2. Definition of Visual Field
■ The visual field is that portion of
the external environment of the
observer wherein the steadily
fixating eye can detect visual
stimuli
International Perimetric Society (1978)
3. Extent of the Visual Field
Anderson RA. Automated Static Perimetry
7. Definition of Perimetry
■ Measurement of visual functions of the
eye at topographically defined loci in
the visual field1
■ Measures differential light sensitivity, or
the ability of a subject to distinguish a
stimulus light from background
illumination2
1. International Perimetric Society (1978)
2. American Academy of Ophthalmology
8. Clinical Perimetry
■ Two major perimetry types
➢ Manual kinetic
➢ Automated static
(gold standard)
9. Automated Static Threshold
Perimetry
■ Measures the retina's sensitivity to
light at predetermined locations in the
visual field
■ While the patient focuses on the point
of fixation, stimuli are presented in
random order at each of the
predetermined locations w/in the
visual field
13. Clinical Perimetry
▪ Stimulus intensity is varied but w/ fixed
size & duration
➢Determines the minimum intensity at w/c
patient responds to 50% of the time
(threshold)
▪ Determined by bracketing - stimulus
intensities moved above & below the
threshold
Threshold strategy
15. Why test the Visual Field?
■ Defines state of optic nerve function
■ Defines visual impairment1
■ To detect eye diseases (glaucoma,
retinal, neuro-ophtha, etc)
■ To monitor an eye disease/visual
impairment
1. Asia Pacific Glaucoma Guidelines (2003-2004)
16. What is being tested in Perimetry?
■ Light sensitivity is measured in
different retinal areas
➢Foveal/central areas more sensitive than
peripheral areas
■ Light sensitivity compared to a
normative database derived from
multicenter studies
17. Interconnecting cells
▪ Bipolar
▪ Horizontal
▪ Amacrine cells
Visual Physiology of the Retina
Light
photoreceptors
RPE
Transmitting cells
▪ Ganglion cells
G G
21. 3
4 5
12 HumphreyTM
• 5 Zones
• Counter-clockwise
1) Parameters
2) Reliability
3) Age Corrected
4) Tests
5) Indices
6) Correlate
clinically
7) Evaluate
22. 1
2
3
4
5
OctopusTM
• 5 Zones
• Clockwise
1) Parameters
2) Reliability
3) Age Corrected
4) Tests
5) Indices
6) Correlate
clinically
7) Evaluate
23. ▪ Test strategy
➢ Full threshold, SITA-standard, SITA fast
▪ Region/pattern used
➢ 30-2, 24-2, 10-2
▪ Patient details
➢date of birth, date of VF, pupil size, test
time, VA, correction, eye tested
1.Parameters
HumphreyTM
24. Perimetry Programs
■ Full Threshold 30-2
■ Standard
■ 18-20 minutes per eye
■ 4-2-1 staircase with double crossover for
Octopus; 4-2 staircase for Humphrey
■ Light stimulus size is standard (Goldmann
Size III)
26. SITA Standard
▪ Diagnostic sensitivity similar to full
threshold (both 95%)1
▪ Sensitivity, specificity, characterization, &
reliability of determining VF properties > vs
other threshold tests2-4
▪ 50% reduction in testing times
➢ 4 minutes for a normal field
➢ 8 minutes for a glaucoma field
1. Delgado, et al, Ophthalmology Dec 2002
2. Bengtsson B, et al. Acta Ophthalmol Scand. 1998
3. Bengtsson, B, Heijl. A. Acta Ophthalmol Scand. 1998
4. Budenz DL, et al. Ophthalmology. 2002
28. ■ 2-6 minutes
➢ 3 minutes normal field
➢ 5.5 minutes glaucoma field
■ 93% sensitivity vs 95% for SITA
standard1
For patients : Younger
➢ Restless
➢ “Learning”
1. Delgado, et al, Ophthalmology Dec 2002
SITA Fast
29. • 24-2 tests 54 points
• 30-2 tests 76 points
24-2 or 30-2?
HumphreyTM
10-2?
• For advanced
glaucoma
• Tests 68 points
in the central
10 degrees
33. Is the field reliable?
▪ false (+): pressing button even w/o
visual stimulus
▪ false (-): failure to respond to a
threshold stimulus previously seen at
the same point
▪ if > 33% FP or FN, then unreliable
▪ if > 20% fixation losses then unreliable
35. Compare total & pattern deviation
3.Age Corrected plots
HumphreyTM
Zero in on the probability plots
36. Compare total deviation (TD) & pattern
deviation (PD) probability plots
HumphreyTM
▪ If defect in TD & PD plots look similar
➢ Focal field defect
▪ Depressed TD w/ a normal PD
➢ Diffuse or generalized field defect
40. ■ Outside normal limits
➢if sensitivities in > 1 of the
5 zones in upper half of
the field are different
(p<0.01) from those in the
corresponding lower half
zones
4.Tests: glaucoma
hemifield test (GHT) HumphreyTM
43. Mean deviation (MD)
▪ Average difference between
overall sensitivity of patient and
age-matched controls
▪ Indication of generalized defects
or elevation (+ or - 2 dB normal)
▪ Good measure of diffuse defects
45. Pattern standard deviation (PSD)
shape of VF departs from normal age-
corrected field
▪ Focal / localized defects
▪ Single most useful analysis
▪ Beginning VF loss appear earlier in
probability plots vs grayscale
▪ Normal value : 0 to 6 dB
46.
