Amsler grid chart

AMSLER GRID CHART

MADE BY : SWATI PANARAFROM : BHARTIMAIYA

COLLEGE OF OPTOMETRY

INTRODUCTION

• After series of attempts to develop unique charts for the diagnosis of central vision disorder & its effects on day to day activities of the sufferer ,Dr.Marc Amsler, noted Swiss ophthalmologist developed the first Amsler grid chart manual in 1920.

PURPOSE OF AMSLER GRID CHART

• -Important in testing macular function when v/a decreased or distorted -Chart consisting of white lines on black background & central white dot for fixation -10 cm square divided in 5mm square -It is use to evaluate 20 degree of v/f surrounding fixation. -This test is use for screening & diagnostic purpose

• 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 30cm 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-

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?

CHART 1

• The most familiar and widely used of the charts is the first in the manual, the Standard Amsler grid.

• This is merely a grid pattern consisting of 0.5cm white squares, each corresponding to 1 degree of visual field, set against a black background.

• This is arranged in 20 horizontal & vertical rows making 20 squares each.

7

CHART NO 1

• This grid pattern is the most versatile of the charts

• This enables the clinician to identify various forms of distortion as well as Relative and Absolute scotoma.

• Relative scotoma: The area in the visual field which is seen as blur or not seen clearly

• Absolute scotoma: The area in the visual field which is not at all seen or unrecognizable, usually reported by the patient as a black area

CHART 2

• The patient with a central scotoma may respond better if this chart is used.

• The only difference between this and Standard grid chart is that diagonal lines intersect at the center of the grid to form an ‘X’.

• This gives the patient a better idea of where the fixation point is located.

• A larger white central spot may be applied with tape to the center of the grid if the patient is still unable to achieve or maintain central fixation.

10

CHART NO 2

CHART 3

• This chart has an identical configuration with that of the Standard Amsler chart, except for having red squares instead of white ones in the black background.

• The patient suspected of having a central or cecocentral scotoma associated with nutritional amblyopia, as from alcohol-related thiamine deficiency, or toxic maculopathy, as from quinine and its derivatives, should be tested with this chart.

12

CHART NO 3

13

OTHER USES

• This chart can also be used to differentiate patient with functional vision loss , as from malingering with the conjunction of red-green lenses, the red grid may allow detection of artificial monocular field/vision loss.

• Under normal circumstances, the grid will disappear when viewed through the green lens; conversely, it will remain visible when viewed through the red lens.

14

CHART NO 4:• This chart has no lines to distort; instead it

consists of small white dots randomly distributed over a black background like stars in the sky.

• Amsler hoped that the patient with one or more paracentral scotomas may be able to delineate the area[s] of involvement more easily with this chart.

• But its credibility is doubtful since the background and scotoma use to appear same in color for the observer may result in false results

15

CHART NO 4

16

CHART NO 5:• This chart consists of 20 evenly spaced white

horizontal lines on a black background.

• This design makes it possible to rotate the chart to any meridian to check for irregularities in a particular/specific area.

• The patient with central or paracentral metamorphopsia resulting from various retinal and choroidal disorders may be especially sensitive to this chart

17

CHART NO 5

18

CHART NO 6:• This chart varies slightly from chart no 5

• It contains black lines against a white background and the areas 1 degree above and below the fixation dot are bisected by additional horizontal lines.

• Metamorphopsia along the reading level may be more easily observed with this chart.

19

CHART NO 6

20

CHART NO 7:• This chart breaks the horizontally oriented 6 degree

X 8 degree central area, which corresponds anatomically to the normal macula, into 0.5 degree squares, rather than 1 degree squares.

• This making it a more sensitive detector to insidious macular compromise

• 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

21

CHART NO 7

22

CLINICAL IMPLICATIONS• Disturbances that appear on the Amsler grid should

alert the clinician to the possibility of either acute or longstanding disease of the retina, choroid, optic nerve, anterior visual system, visual pathways and cortex.

• The clinician should consider dispensing an Home Amsler grid chart [Black lines in white background] with complete instructions for self-assessment to three categories of patients.

INTERPITATION

(1) Can you see the central white dot?• The purpose of this question is to rule out a

central scotoma.

• If the answer is ‘Yes’, a central scotoma is unlikely unless the clinician is obtaining a false-positive response due to poor patient compliance.

• If the answer is ‘ It looks washed out’ or ‘It seems slightly blurry’, one should suspect for a relative central scotoma.

24

RELATIVE CENTRAL SCOTOMA

25

• If the patient says he/she is unable to see the central white dot at all, an absolute central scotoma may be present.

• This type of defect may arise from several retinal, choroidal , and optic nerve disorders, as well as lesions of the anterior visual system.

26

ABSOLUTE CENTRAL SCOTOMA

2) Can you see all the four sides of the large square as well as all four of its corners?

• The purpose of this question is to rule out arcuate, altitudinal, quandrantic,or hemianopic field defects, as well as overall field constrictions.

• If the answer is ‘Yes’, the clinician may then proceed to Question no 3.

• If the answer is ‘No’ then the patients should be asked to document the missing sides/corners as accurately as possible in the tear-off chart with the help of pencil.

28

3) Are any of the small squares blurry or missing on any part of the grid?

• The purpose of this question is to rule out relative or absolute paracentral, cecocentral, or altitudinal scotomas.

• If the answer is ‘No’ then the clinician may proceed to Question no 4.

• If the answer is ‘Yes’, the clinician must initially rule out the false-positive responses that may occur if the patient is not properly corrected for the test distance or if media opacities create a blurriness or a doubling of the horizontal or vertical lines (monocular diplopia).

29

4) Do any of the horizontal or vertical lines that make up the squares appear wavy or bent?

• The purpose of this question is to rule out metamorphopsia and other forms distortions.

• If the answer is ‘No’, then clinician may proceed to Question no 5.

• If the answer is ‘Yes ’, the clinician must initially rule out false-positive responses that may occur if the patient is looking through the line of a multifocal segment he/she is wearing or noticing the peripheral distortions of a progressive addition lens.

Gaurav Bhardwaj

Central Metamorphopsia

Gaurav Bhardwaj

• The purpose of this question is to rule out scintillating scotomas.

• If the answer is ‘No’ the series of questions are complete and one can expect patient to have normal central visual field.

Is any part of the grid shimmering, flickering, or colored?

• If the answer is ‘Yes’, this may herald the onset of a scotoma of retinal origin, particularly if early serous or hemorrhagic detachment is disrupting retinal topography.

33

HOME AMSLER CHART

34

• The first category is the patient with progressive disease, such as toxic maculopathy or atypical retinitis pigmentosa [field defect starts from center to periphery] , who is predisposed to developing significant alterations in the functional vision over time.

• The second category is the patient with active disease, such as optic neuritis or macular neuroretinopathy, whose visual acuity may improve or worsen within a relatively short time span.

35

The third category is the patient with recurrent disease, such as central serous retinopathy or toxoplasmic retinochoroiditis, who may have already suffered vision loss, but is at risk of experiencing a reactivation of the disease process.

36

INSTRUCTIONS FOR HOME AMSLER GRID SELF-ASSESSMENT

1) Patient should hold Home Amsler chart at his/her reading or working distance while wearing proper reading glasses for that particular distance.

2) Patient should cover/occlude one of his/her eye, chart should be viewed only with one eye open.

(4) Patient should be always looking directly at the central white dot at all times.

(5)If patient notice any [new] missing or distorted areas, he/she should mark them with a pencil.

(6) Patient should report the clinician along with Home Amsler chart used as soon as possible for any new symptoms found with the chart.