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Disease/glaucoma Dr. Davey 2016 > Lecture 4 Visual fields > Flashcards

Lecture 4 Visual fields Flashcards

1
Q

(T/F) A symptom of glaucoma is visual field deficit and a sign is NFL damage.

A

True.

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2
Q

Match the following:

1) the first automated visual field analyzer
2) universal “gold standard”

A) Octopus
B) Humprey’s field analyzer

A

1=A 2=B

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3
Q

The optic nerve blind spot is located ____ degree’s temporally

a) 5*
b) 10*
c) 15*
d) 20*

A

c) 15*

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4
Q

(T/F) The optic nerve blind spot is visible binocularly and monocularly.

A

False. It is only visible monoculalry. When both eyes are open, the visual fields of each eye overlap and fill in the blind spot.

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5
Q

Which of the following is NOT true in regards to the hill of vision:

a) central vision is greatest, vision decreases as one moves away from the center to the periphery
b) low threshold=high sensitivity=weak stimulus (dim light)
c) high threshold=low sensitivity=strong stimulus (bright light)
d) The hill of vision represents the height of vision at the optic nerve

A

d) The hill of vision represents the height of vision at the optic nerve. No, it represents the height of vision at the macula.

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6
Q

A reliable perimetry measurement should not test father than ____ degrees from the center of vision

a) 15*
b) 30*
c) 45*
d) 60

A

b) 30*

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7
Q

Which one of the following is NOT a basis of quantitative perimetry?

a) apparent size (diameter of the area) of the spot
b) luminous intensity of the spot
c) background illumination
d) color variation of the spot

A

d) color variation of the spot (color of stimulus was not named as one of the three basis of quantitative perimetry, however, color of stimulus does affect perimetry because color is easier to see)

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8
Q

A spot that is 1mm in diameter at a distance of 0.33 meters is also 3mm in diameter at 1 meter. This is an example of which of the 3 basis’ of quantitative perimetry?

A

Apparent size. HFA (Humphreys field analyzer) has a constant distance: HFAI=33cm, HFAII=30cm.

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9
Q

A spot is half the size but more intense (bright) than another. This makes the 2 spots look roughly equivalent. This is an example of which of the 3 basis’ of quantitative perimetry?

A

Luminous intensity

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10
Q

A bright background needs a brighter stimulus. A Visual fields perimetry device is calibrated by the room lighting. It is used in dim lighting, therefore needs to be powered on in dim lighting. This is an example of which of the 3 basis’ of quantitative perimetry?

A

Background illumination

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11
Q
  • Which one is not considered as an important point of perimetry?
    a) color of stimulus
    b) pt attentiveness
    c) moving vs non-moving target (moving targets are more visible-RIDDOCH’S phenomenon)
    d) duration of stimulus (1/100 of the a second compared to 2/100 of a second can make a difference, however, the critical duration is 1/3 of second, in which longer duration has no effect)
    e) all of the above are true
A

e) all of the above are true Riddoch’s phenomenon–> moving targets are more visible than non-moving targets

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12
Q

What is the European unit for luminance and the standard for perimetry?

A

(asb) apostilib.
HVF max luminosity=10,000 asb
Goldman=1000asb
Octopus (original)=1000asb

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13
Q

Describe the relationship between decibel (dB) of stimulus and intensity?

A

As decibel’s (dB) increase, intensity of stimulus decreases. (dB is measured on a logarthmic scale) For example, 10dB stimulus=1/10th as intense, 20dB=1/100th as intense, 30dB=1/1000th as intense, 40dB=1/100000th as intense.

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14
Q

What is the absolute max intensity (in decibels, dB) that the human can see?

A

40dB

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15
Q

Describe the difference between a threshold visual fields test and a suprathreshold visual fields test.

A

Threshold is defined as the intensity that is just marginally visible, there is a 50% chance the pt will see the stimuli. If you wish to check for glaucoma, do a threshold test.

Suprathreshold will test visual fields using a stronger stimuli where 95% of pt’s will see it. This is used for screening.

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16
Q

Kinetic perimetry tests visual fields with a target that comes in from the non seeing region to the seeing region. This determines the _____.

A

isopter. When repeating the test, you will find variance. When the variance is within a narrow range, the retina is more likely to be normal. When the variance is a wider range, the retina is more likely to be diseased.