Short term fluctuations (SF)
▪ 0-2dB normal
▪ Average between 2 determinations
should be:
➢ < 2dB in normal field
➢ < 3dB in early damage
➢ < 4dB in moderate damage
• Increased fluctuation
47. ▪ Pattern Standard Deviation
(PSD) corrected for the SF
▪ Better measure of localized
field loss (0-4 dB normal)
Corrected Pattern
Standard deviation (CPSD)
HumphreyTM
5.Indices (global)
51. ▪ Test strategy
➢ Normal, Dynamic, TOP
▪ Pattern/region used
➢ G1, 32, M2, LVC
▪ Patient details
➢ Date of birth, date of VF, pupil size, test
time, VA, correction, eye tested
OctopusTM
1.Parameters
52. ▪ Points positioned in
areas of concern in
glaucoma
➢Accentuates nasal
step
➢Higher resolution in
paracentral area
G1 program
OS
OctopusTM
1.Parameters - pattern
55. Perimetry Programs
■ Dynamic Program 30-2 (Octopus)
■ ~ 7 minutes per eye
■ Stimulus presentation adapted to
measured threshold value
■ Higher sensitivity ! smaller steps (2 dB)
■ Lower sensitivity ! larger steps (6-10 dB)
■ Single crossover
■ Light stimulus size is standard (Goldmann
Size III)
56. Perimetry Programs
■ Tendency Oriented Perimetry (TOP)
Program 30-2
■ ~ 2-3 minutes per eye
■ Screening
■ Only 1 test question per location
■ Single answer influences the value of 8
neighboring points
■ Light stimulus size is standard (Goldmann
Size III)
■ Phase 1 only
■ No SF (short term fluctuation)
59. ▪ For detection and/or
f/up of defects in the
central 100
➢ Neurological
➢ Macular
➢ Peri-macular
M2 program
00 100
OctopusTM
1.Parameters - pattern
61. ▪ Tests sensitivity in
central foveal area
➢ Same grid as 32
program
➢ End stage glaucoma
➢ Goldmann stimulus V
LVC program
00 300
1.Parameters - pattern
OctopusTM
67. ▪ Quickly assesses defect
characteristics & depth
▪ Diffuse vs focal defect
➢ Diffuse: curve below & parallel to the
normal curve
➢ Focal: steep fall-offs on the right side
of the curve
OctopusTM
4.Tests: Bebie curve
68. Diffuse defect: curve below & parallel
to normal curve
OctopusTM
4.Tests: Bebie curve
71. mean sensitivity (MS)
mean deviation (MD) mean defect (MD)
pattern std deviation (PSD) loss variance (LV)
short term fluctuations
(SF)
short term fluctuations
(SF)
corrected pattern standard
deviation (CPSD)
corrected loss variance
(CLV)
OctopusTMHumphreyTM
5.Indices (global)
72. Visual Field Indices
Normal Values
■ Mean Defect ( -2.0 to +2.0 db )
■ Loss Variance ( 0 to 6.0 db )
■ Short-term Fluctuation ( 0 to 2.0 db )
■ Corrected Loss Variance ( 0 to 4.0 db )
77. What kind of a defect is this?
diffuse or focal?
combined diffuse & focal defect
78. If the defect is Focal
STEP 2:
Is the focal defect glaucomatous?
79. Glaucomatous Visual Field Defects
(Seagig Glaucoma Guidelines ‘08)
▪ Asymmetrical across horizontal meridian*
▪ Are located in mid-periphery* (5–250
from fixation)
▪ Reproducible
▪ Not attributable to other pathology
▪ Clustered in neighboring test pts (localised)
▪ Correlate with optic disc and RNFL
* Applicable to early/moderate cases
80. Localized patterns of glaucoma
VF defects
▪ Nasal step (earliest)
▪ Paracentral scotoma
▪ Arcuate (Bjerrum) scotoma
➢ Later becoming altitudinal
▪Temporal island
▪ Central island
85. Reproducibilty
■ A visual field defect must be real. To be real, it
must be confirmed on repeated exams
86. 1. Anderson DR, Patella VM. Automated Static
Perimetry. 2nd Ed. St Louis: Mosby 1999
2. Hodapp E, Parrish RK, Anderson DR. Clinical
decisions in glaucoma. St Louis: Mosby
▪ What is the minimum criteria for a defect to be possibly glaucoma?
1
▪ When do you classify a glaucoma
defects as:2
➢ Early?
➢ Moderate?
➢ Severe?
