Amslers grid test is one of the macular function test, it assess central 10 of visual field

1. Amslers Grid Test
Rashad Ibn Muhammed
Assi. Prof Optometry
Ahalia School of Optometry

2. Amslers
• The Amsler Grid is a rapid, qualitative technique designed to test the
central 10° of the visual field, using a standard chart with a grid of
white lines on a black background
• Each square of the grid is 5 mm, subtending approximately 1° at 30
cm. The patient is requested to describe lines that are missing or
distorted.
• The chart consists of a grid of lines with a central fixation dot, the
whole chart at 30 cm. distance subtending an angle of 20°
• It is one of the macular function test
• And is a test to observe or treat the macular diseases

3. Some points to know
• The macula is a round area at the posterior pole, lying inside the
temporal vascular arcades. It measures between 5 and 6 mm in
diameter, and sub serves the central 15–20° of the visual field
• Relative scotoma –Blurred Image
• Absolute scotoma- Complete absence of image
• Metamorphopsia- Distortion of images
• Micropsia-image is smaller than normal
• Macropsia-image is larger than normal

5. Home Chart

6. Procedure
1. Seat the patient comfortably in the examining chair with the appropriate
near correction.
2. As the working distance for the test is 30 cm, ideally a 3.25 D near add
should be used for absolute presbyopes. However, the patient’s own
spectacles are usually satisfactory given sufficient depth of focus
3. Use single vision glasses or trial lenses, but avoid multifocal lenses.
4. Position yourself so as to be able to occlude the non-viewing eye and
measure the working distance. Get the patient to hold the chart at 30
cm.
5. Keep the room lights on. The method is qualitative and critical light levels
are not essential; however, it is useful to be able to reproduce
approximate ambient luminance levels.

8. 6. Patient is asked to look at the central dot of the chart at all the
time.
7. Patient is instructed to draw on the chart if he notices any missing
and distorted areas/ lines
8. In some cases central vision become blurred due to fluid
accumulation in the Macula. So in Amsler Grid testing we get
central scotoma (non seeing area) along with distorted line or wavy
line.
9. Repeat the procedure for left eye

9. Amsler grid superimposed on the macula of
central 20°

10. Type of charts available Chart no -1
There are seven charts, each
consisting of a 10 cm square
1. Chart 1: the standard chart used
in every case. Consists of a 5mm
square, white grid with each square
subtending approximately 1° from
30cm, on a black background with a
central, white fixation target.

11. 2. Chart 2: similar to Chart 1 but with two diagonal white lines to assist
steady fixation in patients with a central scotoma.
3. Chart 3: similar to Chart 1 but with a red grid. It has been reported to
be useful in the toxic amblyopia's and optic neuritis, but is also
capable of testing the malingerer when used in conjunction with red
and green filters.
4. Chart 4: consists of scattered white dots with a central, white fixation
target. It appears no more sensitive than the standard chart for
relative scotoma’s and cannot detect metamorphopsia.
5. Chart 5: consists of white parallel lines only and a central, white
fixation point. The chart can be rotated to change the orientation of
the lines and is used to investigate metamorphopsia along specific
meridians.
6. Chart 6: similar to chart 5 but has black lines on a white card with
additional lines at 0.5° above and below fixation.
7. Chart 7: similar to Chart 1 but with additional 0.5° squares in the
central 8°. This chart is used for detection of subtle macular disease.

13. Recording
• Record defects or disturbances on an Amsler recording sheet. Always
record the eye tested, the date of examination and the patient’s
name.
• Ensure that if no defects are detected, this is recorded clearly in the
patient’s file,
• e.g. Amsler charts: central fields full R and L (OD & OS)

14. Interpretation
• Metamorphopsia and relative scotoma may indicate macular oedema
• Absolute scotoma indicates scars, atrophy and lesions in macular
region
• Advanced glaucoma can show a peripheral absolute scotoma
• ARMD, retinal edema, exudates and epiretinal membrane can show
distortion

22. Binocular Amsler test
1. Use of an Amsler chart can be very helpful in understanding the
difference between anisometropic amblyopia and the amblyopia of
microtropia.
2. Amblyopia with anisometropia a central scotoma is almost always
indicated by the patient, whereas in microtropic amblyopia with
central fixation the scotoma is as a rule paracentral and on the
temporal side.
3. The Amsler chart with red lines has proved to be more sensitive
than that with white ones.
4. The patient must always be asked to compare the amblyopic eye
with the good eye.

23. Infront of good eye Infront of Amblyopic eye

25. Common Errors
1. Not ensuring that the patient views the central fixation target
throughout the test.
2. Using an incorrect working distance.
3. Using an inappropriate near correction.
4. Using the patient’s bifocals with a small reading area.
5. Using monocular test binocularly

26. • The Amsler chart is a simple, inexpensive, noninvasive, harmless,
portable, and suitable tool and of a mass screening ability that easily
detects different macular lesions

27. The end