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17
Q

*Name the phenomenon: You fixate on a point for about 20 seconds and low-contrast/small/blurry visual information in the periphery began to disappear.

A

Troxlers effect. This can happen when measuring visual fields, have pt blink frequently.

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18
Q

Of the following 2 types of visual field tests used, which is the test everyone has agreed on?

a) 24-2
b) 30-2 (extra 6 degrees field of view)

A

a) 24-2. It is believed that testing more in the outer reaches of the periphery is not advantageous, it creates too much variation.

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19
Q

SITA (Swedish interactive threshold algorithm) uses the 24-2 visual field testing application. What are the normal values a pt should get in the center and periphery?

A

low 30’s dB in the center and high 20’s dB in the periphery

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20
Q

SITA is a time efficient method of estimating threshold. Which one of the following factors is not a reason why?

a) visual field modeling
b) info index to determine threshold endpoints
c) test paced to pt needs (speeds up for fast responders and slows down for slow responders)
d) post test re-computation of threshold values
e) increased number of “catch trials” needed to determine reliability indices.

A

e) increased number of “catch trials” needed to determine reliability indices. There is actually a reduced number of catch trials to save time.

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21
Q

Visual field modeling is an important feature of SITA. Which of the following does NOT describe this model?

a) Starts with prior probability models of normal and abnormal fields
b) It has age corrected normative data of normals and glaucoma pts
c) it shows correlations between adjacent test points
d) testing is not adjusted continuously based on pt responses

A

d) testing is not adjusted continuously based on pt responses. This is false, it IS continuously adjusted.

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22
Q

Which of the following is the “gold standard” for visual field testing for glaucoma?

a) SITA fast
b) Heijl-Krakau
c) Pascal dynamic
d) SITA standard

A

d) SITA standard. SITA fast is sometimes used when a pt cannot physically perform the test for the duration of the SITA standard.

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23
Q
  • Match the following:
    1) SITA standard
    2) SITA fast

a) 5-8 minutes
b) 3-4 minutes
c) lower resolution
d) higher resolution
e) threshold +/-2
f) threshold +/-3

A

a=1, b=2, c=2, d=1, e=1, f=2

SITA std: 5-8 min, higher res, +/-2
SITA fast: 3-4 min, lower res, +/-3

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24
Q

An important part of correctly measuring visual fields is knowing that the pt is looking straight ahead as instructed. SITA has a fixation monitoring system. Which one of the following is not a method of SITA fixation monitoring?

a) Heijl krakau blind spot method
b) grey scale
c) gaze tracking

A

b) grey scale. This is the shaded representation of the visual field located on the print out containing all the test results.

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25
Q

*Describe how the Heijl-krakau blind spot method monitors pt fixation during visual fields testing.

A

If the pt is looking straight ahead (one eye is properly patched) then a stimulus will present in the optic nerve blind spot region of the monocular visual field. The pt should not be able to see this. If they do detect it, they are either not looking straight ahead, their head is tilted, or they are not properly patched. *Size is not an issue. There are 5 different sizes of stimulus and they all fit into the size of the blind spot.

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26
Q

Which one of the following does NOT describe the gaze tracking method of fixation monitoring?

a) UV light source is used to track corneal reflexes
b) uses a 2 image analysis method to locate the center of the pupil
c) Pt has to look at the fixation and not blink
d) gaze monitor initialization at the beginning of the test is used for calibration and adjusting the system for individual pt.

A

a) UV light source is used to track corneal reflexes. No, Infrared light source is used to track corneal reflexes.

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27
Q

When reviewing the gaze tracking, which one of the following is NOT true?

a) an upward line represents a fixation error
b) a downward line represents a situation where the position of the eye is not available (a blink or other eye closure)
c) An upward line of max height is equal to 10 degrees of fixation error
d) gaze tracking records eyes even when stimulus is not present

A

d) gaze tracking records eyes even when stimulus is not present. This is false, gaze tracking is NOT recorded when stimulus is NOT present.

When the lines are mostly up, you have a pt looking all over the place. When the lines are mainly down, you have a pt who fell asleep.