Identification & Classification of
a glaucoma defect
87. Minimum Criteria for glaucoma
defects (1)
▪ ≥ 3 non-edge points w/
p< 5%
▪One point w/ p< 1%
▪Cluster in arcuate area
Anderson DR, Patella VM. Automated Static
Perimetry. 2nd Ed. St Louis: Mosby 1999
Pattern
deviation plot
88. Criteria for glaucoma defects (2)
CPSD or PSD
depressed,
with p < 5%
Anderson DR, Patella VM. Automated Static
Perimetry. 2nd Ed. St Louis: Mosby,1999
89. Criteria for glaucoma defects (3)
Abnormal GHT
Anderson DR, Patella VM. Automated Static
Perimetry. 2nd Ed. St Louis: Mosby 1999
90. 3 minimum criteria for glaucoma
defects
2) CPSD or PSD depressed
w/ p < 5%
3) Abnormal GHT
Anderson DR, Patella VM. Automated Static
Perimetry. 2nd Ed. St Louis: Mosby 1999
1) PD plot
a) ≥ 3 non-edge points w/
p< 5%
b) 1 point w/ p < 1%
c) Cluster in arcuate area
91. Hodapp E, Parrish RK, Anderson DR. Clinical
decisions in glaucoma. St Louis: Mosby
Criteria for Early Glaucoma Defect
▪ MD < -6 dB
▪ On PD plot, < 25% (18
pts) below 5% level and
< 15% (10 pts) below
1% level
▪ No pt w/in central 50 :
sensitivity < 15 dB
93. ▪ MD > -6 dB but < -12 dB
▪ PD plot, < 50% (37 pts) < 5%
level and < 25% (20 pts) < 1%
level
▪ No absolute deficit (0 dB) in the
central 50
▪ Only 1 hemi-field has point w/
sensitivity < 15 dB in the central
50
Hodapp E, Parrish RK, Anderson DR. Clinical decisions
in glaucoma. St Louis: Mosby
Criteria for Moderate Glaucoma Defect
95. ▪ MD > -12 dB
▪ On PD plot
➢ > 50% of pts < 5% level
➢ > 25% of pts < 1% level
▪ Absolute deficit (0 dB) in the central 50
▪ Both hemi-fields w/ pt(s) w/ sensitivity <
15 dB w/in th central 50
Hodapp E, Parrish RK, Anderson DR. Clinical
decisions in glaucoma. St Louis: Mosby
Criteria for Severe Glaucoma Defect
97. Detecting Progression
➢ Widening or deepening of an
existing scotoma
➢ Development of a new
glaucomatous scotoma
➢ Occasionally generalized field
depression (although usually caused by
media opacity or miosis)
Asia Pacific Glaucoma Guidelines (2003-2004)
98. ■ Requires a series of at least 3 or 4 fields
■ Basing judgements on only 1 progressed
field is very risky unless the changes
encountered are
➢ Very large and/or
➢ Confirmed by other clinical findings, such as
changes in optic disc configuration
Detecting Progression
99. Octopus
▪ Series Program
➢3 examinations arranged in one
printout
▪ PeriTrend® Statistical Software
▪ EyeSuite®
Detecting Progression
106. Structure-Function Correlation
■ Combined w/ other examinations
■ No isolated interpretations
■ Disc features must match visual field
defects (clinical picture takes
precedence)
107. New Perimetry Technologies
■ Short Wavelength Automated
Perimetry (SWAP)
➢Blue light stimulus on yellow
background (“blue on yellow”)
➢Detects VF loss 3-5 yrs before white on
white perimetry1
➢Utilizes the “K” ganglion cells
1. Racette L et al. Ophthalmol Clin North Am. 2003: 16: 227-236
108. Goldmann size V
440 nm, 1.80
> 500 nm yellow background
• Except for these differences, SWAP is still a basic
threshold perimetry test, in w/c std Goldmann stimuli
are presented in the conventional way
109. New Perimetry Technologies
■ Frequency Doubling Technology
(FDT) perimeter
➢Motion/flicker perimetry
➢FDT can detect VF loss 4 yrs before
SAP1
➢Utilizes the “M” ganglion cells/
Magnocellular pathway
1. Johnson CA et al. J Vision. 2002; 2:100a
110. ▪ Functional testing essential: SAP
▪ Know retinal anatomy & its relation to
visual function
▪ Know programs/parameters
➢ Stick to a single one for ff-up
▪ Glaucoma defects are focal
▪ Progression is a hallmark of
Glaucoma
▪ CLINICAL CORRELATION
Summary
121. • elevated false “+” score
• GHF – “abnormally high sensitivity”
• “white scotoma” on grayscale
• larger defects on the pattern
deviation plots than in the total
deviation probability plots
• highly positive mean deviation (MD)
“Trigger happy” field
136. Are the VF defects artifacts?
▪ “Learning effect” ?
▪ Rim effect ?
▪ Ptosis, prominent brows ?
▪ Lack of instructions or supervision ?
▪ Anxiety/fatigue/drowsiness ?
▪ Malingering ?
137.
138.
139. Learning effect
▪ Depressed sensitivity in mid-periphery
20-300
▪ Less common in shorter algorithms
▪ 10-20% of normal patients don’t
produce normal VF’s on their first test