MIDTERM Flashcards
It is the line that connects visual thresholds
Isopter
It uses a black-felt background
Tangent screen
It has a semi-black stitching
Tangent screen
T/F
Test target is the white button at the center
T
T/F
Test object is the white button at the center of the screen
F- objects placed at the tip of wand
Advantages of tangent screen
More sensitive than confrontation test or FCVF
Provides accurate charting of central and paracentral VF defects
Useful in testing patient with hysterical fields
If you are checking the right eye, the location of the blindspot is at
Right
If you are checking the left eye, the location of the blindspot is at
Left
Purpose of tangent screen
To assess the integrity of the central 30 degrees (radius) of the patient’s field of vision
Equipment use in tangent screen
• Tangent screen
• Thirty to fifty 1 to 2 mm diameter nonglossy, short black pins
• Test target (1, 2, 3 or 5 mm diameter white test object attached to a black non glossy wand)
• Eye patch
• Tangent screen should be a flat, non reflective, black screen usually made of cloth, with a small white object attached to the center of the screen to serve as a fixation target. On most tangent screens, the fixation target is surrounded by concentric circles, stitched into the surface of the screen at intervals of 5 degrees when viewed from 1 meter
Extent of Binocular visual field
180 degrees
Extent of common bino field
120
Extent of monocular field
150
Extent of temporal crescent
30 degrees
Extent of VF nasally
60
Extent of VF superiorly
55-60
Extent of VF inferiorly
70
Extent of VF temporally
90-100
The shape of a monocular VF
Horizontal oval
Eye position of relative VF
Fixed
Head position of relative VF
Steady
Paraorbital structures of relative VF
Limited
Eye position of absolute VF
Fixed
Head position of absolute VF
Moving
Paraorbital structures of absolute VF
Not limited to
Highest area of sensitivity of an island
Peak of an island
Highest area of sensitivity of hill of vision
Peak of the hill
Blind area of an islamd
Bottomless pit
Blind area of hill of vision
Beyond the borders of the hill
Presentation of stimulus/target of known size and intensity outside the borders of VF or within blindspot
Kinetic peri
It is the science of measuring visual field
Perimetry
Target is being moved. From the point of invisibility to point of visibility
Kinetic peri
is useful to determine borders of larger or deeper visual field defects
Kinetic
s better at detecting small scotomas (e.g. early glaucomatous VF change)
Static peri
In TS, the center refers to the peak of the island/hill or also called the
Point of fixation
T/F
In TS, when you move the wand away from the center, what happens in the island/hill is that it also goes down. So when it goes down away from the peak, px’s sensitivity to the target also decreases.
T
T/F
In TS, when you place the wand outside the borders/extent, px cannot detect it because it is already beyond his visual field
Test target of tangent
White button
To screen for previously unnoted visual field defects.
Confrontation test
Should be arranged concentrically
Interlacing
more on the temporal than nasal with soft isometric lines with smooth progression
Accordion field
The technique is generally effective only for substantial field losses.
FCVF
Colorless → gray →
Blue
Colorless → yellow → _______ → red
Terraccotta
lines are bent away
Macropsia
lines are bent towards each other
Micropsia
Appearance: 2 diagonal linesintersect at center of the grid
Chart 2
Used for patient with a central scotoma that cannot fixate the central dot
Chart 2
Appearance: similar to the first but squares are red
Chart 3
Useful for patients with suspected central or cecocentral scotomas
Chart 3
common in cases of patients who were held captive in war and are malnourished.
Nutritional ambly
Appearance: Composed of smallwhite dots (no lines) on a black background
Chart 4
Purpose: Indicated for patients with one or more paracentral scotoma making it easier to delineate the affected areas.
Chart 4
Appearance: Chart consists of 20white horizontal lines evenly spaced by 5 mm on a black background
Chart 5
to facilitate the identification of “oriented” metamorphopsia which primarily affects lines going in one direction
Chart 5
Appearance
- Similar to 5th chart except its made of black lines on a white background
Chart 6
Chart is meant to facilitate the observation of metamorphopsia along the reading area
Chart 6
Smaller grid is intended to facilitate detection of subtle visual disturbances in the macular area
Chart 7
Useful for high myopic patients (who held at the punctum remotum of the uncorrected eye)
Chart 7
