Coa Visual Field Defect

Front 1

Damage to the optic nerve chiasm may result in what type of defect because it is the crossing fibers that are the most vulnerable to damage. It is the nerve fibers from the nasal half of each eye that cross at the chiasm, affecting the temporal visual field areas. Chiasmal damage is often caused by pituitary gland enlargement.

Back 1

Bitemporal defect

Front 2

What does hemianopsia mean?

Back 2

is the term for a defect affecting half of the eye.

Front 3

If a defect is Homonymous this means what?

Back 3

affects the same half of the field in each eye) field defects that are incomplete or incongruous give the ophthalmologist clues as to the location of the damage in the nerve pathwa

Front 4

Defects that are identified as inferior or superior are sometimes referred to as?

Back 4

Alitudinal defects

Front 5

A defect that affects the right side of both fields and it is a complete loss of half the visual field. Such a defect is often caused by a stroke.

Back 5

homonymous hemianopsia

Front 6

What are the types of visual field testing?

Back 6

Kinetic and static perimetry

Front 7

If there is a general reduction in overall sensitivity of the visual field, it is called?

Back 7

Depression or constriction, It is called a depression if the method of measurement is static perimetry. It is called a constriction if the method of measurement is kinetic perimetry.

Front 8

Static perimetry measures?

Back 8

the sensitivity of the retina in a grid of individual points. The threshold sensitivity is measured at each point and the sensitivity measured is given a value in decibels (dBs). A normal threshold field in the central 30 degrees has dB values around 30, as pictured below.

Front 9

A visual field defect that is contained in an area within the boundaries of the overall visual field is termed a?

Back 9

Scotoma

Front 10

marks an area of retina that is not sensitive to relatively dim stimuli, but is sensitive to brighter stimuli is a?

Back 10

Shallow scotoma

Front 11

refers to a defective area of retina that cannot see any but the brightest stimuli is a?

Back 11

Deep scotoma

Front 12

an area that cannot see any of the stimuli, not even the brightest is a?

Back 12

Absolute scotoma

Front 13

The ???? tests a grid of points on the retina with stimuli of varying brightness levels. For each point the perimeter determines the dimmest light that can be seen at least 50% of the time. This is the threshold stimulus value for that point.

Back 13

Static perimetry

Front 14

centro-cecal scotoma is what type of defect?

Back 14

meaning it extends from the blind spot toward the central vision. This type of scotoma is caused by an optic nerve lesion.

Front 15

What type of perimetry testing involves the presentation of a moving stimulus of a particular size and intensity. The stimulus is moved from a non-seeing area toward the fixation point until it is seen.

Back 15

Kinetic

Front 16

Amsler grid test how many degrees?

Back 16

20 degrees

Front 17

Amsler grid test how many degrees?

Back 17

20 degrees

Front 18

What is a artifactual field loss?

Back 18

A defect in a visual field test that is due to a "mechanical" obstruction and is not due to decrease retinal sensitivity. Ex rim of trial frame, small pupil, ptosis.

Front 19

Blind spot monitor

Back 19

The event is recorded on the screen as a "fixation loss". Fixation losses are presented as a fraction with the numerator representing the number of losses and the denominator representing the number of presentations. For example: 2/7 indicates that fixation has been tested 7 times and there were 2 fixation losses.

Front 20

False positive errors

Back 20

This is another reliability indicator. This indicates that the patient is responding when no stimulus has been presented. The patient is "trigger happy". Results are presented as a fraction. A patient with high false positives should be instructed to respond only when a stimulus is seen and that she will not be able to see all the stimuli that are presented.

Front 21

False negative errors

Back 21

This is a reliability catch trial that indicates the patient is not responding to stimuli that were previously seen. This likely indicates that the patient is becoming fatigued or is inattentive and should be re-instructed and encouraged. The pause control can be used to give the patient a rest.

Front 22

Gaze tracking

Back 22

Gaze tracking is an electronic system that graphs the movement of the patient’s eye during the test. Gaze Tracking can be used without the Blind Spot Monitor. Upward markings on the line indicate deviations from the fixation point. The higher the mark is, the greater the deviation was. Blinks are indicated by downward markings on the line.

Front 23

VF trial lens parameters

Back 23

The full cylinder correction is used for cylinder powers 1.50 D and above.Under age 30, no add

Age 30 to 39, add +1.00

Age 40 to 44, add +1.50

Age 45 to 49, add +2.00

Age 50 to 54, add +2.50

Age 55 to 59, add +3.00

Age 60 and up, add +3.25

Example: For a 40 year old, +1.00+1.50X90 becomes +2.50+1.50X90.