2. VISUAL FIELDS
Localized measurement of visual perception
using manual or automated methods to
determine normal status or to evaluate and
track an ocular or neurological disease state.
3. NORMAL FIELDS
• Visual Field - Roughly
140 degrees
monocularly and just
over 180 degrees
binocularly
• Field of Gaze – Over
200 deg
• Field of View – Over
4. COMMON METHODS OF FIELDS
TESTING
• Confrontation –gross target movement - in from periphery
• Manual kinetic central fields – Tangent screen, Autoplot
• Microperimetry – Amsler Grid, automated units
• Manual kinetic widefield perimetry – Goldmann
• Automated static perimetry – Computer algorithm, tester
independent
Humphries HFA and FDT/Matrix
Haag-Streit Ocotopus
Oculus and others
11. SUPRATHRESHOLD
• Targets set at moderate brightness
with wide field
• Either seen or not seen
• Useful for lid/ptosis evaluation
• Two field tests, taped and untaped
12. THRESHOLDING
• First stimuli in each of the 4 quadrants
• Lowered by 3-4 Db until not seen and vise
versa
• Moves to different area and repeats process
• Cloverleaf pattern in poor pt.
management and cooperation
13. SITA / SITA FAST (HFA)
Swedish Interactive Thresholding Algorithm
SITA 50% faster than standard, but 90% accuracy
SITA FAST 70% faster, 80% as accurate
14.
15. FDT/FDP
• Frequency Doubling
Technology (Perimetry)
• Grating target flickered
quickly creates and illusion
of a doubled grating,
stimulating a different
neuro pathway
• For early detection of
glaucoma
• Resistant to blur (Rx) and
pupil size effects
16. MATRIX FDT
• Hybrid of FDT and SAP
• Even more sensitive to early glaucoma
defects
• Too hypersensitive for neuro field testing and
poor for
tracking glaucoma progression
• Best for glaucoma suspects / pre-perimetric
glaucoma
17. SWAP – SHORT WAVELENGTH AUTO
PERIMETRY
• Yellow background and large blue stimulus
on HFA
• Catches early defects in pre-perimetric
glaucoma
• Very time consuming and sensitive to media
opacities
• Matrix now more commonly used
18. 30-2 VS 24-2
• 30-2 = 76 test locations
Most accurate, 0.2 sec.
stimulus vs. 0.25 sec
latency for eye movements
• 24-2 = 54 test locations
Used for the difficult patient
19. HFA 10-2
• Central field testing
• Most commonly
used for patients
with risk for macular
toxicity
• Plaquenil –
hydroxychloroquine
used chiefly for
rheumatoid arthritis
• OCT of macula also
part of new protocol
21. WHEN TO USE WHAT
• Glaucoma suspect or pre-perimetric
pt.
• Established glaucoma patient with
field loss
• Neuro patient
• Ptosis patient
• High risk meds patient
22. GLAUCOMA SUSPECT
• Minimal or no nerve head cupping –
Matrix/FDT
• Obvious nerve damage – SITA Standard
30-2
• Difficult patient w/ damage– SITA Fast
24-2
26. HIGH RISK MEDS
• SITA 10-2
• For subtle central defects from retinal
toxicity
• Used in conjunction with SD-OCT for
Plaquenil (hydroxychloroquine)
screening
27. QUALITY MEASURES
• Fixation losses – targets blind spot, need
<15%, use gaze tracker for confirmation, ?
misaligned
• False positives – notes positive response
when no target is shown < 20% or not a
reliable study
• False negatives – notes lack of response
in area previously seen at lower
illumination <33%
• Gaze tracker - camera notes eye
29. COMMON ARTIFACTS AND ERRORS
• Ptosis
• Prominent brows
• Lens holder positioning—ring scotoma
• Patient positioning—high FL, ring
scotoma
• False positives based on patient
expectations of stimulus timing
30.
31. DATA ANALYSIS
• Grey scale
• Threshold values in Db
• Variance from normal threshold in Db
• Mean Deviation (MD)
• Positive Standard Deviation (PSD)
• Glaucoma Hemifield Test (GHT)
32.
33. GREY SCALE / THRESHOLD
VALUES
• Quickly identifies overall depressions
• Good for patient education
• Shows thresholds for each spot tested in Db
• No comparison for age related normals
• No adjustment for media opacities
• Under represents shallow gen. depression
and overemphasizes midperipheral non-
significant defects
34. TOTAL DEVIATION PLOT
• Graph and
numeric
representation
• Compared to
age-matched
normals
35. PATTERN DEVIATION
PLOT
• Probably the most
important data
• Takes total deviation
and filters out overall
depression
• Looks for focal
damaged areas
pertinent to glaucoma
36. GLAUCOMA HEMIFIELD TEST - GHT
• Compares top and bottom half of field
• General reduction in sensitivity
• Abnormally high sensitivity
• Outside Normal Limits – difference not found in 99% of
patients without glaucoma
• Borderline – difference not found in 97% of normals
37. GLOBAL INDICES
• Single number
representations of the
visual field
• Overall guidelines to
help assess the field
• Probability values when
numbers reach
significant levels
38. MEAN DEVIATION (MD)
• Overall level of sensitivity
compared to age-matched
normals
• Not corrected for
generalized depression from
media opacities
• Important for following
diffuse loss in glaucoma
• MD of -2.00 or worse is
suspicious
• Mild damage at <-6
• Moderate at -6 to-12
severe >-12
39. VISUAL FUNCTION INDEX (VFI) AND
PROGRESSION ANALYSIS
Seen in newer units
VFI similar in meaning to MD
but easier to conceptualize--
100% is normal
75-80% is approaching
significant loss = -6 or worse on
MD
40. PATTERN STANDARD DEVIATION
(PSD)
• Sensitive measurement of localized loss
• Especially useful in glaucoma
evaluation/progression
• The higher the number, the greater the loss
41. COMMON GLAUCOMA DEFECTS
(SCOTOMAS)
• Arcuate
• Nasal step
• Temporal wedge
• Localized paracentral
• Generalized depression
• Compare to clinical picture – know what to
expect
47. NEURO FIELDS
Unilateral – usually
involves the retina or optic
nerve
Bilateral – involves both
nerves or the optic
chiasm/tract/brain
Homonymous – alike,
same side on both eyes
Heteronomous – different,
opposite sides
Congruous – symmetric in
both eyes
Hemianopia – defect
respects vertical midline
48. HOMONYMOUS
• Hemianopsia – right homonymous, congruous,
points to cortical lesion such as stroke
• Quadranopsia or sectoranopsia– cerebral
(congruous) or lateral geniculate nucleus