visual field defects? where is the pathology?

Question 1

how do you instruct your patient ?

Answer 1

> This test will test all the area you can see with each eye
I want you to always look straight ahead at the fixation light in the centre ( show them)
other lights will now flash in different places. Every time you see a light press your button
You will not see all the lights
the most important thing to remember is to always keep watching the fixating light in the centre

Question 2

How to improve accuracy with your patient?

Answer 2

: ensure they are comfortable

• neck/ head position
• coat on or off

: explain how long it will take
-xx no of minutes

: patient can cause pause the test on a humphrey

Question 3

define visual field defect?

Answer 3

A visual field defect is defined as a departure from the topography of the hill of vision from normal limits

Question 4

why is it important to accurately describe type of visual field defect?

Answer 4

helps to determine the type of pathology

Helps to monitor the condition

Question 5

what is contraction of visual field?

Answer 5

defect starts from peripheral to inside

Question 6

what is depression or diffuse visual field loss?

Answer 6

a generalised reduction in the height of the hill of vision

Question 7

what is localised defect?

Answer 7

small area of defect

Question 8

what are defects called in visual fields?

Answer 8

Scotoma

Question 9

How can Scotoma be classified?

Answer 9

Area of vision loss 
margins 
shape of defect 
central  visual field 
baring of the blind spot

Question 10

what type of scotomas with area vision loss do you get?

Answer 10

A. Absolute

B. Relative

Question 11

what does absolute defect mean?

Answer 11

can see
can see
cannot see anything

Question 12

What does relative defect mean ?

Answer 12

Can see , can see little,
cant see much
cannot see at all

Question 13

what type of scotoma margins do you get?

Answer 13

A. Steep

B. Sloping

Question 14

what does steep margins of scotoma look like?

Answer 14

from normal to not seeing nothing

Question 15

What does sloping margins of scotoma look like?

Answer 15

from normal to little bit less to nothing at all seen

Question 16

what type of shape defect to you get?

Answer 16

Hemianopia 
Altitudinal Hemianopia
Macula sparing 
Macula splitting 
quadrantanopia

Question 17

what does hemianopia look like?

Answer 17

Half of visual field not seen

Question 18

What does altitudinal hemianopia look like?

Answer 18

superior or inferior loss of visual field

Question 19

What does macula sparing defect look like?

Answer 19

visual field defect but macula is spared

Question 20

What does macula splitting defect look like?

Answer 20

Half of the macula has defect ( macula split in half)

Question 21

what does quadrantanopia defect look like?

Answer 21

a quadrant of the visual field cannot be seen

Question 22

what type of central visual field are there?

Answer 22

Central scotoma 
Pericentral Scotoma 
Paracentral Scotoma 
Centrocecal Scotoma 
Nasal step
Arcuate scotoma 
Ring scotoma

Question 23

What is central scotoma?

Answer 23

scotoma in the centre of visual field effecting the fixation point on the fovea

Question 24

What is pericentral Scotoma?

Answer 24

ring of defect surrounds the fixation point fovea but does not effect the fovea

Question 25

What is paracentral scotoma?

Answer 25

Adjacent to fixation point fovea not surrounding it

Question 26

What is centrocecal scotoma?

Answer 26

Extends from fixation point to blind spot

Question 27

what is baring of the blind spot?

Answer 27

defect leaves the blind spot out

Question 28

what is nasal step scotoma?

Answer 28

classic glaucoma defect that 1st effects nasal side and will not cross the horizontal midline

Question 29

what is arcuate scotoma?

Answer 29

defect that arcs around from the blind spot

Question 30

What is ring scotoma?

Answer 30

Defect ring around the visual field

Question 31

what does homonymous hemianopia mean?

Answer 31

Half of the same side of visual field loss

Question 32

What does Bi temporal hemianopia mean?

Answer 32

Half of temporal side of each eye visual field loss

Question 33

What types does Homonymous hemianopia are there?

