VF

Question 1

relative unit of sensitivity in perimetry

Answer 1

Db

Question 2

Unit of luminance/light density

Answer 2

Apostilb

*max luminance varies with VF

Question 3

Hill of vision

• What is it
• Varies with what
• Max sensitivity at

Answer 3

3D profile of pt’s retinal sensitivity

• Varies with age, response of patient and light adaptation.
• Fovea

Question 4

Isopter

Answer 4

Line of equal retinal sensitivity plotted on a VF

Horizontal slice of HOV

Question 5

Two types of scotoma

Answer 5

Absolute or relative

Question 6

Two types of depression

Answer 6

Localized or general (real or artifact)

Question 7

Causes of general depression

Answer 7

Could be due to media opacities, refractive error, ON disease, small pupil, poor pt attention, age

Question 8

Contraction/constriction

Answer 8

Peripheral boundaries are moved inward

Question 9

5 types of test paradigms

Answer 9

1. Kinetic field. Goldman and tangent screen.
2. Static field.
3. Threshold. Stimulus that has 50% probability of being detected.
4. Superthreshold. Screening. Presenting stimuli above expected threshold. Points noted as seen or not seen.
5. Threshold related. 4 threshold test points. Remaining points tested at 6dB above threshold. More sensitive than 4

Question 10

Visual field projection

Answer 10

VF on paper represents field as seen by the patient

Question 11

Increasing or decreasing test distance.

What stays the same, what changes

Answer 11

Angular dimension does not change.
Lateral dimension will change proportionally with distance. Tangent screen utilizes this to check for hysterical amblyopia/tubular fields.

Question 12

Damage to papillomacular fibers

Answer 12

Enter ON on the temporal side. Centrocecal defect.

Involves macula and blind spot.

Question 13

Damage to temporal fibers

Answer 13

Arcuate defect

Question 14

Damage to nasal fibers

Answer 14

Wedge defect

Question 15

Superior and inferior fiber defects

Answer 15

Defects do not cross midline

Question 16

Macular fibers initially run along which portion of ON

Answer 16

Outer

Question 17

Altitudinal defect

Answer 17

Anterior ON damage close to retina

Question 18

ON tract. The more posterior the damage

Answer 18

More likely it is to be congruous

Question 19

Optic radiation is located after the

Answer 19

LGN

Question 20

Pie in the sky defect

Answer 20

Damage to temporal/inferior/myers loop in optic radiation

Question 21

Pie on the floor defect

Answer 21

Damage to the parietal/superior loop in optic radiation

Question 22

Occipital cortex damage

Answer 22

Lesions here are highly congruous

Could exhibit macular sparring

Question 23

Frequency of seeing curve

Answer 23

Plots the percentage of time a stimulus is seen at a given intensity.
The gradient of the curve is a measure of the patient reliability. Steep is better.
Reliability increases with patient attention, previous test experience, additional auditory cues, multiple stimulus presentations.

Question 24

Sensitivity profile

Answer 24

Plots the change in retinal sensitivity with eccentricity. Varies with dark/light adaptation.

Photopic- steep
Mesoptic- flat
Scotopic- central depression

Affected by level of background illumination.
Pre adapted state of patient
Stimulus size

Question 25

Background illumination

Answer 25

Controls sensitivity profile and length of adaption of the patient.

Question 26

Adaptation time depends on

Answer 26

Background illumination Prior state of adaption Length of pre adaption period Retinal eccentricity (greater sensitivity potential take longer) -Local effect (ex bright fixation light will result in local area of reduction)

Question 27

Stimulus size - Due to ____ summation - Inverse relationship between size and ___ - Based on what law - Spatial summation increases with

Answer 27

- Spatial summation. - Between size and threshold. Small stimulus, complete inverse relationship. (Riccos law) with large stimuli, partial. - Riccos is luminance x area = constant - Spatial summation increases with eccentricity and dark adaption. (bigger fields in periphery)

Question 28

Blur can affect sensitivity due to increased spatial summation

Answer 28

True

Question 29

Goldman stimulus size ___ is normally used

Answer 29

III

Question 30

Stimulus duration - Due to ___ summation - Inverse relationship between duration and - Critical duration varies with - Saccadic reaction time

Answer 30

- Temporal. - Threshold up to critical duration according to Bloch. - Bloch: luminance x duration = constant - Size, background illumination and retinal eccentricity. - Saccadic reaction time is 250 ms

Question 31

Keep stimulus duration between __ and __ msec

Answer 31

100 and 250

Question 32

5 types of perimetry

Answer 32

Confrontation - Static or kinetic Ampler Tangent - Kinetic or static. Tubular field. Goldman- gold standard. Manual. Kinetic and static. Longer in duration than other forms. automated

Question 33

4 types of automated perimetry

Answer 33

Humphrey - projects stimuli in bowl. Must correct for test distance for presbyopes. Static. Octopus- Projects stimuli onto retina. Tests 30 degrees only. Only correct distance Rx. Static. Dicon- Kinetic/dynamic only. Has sounds. Frequency doubling tech (FDT)- Static.

Question 34

3 components of automated perimetry

Answer 34

1. LED vs projection stimuli. - LED cannot alter size or color. Silent. - Projection can alter size and color. Makes noise. 2. Fixation target - Humphrey, octopus and FDT all use static. - Dicon uses dynamic/kinetic 3. Fixation monitor using Heijl Krakau method. - K purkinje image alignment used for humphrey gaze tracking.

Question 35

Quantify defects test strategy

Answer 35

Missed points are ran at threshold level. All others are super

Question 36

Humphrey analyzer algorithms

Answer 36

1. Fast Pac. 40% less time than full threshold. 2. SITA standard. 50% less than full threshold. 3. SITA Fast. 50% faster than Fast pac 4. SWAP. Blue stimulus on yellow background. Early detection of glaucoma since glaucoma damages short wavelength fibers first.

Question 37

SWAP test - What is it for - Significant dB values - Requires what type of patient

Answer 37

Blue stimulus on yellow background. Early detection of glaucoma since glaucoma damages short wavelength fibers first. HOV drops more rapidly. 9db Centrally or greater than 9Db peripherally is significant. Requires young attentive patient with no lens opacities.

Question 38

Greater than what percentage indicates low patient reliability for Fixation loss False Positive False negative

Answer 38

more than 20 more than 33 more than 33

Question 39

High FN rate could indicate

Answer 39

Disease

Question 40

Short term fluctuation (SF) - Greater than what is considered high - What does it indicate if high - Could be early detection of

Answer 40

- Greater than 0.3 is high - Indicates variability of patient response. - Could be early indication of pathology

Question 41

4 types of reliability indicies

Answer 41

Fixation loss False Positive False negative Short term fluctuation (SF)

Question 42

Types of statistical analysis

Answer 42

Raw data Grey scale Probability plots Central reference level Defect depth plot Total deviation plot - Shows local and overall defects Pattern deviation plot- only shows local defects

Question 43

Types of global indicies

Answer 43

Mean deviation - elevation of depression of overall sensitivity. Normal is +/- 2 Pattern standard deviation: 0 to 2. High value indicates patient variability in responses. Short term fluctuation- Normal is less than 3. Response consistency. Corrected pattern standard deviation- Corrects for SF. Abnormal is p < 5%. Indicates field abnormalities. Can be fooled by advanced glaucoma !