visual field

visual pathway

1. optic nerve

2. optic chiasm

3. optic tract

4. LGN

5. optic radiations

6. visual cortex

parts of the optif nerve

1. intraocular part - optic nerve head

   1. pre laminar

   2. laminar

   3. post laminar

2. intraorbital part

   1. longest

3. intracanalicular part

4. inctracranial part

damage to the temporal papillomacular bundle may lead to a ___________ defect

temporal

what does an on vf defect look like

1. unilateral

2. asymmetric

3. horizontal respect expected due to horizontal raphe on the temporal retina

4. types

   1. nasal step

   2. arcuate

   3. bjerrum scotoma

   4. enlarged blind spot

   5. ceco central defect

   6. altiduinal defect

what can cause defects at chiasm

pituitary

lesions below the chiasm will have denser ______ defect

above

optic chiasm vf defect

vertical respect

if there is an APD it will be __________ to the VF defect

ipsilateral

optic tract vf defect

1. right optic tract lesion results in L homonymous hemianopia

   1. small left RAPD

   2. higher area of palor on L nerve

2. L optic tract lesion results in R homonymous hemianopia

   1. small Right RAPD

   2. higher area of pallor on the R optic nerve

3. vertical respect

what LGN layers are magno

1

2

what LGN layers are parvo

4-6

what LGN layers are contralateral

1

4

6

what LGN layers are ipsilateral

2

3

5

where does the optic pathway synapse

LGN

after this point we wont have an RAPD

LGN VF defect

vertical respect

rare

lesions in the parietal lobe cause ________ defects

inferior

PITS

lesions in the temporal lobe cause ____________ defect

superior

PITS

what respect do optic radiation vf defects have

vertical

when does macular sparing in the occipital lobe happen

ischemic event

there is dual blood supply to the macular region

how are the pars of the VF arranged in the occipital lobe

in the brain is more peripheral VF

the tip of the brain is most central

occipital lobe vf defects

1. the more dorsal the lesion the more central the VF defect

2. more ventral the lesion the more peripheral the VF defect

3. monocular temporal crescent possible on contralateral field due to unmatched nasal fibers on th emost ventral aspect of the occipital lobe

4. vertical respect

superior retinal fibers project to the _______ LGN

medial

superior retinal fibers synapse above the calcarine fissure on their way to the _________

cuneus

inferior retinal fibers project to _______ LGN

lateral

inferior retinal fibers eventuall synapse in the

lingual gyrus

whats campimetry

flat screen

what are campimetry methods

1. confrontation VF

2. Red target fields

3. amsler grid

4. tangent screen

whats perimetry

curved surface

1. kinetic

2. static

perimetry kinetic types

1. goldmann bowl perimetry

2. octopus

perimetry static tests

1. Humphrey VF

2. Medmont VF

3. Octopus

4. Frequency Doubling Technique

how does kinetic perimetry work

1. goes from non seeing (infrathreshold) to seeing (suprathreshold)

2. change the intensity/size

3. movement

how does static perimetry work

1. pre determined spots of testing

2. changes in intensity of the light in the pre determined spots

3. stationary

wheres the physiological VF blind spot

15 deg temporally and 1 degree inferior to fixation

6 degrees wide adn 8 degrees tall

whats our superior range of vision

60

whats our inferior range of vision

75

whats our temporal range of vision

100

whats our nasal range of vision

60

isopter

1. a line that connects points in a VF where a paerson can detecta specific light intensity and size

2. when the light intensity or size change this is considered a new isopter

3. this is important when it comes to billing

   1. 1 isopter VF - suprathreshold VF

      1. ptosis adn Estermann

   2. 2 isopter VF

      1. only done w manual perimetry

   3. 3+ isopter automated VF

      1. threshold VF fields

what is tangent screen good for

malingeres

goldmann powl perimetry target size

first digit - roman numeral (I-V)

indicates size of target

V is largest - 9 mm

every drop in roman numeral about halves the size

goldmann bowl perimetry brightness

combinatin of second and third digit

second digit = 1-4 = brihtness of stimuluts

• 4 is brightest

third digit = a-e = finer calibration of luminace

• e is brightest

whats the commonly uesd std for classification of visual disability goldmann perimetry isopter

