersøkelse. Observasjon og registrering av endringer av synsnervehodet er en viktig del av screening og oppfølging av progredierende øyesykdommer. I dagens praksis er mange forskjellige teknikker tilgjengelig. I de fleste praksiser er muligheten for fundusfotografering til stede og muliggjør bruk av stereoskopisk vurdering. En teknikk som har eksistert lenge og er lett tilgjengelig. For å forberede seg til mulige nye arbeidsoppgaver for optometrister er det nyttig å undersøke konformiteten av graderinger av synsnervehodet gjort av erfarne optometrister.
Metode: Dette var en tverrsnittsstudie. Deltakerne ble rekruttert til to ulike grupper. Deltakerne i gruppe i var pasienter rekruttert fra hovedforskerens optometriske praksis, Brilleservice Bodø. Fundusfotografering enkeltvis og i rekkefølge ble tatt med Nidek RS-330 Retina Duo 2 OCT (Rodenstock, Norge) på begge øyne. Bildene ble behandlet og kryptert og deretter gradert av deltakere i gruppe ii, som besto av erfarne optometrister. Deltakerne i gruppe ii ble rekruttert fra optometrister med fullført etterutdanning innen glaukom ved Universitetet i Sørøst-Norge. De innsamlede dataene ble analysert ved hjelp av beregninger i Microsoft Excel, og ved paret t-test og grafisk visualisering i R Commander programvareversjon 4.4.3. En p-verdi på mindre enn 0,050 ble ansett som statistisk signifikant.
Resultater: Totalt ble 25 deltakere rekruttert i gruppe i med en gjennomsnittsalder på 51,9 år (fra 22-68). 25 par fundusfotografier fra 50 øyne ble samlet inn og etter kvalitetskontroll og bildebehandling ble 18 bilder og bildepar inkludert. Ingen av deltakerne i gruppe i hadde noen kjente underliggende helsetilstander som mistenkes å forårsake patologiske funn på synsnervehodet. 8 deltakere ble rekruttert til gruppe ii. Med 6 som fullførte både 2D- og 3D-vurderingen. Statistisk signifikans ble funnet for vertikalt og horisontalt cup/disc-forhold (p-verdier <0,001 og 0,003). For det tynneste rim/disk-forholdet var det ingen statistisk signifikans (P=0,070). P-verdien var litt høyere enn det forhåndssatte α-nivået og gir indikasjon på at et større utvalg i gruppe ii kan føre til et annet resultat. Plasseringen av den tynneste rim/disken ga ingen statistisk signifikans (P=0,145).
Konklusjon: Funn fra denne studien indikerer at gradering av cup/disk-forholdet fra fundusfotografier av erfarne optometrister resulterer en litt større gradering av vertikalt og horisontalt cup/disk-forhold vurdert stereoskopisk enn ikke-stereoskopisk. En lignende trend sees for graderingen av rim/disk-forholdet, men rim/disk blir da gradert som litt smalere ved stereoskopisk vurdering enn ikke-stereoskopisk. Denne studien viser at stereoskopisk vurdering av synsnervehodet er en nyttig metode for å undersøke synsnervehodet og at det er grunnlag for videre forskning.
Nøkkelord: synsnervehodet, fundusfotografi, stereoskopisk fundusfotografiPurpose: The primary objective was to obtain knowledge about the conformity of optic nerve head (ONH) gradings based on non-stereoscopic (2D) and stereoscopic (3D) assessment of fundus photographs by experienced optometrists.
Background: Evaluation of the posterior segment of the eye is part of routine eye examination. The observation and recording of changes of the optic nerve head (ONH) is an important part of screening and following progression of eye diseases. Today many different techniques are available. In most practices the option of fundus photography is available and enables the use of stereoscopical assessment, a longstanding and easily available technique. To prepare for possible new work tasks for optometrists it is useful to investigate the conformity of gradings of the ONH performed by experienced optometrists.
Methods: This was a cross-sectional study. The participants were recruited into two different groups. Subjects in group i were patients recruited from the principal researcher’s optometric practice, Brilleservice Bodø. Fundus photography singularly and in sequence were taken with Nidek RS-330 Retina Duo 2 OCT (Rodenstock, Norway) of both eyes. The images were processed and encrypted and then graded by participants in group ii, which consisted of experienced optometrists. Subjects in group ii were recruited from optometrists with completed continuing education in glaucoma at the University of South-East Norway. The collected data was analysed using calculations in Microsoft Excel, and Paired t-tests and graphical visualisation in R Commander software version 4.4.3. A p-value of less than 0.050 was considered statistically significant.
