Global indices visual fields
Global indices are often utilised to assess the visual field. An important feature of any such statistic is that it can be put into some context; consequently, every 22 Dec 2016 stimuli in visual field testing: the importance of complete and partial spatial Visual field global indices using aGIII, aGV and pGIII values. automated perimetry, linear regression of global indices such as mean deviation (MD) and visual field index (VFI) are commonly used to assess glaucoma PurposeTo determine changes of visual-field (VF) global indices after cataract surgery and the factors associated with the effect of cataracts on those indices in 11 Jun 2010 Another analytic index the Field Analyzer provides is the pattern It looks at the global visual field and attempts to notify you whether or not,
To investigate the usefulness of visual field (VF) reliability indices and gaze of VFs needed to assess VF progression accurately using a global index is a
Finally the visual field indices (global indices) are at the bottom right hand side of the printout page. Figure 10a Removing the effect of the short term fluctuations (SF), reveals the true difference (in green) between the regular “expected” pattern of the hill of vision, and the patient's hill of vision. 3.5. RNFL Thickness and Visual Field Indices. A significant association was observed between the overall RNFL thickness and global visual field indices. A thicker overall RNFL was significantly associated with a decreased MS and increased MD. Although nonpathologic myopia does not significantly affect central visual field global indices, its effects on the RNFL may be linked with performance on the central visual field test. The aim of the current study was to investigate the association between the thickness of the retinal nerve fiber layer (RNFL) and central visual field indices in otherwise healthy myopes. the visual field – overall guidelines to help assess field – probability values given when numbers reach significant values global indices • mean deviation (md) – height of the hill of vision compared to age-matched normals • pattern standard deviation (psd) – degree to which the shape of the visual field differs from reference field Visual Field Index (VFI) is a global index that assigns a number between 1% and 100% based on an aggregate percentage of visual, function with 100% being a perfect age-adjusted visual field. Central visual field points are more heavily weighted, and the percentage of visual field loss is calculated based on pattern or total deviations depending on the depth of loss. The global indices show the mean deviations, which can help to monitor progression, especially in glaucoma. Three summary indices appear on the printout 4 : The visual field index is a staging index designed to correspond to ganglion cell loss, that is, 100% represents normal fields and 0% represents blind fields. Global indices also will be recorded; these give numerical quantification in decibel units of visual field loss. and include: mean deviation - the average of all decreased perception, pattern deviation which highlights localized losses and pattern standard deviation which quantifies the amount of loss and gauges progression.
Global indices are often utilised to assess the visual field. An important feature of any such statistic is that it can be put into some context; consequently, every
The mean visual field global indices (mean deviation and pattern standard deviation) improved in patients with IOP reduction of 40% or greater, in statistically significant contrast to no improvement of mean global indices with IOP reduction less than 35%. 6 Steps in Analyzing Visual Field •Global Indices –Mean Deviation (MD) •Average loss for entire field with weighting of points closest to fixation •Can not recognize pattern of loss from number –When negative, could be due to anything from cataract to scar to glaucoma •If significant, a p value if provided telling how often • global indices – single number representations of the visual field – overall guidelines to help assess field – probability values given when numbers reach significant values global indices • mean deviation (md) – height of the hill of vision compared to age-matched normals • pattern standard deviation (psd) – degree to which the shape of the
10 Nov 2014 The Relationship between Visual Field Global Indices and Retinal Nerve Fiber Layer Thickness in Healthy Myopes. Yuan-zhi Yuan, Chen-li Feng,
15 May 2014 Visual field global indices provide an indication of visual field abnormality relative to an age-matched normative database. Absolute defect Visual field: It is that portion of the external environment of the observer wherein Interpretation of the global indices : All the indices are considered together for Visual Field Index™ (VFI™) is a simple and intuitive global index to determine percentage of field loss on every visual field.²,³. • Pattern Deviation Plots identify 28 Aug 2015 Most of the visual field global indices we use today have been specifically designed for the detection and monitoring of glaucoma.
automated perimetry, linear regression of global indices such as mean deviation (MD) and visual field index (VFI) are commonly used to assess glaucoma
PurposeTo determine changes of visual-field (VF) global indices after cataract surgery and the factors associated with the effect of cataracts on those indices in 11 Jun 2010 Another analytic index the Field Analyzer provides is the pattern It looks at the global visual field and attempts to notify you whether or not, Visual Field Index (VFI) - intuitive new global index to determine percentage of field loss; Pattern Deviation Plots - identifies local field loss, minimizing ocular To investigate the usefulness of visual field (VF) reliability indices and gaze of VFs needed to assess VF progression accurately using a global index is a Visual field progression may be analyzed by either the rate of progression of suitable global indices (MD or VFI, but Perimetric progression using the Visual Field Index and the Advanced points of the VF have more impact on this global index than the peripheral points. “The VFI is a new global metric that represents the entire visual field as a single percentage of normal,” said Richard Madonna, O.D., SUNY State College of Optometry, New York. “It is based largely on the pattern deviation and weighs central points more than peripheral ones.” He added,
• global indices – single number representations of the visual field – overall guidelines to help assess field – probability values given when numbers reach significant values global indices • mean deviation (md) – height of the hill of vision compared to age-matched normals • pattern standard deviation (psd) – degree to which the shape of the Furthermore, the visual field may be described in terms of several numerical values, termed the global indices. 5 6 These comprise the mean deviation (MD) and the pattern standard deviation (PSD) or the average defect (AD) and the pattern defect (PD) on the HFA and MAP, respectively. Finally the visual field indices (global indices) are at the bottom right hand side of the printout page. The indices are MS (mean sensitivity) which is the mean value of all test results, MD (mean defect) which is the same as mean deviation, LV (lost variance) which is the same as pattern standard deviation, and CLV (corrected lost variance, which is the same as corrected pattern standard deviation). "The visual field can be inconsistent since the patient may not be very good at taking it or it may be inherently variable, and this can lead to false positive results. VFI is a trend-based analysis. It looks at the global visual field and attempts to notify you whether or not, based on statistical analysis of this series of fields, the glaucoma is getting worse. Visual fields in glaucoma Wood, Swann and Stavrou supra-threshold values noted. It is always useful to review the raw numerical plots to look at the suspicious areas indicated by these maps. The global indices give an indication of any generalised depression in the visual field (average defect [AD]/ mean defect [MD]) and localised changes The perimeter provides a STATPAC analysis for each visual field exam that includes the global indices: mean deviation (MD), pattern standard deviation (PSD), visual field index (VFI), and the Glaucoma Hemifield Test (GHT) output. Detection of early glaucomatous visual field loss from a single point analysis or global indices is not always easy. Cluster Analysis supports detection of glaucomatous defects by clustering visual field defects along nerve fiber bundles and displays them as a Cluster MD (Mean Defect) to highlight significant pathological regions.