Visual Fields Flashcards
If you have bi-temporal (opposite sides) visual field loss where is your lesion and what is the name of this visual field deficiency
Lesion at the chiasm and Heteronymous
What is a central scotoma caused by
inflammation of the optic disc or optic nerve
What visual field defect will you get from a complete lesion of the left optic radiation
right homonymous hemianopia
What did Leonardo DaVinci discover/realize
visual fields extend more than 90 degrees
Who discovered and assigned the blind spot to the optic nerve
Mariotte
What did Goldmann introduce
bowl perimeter
Who is the father of classic perimetry and the “island of vision…”
Traquair
on threshold visual field, what does a slip with no blind spot indicate
test is no good and should be repeated
Nasal fibers represent what visual field
temporal
What fibers cross at the chiasm
nasal fibers
what percentage of post-chiasmal fibers continue to the Lateral Geniculate Nucleus
80%
What fibers go to pre-tectal nucleus and what do they control
20% of the post-chiasmal fibers and they control the pupils
What visual field defect is present when a pt has right temporal field loss and left nasal field loss
right hemianopsia/homonymous loss
How many nerve fiber layers enter the Lateral Geniculate Nucleus
6 layers
Which layers are for moving stimuli
Layers 1 and 2 (magnocellular)
Which layers are for color, acuity, and fine detail
Layers 3, 4,5, and 6 (parvocellular)
Lateral Geniculate Nucleus is a relay station sending striations to what two areas
temporal and parietal lobes
Striations going to the temporal lobe travel through what area and what happens if there is a lesion here
Meyer’s loop, pt has pie in the sky (right or left homonymous superior quadrantanopia)
What is the working distance for static confrontational fields
50-60 cm (Rx off if low Rx)
What areas do you check with the kinetic finger counting fields
central 20-30 degrees, both sides of horizontal and vertical meridians
What other gross field test can you perform
Facial Amsler
Who should the Amsler Grid test be performed on
all patients 50 and older, all diabetics, patients with history of macular degeneration, patients on toxic medications, and patients with reduced acuities
What 6 questions do you ask when performing the Amsler Grid test
- can you see the center dot
- are there any squares missing
- can you see all 4 corners of the card
- can you see all 4 sides of the card
- are the lines straight and even
- are any of the lines wavy or distorted
How do you record a normal amsler grid result
Amsler OD: (-) scotoma (-) distortion
At what distance is the Amsler Grid test performed at and with or without Rx
30cm and with Rx
