Written by: Liz Trauernicht – MDF President
Edited by: Joe L Fontenot MD
What is an AMSLER GRID?
The Amsler Grid is basically a square of horizontal and vertical lines. According to one source, a similar design may have been used in the late 1800’s. But the Amsler Grid we know today gets its name from Marc Amsler, a Swiss ophthalmologist who began promoting its use in 1947.
When used properly, it can help the user to detect visual distortions and loss of vision caused by such diseases as macular edema, central serous chorioretinopathy (CSC) and age-related macular degeneration (AMD).
Early detection of macular disorders is very important … especially today when effective treatments are available when caught early in the process. The Amsler Grid has helped people with macular disease to identify changes in their condition and report it to their eye doctor for evaluation.
What Forms Do Amsler Grids Take?
1. Amsler Grids on paper are the most common form and are available from your doctor and many sources over the Internet. In an attempt to improve accuracy, some use colored backgrounds and lines, while others use a special number of lines and line spacing.
2. Amsler Grid “Apps” are also available for mobile devices like your tablet or cell phone. These are just two that can be downloaded:
3. Portable viewer: We evaluated a portable key chain “viewer”. It is a novel approach, but we found it to be imprecise and subject to misinterpretation.
4. If you prefer using your computer monitor to check your vision, we have a specialized Amsler Grid called the “Blind Spot Amsler™” available using this link.
How to Use the Amsler
(American Academy of Ophthalmology)
Limitations of the AMSLER GRID
Because the Amsler Grid has limitations, some eye care professionals do not recommended it as a way to “self-assess” disease progression. Here are some of the reasons why:
1. It requires reasonably good near vision to discern the grid lines.
2. Poor patient compliance. Meaning, not everyone is willing or able to maintain a good routine of self-assessment.
3. It is a “subjective” test and prone to misinterpretation.
4. When compared to the tools available to eye doctors, the Amser Grid detects only about one-half of the areas in the visual field where vision is absent or deficient.
5. The eyes and brain can play tricks on you. One of these is called “Perceptual Completion”. This is when the brain fills in or completes gaps in the visual field of each eye. Another challenge is called “Central Fixation”, which causes visual confusion when looking at multiple lines. Perceptual completion and central fixation can make the Amsler Grid unreliable.
Specialized Amsler Grids
A search of the Internet will find references to these less common, high-tech Amsler Grids.
* Threshold Amsler Grid (TAG)
* Accelerated Amsler Grid
* Deformable Amsler Grid
* Three-dimensional Computer-automated Threshold Amsler Grid (3D-CTAG)
These (and other) modified Amsler Grids are attempts to improve the test for use at home between routine eye examinations. Progress is being made in the area of computer and tablet based software to identify macular disorders. All, however, have limitations that make regular visits to your optometrist, ophthalmologist and/or retinal specialist the best way to monitor your vision.
1. First and foremost, have your eyes examined on a regular basis. How often depends on your age, risk factors and whether you currently wear eyeglasses or contact lenses. Most eye care professionals recommend a comprehensive test every year or two.
2. If you notice a change in your vision, contact an eye care professional immediately.
3. If you have a diagnosis of macular degeneration, an AMSLER GRID may be useful as a “follow-up” tool for monitoring changes in your central vision between eye exams. However, it should never be used to screen yourself for macular disease. Leave that to a trained professional.