The blue Amsler grid

Abstract

Black and red Amsler grid charts are frequently used for detecting central scotomas in optic nerve diseases. Red is the most commonly affected color hue in optic nerve diseases. It has been emphasized that blue is also affected in optic nerve diseases like in retinal disorders. In order to compare red versus blue versus black Amsler charts, blue Amsler grid charts have been produced. Twenty-two patients with optic neuritis were tested three times with black, red, blue Amsler grid charts and the mean areas of the scotomas were compared. The largest mean area was obtained with blue Amsler grid. There was a statistical difference between black and blue (p = 0.014), black and red (p = 0.005). A linear relationship was found between Sahlgren's color saturation test scores and blue Amsler defects only. The authors believe that blue color defects should also be examined in optic nerve diseases for optimal assessment of the visual function and the blue Amsler grid may be helpful for this purpose.

Key Words:

• Amsler grid
• Sahlgren saturation test
• optic nerve disease
• acquired color defects