Visual Field Testing 4% Flashcards
*Point of fixation
Fovea
(Had a couple question about fovea, including both fovea’s traveling the same pathway)
Blind spot
Optic Nerve
VF is recorded from _________point of view.
Patient’s
VF: Blind spot prints on the____ for OD and the ____ for OS.
Right for OD
Left for OS
________visual field is opposite the blind spot.
Nasal
*Normal blind spot________ degrees temporal and _____ degrees inferior to fixation.
15
1.5
*VF that does not cross _________meridian indicates Neurological/brain issue
Vertical
*VF that does not cross _____________ indicates Retinal or optic nerve problem.
Horizontal Raffe
*Amsler Grid evaluates __________ degrees of the VF using ____degree (5mm)spaced grid, holding out about 12”-14”.
20
1
Gross VF assessment using fingers, checked monocularly, documented from pt point of view.
CVF(Confrontation VF testing)
VF: Stationary stimulus (non moving)
Static
VF: Moving stimulus (like bleph field in Chas)
Kinetic
CVF fields are ____degrees superior, ____degrees inferior, ___degrees nasal, _____degrees temporal.
60, 70, 60, 90
_______, Swedish Interactive Threshold Algorithim, Combined with Standard Automated Perimetry (SAP). Faster test time without reduction in data quality.
SITA
Automated Perimetry that uses varying level of stimuli. The dimmest stimuli the patient responds to at least 50% of the time sat each point in the VF is their ‘threshold’ for that point. Stair step illumintion.
Threshold Perimetry
Automated Perimetry that filters out overall depression to how focal areas damage. Differentiates glc and other defects from ‘global depressions’ such as CAT. Shows just focal areas of damage on print out. Filters out global depression.
Pattern Deviation
VF: False Positives
Pt responds when no stimulus is presented.
Pt may be anxious. Reassure, reinstruct.
Pt may not have understood instructions. Reinstruct.
Pt responded.
VF: False Negative
Patient does not respond to a very bright light at same point at which previously responded to a dimmer light.
Pt may be fatigued. Rest, coach, reschedule.
Pt may be distracted. Take a break, reinstruct.
VF: Fixation losses
Check that fellow eye is patched properly.
Retry to find blind spot. If continued fixation losses: Pt may be distracted, anxious or fatigued. Coach and reinstruct.
VF: Artifacts
Lids- lashes-tape upper lid
Positioning error-Lens Rim: Place closest to eye without touching eyelashes. High plus pts best tested w/CL’s
Forehead
Chin
Goldmann Perimetry is what type of VF?
Threshold
Goldmann Perimetry uses_________code.
Alphanumeric
Goldmann Perimetry: Each step a-e represents a brighter illumination of ____log unit.
0.1 (1 dB) decibels
In Goldmann Perimetry each step 1-4 represents a ____log unit change in intensity.
0.5 (5dB)
Goldmann Perimetry: _____________(20dB is 10 times brighter than 10dB)
Logarithmic
In Goldmann Perimetry Roman Numerals indicate…..
Stimulus size (not brightness)
Goldmann Perimetry: V4e for pt with …..
Hand motion VA
Goldmann Perimetry: i1e for pt with
20/15 VA
Apostible=
Unit of illumination
Decibel (dB):
_____low senstivity/significant field loss
_____normal
_____high sensitivity/may be trigger happy
0-20
30
40-50
Line connecting points that are of equal sensitivity to light.
Isopter
A complete map of the VF with a given test illumination show an___________.
Isopter
Apostilbs and dB are ________related.
Inversely
0 dB=max stimulus on _____________ but absolutely to illumnation at all on _______________
Automated perimeters
Goldmann Perimeters
How often should Goldmann VF test be calibrated?
Before every test
Goldmann VF test facts:
Calibrate before every test
Calculate Trial lenses
Make sure pt comfortably seated, face in chinrest and vertical (no tilt)
Cover eye not being tested
Pt fixates on white fixation target at center of bowl.
Goldmann VF Test:
Size of stimulus depends on……
Accuracy of patient’s fixation
Patient’s reaction time
Goldmann VF test:
Young, 20/20 begin with ________mm white target.
Old, senile, 20/200 begin with ________or ____larger target.
1 or 2
10mm or 20mm
In Goldmann Perimetry, always move________target from _________(non-seeing area) toward_______(seeing area).
kinetic
periphery
fixation
Why should you move slowly with Goldmann VF test?
so lag time between pt’s first view of light and response is short
Goldmann VF: Test approximately ___meridians ______ and _____ ____ sector. Carry test object to _________
12
peripherally
central 30
fixation point
Goldmann VF: If target is _________ then you will have threshold defects, tire patient, and waste time. Never use target smaller than ____
too small
‘e’
Center of blind spot is_________degrees temporal to fixation and ______degrees below horizontal meridian.
12-15
5
True or False: You must remove lens when testing outside of central 30 degrees with Goldmann VF.
True
In Goldmann VF: Pt should respond when test object________, when object _______ and when it ___________.
becomes visible
disappears
flickers or grays out
Goldmann VF: The larger the target, the__________the VF.
Larger
Why should you use the same target in follow up tests when doing VF.
It shows progression or regression of VF.
Stationary stimulus
Static
Moving stimulus
Kinetic
Patient responds when no stimulus present
False positive
Pt does not respond to a very bright light at same point at which previously responded to a dimmer light
False negative
Causes of false positives
Solution
Anxious(reassure, reinstruct)
Didn’t understand instructions (reinstruct)
Causes of false negative
Solution
Fatigue (test, coach, reschedule)
Distracted ( take a break, reinstruct)
Pt responds to a stimulus that was shown in their previously mapped out blind spot
Fixation losses
Causes and Solution for fixation losses
Pt distracted, anxious, fatigued
(Coach, reinstruct)
Unit of illuminence
Apostilb
A level of sensitivity
Decibel (dB)
0-20 low(significant field loss)
30 normal
40-50 high (trigger happy)
A line connecting points that are of equal sensitivity to light
Isopter