28
Q
  • Match the following in regards to SITA catch trials:
    1) False positive
    2) False negative

a) pt fails to respond
b) trigger happy pt

A

a=2, b=1

29
Q
  • SITA acceptable rates are:
    a) less than 20% fixation loss, less than 33% false pos, less than 33% false neg
    b) less than 20% fixation loss, less than 20% false pos, less than 20% false neg
    c) less than 15% fixation loss, less than 15% false pos, less than 15% false neg
A

b) less than 20% fixation loss, less than 20% false pos, less than 20% false neg (SITA acceptable rates)

a) less than 20% fixation loss, less than 33% false pos, less than 33% false neg (this is full threshold acceptable rates)
c) less than 15% fixation loss, less than 15% false pos, less than 15% false neg (this is the goal)

30
Q

(T/F) Other considerations for visual field testing is: pupil size, refractive error, and testing environment.

A

True.

PUPIL: should be >3mm. However, it is best done undilated because if you dilate then all future visual field tests must be done dilated to be consistent. Exceptions are in pt’s with cataracts or very small pupil.

REFRACTIVE ERROR: less than 1.00D can be ignored.

TESTING ENVIRONMENT: Low to dark, machine does indicate if room is too bright, machine needs to be turned on in dim room for calibration purposes.

31
Q

Which one of the following is NOT true regarding the criteria for determining if a pt is a glaucoma suspect when analyzing the HFA single field analysis?

a) Is GHT outside normal limits?
b) Is PSD less than 5%?
c) Can you find clusters of 3 or more in the pattern deviation with respect to the horizontal midline?
d) all of these are the 3 criteria and all must be met.

A

d) All of these are the 3 criteria and all must be met. not true, They are the 3 correct criteria but only 2 of the 3 criteria needs to be met to label a pt as a glaucoma suspect.

32
Q

To determine if the HFA single field analysis is first an accurate assessment, what are some of the things you must pay attention to?

A

1) How big was the pupil? It should be >3mm, if it is less it can cause a ring scotoma. Also placing the lens far from the eye can cause a ring scotoma.
2) Is the age of the pt correct? This data is being compared to their age group.
3) Be sure that these fall within the acceptable limits:

33
Q

(T/F)In regard to the HFA single field analysis; Grey scale is represented in gradations of 10dB and range from 1-40dB

A

False.Grey scale is represented in gradations of 5dB and range from 1-40dB

34
Q

In regard to the HFA single field analysis; Is an inferior defect more common than a superior defect? why or why not?

A

A superior defect is more common than an inferior defect because of the isnt rule. (A nasal step shows greater damage in superior than in inferior) remember-a superior visual field defect represents the actual inferior portion of the retina

35
Q

If the total deviation plot on the HFA single field analysis has negative numbers, what does that mean?

a) the pt’s data is worse than others in their age range
b) the pt’s data is better than others in their age range
c) the pt’s data is worse than others that have been tested at that site
d) the pt’s data is better than others that have been tested at that site

A

a) the pt’s data is worse than others in their age range. Rule of thumb, all data points with a (-5) should be viewed as suspicious. a positive value means that the pt is better than those in their age range. This is for the Humphrey’s visual field only, not the octopus.

Also keep in mind this is only true for the 24-2. On the 30-2 test the periphery testing is 6 degrees larger and more susceptible to variation. In this situation (-10dB) may still be normal.

36
Q

In regards to the HFA single field analysis, which is true regarding the “P” value on the mean deviation?

a) mild is a P value less than -6
b) moderate is a P value between -6 and -12
c) severe is a P value greater than -12
d) all of the above are true

A

d) all of the above are true

37
Q

In regard to the HFA single field analysis; Which one of the following is not a purpose for the pattern deviation numerical plot on the single field analysis?

a) it exposes localized defects which may be masked by elevated hill of vision
b) it exposes localized defects which may be masked by generalized depression (cataract)
c) it exposes discrepancies which may be masked by operator or pt error

A

c) it exposes discrepancies which may be masked by operator or pt error

38
Q

In regards to the HFA single field analysis, what is the #1 representation of the visual field?

a) Grey scale
b) total deviation plot
c) pattern deviation numerical plot
d) global indices

A

a) global indices. The global indices contain 4 components:
1) Mean deviation (md)
2) Pattern standard deviation (psd)
3) short term fluctuation (sf)
4) corrected pattern standard fluctuation (cpsd)

md and psd are the most important

39
Q

In regard to the HFA single field analysis;Which one of the following does the global indices NOT do?

a) summarizes the total or pattern deviation into one value
b) gives significant limits (example: p

A

d) indicates reliability of test.

