منابع مشابه
Test-retest variability underlying fMRI measurements
INTRODUCTION A high test-retest reliability is of pivotal importance for many disciplines in fMRI research. To assess the current limits of fMRI reliability, we estimated the variability in true underlying Blood Oxygen Level Dependent (BOLD) activation, with which we mean the variability that would be found in the theoretical case when we could obtain an unlimited number of scans in each measur...
متن کاملExploring Test–Retest Variability Using High-Resolution Perimetry
PURPOSE Test-retest variability (TRV) of visual field (VF) data seriously degrades our capacity to recognize true VF progression. We conducted repeated high-resolution perimetry with a test interval of 0.5° to investigate the sources of TRV. In particular, we examined whether the spatial variance of the observed sensitivity changes or if their absolute magnitude was of more importance. METHOD...
متن کاملTest-retest variability of multifocal electroretinography in normal volunteers and short-term variability in hydroxychloroquine users
PURPOSE To determine measurement variability of N1P1 amplitudes and the R1/R2 ratio in normal subjects and hydroxychloroquine users without retinopathy. DESIGN Retrospective, observational study. SUBJECTS Normal subjects (n=21) and 44 patients taking hydroxychloroquine (n=44) without retinopathy. METHODS Multifocal electroretinography (mfERG) was performed twice in one session in the 21 n...
متن کاملEffect of Restricting Perimetry Testing Algorithms to Reliable Sensitivities on Test-Retest Variability
Purpose We have previously shown that sensitivities obtained at severely damaged visual field locations (<15-19 dB) are unreliable and highly variable. This study evaluates a testing algorithm that does not present very high contrast stimuli in damaged locations above approximately 1000% contrast, but instead concentrates on more precise estimation at remaining locations. Methods A trained op...
متن کاملChoice of Stimulus Range and Size Can Reduce Test-Retest Variability in Glaucomatous Visual Field Defects.
PURPOSE To develop guidelines for engineering perimetric stimuli to reduce test-retest variability in glaucomatous defects. METHODS Perimetric testing was performed on one eye for 62 patients with glaucoma and 41 age-similar controls on size III and frequency-doubling perimetry and three custom tests with Gaussian blob and Gabor sinusoid stimuli. Stimulus range was controlled by values for ce...
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ژورنال
عنوان ژورنال: Indian Journal of Ophthalmology
سال: 2013
ISSN: 0301-4738
DOI: 10.4103/0301-4738.109384