prefi oral Flashcards
Purpose
To screen for acquired or hereditary color vision defects.
color vision test
These clinical screening tests are particularly significant for the assessment of macular cone and optic nerve function.
color vision
equipment for color vision (3)
-Occluder.
-Lamp of the correct color temperature (Illuminant Source C) or a pair of C-daylight glasses for the patient to wear during testing.
-Test book for color vision testing
color vision test book samples
PIP: pseudoisochromatic plates
HRR: hardy rand rittler (edition 4)
recommended for screening since it has plates to screen for protan, deutan, tritan, and tetartan defects, making other color vision screening tests obsolete since they only screen for protan and deutan defects.
hardy rand rittler
Hardy-Rand-Rittler (HRR) test, Edition 4, is recommended for screening since it has plates to screen for ___ (4) making other color vision screening tests obsolete since they only screen for protan and deutan defects.
protan defects
deutan defects
tritan defects
tetartan defects
other color vision plates are obsolete because:
they only screen for protan and deutan defects. the HR test is available in both adult and pediatric versions.
Setup
The patient wears his____
The patient holds the___
The examiner holds the test book______ or the test book is placed on the easel of a daylight illuminator stand
Habitual correction for near
Occluder
75 cm from the patient
color vision procedure:
Step-by-Step Procedure
1. Instruct the patient to occlude his left eye to test his right eye. It is essential to test color vision monocularly so that the two eyes can be compared to one another.
2. Observe the patient to make sure that only one eye can see the test plates.
3. Turn the pages one at a time at a rate of one every 3 seconds, asking the patient to identify the figure and the location of the figure on each page. To prevent the patient from touching the figures, give the patient the brush that comes with the test book to show the examiner where on the page he sees the figures.
4. Instruct the patient to occlude his right eye and repeat steps 2 and 3 to test the left eye.
5. Use plates 5 through 10 in the HRR #4 test for screening. Plates 5 and 6 test for blue-yellow defects and plates 7 through 10 test for red-green defects. If the patient misses plate 5 or 6, he has a blue-yellow defect and plate 21 through 24 should now be tested. If the patient misses any of the plates 7 through 10, he has a red- green color defect and plates 11 through 20 should now be tested. If the patient misses plates in both sections, 5-6 and 7-10, then all remaining plates (11-24) should be tested.
recording for color vision
• For each eye, write the number of correctly identified plates, a slash mark, and then the number of plates tested (ie, a fraction) when a screening test is done. In the HR #4 test, the first four plates are for demonstration and are not scored. Plates 5 through 10 are screening plates.
Plates 11 through 24 are used to diagnose the type of defect and the extent of the defect. Use the recording sheet that comes with the HRR #4 test when plates 11 through 24 are used.
Record the name of test used.
Approximately ____ of the general population will have congenital color vision anomalies, most of these patients are ___.
In these patients, the color vision in each eye is usually the same and is most often a protan or deutan defect. These defects remain stable over time.
In patients with acquired color vision anomalies due to ocular disease, the two eyes are often different from one another.
8%
males
Expected Findings color vision
Each PIP test booklet comes with instructions. These should be read to ascertain what is considered normal for the particular test. In some tests it is normal for the patient to make some mistakes.
Purpose
To assess the integrity of the visual feld corresponding to the macular region of the retina.
amsler grid
An Amsler grid should be performed whenever_____ is a possible diagnosis (eg, when the patient’s best-corrected VA is reduced, when the patient has an acquired color vision anomaly, or when the macula has any unusual appearance).
If only one eye is affected, both eyes should nevertheless be tested. Some authorities include Amsler grid testing among the routine entrance tests, particularly for_____
macular disease
elderly patients.
Equipment for amsler grid (3)
Amsler grid book.
Occluder.
Illumination source.
Setup
Te patient wears his best near correction and holds the occluder.
Te examiner holds chart #1 at a distance of 30cm from the patient under bright illumination.
amsler grid test
amsler geid procedure
- Have the patient occlude his left eye, unless one eye sees much better than the other. In that case, test the better seeing eye frst. T is will enhance the patient’s understanding and thus the reliability of his responses to the test.