40
Q
  • In regards to the HFA single field analysis; Match the following:
    1) mean deviation
    2) pattern standard deviation

a) degree to which the the total deviation plot points are not similar to each other (always a positive value)
b) measure of entire field loss (elevation or depression (could be negative or positive)

A

A=2, B=1.
For mean deviation (md) a positive number indicates an avg sensitivity is above avg normal for age (or trigger happy). A negative md value indicates an avg sensitivity is below avg normal for age (depression). For pattern standard deviation, values closer to zero indicate more advanced cases of glaucoma.

41
Q

GHT (glaucoma hemifield test) is another parameter on the HFA single field analysis. What is its purpose?

A

GHT compares superior and inferior visual fields. This test is only useful for glaucoma pt’s/suspects and not other retinal neuropathies.

42
Q

What are the 5 possible GHT results?

A

1) outside normal limits (p less than 0.01)
2) borderline (p les sthan 0.03)
3) generalized reduction (low sensitivity p less than 0.05)
4) abnrmally high sensitivity (high sensitivity p less than 0.05)
5) within normal limits

43
Q

Which one of the following is NOT a feature of the Octopus fixation control system?

a) most accurate test possible
b) no stimuli presented during fixation loss
c) automatic repetition of stimuli after blinking or darting
d) all of the above are true statements

A

d) all of the above are true statements

44
Q

(T/F) Regarding the Octopus: if the eye moves, then the machine automatically realigns to the eye’s new position by locating the eye’s optical axis.

A

True. This makes for less interruptions and makes the testing time less.

45
Q

In regards to the numbers in the quadrants of the greyscale on the octopus and of the raw numerical data: Match the following:

1) positive number
2) negative number

a) damage
b) no damage

A

A=1, B=2 (remember on the HFA single field analysis it was the “total deviation plot” where the negative numbers meant worse than others in age group and positive numbers meant better than others in age group)

46
Q

In regards to the octopus, which are the 2 global indices?

a) mean deviation
b) mean defect
c) pattern standard deviation
d) loss of variance

A

b) mean defect–>Octopus
d) loss of variance–>Octopus
a) mean deviation–>HFA
c) pattern standard deviation–>HFA

47
Q

Which one of the following is NOT something you can determine by analyzing a Bebie curve?

a) diffuse defect (DD)
b) arbitrary defect (AD)
c) detection of false positives
d) local defects (LD)

A

b) arbitrary defect (AD)–I just made this up, “AD” is not anything (a localized defect will show a sharp drop in the curve, a false-positive curve will start really high; pt didn’t understand the test, a diffuse defect will look more steady before it drops off)

48
Q

In regard to HFA single field analysis, Which one of the following is NOT a criteria for glaucomatous damage?

a) GHT is outside normal limits
b) PSD less than 5%
c) Pattern deviation numerical plot has positive numbers
d) Pattern deviation probability plot has clusters of 3 or more with respect to the horizontal midline

A

c) Pattern deviation numerical plot has positive numbers. The numerical plot is not a criteria and positive numbers would mean the data is better than their age group.

49
Q

Staging glaucoma helps to better treat and manage glaucoma. What factor do you determine your staging on?

a) MD (mean deviation)
b) PSD (pattern standard deviation)
c) TD (total deviation)
d) GHT (glaucoma hemifield test)

A

a) MD (mean deviation)

  • MILD=Better than -6db
  • MODERATE= worse than -6db but better than -12db
  • SEVERE= worse than -12db
50
Q

How can you use the Brusini glaucoma staging system 2 (GSS2)?

A

Find the PSD on the “Y” axis and the MD on the “X” axis. Meet them up in the graph and see where they land. Possible outcomes: S1, S2, S3, S4, S5.

51
Q

In regards to Brusini’s staging system; Match the following

1) Early VF defects
2) Moderate VF defects
3) Advanced VF defects
4) Severe VF defects
5) Most severe VF defects

a) Brusini stage 1
b) Brusini stage 2
c) Brusini stage 3
d) Brusini stage 4
e) Brusini stage 5

A

1) Early = stage 1
2) Moderate = stage 2
3) Advanced = stage 3
4) Severe = stage 4
5) Most severe = stage 5

52
Q

(T/F) Linear regression of Mean Deviation means changes in mean deviation over time. This includes changes in “p” values and dB values.

