Visual Field Defects

Question 1

Macula

Answer 1

Central retinal area where cones predominate

Question 2

Fovea

Answer 2

Central area of the macula where only cones are found and is specialized for the highest visual acuity

Question 3

An image in the right field of vision will be projected where

Answer 3

Onto the nasal half of the right retina and the temporal half of the left retina

Question 4

Nasal fibers project how

Answer 4

Contralaterally due to crossing at the chiasm

Question 5

Temporal fibers project how

Answer 5

Ipsilaterally

Question 6

How does the brain process visual information

Answer 6

It processes information from he contralateral 1/2 or hemi-field of vision.

Question 7

Axons of RGC’s representing the RIGHT half of the retina terminate where

Answer 7

The right lateral geniculate nucleus which then projects to the right visual cortex and represents the LEFT visua hemifield

Same for the left eye

Question 8

Axons of RGC’s representing the superior right RETINAL quadrant project where

Answer 8

to the MEDIAL portion of the RIGHT lateral geniculate nucleus, which then projects to the ANTERIOR 2/3 of the cuneate gyrus of the RIGHT calcarine cortex and represents the LOWER LEFT quadrant of vision

Question 9

Axons of RGC’s representing the lower right retinal quadrant project where

Answer 9

To the lateral portion of the right lateral geniculate nucleus to the anterior 2/3 of the right lingual gyrus of area 17 and represents the upper left field of vision

Question 10

Left homonymous hemianopsia

Answer 10

A visual defect in both left halves of the visual field of each eye. Nasal visual field of the right eye and temporal vision field of the left

Question 11

A lesion in the right optic nerve results in what

Answer 11

Blindness of the right eye

Question 12

What can cause a biteporal hemianopsia

Answer 12

Compression of the optic chiasm, usually due to a pituitary tumor or aneurysm in the circle of willis

Question 13

A lesion if the right temporal retinal fibers result in what

and what is a common cause of this

Answer 13

(They project tot he ipsilateral LGN) it causes blindness in the nasal visual field of the right eye

Common cause is an aneurysm of the right internal carotid

Question 14

A lesion in the right optic tract will result in what

Answer 14

A left homonymous hemianopsia. The left visual field of each eye will be lost because this will involve the left eye nasal and right eye temporal

Question 15

A lesion of the right geniculo-calcarine tract will result in what

Answer 15

(This is after both parietal and temporal coursing axons have joined in the internal capsule). A lesion in the right visual cortex (area 17) will result in a left homonymous hemianopsia

Question 16

What vessels supply the optic radiations

Answer 16

The middle cerebral artery

Question 17

Meyers loop represents what? And a lesion of this will result in what

Answer 17

It represents fibers coming out of the lateral geniculate that represent the inferior right retinal quadrant. The patient will show a deficit in the left upper quadrant of vision and can result from a lesion in the temporal lobe

Question 18

What vasculature supplies area 17

Answer 18

The posterior cerebral artery

Question 19

With infarction of the posterior cerebral artery involving area 17 will result in what

Right side

Answer 19

Contralateral (left) homonymous hemianopsia with macular sparing because the middle cerebral artery also supplies the macular area of the visual cortex