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
