Grid, Amsler: A grid pattern that resembles a checkerboard utilized for examination of the eye. The patient covers one eye and stares at a black dot in the center of the grid. While staring at the dot, the patient may notice that the straight lines in the pattern appear wavy.
This kind of wavy pattern on viewing the Amsler grid is abnormal. It can be an important warning sign of what is called wet age-related macular degeneration. The macula is an area in the retina that is responsible for central (straight-ahead) vision. It deteriorates most often after age 60 resulting in age-related macular degeneration (AMD). An early sign of the dangerous "wet" type of AMD is the wavy appearance of the lines on the Amsler grid. The early diagnosis of wet AMD is critical since laser surgery is urgently needed to preserve sight.
The Amsler grids shown here are reduced in size; eye care specialists have full-size grids in their office and for the patient to use at home.