III 4

how do you map on goldmann bowl

1. map at leat 3 isopters

2. V4e first

3. decrease isoptric value to map out every 10-20 degrees of the entire VF

4. for central 30 degrees a trial lens should be added

   1. bowl is 30 cm depth

5. blind spot is mappen manually btw 10-20 degrees on temporal aspect of field

6. arcuates adn 4 macular points are spot checked

7. scotomas are checked w larger isopters when found to determine density of scotoma, relative vs absolute

whats the 1st isopter for goldmann bowl

V4e

what do you add for central 30 degrees of Goldmann bowl

trial lens

whats the order of isopter

1. V4e

2. III4e

3. I4e

4. I4c

5. I3e

6. I3c

describe octopus 900 VF kinetic perimetry options

1. 1. automated Goldmann Bowl perimetry

   2. Manual goldmann bowl perimetry

Octopus 900 VF static perimetry

1. full field static perimetry possible

2. 24-2

3. 30-2

4. estermann

5. comparable to HVF

HVF describe

1. target appears for 200 ms, 30 cm away

2. predermined location on grid

3. trial lens

4. different options for

   1. testing patterns

   2. testing algorithms

   3. stimulus size

   4. stimulus color

what does the -2 mean on VF

1. second pattern to be devveloped

2. also differs fro where the stimuli are presented in comparison to the x and y axis

   1. -2 pattern —> stimuli on either side of axises

   2. -1 —> stimuli presented directly on the x and why axises

how many points for 30-2

76

how away are the 30-2 test points

6 degrees

whats the 30-2 more helpful in

non glaucoma neurological conditions

how many points no 24-2

54

how many degrees are 24-2 points apart

6

24 - 2 covers ____ nasal and _________ temporal, superior, and inferior

30 nasal

24 S, T, I

what was 24-2 created for

glaucoma

how many test poins for 10-2

68

how far apart are the 10-2 points

2 deg

1 deg from horizontal and vertical midline

what are 10-2 good for

plaquenel testing

central defects

does 10-2 include blind spot

naur

threshold

light seen 50% of time

supra threshold

stimuli that are above the trehsold and are visible greatere than 50% of the time

infra threshold

stimuli taht are below the threshold and are visible less than 50% of the timer

threshold test options

1. full threshold

2. FASTPAC

3. SITA

whats the difference btw threshol dand suprathreshold testing

1. threshold

   1. an attempt is made to measure the intensity of the dimmest stimulus whihc can be detected 50% of the time in each test spot

   2. SITA

2. supra threshold

   1. intesnity of predetermined brightmess is shown at each test location

   2. the precise sensitivity of each test location is not known

   3. just trying to make sure the light can be seen in each spot

SITA meaning and fxn

Swedish Interactive Threshold Algorithm

continuosuly estimates what the expected threshold of a point would be

• reduces time

• dec pt fatigue

• increases reliability

SITA STd facts

1. very high accuracy

2. relaticely short test time (4-8 mins per eye)

SITA FAST facts

1. very fast threshodl test (2-6 min per eye)