2. Say to the patient, “Look at the center white dot. Can vou see it? T roughout this test you must continue to look at the white dot, while I ask you some questions about this drawing” If the patient cannot see the white dot, use chart #2. - Say to the patient, “While continuing to look at the white dot and without moving your eves”.
”Can you see the four corners?
”Notice the lines. Are any of them missing pieces? Do any have holes in them? If so, where?”
’Are all the lines straight? Are any wavy, and if so, where?”
”Are all the little squares the same size? If some are larger or smaller, which ones?”
4. Note the patient’s response to each of the above questions.
5. T roughout the test watch the patient. Make sure that the nontested eye remains occluded and that the patient maintains fxation on the white dot. T roughout the test maintain the testing distance at 30 cm.
6. Repeat steps 2 through 5
Recording amsler grid tes
If there are no problems, record “______” and the___, followed by____, which means ____.?
amsler
eye tested
WNL
within normal limits
amsler grid test
If there is a problem, record the___, the____, and its___ on the grid.
If there are problems, attempt to___ what the patient sees or ____on an Amsler recording chart (see Figure 5-39).
It is understood that plate #1 was used unless otherwise noted. If another plate was used, it must be specified.
eye
nature of the problem
location
draw
have the patient draw what he sees
Purpose
To assess the integrity of the central 30° (radius) of the patient’s feld of vision.
tangent screen
Recording for tangent screen test
Mark the locations of each black pin on the tangent screen by putting small Xs on a standard tangent screen recording diagram and connect with straight lines.
Cross-hatch areas of nonseeing, including the blind spot.
a flat, nonreflective, black screen, usually made of cloth, with a small white object attached to the center of the screen to serve as a ixation target. On most tangent screens, the fxation target is surrounded by concentric circles, stitched into the surface of the screen at intervals of 5° when viewed from 1 meter.
Tangent screen
tangent screen
flat, nonreflective, black screen, usually made of cloth, with a small white object attached to the center of the screen to serve as a ixation target.
On most tangent screens, the fxation target is surrounded by____, stitched into the surface of the screen at intervals of___
concentric circles
5° when viewed from 1 meter.
equipment for tangent screen
tangent screen
30-50 1.0-2.0mm diameter non-glossy short black pins.
test target 1.0,2.0,3.0,5.0mm white test object attached to a nonglossy black wand
eye patch
Setup tangent screen
The tangent screen should be moderately and evenly illuminated (standard illumination is _____). The light___ directly into the patient’s eyes.
The patient wears his___ correction.
___the left eye to test the right eye frst.
Have the patient sit with his eye____ from the tangent screen and level with the___
•The examiner initially stands to the____. In general, the examiner stands on the side being tested.
7 foot-candles
should not shine
habitual distance
Patch
I meter
central fixation target.
left of the screen
what details to include in recording tangent screen test
target size
target color
testing distance
pupil size
vision
tension
cooperation
target size: 3
target color: white
testing distance: 1000
pupil size: 4mm
vision: 20/20
tension: 31
cooperation: good
tangent screen
Purpose
To provide in-depth analysis of color vision defects identifed through clinical screening tests.
D-15 color test
is performed when routine color vision testing or the case history indicate the presence of a color vision anomaly.
D-15 color test
is sensitive to acquired and congenital color vision defects of both the red-green and blue-yellow types.
D-15 color test
equipment d15
D-15 Test, including standard scoring sheet.
Proper illuminant (MacBeth easel lamp).
Eye patch.
Setup
The patient wears his ___
Both the examiner and the patient should wear___ to protect the colored caps of the test from____
The D-15 box should be____.
Place the caps color up in a ____ order on the lid closer to the examiner.
To ensure the validity of the test, work under the proper____, with other light sources in the room turned off.
habitual near correction.
white cotton (photog-rapher’s) gloves
skin oils.
open
random (scattered)
illuminant
Step-by-Step Procedure
Instruct the patient to place the patch over his left eye to test his right eye.
Instruct the patient to ___ the caps in order of___, starting with the reference cap which is___ down and to the patients___.
