Lecture 13: Visual Pathways (p1-31)

Question 1

The risk factors for developing primary angle-closure glaucoma are:

Answer 1

• increasing age
• increasing lens thickness
• female gender
• hyperopia
• ethnicity (Eskimo, East Asian)

Question 2

Acute angle-closure glaucoma is characterized by

Answer 2

rapid increase in IOP

Question 3

A patient suffering from acute angle closure will usually present with:

Answer 3

1. severe pain, tearing, photophobia
2. blurry vision, halos around lights
3. corneal edema, a fixed mid-dilated pupil
4. IOP of 50-70 mmHg.

Question 4

Human visual system is comprised of the (8):

Answer 4

1. Retina
2. optic nerves
3. optic chiasm
4. optic tracts
5. lateral geniculate nuclei
6. geniculostriate radiations
7. striate (visual) cortex
8. visual association areas & related interhemispheral connections.

Question 5

T/F: vision is not the dominant sense

Answer 5

F: Vision may be considered the dominant sense

Question 6

why is vision considered to be the dominant sense?

Answer 6

the number of axons devoted to the optic nerve alone is 1 million to 2.2 million vs. acoustic nerve that has ~31,000

Question 7

what are the retinal cells?

Answer 7

1. PR
2. horizontal
3. bipolar
4. amacrine
5. ganglion

Question 8

A lesion in the retina will cause a field defect that is

Answer 8

similar

in shape to the lesion and is in the corresponding location in the field

Question 9

travels contralateral or ipsilateral: inferior nasal fibers

Answer 9

contralateral

Question 10

travels contralateral or ipsilateral: superior nasal fibers

Answer 10

contralateral

Question 11

travels contralateral or ipsilateral: superior temporal

Answer 11

ipsilateral

Question 12

travels contralateral or ipsilateral: inferior temporal fibers

Answer 12

ipsilateral

Question 13

central visual pathway

Answer 13

1. retina
2. optic nerve
3. optic chiasm
4. optic tract
5. LGN
6. optic radiation
7. visual cortex

Question 14

central visual pathway

Answer 14

1. retina
2. optic nerve
3. optic chiasm
4. optic tract
5. LGN
6. optic radiation
7. visual cortex

Question 15

lesion of left optic nerve

Answer 15

total blindness in left eye (ipsilateral blindness)

Question 16

lesion on the left optic tract

Answer 16

contralateral hemianopia (both of the ride sides of the circles are dark)

Question 17

lesion at chiasm

Answer 17

bitemporal hemianopia

Question 18

optic chiasm compression

Answer 18

binasal hemianopia

Question 19

a complete transection of the right optic nerve fiber will most likely result in

Answer 19

right homonymous hemianopia

Question 20

A CT scan showing pituitary adenoma will most likely

result in

Answer 20

binasal hemianopia

Question 21

Complete interruption of left optic nerve

Answer 21

resulting in

complete loss of visual field for left eye.

Question 22

Interruption in midline of optic chiasm

Answer 22

resulting in

bitemporal hemianopia.

Question 23

Interruption in right optic nerve at junction with chiasm,

Answer 23

resulting in complete loss of visual field for right eye and
superior temporal loss in field for left eye (due to anterior
knees).

Question 24

Interruption in left optic tract,

Answer 24

causing incongruent

right homonymous hemianopia.

Question 25

Complete interruption in

right optic tract, lateral geniculate nucleus, or optic radiations,

Answer 25

resulting in total left homonymous hemianopia.

Question 26

Interruption in left optic radiations involving Meyer’s loop,

Answer 26

causing incongruent right homonymous hemianopia.

Question 27

Interruption in optic radiations in left parietal lobe,

Answer 27

causing incongruent right homonymous hemianopia.

Question 28

Interruption of all left optic radiations

Answer 28

resulting in total right homonymous hemianopia.

Question 29

Interruption of fibers in left anterior striate cortex

Answer 29

resulting in right homonymous hemianopia with macular sparing.

Question 30

Interruption of fibers in right striate cortex

Answer 30

resulting in left homonymous hemianopia with macular and temporal crescent sparing.

Question 31

Interruption of fibers in right posterior striate

cortex

Answer 31

resulting in left macular homonymous hemianopia.

Question 32

, Interruption of fibers in right anterior striate cortex

Answer 32

resulting in left temporal crescent loss.