The Amsler grid is a tool that you can use at home to test your eyes for vision problems. It’s most commonly used to test for signs of age-related macular degeneration (AMD). It’s also occasionally used to test certain eye functions before cataract surgery.
This tool is named after Marc Amsler, who lived from 1891 to 1968. He was a Swiss ophthalmologist, or eye doctor, who first described the tool in 1947.
The basic Amsler grid is a 10-centimeter by 10-centimeter square filled with evenly spaced straight lines in a grid pattern. The lines form very small squares that measure 5 millimeters on each side. There’s a dot to mark the center. The basic grid is typically black lines on a white background, but variations exist.
What Is Age-Related Macular Degeneration?
Age-related macular degeneration is an eye condition that affects your central vision. This is the type of vision that you use to see details right in front of you. For example, you use your central vision when threading a needle, reading a book, or recognizing a face.
The condition is caused by age-related damage to your macula, which is part of your retina. Your retina is the light-sensitive tissue at the back of your eye. AMD is the leading cause of severe vision loss in older adults.
The vision loss is progressive. It happens quickly for some people and progresses slowly in others. There are two main kinds of AMD — dry and wet AMD. Dry AMD can have early, intermediate, and late stages. Wet AMD is a more severe condition and always counts as late-stage AMD. Dry AMD can progress into wet AMD at any point in time.
Dry AMD tends to progress more slowly than wet AMD. With dry AMD, your vision loss gets worse over the course of years.
This means that it’s incredibly important for you to monitor your vision as much as you can once you’re at risk for — or have begun to develop — AMD. You’re more at risk if you:
- Are older than 55
- Have a family history of AMD
- Are Caucasian
- Smoke tobacco products
What Are the Symptoms of AMD?
Since AMD is a progressive condition, early stages can be hard to detect. There aren’t any early symptoms.
In the intermediate stages, your central vision begins to deteriorate. Things may appear blurry when you look right at them. You could also have a harder time seeing in dim lighting.
Late stages can include both wet and dry AMD. This is when symptoms become most severe. Your central vision will likely be quite blurry at this point, and the blurry region might grow. It can also lead to blank spots where you can’t see anything.
Colors may seem less vivid, and straight lines can appear blank or wavy.
How Is AMD Treated?
Your AMD treatment will depend on the stage that you’re in. If you’re still in the early, symptomless stages of dry AMD, then your eye doctor will likely just want to monitor your condition using tools like the Amsler grid.
For later stages of AMD, the goal of treatment is to slow down your vision loss.
One option for intermediate dry AMD is to take certain vitamin and mineral supplements. Your eye doctor will know which ones are best for you. These are meant to slow down the progression of your condition. If you only have AMD in one eye, then supplements can help prevent vision loss in your other eye.
There currently aren’t any treatment options for late-stage dry AMD.
If you have wet AMD, there are two treatment options you can consider. One is to have medications called anti-vascular endothelial growth factor (anti-VEGF) drugs injected directly into your eye. Another is a combination treatment of injections and lasers that’s called photodynamic therapy (PDT).
How Can the Amsler Grid Help With AMD?
The Amsler grid is able to test your vision for many of the signs of intermediate and late-stage age-related macular degeneration. When your vision is normal, you should be able to see all areas on the grid, and all lines should appear straight.
If you have AMD, you could notice defects on the grid. These can include:
- Blank spots
- Warping lines that converge at a spot
- Wavy lines
- Blurriness in parts of the grid
It’s a portable test that you’re meant to use every day at home. You can use it to test for the start of any of these problems or to see if your vision is getting worse. This is particularly helpful if your eye doctor has diagnosed you with early-stage dry AMD and wants to monitor the progression of your condition.
The main goal of the test is to decrease the time between the start of your vision problems and the beginning of treatment. The hope is that using the grid will slow down or prevent the progression of your vision loss.
How Do You Use the Amsler Grid Test?
If your doctor has told you to use the Amsler grid at home, then it’s important that you follow their instructions precisely and do the test the same way every time. This will increase the accuracy of your results.
To use an Amsler grid, you should:
- Find a place with good lighting.
- Wear any glasses that you need to see up close.
- Hold the grid about 12 to 15 inches in front of your face — it’s important to keep it at about the same distance every time you use it.
- Cover one eye.
- Focus directly on the center dot with your open eye.
- Without shifting your focus, notice with your side vision if there are any blank points on the grid, if any of the lines appear wavy or seem to converge anywhere, or if there are any other variations from a grid of even, straight lines.
- Mark the location of any defects that you see on the chart.
- Repeat the process with your other eye.
Your eye doctor may be able to give you an Amsler grid to use at home, or you can find one online to print out. The basic grid just requires black ink and normal computer paper.
Other variations on this grid do exist. Some include diagonal lines to help you focus. Others use red lines for the grid, which may increase the sensitivity of the test. Your eye doctor may have you try multiple different versions. Ask your eye doctor for advice on the best type of grid to use at home.
When Should You Talk to Your Eye Doctor?
The Amsler grid is not a replacement for regular eye exams. But Amsler grid results can indicate that you need to see your eye doctor as soon as possible. Make sure to contact your doctor if you notice any new abnormalities while using the Amsler grid. You should also let them know if your vision seems to be getting worse.
Make sure that you know how to properly use the grid before trying it at home. Proper patient education is key to getting the most benefits from the Amsler grid for macular degeneration.