types of amsler charts and color vision testing

1. Amsler grid and
color vision charts
G.SHIRISHA
13IMMO20

2. Amsler grid
• Amsler chart is designed to evaluate the central visual field
of 20°.
• It is a diagnostic tool that is used mainly in screening,
detection and monitoring macular diseases(e.g. Macular
degenerations)as well as the optic nerve and the visual
pathway.

3. • Procedure-
 Test is done uniocularly
 Patients pupil should not be dilated
 Patient should were their full refractive correction
 Use good illumination on chart
 Hold the chart at 40cm from patients eye.
 Ask the patient to fixate on central white dot & tell patient while
looking on central dot give the answers of following questions-

4. 1.Can you see the central white dot in the center of grid?
2.While looking at central dot ,can you see all four quadrants of
chart simultaneously?
3.Does the grid appears to have any missing or distorted area?
4.Are there any area of grid that have an unusual appearance?
5.Are any square blurring/missing?
All the observations and information given by the
patient should be noted and can be used for further examination
and diagnosis

5. There are seven charts, each consisting of a 10cm square.
CHART 1: Standard Amsler grid
 It is most commonly used. It
comprises a high contrast white grid
on a black background.
 To identify various forms of distortion
as well as Relative and Absolute
scotoma.

6. Chart 2
• Is a similar to chart 1 but has
diagonal lines that aid fixation in
patients unable to see the central
spot as a result of a central scotoma

7. Chart 3
• Is to identical to chart 1 but
has red squares. The red on
black design aim to stimulate
long wavelength fovea cones.
• It is used to detect color
scotomas and desaturation that
may occur in toxic
maculopathies , optic
neuropathies and chiasmal
lesions.

8. Chart 4
• Consisting only of random dots
is used mainly to distinguish
scotoma from metamorphosia,
as there is no form to be
distorted.
Central metamorphosia

9. Chart 5
• This chart consists of 20
evenly spaced white
horizontal lines on a black
background.
• and is designed to detect
metamorphosia along
specific meridian.
• It is of particular value in
the evaluation of patients
with reading difficulties

10. Chart 6
• It a similar to chart 5 but has
a white background and the
central lines are closer
together enabling more
detailed evaluation.
• Metamorphopsia along the
reading level may be more
easily observed with this
chart.

11. Chart 7
• Exhibits a fine central grid ,
each square subtending an
angle of a degree and is
therefore more sensitive.
• This chart is more useful in
cases where there is a subtle
visual disturbance from
macular disease, especially
early in the course of the
disease

12. Color vision charts
• Color vision is the ability of the eye to
discriminate between colours excited by lights of
different wavelengths.
• Cones are responsible for the color vision .
• 6 – 7 millions in number .
• Good reactants in photopic condition.

13. Tests for color vision
• Screening tests.
• Grading tests.
• Classifying tests.
• Vocational tests.
Color vision and principle function

14. Pseudoisochromatic plate
test
• Most commonly used tests,
• Easily and rapidly administered.
• Designed to screen for the presence of red-green inherited
color vision defects.
 Ishihara Plates
 American Optical Hardy-Rand-Rittler Plates
 Standard Pseudoisochromatic plates
 City University test

15. Ishihara plates
• Comes in three different forms: 16 plates, 24 plates, and
38plates.(10th edition)
• Plates should be held at 75 cm under good illumination .
• Numerals should be answered in not more than 3 sec
• Pathway tracing should be completed within 10 sec.
• Designed in four ways
1st plate-
for demonstration and malingerers

16. Transformation plate:
• 2-9 plates
• A number seen by a color normal
appear different to color deficient
subject.
Vanishing plats :
• Plate no. 10-17th
• A number is seen by a color normal but
cannot be seen by a color deficient subject

17. (18-21)plate-Hidden-digit plates:
normal person does not see a
figure
(22-25)plate-Diagnostic plates:
seen by normal subjects.
• Out of initial 21 plates, if 17 or more plates are
read correctly by an individual his color sense
should be recorded as normal.
• If 13 or less plates are correctly read then the
person has a red-green color defect.
• Plates 22 to25 are for differential diagnosis of
Protans and Deutans.
• Disadvantage of this test is that it neither test for
tritanope nor grade the degree of deficiency

18. American optic hardy rand
ritter
• There are plates with paired vanishing designs
• Contain geometric shapes (circle, cross and triangle)
• Shape is in neutral colours on a background matrix of grey
dots.
• Six plates for screening (four red-green and two tritan),
• 10 plates for grading the severity of protan and deutan
defects
• Four plates for grading tritan defects
• Ideal for paediatric testing of congenital
color blindness

19. CITY UNIVERSITY COLOR
VISION TEST
• 10 Plates ,35 cm,daylight,right angle.
• Where a centre colored plate is to be matched to its
closest hue from four surrounding color plates.
• Three peripheral colors are typical isochromatic
confusions with the central color in color deficiency.
• The fourth color is an adjacent color in the D15
sequence and is the intended normal preference
• Identifies moderate and severe color
deficiency only

20. FARNSWORTH- MUNSELL 100
HUE TEST
• Very sensitive reliable and effective method of
determining color vision defect.
• The test consists of 85 movable color samples arranged
in four boxes of 22 colors.
• Subject has to arrange 85 color chips in ascending
order.
• The color vision is judged by the error score.
 The results are recorded in a circular graph
 The Farnsworth-Munsell Hue Test Scoring Software has
been developed to speed up and simplify scoring of the
FM 100 Hue test and to provide a powerful set of
analytical and administrative tools

21. FARNSWORTH- MUNSELL D-15 HUE
TEST
• Abridged version
• Patients are asked to
arrange 15 colored caps
in sequential order based
on similarity from the
pilot color cap
• Intended for screening
color vision defects only.
• Used to detect color
vision defects such as
red-green and blue-
yellow deficiencies as
opposed to color acuity.

22. FARNSWORTH- MUNSELL D-15
HUE TEST
• Abridged version.
• Patients are asked to arrange 15
colored caps in sequential order
based on similarity from the pilot
color cap.
• Intended for screening color
vision defects only.
• Used to detect color vision defects
such as red-green and blue-
yellow deficiencies as opposed to
color acuity.

23. Spectral anamaloscope
• Accepted as the most accurate for diagnosis
• unlike most other tests,they require a fair amount of skill on the
part of the examiner.
1. Nagel anomaloscope.
2. Oculus HMC (Heidelberg Multi Color) anomaloscope
3. Neitz anomaloscope
4. Pickford-Nicolson anomaloscope

24. Nagel’s anomaloscope
• GOLD STANDARD
• Extraordinarily sensitive.
• In this test the observer is asked to mixed red and green
colors in such a proportion that the mixture should match
the yellow color disc.
• Indication of defect is relative amount of red and green
required.

25. Lantern test
• The test is performed in a dark room at 6 meters distance
• It has five rotating discs
• Disc 1 – aperture sizes varies 1.3 to 13 mm.
• Disc 2-4 – Eight color filters (2 red, 2 green, white, yellow, blue,
Purple)
• Disc 5 – a clear aperture, 5 neutral density filters, a ribbed glass
(simulate rain), frosted glass (simulate mist)
• Recommendations of the test state that a candidate should be
rejected if he calls:
• Red as Green
• Green as Red
• White light as Green or Red or vice versa
• Red-Green or White light as black