Results: In total 25 participants were recruited in group i with an average age of 51.9 years old (from 22-68). 25 pairs of fundus photographs from 50 eyes were collected and after quality control and image processing 18 images and image-pairs were included. None of the participants in group i had any known underlying health conditions suspected to cause any pathology to the ONH. 8 participants were recruited for group ii. With 6 completing both the 2D and 3D assessment. Statistical significance was determined in vertical and horizontal cup/disc ratio (p-values of <0.001 and 0.003). For the thinnest rim/disc ratio there was no statistical significance (P=0.070). The p-value was slightly higher than the set α-level and gives indication that a larger sample could lead to a different result. The location of the thinnest rim/disc gave no statistical significance (P=0.145).
Conclusion: Findings from this study indicate that grading of the cup/disc ratio from fundus photographs by experienced optometrists results in vertical and horizontal cup/disc ratio that are slightly larger when assessed stereoscopically than non-stereoscopically. A similar trend is seen for the grading of the rim/disc ratio, but the rim/disc is then graded as slightly thinner when assessed stereoscopically than non-stereoscopically This study shows that stereoscopic assessment of the ONH is a useful method for examining the ONH and that there is basis for further research.
Keywords: optic nerve head, fundus photography, stereoscopic fundus photograph
Assosiasjon mellom sakkade reksjonstid med BulbiCAM® og den estimerte risikoen for å utvikle primær åpen-vinklet glaukom
No full textBakgrunn: Primær åpenvinklet glaukom (POAG) medfører strukturelle forandringer som fører til irreversibelt tap av visuell funksjon. Å finne balansen mellom å identifisere tidlige tilfelle av glaukom og å unngå unødvendige henvisninger er i økende grad en utfordring i primær øyehelsetjeneste. Tidlige studier indikerer at øye bevegelses perimetri (EMP) har potensial for å oppdage utvikling av POAG når funksjonell skade ennå ikke har oppstått. BulbiCam® er et instrument utviklet med et mål om å kartlegge visuell funksjon basert på EMP.
Formål: Formålet med studien var å undersøke assosiasjonen mellom sakkade reaksjonstid (SRT) målt med BulbiCam®, og den estimerte risikoen for å utvikle POAG. Det er funnet at SRT er økt i områder av synsfeltet uten funksjonell skade hos personer med POAG. Sekundært mål var å undersøke korrelasjonen mellom SRT og alder for å gi nyttig informasjon til den kliniske vurderingen av POAG.
Metoder: En tverrsnittstudie med prospektive data fra tre måneder ble gjennomført. Pasienter mellom 40 og 70 år som besøkte en optometrisk praksis i Norge for å gjennomføre en synsundersøkelse, ble fortløpende rekruttert inn i studien. Optometrisk undersøkelse inkluderte vurdering av okulær struktur og funksjon basert på subjektiv evaluering av optisk nervehode, synsfelt, struktur-funksjon-forhold og intraokulært trykk, samt store risikofaktorer, og resulterte i en total estimert risiko gradert som lav, medium og høy. Tilleggsundersøkelser med BulbiCam® ble gjennomført for å innhente SRT. SRT for 26 punkter i synsfeltet ble brukt i statistiske analyser i R og SAS. Kontinuerlige variabler, parvise forskjeller mellom grupper, sannsynlighet for risiko og korrelasjon mellom SRT og alder ble analysert. Statistisk signifikans var satt til p < 0.05.
Resultater: 48 pasienter i alderen 56.3 (± 9.27, 62.5% kvinner, 37.5% menn) år var inkludert i studien. Økt SRT var assosiert med økt risiko for POAG (p<0.001). Signifikant forskjell mellom venstre (p < 0.0001) og høyre (p= 0.08) øye ved vurdering av forskjell i gjennomsnittlig SRT mellom lav (n =32) og høyere (medium (n=10) /høy (n=6) risikogrupper. Predikert sannsynlighet for å ha medium eller høy risiko for personer 60 år var nær 100% for en SRT på 450 ms. Sekundært, en svak positiv korrelasjon (r = 0.15, p = 0.33) mellom SRT og alder ble funnet.
Konklusjon: Det har for første gang blitt demonstrert at SRT fra BulbiCam® ver relatert til risikoen for utvikling av POAG basert på evidensbaserte kliniske metoder. En økning i SRT ble funnet å være sterkt assosiert med en økning i estimert risiko. Sannsynligheten for å ha høyere estimert risiko for POAG ble funnet å øke med både alder og gjennomsnittlig SRT. Sekundært, svak positiv korrelasjon mellom SRT og alder ble funnet. Videre forskning er berettiget for å videre undersøke om SRT med BulbiCam® tilfører nyttig diagnostisk informasjon til den kliniske vurderingen av glaukom og hvordan SRT forandres med alder.