2. sensitibity similiar to threshold testing

3. less tolerant of pt mistakes

SITA Faster facts

1. In new HVF3

2. 24-2 in 2 mins or less

   1. removes dead time of test

3. no FL or FN errors —> only false pos and gaze tracking

4. comes in 24-2 and 24-2C

   1. 24-2C has 10 points from 10-2

24-2C testing pattern

1. new

2. includes the same points as the 24-2 but includes 10 poitns from 10-2

3. available in SITA std and SITA faster

HVF SWAP

1. short wavelength automated perimetry

2. Blue - yellow perimetry

3. blue goldmann size V stimuli

4. though to detect glaucomatous loss earlier than white on white perimetry

5. limitations

   1. high test - retest variability

   2. media opacity

   3. prolonged test time

estermann test

1. suprathreshold test - can you see it or not

2. can be monocular or binocular

3. yes or no test

4. onle one brightness/zise tested

5. used for driver liscences

36 ptosis

1. suprathreshold test

2. yes or no

3. only one brightness/ stize test

4. peformed taped and untaped

5. used to determine medical necessity of ptosis

6. only tests superior field

FDT facts

1. ues magnocellular pathway

   1. low spatial frequency and high temporal freq

2. studies show high sensitivity and specificity for EARLY glaucoma

3. relies on detection of flickering grating

4. cheap desk mounted, sensitive

5. no reliable progression analysis

whats an idea fixatino loss

15% or less

what size (I-V) is std for VF

III

what should you do for pt w poor VA

inc stimulus suze

size V for pt w VA <20/200

interpretting a VF

1. blind spots hould be 0

describe threshold values on VF

1. gives you raw decibel (dB) values

   1. refers to stimulus intensity

   2. 0dB = max brightness

   3. 51dB= min brigntess

what does a higher # on a VF mean

less intense the light = MORE sensitive

total deviation plots

1. identigies test poitns that are outsdie normal limits

2. compares to age corrected norms

3. stat sign w darkness of pt

pattern deviation plot

1. most useful for interpretation

2. identifies sensitivity losses after an adjustment has been made

3. uses same symbols as total devition plot

total deviation vs pattern deviation

1. TD = any test points that are outside age matched norms

   1. affected by media opacity

   2. for the “whole eye”

2. PD = any test points that are abnormal from the TD plot but adjusted for a generalized depression

   1. ex: cataract, miosis, wrong TL

Glaucoma hemifield test

1. gives a classification for 30-2 and 24-2 results based on patterns commonly seen in glaucoma

2. 5 categories

   1. outside normal limmits

   2. borderling

   3. general depression

   4. abnormally high sensitivity

   5. wi normal limits

3. compares sup and inf hemifields

   1. bc glaucoma affects the hemifields and follows the horizontal

visual field index

1. normal = 100%

2. blind = 0%

3. more correspondence to ganglion cell loss vs mean deviation

4. less affected by cataract

mean deviation

1. on average, how much whole field departs from age norms

2. metric for rate of change over time

3. 0dB in normal filds

4. -35 dB in extreme VF loss

PSD - pattern standarad deviation

1. irregularities in field loss due to localized defects

2. should be small and close to 0

3. nonlinear change vs VFI and MD

MD number

1. takes the total deviation numerical and probability plots and averages them to give a numerical value

   1. + MD for someone who sees better than age matched norms

      1. can see dimmer targets than expected

   2. - MD for someone who can see worse than age matched norms

      1. need to turn brightness higher than expected

PSD number

1. takes the pattern deviation numerical and probability plots and provides a numberical value

2. quantifies the irregularity in the VF

3. will be low for normal or really bad VF

4. will be highest in focal and deep defects

pupil testing expected from VF calc

(MD of worse VF - MD of better VF) / 10 = log unit APD in eye w worse VF defect

how do we meausre an APD clinically

neutral density filter

lines up gaze tracker

gaze error

lines down gaze tracker

blink

whats the ADD for VF if dilated

+3.00

1.00 D of blur can create ________ of depression

1dB

how much cyl can you account for in SE for TF for VF

<1.25

<1/4 of sphere

age appropriate ADD formula

(AGE - 35)/10

works up to 60

what are the steps in analyzing a VF

1. make sure the right test was done

2. reliability

3. probabliity plots

4. name pattern of loss

5. reaffirm diagnosis

what does a white scotoma mean

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