A

TRUE. Also good to note that cataracts can make MD get worse

53
Q

Which of the following is NOT true regarding GPA (guided progression analysis)?

a) can be used with SITA standard and SWAP but not SITA fast
b) full threshold tests can still be used for the baseline
c) corrects for cataracts and media effects
d) MD plotted over time and regression analysis done to quantify dB change over a year
e) verifies reliability “low test reliability” and “excessive false positive”

A

a) can be used with SITA standard and SWAP but not SITA fast.

54
Q

Which of the following is NOT true regarding GPA (guided progression analysis)?

a) flags change
b) establish baseline; it is important pt understands test. If pt’s IOP is ridiculously high you do not want to use that visit as a baseline
c) 2 tests are needed and an average on the 2 to make a baseline.
d) Only 24-2 can be used for baseline

A

d) Only 24-2 can be used for baseline

55
Q

(T/F) 2 consecutive VF tests may not be accurate because 14% of the time, the 2nd test shows progression. This is why it is very important to have a good baseline

A

TRUE

56
Q

Which one of the following is NOT true regarding Visual Field Index?

a) Contains percentage of normal age
b) Greater the number, the more abnormal
c) Trend overtime is given with a probability values as well.

A

b) Greater the number, the more abnormal. False, the greater the number the more NORMAL

57
Q

Which one of the following is NOT a unique feature of the Octopus?

a) Cluster analysis–>organizes NFL bundles
b) Trend analysis–>prob of worsening/recovering
c) Global trends–>MD, DD, LD, sLV
d) Tundra graph–>bridges structure and function

A

d) Tundra graph. False, I made that up, but the Octopus also includes a unique feature called the Polar graph which bridges structure and function .

58
Q

Which one of the following is NOT a source of error with the Octopus?

a) miosis or ptosis
b) lens opacities
c) uncorrected refractive error or spectacles
d) inadequate dark adaption
e) All of the above are true

A

e) All of the above are true

59
Q

Match the following:

1) M cells
2) P cells
3) Kcells

A) 10%
B) 9%
C) 80%

A

M cells–> 10%
P cells–> 80%
K cells–> 9%

60
Q

Match the following:

1) Parasol
2) Konio
3) Midget

A) magno
B) Parvo
C) intercallated (K)

A

Parasol–>Magno–>(phasic)
Konio–>intercallated (K)–> (interlaminar)
Midget–> Parvo–>(tonic)

61
Q

Which one of the following is NOT true regarding Frequency doubling technology?

a) High spatial frequency sinusoidal grading
b) counterphase flicker
c) it appears to have twice the number of black and white bars

A

a) High spatial frequency sinusoidal grading

62
Q

Which of the following is NOT a frequency doubling test option?

a) 19 targets in central 30 degrees, 0.25Hz temporal frequency
b) 40 test locations, 3 degree by 3 degree, spatial frequency 0.25Hz.
c) 55 test locations, 5 degree by 5 degree, spatial frequency 0.5Hz
d) 69 test locations, 5 degree by 5 degree, spatial frequency 0.5Hz

A

b) 40 test locations, 3 degree by 3 degree, spatial frequency 0.25Hz.

63
Q

What does SWAP stand for and what does it target?

A

Short Wavelength Automated Perimetry. It targets K cells.

64
Q

Which accurately describes the SWAP target and background?

a) blue target on a white background
b) yellow target on a blue background
c) blue target on a yellow background
d) white target on a blue background

A

c) blue target on a yellow background. This isolates the Konio cellular layer (blue cone system)

65
Q

Which one of the following does NOT accurately describe SWAP?

a) It is an easier test requiring less pt learning time
b) SITA options are available
c) SWAP and FDT may not be picking up defects sooner than white on white perimetry
d) The bright yellow background depresses the sensitivity of the green (middle) and red (long) wavelength mechanisms and permits the sensitivity of the short wavength mechanisms to be evaluated

A

a) It is an easier test requiring less pt learning time. False, it is actually more difficult and requires greater learning time

Disease/glaucoma Dr. Davey 2016 (13 decks)

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