Tell the patient to do the test____, allowing___ per eye.
When the patient has rearranged the caps, close the lid, turn the box over, and open it upside down.
The______, of each cap is printed on the bottom of the cap and will now be visible.
Record the fndings for the right eye.
Instruct the patient to place the eye patch over his right eye and test his left eye by repeating steps 2 through 5.
rearrange
similarity
left
quickly
2 minutes
number
D-15
If any abnormality is found on the frst test,___ each eye.
retest
Recording D-15
Use the standard recording sheet, as shown in Figure 5-40.
Write down the numbers of the caps in the patient’s order in the space where it says ‘Subject’s order?
Connect the dots on the chart according to the numerical order of the caps.
Make a notation if the patient was unusually slow.
We can check the integrity of the nervous system by
somehow observing the eye thru: (4)
VAT
CVT
VFT
PT
Check the Integrity of visual system and pupillary system
Pupil Tests
to assess the
- Integrity of visual pathway
- Integrity of cones (central vision)
- Integrity of rods (peripheral vision)
Visual Field Tests
The macula is responsible for our central vision.
Because that part of the eye is already very ___.
We can check the thickness and integrity of retina
and macula thru ____.
thin
Optical Coherence Topography
Only ____ cones are found in the macula.
- Inside the macula, there is fovea. Inside the fovea,
there is a foveola.
high quality
______– highest quality of cones
Foveola
Techniques in Direct Ophthalmoscopy:
● Make sure px fixates at far to have higher chance in
seeing px’s optic disc
● Place yourself beside the px temporally to see the optic
disk
● You can also tell patient to look up (don’t let them look at
the light)
● The optic disc is located nasally but projected temporally and the macula is located temporally but projected nasally.
-
● Also called as field of vision
● It is the entire area that can be seen while the eyes are
focused on a single point.
VISUAL FIELD
EXTENT OF VISUAL FIELD
● Extent of Binocular Visual Field = ___
● Extent of Common Binocular Visual Field = ___
- Combined VF of OD and OS when both eyes are
open
- ___
● Extent of Monocular Visual Field = 150 degrees
- One eye is occluded/closed
- ____
● Extent of Temporal Crescent = ___
180 degrees
120 degrees
180 - 30 - 30 = 120
120 + 30 = 150 | 90 + 60 = 150
30 degrees- Side vision
EXTENT OF VISUAL FIELD (MONOCULAR) -150° horizontally
NTIS
● Nasally – 60 degrees
● Temporally – 90 to 100 degrees
● Inferiorly – 70 degrees
● Superiorly – 55-60 degrees
CLINICAL TESTING OF VISUAL FIELD
● We measure the extent of the visual field monocularly by plotting the___
- y axis = vertical | x axis = horizontal
- If you draw it, it is not a perfect circle. The extent of
VF (mono) is limited nasally and superiorly because
there is __of nose & eyelids, respectively.
● The shape of a monocular visual field is __
y and x axis
obstruction
horizontal oval
- It is the line that connects these similar visual
thresholds (the points px detected, also called as
locus of points) - Boundary when first seen → ring-shaped locus of
points
Isopter
makes use of concentric graphs but its limit
is only up to 30° of central vision. Perimetry measures all the degrees of visual field
Tangent Screen
RELATIVE VISUAL FIELD (eye position, head position, paraorbital structures)
fixed, steady, limited
ABSOLUTE VISUAL FIELD (eye position, head position, paraorbital structures)
fixed, moving, not limited
structures around the eyes such as nose,
eyebrows, lashes, high cheekbone, etc
*Paraorbital structures –
CHARACTERISTICS OF VISUAL FIELD
MOTION
FORM
COLOR
● Motion field – confrontation test or hand motion
● Form field – or field for white – our periphery has plenty of rods,
rods are useful in the detection of motion and white target. (we
measure form field by using white target)
● Color fields – (from largest to smallest: Blue – Red – Green)
-
The confrontation test
(FCVF) is commonly performed. It is
the biggest because you are using
fingers as targets.
MOTION
Thru tangent screen. Attach a
white target on the wand.
FORM
