THE AIM of this investigation was to test the diagnostic value, in glaucoma, of two foveal entoptic phenomena, the Maxwell spot and the Haidinger brushes. Maxwell's spot, so named for James Clerk Maxwell (1856), was long considered to be produced by a local depression of the effective retinal illumination through the strong absorption of blue light in the macular pigment. Walls and Mathews,1 after reviewing and accepting earlier evidence given by other authors, came to the conclusion that it is caused by a local nonuniform distribution of the chromatic receptors in the fovea, the receptor-type distribution pattern (RDP). However, in the present report the name with the longer tradition has been retained and will be abbreviated MS herein.
Little is known about the perceptibility of the MS in pathological cases. It was studied in color-defectives by Ahlenstiel.2 When looking toward the overcast sky (color temperature about 6500° K,
SCHMIDT I. DIAGNOSTIC VALUE OF FOVEAL ENTOPTIC PHENOMENA IN GLAUCOMA. AMA Arch Ophthalmol. 1954;52(4):583-597. doi:10.1001/archopht.1954.00920050585010