2. HUMPHREY VISUAL FIELD
STANDARD AUTOMATED PERIMETRY
STATIC PERIMETRY
MEASUREMENT OF THRESHOLD VALUES
STATPAC (HFA)- comparison to normative data
Inbuilt program for analysis- diagnosis and progression
3. WHITE ON WHITE
BACKGROUND ILLUMINATION – 31.5 asb
Stimulus size- Goldmann III
DURATION OF SPOT EXPOSURE 0.2s
4. PROGRAMS/PATTERNS
30-2 – gold standard
24-2
10-2
MACULA
C40 SCREENING
Estermann test – for binocular 120 deg field
5.
6. BEFORE RUNNING THE TEST:
Selection of adequate test
VA
Proper environment
Comfortable sitting position
Adequate size of pupil >3mm
Adequate Near correction
Proper explanation – running of demonstration
Reassurance – not all points will be seen
- test can be paused by keeping the response button pressed
7. WANDER
What was done?
Accuracy (Reliability)
Normal or abnormal
Defect pattern
Evaluate compatible disease
Review
15. ZONE 2: RELIABILITY
• Fixation monitor
• Fixation target – central, small diamond, large
diamond, bottom LED
• Test duration
• Reliability indices
Fixation losses ( Heijl Krakau) <20 %
Gaze tracking
False positives < 33%
(trigger happy)
False negatives < 33 %
16.
17.
18.
19. ZONE 3 : GREY SCALE
Based on actual threshold values at each location
General identification
Patient information
20. ZONE 4: TOTAL DEVIATION PLOT
• Numerical plot – indicates by how much decibels
is each point depressed compared to mean
value in normal population of similar age
• Probability plot- grey scale indicates the
probability of occurrence of the deviation in
normal population
Generalized depression due to media opacities,
refractive error, miosis may hamper appearance
of a pattern
21. ZONE 5 : PATTERN DEVIATION PLOT
• Numerical - calculated by adjustment for
generalized depression or elevation of visual field
• Thus brings out pattern
• Probability plot
• Significance - ANDERSON’S CRITERIA
22.
23.
24. ZONE 6 : GLOBAL INDICES
MEAN DEVIATION : average loss of sensitivity from normal age matched
population along with probability
calculated from total deviation plot
PATTERN STANDARD DEVIATION : range over which change of sensitivity at all
the points has occurred, along with probability
compensates for effect of generalized depression or elevation of field on
mean deviation value
local defects affect PSD > MD
SHORT TERM FLUCTUATIONS
CORRECTED PATTERN STANDARD DEVIATION
25. GLOBAL INDICES
-2 (<-6dB) MILD GENERALISED DEPRESSION
-7 (<-12dB) MODERATE GENERALISED DEPRESSION
-13 (>-12dB) SEVERE GENERALISED DEPRESSION
26.
27.
28. ZONE 7 : GLAUCOMA HEMIFIELD TEST
• Comparison of 5 clusters of points in superior hemifield with
mirror images in inferior hemifield
29.
30.
31. ANDERSON CRITERIA
• 3 or more congrous ‘non edge points’ in typical arcuate
area on 30-2 program
depressed @ p< 5 % with at least one point @ p<1 %
•PSD / CPSD @ p< 5%
•GHT – outside normal limits
Must be demonstrated on 2 field tests
32.
33. QUALITY OF VF
Good eye-hand coordination
-not suitable for pt with nystagmus, parkinson,
Corrected rx
Poor result lead to misdiagnosis
Bad day
34. VF ARTIFACTS
OBSTRUCTION
RIM ARTEFACTS
PTOSIS
MEDIA OPACITIES
MIOSIS
REFRACTION ARTEFACTS
High power plus and minus lenses
45. MONITORING VF PROGRESSION
New case/glaucoma suspect : 2 VF IN FIRST 6 MONTH.
2 MORE VF IN NEXT 18 MONTH
4 VF in 2 years
MD ≥-2DB/ year : 6 VF in the first 2 year
After first 2 years stable / slow risk : once a year
Low mod risk – once yearly
High risk – 6 month
