how to understand basic aspects of visual field recent instruments and recent programs in visual fields

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2. • Perimetry normally tests the light-difference
sensitivity across the visual field.
• This sensitivity reflects the capability of the
eye to perceive a brightness difference
between a test target and its background.
• Light-difference sensitivity depends upon the
tested location on the retina and upon the
parameters of the measurement technique,
such as intensity of background luminance
and target size.
Perimetry
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3. Perimetry
• The normal visual field extends further away
from fixation temporally and inferiorly than
superiorly and nasally.
• The physiological blind spot corresponds to the
location where the optic nerve enters the eye
and its center is located about 15° temporal from
fixation.
• From the center of the retina this sensitivity
decreases towards the periphery, evoking the
classically defined ‘hill of vision:’ a three-
dimensional representation of retinal light
sensitivity.
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4. Importance of visual field testing
It reflects topographic sensitivity of various
foci on the retina
 Resolution – acuity
 Differential light sensitivty.
 Contrast.
 Colour,
 Motion,
 flickers4/14/2020 Ehab Nafie, basics of primetry 4

5. Physiological basis
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6. Physiological basis
 Resolution – acuity
 Differential light
sensitivty.
 Contrast.
 Colour,
 Motion,
 flickers
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8. Differential light sensitiviy
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9. Factors affecting the visual field
 Apparent size of the spot (actual size, distance),
 Duration of the stimulus,
 Background illumination,
 Intensity of the stimulus,
 Contrast,
 Colour of the stimulus,
 Patient factors:
 Light dark adaptation,
 Refraction,
 Education, attentiveness.
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10. Physiological blind spot
 Corresponding to the optic n head,
 15 ⁰ temporal to the point of fixation,
 2/3 below the horizontal meridian,
 Size 5⁰ horizontal, 7⁰ vertical
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11. Hill of vision in Perimetry
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13. Monocular visual field
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14. Binocular visual field
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15. Binocular visual field
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16. Stereoscopic visual field
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17. Goldmann Manual kinetic
visual field testing
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18. Manual visual field testing
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19. Octopus Perimetry
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20. Octopus Automated
perimetry
Test Pattern
 General/Glaucoma 30° (G1-Program, 32, 30-2, 24-2)
 General/Glaucoma Periphery (G2-Program: 60°; 07-Program: 75°)
 Macula (M-Program (10°/30°); 10-2)
 Screening (ST)
 Driving (Estermann monocular/binocular; FG: German Driving
Licence)
 Disability (BT – Blepharoptosis; BG: German Blindness)
 Other Pathology (N1: Neurological; D1: Diabetes)
 Custom tests
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21. Octopus Automated
perimetry
Test Methods
• Standard white-on-white perimetry SAP
• Blue/yellow perimetry SWAP
• Flicker perimetry for early diagnosis
• Red/white perimetry (custom tests only)
• Goldmann Kinetic Perimetry
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22. Humphrey Field Analyzer
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23. Examination Strategies
 SITA, (Swedish Interactive Threshold
Algorithm) (SITA) Standard and SITA Fast
 Full Threshold
 Fast Pac
Humphrey Field Analyzer
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24. Threshold Static Automated
Perimetry
 The most commonly
used visual field test is
Threshold Static
Automated perimetry.
 A specific point is
chosen for examination
and the stimulus is
increased until its
threshold is determined.
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25. Threshold Static Automated Perimetry
 With Threshold Static Automated
perimetry, a computer program is
selected.
 The most commonly used one is the
central 30°, 24° of the visual field using
a six degree spaced grid.
 This is accomplished by keeping the
size and location of a target constant
and varying the brightness until the
dimmest target the patient can see at
each of the test locations is found.4/14/2020 Ehab Nafie, basics of primetry 25

26. Humphrey Gold Standards
 Visual Field Index (VFI) – VFI is a simple and
intuitive global index. Its most powerful
application is GPA, which trends VFI over time
to project remaining vision.
 GPA Alert – A message in simple language that
indicates whether statistically significant
deterioration was identified in consecutive
visits.
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27.  SITA™ Strategies – (Swedish Interactive
Threshold Algorithm)
 SITA is patient responsive: it learns to perform as
fast as the patient.
 Aim to reduce test time while preserving the
quality of information obtained with standard
algorithms. SITA includes two programs, SITA
Standard and SITA Fast, which were developed to
replace the Full-Threshold and Fastpac strategies,
respectively.
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28.  Connectivity – For comprehensive connectivity, HFA3
can be connected to FORUM with Glaucoma Workplace.
 HFA3 also supports common file folder sharing used by
most Electronic Medical Record Systems (EMRs).
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29. Humphrey matrix with FDT
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30. Humphrey matrix with FDT
 An in-office glaucoma screener with 35 second,
 Supra -threshold testing,
 It provides up to 69 stimuli to characterize visual field
defects to facilitate accurate diagnoses.
 It is equipped with Glaucoma Asymmetry Test and serial
field overview software for comprehensive threshold
exams,
 It can performs dependably in ambient light so there’s no
need to darken the room.
 The test results are presented on an LCD color display and
can be printed on an external color printer.
 It can store up to a million exams for historical analysis.
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31. SITA SWAPTM Software
 A valuable tool
for the
Humphrey® Field
Analyzer.
 It uses the blue-
yellow threshold
testing.
 It is used for the
early detection of
glaucoma.
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32. SITA SWAPTM Software
 SWAP (Short
Wavelength
Automated
Perimetry)
preferentially
tests the blue
cones and
their ganglion
cell
connections
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33. SITA SWAPTM Software
 SWAP isolates and preferentially
tests the blue cones and measures
the associated blue-yellow ganglion
cell function.
 The bright yellow background
desensitizes the green and red
cones, with little effect on blue cone
function.
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34.  SITA SWAP is a valuable tool for
managing glaucoma suspects.
 SWAP is a more sensitive test than
white-on-white perimetry for
detecting early loss of vision due to
glaucoma, and for monitoring early
changes before white-on-white
defects appear.
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35. Guided progression
analysis (GPA)
GPA software identifies
statistically significant
changes in visual field
threshold sensitivity
automatically.
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36. Visual field index (VFI),
visual field index (VFI), is a
global index to determine
the percentage of field loss
on every visual field.
This is designed to allow us to
monitor our glaucoma patients
for disease progression across
the glaucoma spectrum,”
The visual field index is a
number that gives you the
age-adjusted visual field
function that is designed
to be less sensitive to
cataract formation, which
can often confound
glaucoma diagnosis in
perimetry.
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