4/2/2015
Humphery Visual Field analyzer By,
Tarek Ragaei,
MD
Professor of Ophthalmology Tanta University
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Field of Vision • Visual field measurement is a critical component in the detection and/or management of blinding conditions such as glaucoma, optic nerve lesions,, papilledema, retinitis pigmentosa, cranial tumors and others.
Humphery Visual Field Analyzer
• The Humphreys visual field Analyzer is most commonly used and will be the focus of this presentation.
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Principals of HVF Analyzer • Unlike Goldman Perimetry that uses different size the HFA uses the size III target unless otherwise instructed • The stimulus is varied in intensity from 0.8 to 10 000 apostilb,
Principals of HVF Analyzer • The differential threshold is inversely related to the intensity of the stimulus and is recorded in decibels(dB) • The background luminance is 31.5asb and the testing distance 33 cm.
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Swedish Interactive Thresholding Algorithm (SITA) • The Swedish interactive threshold algorithm (SITA) is a strategy that dramatically reduces test time. It is available as either SITA standard or SITA fast.
Swedish Interactive Thresholding Algorithm (SITA) • The SITA strategy was intended to gather the same information as a full threshold field in much less time by calculating expected thresholds and begin testing close to the actual threshold value.
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SITA Field Printout 1. Name, ID and Age 2. Type of Test 3.Strategy 4.Rx Used 5.Pupil Diameter 6.Reliability Indices 7.The numeric data 8.The Grayscale 9.Total Deviation 10. Pattern Deviation 11. The Glaucoma Hemifield Test 12. The Global Indices
Systemic interpretation of visual field printout
1. 2. 3. 4. 5. 6. 7.
What type of visual field test was performed? What are the patient demographics and clinical characteristics? How reliable is the visual field? Is the visual field abnormal? What is the pattern of abnormality? Is the field worsening? Is the abnormality or worsening due to disease or artifact?
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What type of visual field test was performed?
Systemic interpretation of visual field printout 1. 2. 3. 4. 5. 6. 7.
What type of visual field test was performed? What are the patient demographics and clinical characteristics? How reliable is the visual field? Is the visual field abnormal? What is the pattern of abnormality? Is the field worsening? Is the abnormality or worsening due to disease or artifact?
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What are the patient demographics and clinical characteristics?
Systemic interpretation of visual field printout 1. 2. 3. 4. 5. 6. 7.
What type of visual field test was performed? What are the patient demographics and clinical characteristics? How reliable is the visual field? Is the visual field abnormal? What is the pattern of abnormality? Is the field worsening? Is the abnormality or worsening due to disease or artifact?
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3. How reliable is the visual field?
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Systemic interpretation of visual field printout 1. 2. 3. 4. 5. 6. 7.
What type of visual field test was performed? What are the patient demographics and clinical characteristics? How reliable is the visual field? Is the visual field abnormal? What is the pattern of abnormality? Is the field worsening? Is the abnormality or worsening due to disease or artifact?
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Dous
Systemic interpretation of visual field printout 1. 2. 3. 4. 5. 6. 7.
What type of visual field test was performed? What are the patient demographics and clinical characteristics? How reliable is the visual field? Is the visual field abnormal? What is the pattern of abnormality? Is the field worsening? Is the abnormality or worsening due to disease or artifact?
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Glaucoma Hemifield Test
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Systemic interpretation of visual field printout 1. 2. 3. 4. 5. 6. 7.
What type of visual field test was performed? What are the patient demographics and clinical characteristics? How reliable is the visual field? Is the visual field abnormal? What is the pattern of abnormality? Is the field worsening? Is the abnormality or worsening due to disease or artifact?
6. Is the field worsening?
Optom. Rawaa A. El Dous
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Systemic Interpretation Of Visual Field Printout 1. 2. 3. 4. 5. 6. 7.
What type of visual field test was performed? What are the patient demographics and clinical characteristics? How reliable is the visual field? Is the visual field abnormal? What is the pattern of abnormality? Is the field worsening? Is the abnormality or worsening due to disease or artifact?
Are the abnormality or worsening due to disease or artifact?
Lens rim artifact
Optom. Rawaa A. El Dous
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Learning effect
After1month
After1month Optom. Rawaa A. El Dous
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Humphery Guided Progression Analysis ( GPA) • The Humphrey Field Analyzer II‐i with new Guided Progression Analysis™ (GPA) software: 1. Delivers current exam results, 2. Trends the entire visual field history and 3. Projects future vision loss all on a single page.
Event and Trend Analysis • GPA helps practioners identify and quantify visual field progression in glaucoma patients using both event and trend analysis. • Event and trend analyses have different but complementary goals.
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• The goal of event analysis is to assess weather there has been any statistically significant worsening in the visual field. • The goal of trend analysis is to quantify any observed rate of change and to help the practitioner assess the risk of future visual field disability associated with that rate which will have reflection on treatment strategy.
Visual Field Index • GPA uses the Visual Field Index™ (VFI), a new summary measurement of visual field status expressed as a percent of a normal age‐ adjusted visual field. • VFI is an enhancement of the MD that is designed to be less affected by cataract and more sensitive to changes near the center of the field in order to be better correlated with ganglion cell loss
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• On the new GPA Summary report, VFI is used to quantify rate of progression, where it is plotted relative to patient age to calculate the rate of functional loss. • So, normal vision is associated with VFI near 100% while perimetric blindness producing VFI values approaching 0%.
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GPA Summary Report • The new GPA Summary report is a powerful one‐page report that provides an overview of the patient’s entire visual field history.
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GPA Summary Report • The report can be divided into three sections: the Baseline Exams at the top, the visual field history and trend in the middle, and the current exam at the bottom.
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GPA Baseline Exams: • At the top of the report are the Baseline Exams. Graytone and Pattern Deviation Plots are shown for both GPA Baselines, along with key indices such as VFI, MD, and PSD. • By default, the oldest two exams of the same type are automatically selected as baseline.
VFI Plot • In the center of the report the VFI Plot graphs the VFI values of all exams included in GPA analysis as a function of the patient’s age.
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VFI Plot • The VFI Plot also provides a linear regression analysis of the VFI over time when appropriate. • A minimum of 5 exams over 3 years or more must be included in GPA for the linear regression results to be presented.
VFI Bar • To the right of the VFI Plot is the VFI Bar, a histogram that indicates the patient’s current VFI value.
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VFI Bar • In addition, when the results of the regression analysis are displayed, the VFI Bar will also graphically indicate the 3 to 5 year projection of the linear regression line, shown as a broken line.
VFI Bar • In addition, when the results of the regression analysis are displayed, the VFI Bar will also graphically indicate the 3 to 5 year projection of the linear regression line, shown as a broken line.
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Deviation from Baseline Plot • Points that have changed by more than the expected variability are identified with a simple and intuitive set of symbols: • A single, solid dot indicates a point not changing by a significant amount.
Deviation from Baseline Plot • A small open triangle identifies a degree of deterioration expected less than 5% of the time (p
