Norm of Amsler Grid Test
The lines are clearly visualized and appear straight. A black dot is visualized in the center of the grid. No distortions of the lines are seen. No blank spots are seen other than within each square.
Usage of Amsler Grid Test
Detection of macular edema, macular blind spots, scotoma.
Description of Amsler Grid Test
An optical screening test using a grid of intersecting lines with a black dot in the center. The visual acuity of the macular portion of the retina can be affected by macular edema, causing distortions of the lines, or by scotomas, causing blind spots, which make the grid appear to the client as having blank areas.
Professional Considerations of Amsler Grid Test
Consent form NOT required.
- Obtain an Amsler grid and an eye occluder (eye patch, hand held, or occluding eyeglasses).
- With one eye covered, have the client view the Amsler grid at his or her usual reading distance.
- Ask whether the black dot is visible, whether the complete square grid is visible when looking at the dot, whether the lines are perfectly straight, and whether any of the lines are blurred or look as though they are moving.
- Ask if there are any blank areas on the grid, other than within each square. Have the client draw what he or she sees if the answer to any of the questions is yes.
- Repeat the test for the other eye.
- Refer the client to a specialist if necessary.
Client and Family Teaching
- The test takes less than 30 minutes.
Factors That Affect Results
- Performing this test before retinal examination with an ophthalmoscope and fundus examination or refraction test avoids falsely abnormal results caused by retinal bleaching from the bright light or loss of focusing ability.
- An abnormal test indicates the need for more specific testing such as fluorescein angiography.
- Amsler grid reports have poor validity and cannot be accurately interpreted for use in the clinical diagnosis of retinal defects or overall ocular disease.