Nøkkelord: POAG, øyebevegelses perimetri, BulbiCAM®, sakkade reaksjonstid, optometristBackground: Primary Open-Angle glaucoma (POAG) causes structural changes leading to irreversible loss of visual function. Finding the balance between identifying early cases of glaucoma and avoiding unnecessary referrals is a growing challenge in primary eye care. Early reports indicate that eye movement perimetry (EMP) has the potential of detecting development of POAG when functional damage has not yet occurred. BulbiCam® is an instrument developed with an aim to map visual function based on EMP.
Objective: The purpose of this study was to investigate the association between saccadic reaction time (SRT) obtained with BulbiCam® and the estimated risk of developing POAG. SRT has been reported increased in areas of the visual fields without functional damage, in people with POAG (Thepass, Lemij, Vermeer, van der Steen, & Pel, 2021). Secondary aim was to investigate the correlation between SRT and age to provide useful information to the clinical assessment of POAG.
Methods: A cross-sectional study with prospective data from three months was conducted. Patients aged 40 – 70 years who visited an optometric practice in Norway to conduct an eye examination were consecutively recruited into the study. Optometric examination included assessment of ocular structure and function based on subjective evaluation of optic nerve head, visual fields, structure-function-relationship and intraocular pressure, along with major risk factors, and resulted in an overall estimated risk graded as low, medium and high. Auxiliary measurements with BulbiCam® was conducted to obtain SRT. SRT for 26 points in the visual fields were used for statistical analyses retrieved from R and SAS. Continuously variables, pairwise difference between groups, probability of risk and correlation between SRT and age was analysed. Statistical significance was set to p < 0.05.
Results: 48 participants aged 56.3 (± 9.27, 62.5% female, 37.5% male) years were included in the study. Increased SRT was associated with increased risk of POAG (p<0.001). Significant difference between left (p < 0.0001) and right eye (p = 0.08) when considering difference in mean SRT between low (n=32) and higher (medium (n=10) /high (n=6)) risk groups. Predicted probability of having medium or high risk in people aged 60 years was close to 100% for an SRT of 450 ms. Secondly, a weak positive correlation (r = 0.15, p = 0.33) between SRT and age was found.
Conclusion: It has for the first time been demonstrated that SRT obtained with BulbiCam® is related with the risk of developing POAG as assessed by evidence based clinical methods. An increase in SRT was found strongly associated with an increase in estimated risk. The probability of having higher estimated risk of POAG was found to increase with both age and mean SRT. Secondly, weak positive correlation between SRT and age was found. Further research is warranted to further investigate whether SRT obtained with BulbiCam® add useful diagnostic information to the clinical assessment of glaucoma and how SRT changes with age.
Key words: POAG, eye movement perimetry, BulbiCAM®, saccadic reaction time, optometris
Dysregulated light/dark cycle impairs sleep and delays the recovery of patients in intensive care units: A call for action for COVID-19 treatment
No full textExposure to an adequate light–dark cycle is important for the speedy recovery of hospitalized and institutionalized patients. Light exposure, including natural light, offers several health benefits to both patients and nursing staff. This includes physical (e.g., decreased confusion and disorientation) and mental health benefits (e.g., prevention of depression) and a reduction in the hospital stay. Improved alertness and performance can also be noted among hospital staff. In this commentary, we discuss disrupting factors that 20 include light during the nighttime along with noise and physical procedures on the patient and others. We then address some of the important steps that can be undertaken to restore a more normal environment for patients in the intensive care unit, which can be particularly important for COVID-19 patients.Fil: Golombek, Diego Andrés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pandi Perumal, Seithikurippu R.. Saveetha University; IndiaFil: Rosenstein, Ruth Estela. Universidad de Buenos Aires. Facultad de Medicina. Laboratorio de Neuroquímica Retiniana y Oftalmología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Lundmark, Per Olof. University of South-Eastern Norway; NoruegaFil: Spence, David Warren. Independent Researcher; CanadáFil: Cardinali, Daniel Pedro. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Reiter, Russel. University Of Texas Health Science Center At San Antonio (ut Health San Antonio) ; University Of Texas At San Antonio;Fil: Brown, Gregory M.. Campbell Family Mental Health Research Institute; Canadá. University of Toronto; Canad
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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