Answer 33

>Partial >Complete >Macula sparing

Question 34

What is partial hemianopia?

Answer 34

defect does not come to midline

Question 35

what does complete hemianopia mean?

Answer 35

defect comes all the way up to midline

Question 36

What does the macula sparing hemianopia mean?

Answer 36

half of visual field lost but macula is spared

Question 37

What is bi nasal hemianopia?

Answer 37

Both nasal half of visual field has been lost

Question 38

what is congruous defect?

Answer 38

same shape and size defect with symmetry in both eyes

Question 39

what is incongruous defect?

Answer 39

Defect that is not same size, shape or symmetry in both eyes

Question 40

Define localisation?

Answer 40

Knowledge of the arrangement of the nerve fibres in the visual pathway will enable you to localise the visual field defect

Question 41

What are the superior Temporal Fibres projected by in visual field?

Answer 41

superior temporal fibres project in inferior nasal visual field

Question 42

What are the superior Nasal Fibres projected by in visual field?

Answer 42

superior nasal fibres projected in the inferior temporal visual field

Question 43

What are the inferior Temporal Fibres projected by in visual field?

Answer 43

inferior temporal fibres projected in the superior nasal visual field

Question 44

What are the Inferior Nasal Fibres projected by in visual field?

Answer 44

Inferior nasal fibres projected in the superior temporal fibres

Question 45

What is nasal step?

Answer 45

the Fibres at the rim are the most crowded at the disc providing less structural and vascular support and are the most likely to become damaged in glaucoma fibres from inferior rim supply the inferior temporal retina damage to this area corresponds to superior nasal visual field defect. The areas supplied by the fibres corresponds to the nasal step and do not cross the horizontal raphe

Question 46

What are the rules for visual field assessment?

Answer 46

Retinal lesions can be : unilateral or bilatera often asymmetrical between eyes do not respect the verticle midline

Question 47

what do macular fibres do?

Answer 47

Macular fibres cross

Question 48

What do nasal fibres do?

Answer 48

Nasal fibres cross

Question 49

What do temporal fibres do?

Answer 49

Temporal fibres uncrossed

Question 50

what does unilateral field defect involve?

Answer 50

involves damage to anterior to the chiasm

Question 51

what does a field which respects the vertical meridian suggest?

Answer 51

chiasmal or posterior to chaism damage

Question 52

what do you get if damage is at the chiasm?

Answer 52

you get heteronymous defect

Question 53

what do you get if the damage is before chiasm?

Answer 53

You get anterior unilateral defect

Question 54

What do you get if the damage is after the chaism?

Answer 54

You get field defect that starts to respect vertical midline

Question 55

What type of defect do you get with post chiasm?

Answer 55

Homonymous defect

Question 56

what do you get with chiasmal defect?

Answer 56

Heteronymous

Question 57

If damage is above the inion?

Answer 57

You get scotoma in inferior Visual Field

Question 58

If the damage is below the inion?

Answer 58

You get scotoma in the superior Visual Field

Question 59

How much doe the V1 relate to the macula?

Answer 59

60%

Question 60

If pathology is in the left cerebral hemisphere?

Answer 60

The scotoma was on the right

Question 61

If the pathology is in the right cerebral hemisphere?

Answer 61

The scotoma was on the left

Question 62

Where do you get incongruent ?

Answer 62

incongruent optic tract

Question 63

Where do you get congruent?

Answer 63

Congruent towards occipital lobe

Question 64

what happens to anterior lesion?

Answer 64

spares the macula

Question 65

what does unilateral field loss suggest?

Answer 65

Unilateral field loss not likely to be neurological ( anterior to the chiasm )

Question 66

What does bilateral defect suggest?

Answer 66

post chiasm and respects the midline

Question 67

Does the field loss respect the vertical meridian?

Answer 67

Suggests chiasmal or retrochiasmal

Question 68

what factors do you look at in glaucoma defects?

Answer 68

Paracentral scotomas Enlargement of the blind spot Nasal step Arcuate scotomas