News & Articles

Joshua Dunaief, MD, PHD
Scheie Eye Institute, University of Pennsylvania

The Amsler grid can help detect early signs of retinal disease and monitor changes in vision after diagnosis.

If you have dry age-related macular degeneration (AMD), it is important to monitor your vision with an Amsler grid. The grid will help you detect the progression of dry AMD to the wet form of the disease at an early, treatable stage.

The grid looks like a piece of graph paper with a small dot in the center. With reading glasses on, hold the grid at a distance that allows you to get most of the lines in focus; it will probably be about the same as book reading distance. Cover or close one eye so that you are testing only one eye at a time. This is important; if you use it with both eyes open, the good eye can compensate for an eye with wet AMD, and you won't notice any abnormalities.

An eye without wet AMD will usually see all the lines as straight. In contrast, an eye with wet AMD will often see some of the lines as curved or even blocked out by a gray, white or black region. This is caused by fluid that accumulates within or under the retina, which can form a blister, making straight lines look curved. Sometimes the fluid interferes with retinal function enough to cause a gray, white, black, or red “blind spot” in or near the center of the visual field.

The good news is that the fluid, caused by new leaky blood vessels in the retina, can often be dried up by treatment with Avastin, Eylea, or Lucentis. These medicines are injected into the eye through a tiny needle, as often as once per month.

If an eye with wet AMD goes untreated for a few months or longer, it can begin to develop retinal scarring. This scarring can lead to irreversible vision loss in parts of the visual field, so it is best to monitor your vision at home at least once a week with the grid, and call your retinal specialist if you notice a change. What constitutes a change? If your eye doctor tells you that you don't have wet AMD, take a look at the grid shortly after the exam. That's your baseline. There may be a little waviness of the lines in a few places due to large "drusen," semi-solid deposits that form under the retina in AMD. Then, if you check again at a later point and think the area of waviness has increased or a new area has appeared, or you have a new "blind spot," it's time to call the retinal specialist .

Even without a grid, you may notice changes in your vision that should prompt a call to your eye doctor:

• reading becomes more difficult;
• straight lines look curved (a door frame, for example);
• it becomes harder to see or recognize faces; or
• computer and TV images are more challenging to see.

You can obtain a grid from your eye doctor download from the web. There are also some nice Apps which you can use on your tablet. They are commonly black lines on a white background, but white lines on a black background is fine too. Just remember to check it once a week. Some people like to put it on their refrigerator so that they remember to use; it's one place you'll look every day!

You are very welcome to see us at any Visioncare branch to obtain your Amsler grid including instructions.