General VF Screening Techniques

Question 1

non automated instruments and techniques

Answer 1

• confrontation fields (count to full fingers, field limits confrontations, color confrontations- red cap, face confrontations)
• tangent screen

Question 2

sensitivity of confrontations to all types of VF loss:

Answer 2

50-60%

Question 3

sensitivity of confrontations to ON-related VF loss:

Answer 3

20-30%

Question 4

what type of VF loss has a high sensitivity with face confrontations?

Answer 4

central scotomas

Question 5

sensitivity of confrontations to chaismal VF loss

Answer 5

40-50%

Question 6

sensitivity of confrontations to post-chiasmal VF loss

Answer 6

> 75%

Question 7

non-automated strategy that is rapid, informal, very gross, often used, and can check for extinction phenomenon

Answer 7

count fingers confrontations

Question 8

extinction phenomenon can occur in some cases of ____ damage

Answer 8

parietal cortex damage

Question 9

extinction phenomenon presents as what type of loss

Answer 9

homonymous hemianopsia contralateral to the lesion

Question 10

what conditions on count fingers confrontations must be present to see the extinction phenomenon?

Answer 10

only if fingers are presented on both sides of the vertical midline simultaneously

Question 11

non-automated strategy that only tests the absolute limits of the VF, has much variability/fluctuation in peripheral VF, has very limited usefulness

Answer 11

field-limits confrontations

Question 12

why are field-limits confrontations much less useful than count fingers

Answer 12

few VF defects affect peripheral VF limits only

Question 13

what can the red cap test (color confrontations) be useful in detecting?

Answer 13

very helpful in detecting mild central or centrocecal scotomas due to optic nerve disease

Question 14

what can the red cap test (color confrontations) in quadrant comparison specifically be useful in detecting?

Answer 14

VF loss from chiasmal compression

• pituitary adenoma
• craniopharyngloma

Question 15

pituitary adenoma would result in what defect on the red cap-quadrant comparison test?

Answer 15

superior temporal quadrants ou red cap is less red than superior nasal

Question 16

craniopharyngloma would result in what defect on the red cap quadrant comparison test?

Answer 16

in inferior temporal quandrants OU, red cap is less red than in inferior nasal

Question 17

face confrontations useful in detection of:

Answer 17

central scotomas, centrocecal scotomas, altitudinal hemanopsias and metamiorphosia

Question 18

tangent screen technique is useful in diagnosis of:

Answer 18

functional vision loss such as hysterical amblyopia

Question 19

SAP automated perimetry

Answer 19

standard automated perimetry, white-on-white perimetry

Question 20

3 alternative forms of perimetry list

Answer 20

1. SWAP
2. FDT
3. HEP

Question 21

SWAP alternative perimetry is:

Answer 21

short wavelength automated, blue stimulus on yellow background perimetry

Question 22

FDT alternative perimetry is:

in FDT and Matrix

Answer 22

frequency doubling testing

Question 23

HEP alternative perimetry is:

Answer 23

Heidelberg Edge Perimetry, “frequency defined form”

Question 24

2 problems in glaucoma detection with standard white-on-white perimetry (SAP)

Answer 24

1. does not detect glaucomatous change early in many cases
2. slow, fatiguing causes artifactuous (due to fatigue not disease) VF loss, so reliability and repeatability are often compromised

Question 25

differences in % of ganglion cell loss needed before earliest VF defect for goldman perimetry, automated threshold perimetry, and SWAP or FDT/Matrix

Answer 25

Goldman perimetry: 40-50%
Automated threshold perimetry: 30-40%
SWAP, FDT, Matrix: 20-40%

Question 26

3 reasons why standard white-on-white perimetry (SAP) doesn’t detect glaucomatous VF loss early

Answer 26

1. if all ganglion cells are damaged (overlap in receptive fields, mass response)
2. selective loss theory in glaucoma (certain types of ganglion cells may be damaged before others)
3. different damage in different eyes (or different types of glaucoma have unique patterns)

Question 27

2 recent strategies to detect glaucomatous field loss earlier

Answer 27

1. reduced redundancy strategy (test only a small % of all ganglion cells)
2. selective loss strategy (test primarily those ganglion cells that might be selectively damaged in early glaucoma)

Question 28

the 3 ganglion cell pathways

Answer 28

• parvocullar pathway
• koniocellular pathway
• magnocellular pathway

Question 29

80% of all retinal ganglion cells are in the ___ pathway

Answer 29

P-cell (Parvocellular)

Question 30

ganglion cell pathway that has thinner axons, slower conduction velocity, most responsive to high spatial frequency/ low temporal frequency

Answer 30

P parvocellular

Question 31

ganglion cell pathway that has a major role in color vision, spatial resolution, and form vision, and concentrated mostly in central VF

Answer 31

P parvocellular

Question 32

15% of all retinal ganglion cells are in the ___ pathway

Answer 32

M-cell (Magnoceullar)

Question 33

ganglion cell pathway that has thicker axons, faster conduction velocity, most responsive to low spatial frequencies/high temporal frequencies

Answer 33

M magnocellular

Question 34

ganglion cell pathway that has a major role in processing rapid locker and motion, and FDT/Matrix targets

Answer 34

M magnocellular

Question 35

K-cell pathway accounts for __% of all RGCs

Answer 35

5

Question 36

ganglion cell pathway that has a major role in b-y color opposite processing

Answer 36

K koniocellular

Question 37

ganglion cell pathway that can be tested selectively by testing with SWAP

Answer 37

K koniocellular