Visual Field in Glaucoma

1. Visual Fields in
Glaucoma
Cesar A. Perez Jr MD DPBO
Philippine Glaucoma Society

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

4. Temporal fieldNasal field
60°
90°
70°
60° 30°
Blind spot
Why only the central
30 degrees?

5. Visual Field vs Anatomy
Anderson RA. Automated Static Perimetry

6. Traquair’s Island of Vision

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

10. static achromatic stimulus
(Gold Standard)

11. Clinical Perimetry
Stimulus size
Size V
Size III (standard)
Blind spot

12. Apostilbs (Asb)
(luminance)
Humphrey
Decibels (dB)
(sensitivity)
Octopus
Decibels (dB)
0.1 50 40
1 40 30
1000 10 0
10,000 0 -
Clinical Perimetry

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

14. Clinical Perimetry
“Bracketing” reveals the threshold
Infrathreshold (can’t be seen)
Suprathreshold (seen)

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

19. Humphrey & Octopus
practical
reading
system

20. Parameters
Reliability
Age Corrected plots
Tests (GHT/Bebie curve)
Indices
Correlate clinically
Evaluate
7 Steps – 5 zones
(PRACTICE) HumphreyTM OctopusTM
1) P
2) R
3) AC
4) T
5) I
6) C
7) E

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)

25. Full
threshold
HumphreyTM

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

27. HumphreyTM
SITA -
Standard

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

30. HumphreyTM

31. advanced
glaucoma
30-2
HumphreyTM

32. 1
2
HumphreyTM
1) Parameters
2) Reliability

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

34. 3
12 HumphreyTM
1) Parameters
2) Reliability
3) Age Corrected

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

37. Focal defect
Compare total &
pattern deviation HumphreyTM

38. HumphreyTM
Generalized defect
Compare total &
pattern deviation

39. 3
4
12 HumphreyTM
1) Parameters
2) Reliability
3) Age Corrected
4) Tests

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

41. 3
4 5
12 HumphreyTM
1) Parameters
2) Reliability
3) Age Corrected
4) Tests
5) Indices

42. 5.Indices (global)
▪ MD: mean deviation
▪ PSD: pattern standard deviation
▪ SF: short-term fluctuation
▪ CPSD: corrected PSD
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

44. 5.Indices (global)
HumphreyTM
Mean deviation (MD)
40
0
30
20
10
90 60 30 0 30 60 90
Normal hill of vision
(age corrected)
dB

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)

48. 3
4 5
12 HumphreyTM
1) Parameters
2) Reliability
3) Age Corrected
4) Tests
5) Indices
6) Correlate
clinically
6

49. 3
4 5
12 HumphreyTM
1) Parameters
2) Reliability
3) Age Corrected
4) Tests
5) Indices
6) Correlate
clinically
7) Evaluate6
7

50. 1
1) Parameters
OctopusTM

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

53. “Full
Threshold”
Normal
Strategy
OctopusTM

54. OctopusTM
➢excellent
correlation
w/ normal
strategy
▪ Dynamic
▪ TOP
Shorter
strategies:

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)

58. G1 vs 32 pattern
OctopusTM

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

60. M2 program
(central 100)
OctopusTM

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

62. LVC program
OctopusTM

63. 2. Reliability Factor
▪ Ideally < 15
▪ Lower the better
OctopusTM

64. 1
2
3
OctopusTM
1) Parameters
2) Reliability
3) Age Corrected

65. Zero in on the probability plots
OctopusTM
Compare C & CC probability plots
3.Age Corrected plots

66. OctopusTM
4.Tests: Bebie curve

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

69. Focal defect: steep fall-offs
4.Tests: Bebie curve
OctopusTM

70. OctopusTM
5.Indices (global)

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 )

73. 1
2
3
4
56
OctopusTM
1) Parameters
2) Reliability
3) Age Corrected
4) Tests
5) Indices
6) Correlate
clinically

74. 1
2
3
4
567
OctopusTM
1) Parameters
2) Reliability
3) Age Corrected
4) Tests
5) Indices
6) Correlate
clinically
7) Evaluate

75. Is the field defect
glaucomatous?
• Is the defect focal?
• Is the defect diffuse?
STEP 1

76. Glaucoma defects are
Focal in nature
Diffuse Focal

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

81. Superior nasal step

82. Inferior paracentral scotoma

83. Arcuate (Bjerrum) scotoma

84. Superior altitudinal w/
inferior arcuate scotoma

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

92. Early Glaucoma Defect

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

94. 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

96. 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

100. Octopus:
Series
Program
Detecting Progression

101. ▪ Calculates regression curves of MD
(mean defect) and LV (loss variance)
▪ Color-coded curves to show
changes:
➢red – depressed
➢green – improved
➢blue – trend isn’t significant/stable
Octopus: PeriTrend®
Detecting Progression

102. Octopus:
PeriTrend®
Detecting Progression

103. Humphrey
■ Overview print-out
■ Glaucoma Progression Analysis®
(GPA®) software
Detecting Progression

104. Humphrey:
Overview
print-out
Detecting
Progression

105. Humphrey:
GPA® software
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

111. Although sometimes it is not
as easy as it seems

112. Thank You!

113. Perimetry Exercises

115. …1 year after

116. …1 year after
Early defects
may show up in
probability plots
and not in the
grayscale

118. …1 year after

119. … 6 mos. after

120. … 6 mos. after
progressing
cataract

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

124. both a focal
and a diffuse
defect

125. ….a year after

126. post cataract
surgery

128. double
arcuate
scotomas

130. superior
paracentral
scotoma

132. inferior nasal
step
extending to
blind spot

134. …1 month
after

135. …1 month
after
withdrawal of
miotic TX

136. Are the VF defects artifacts?
▪ “Learning effect” ?
▪ Rim effect ?
▪ Ptosis, prominent brows ?
▪ Lack of instructions or supervision ?
▪ Anxiety/fatigue/drowsiness ?
▪ Malingering ?

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

141. Rim effect

143. Lid effect seen
on grayscale but
not seen on
probability plots

146. Ptosis effect
seen on
probability
plots

148. same patient
after taping
upper lid

150. “Cloverleaf” pattern
•Initial good responses …..then poor
•Test begins centered around 4 primary
points
• patient misunderstanding, lack of
motivation, and/or fatigue
• poor instruction/supervision by
technician

151. • The first visual field IS NOT THE BASELINE.
• “LEARNING CURVE”