Density profile of blue-sensitive cones along the horizontal meridian of macaque retina.

Intravitreal injection of some fluorescent and nonfluorescent tissue-reactive dyes results in selective intracellular staining of a specific population of cones of macaque retina that have been identified tentatively as blue-sensitive cones. This paper describes quantitative density profiles of these cones as a function of retinal eccentricity. These profiles were measured from 0 deg to about 60 deg eccentricity along the nasal and temporal segments of the horizontal meridian of macaque retina. Stained cones were found to be absent from the very center of the fovea. These cones reach peak densities at 0.75-1.50 deg eccentricity, and decrease with greater eccentricity, more rapidly on the temporal than on the nasal segment of the horizontal meridian. Peak densities were found to be slightly closer to the foveal center of the retinas of adult male than of adult female macaques. Packing patterns of stained and unstained cones are discussed as is the mathematic expression of stained cone distribution. The spatial properties of the retinal distribution of stained cones agree very closely with those obtained in psychophysical human studies and other anatomic simian studies of blue-sensitive cones.