Responses of Primate Retinal Ganglion Cells to Perimetric Stimuli

PURPOSE. Perimetry is used clinically to assess glaucomatous ganglion cell loss. It has been proposed that frequency-dou-bling stimuli are better than the conventional size III perimetric stimulus in preferentially stimulating magnocellular (M) versus parvocellular (P) ganglion cells. However, little is known about how primate ganglion cells respond to perimetric stimuli. The authors recorded contrast responses of M and P ganglion cells to size III and frequency-doubling stimuli and compared con-trast gain of M and P cells to these stimuli to assess the ability of these stimuli to preferentially stimulate M versus P cells. METHODS. Data were recorded from 69 macaque retinal gan-glion cells, by an in vivo preparation, at eccentricities of 5 ° to 15°. The size III stimulus was a circular luminance increment 26 min arc in diameter, 200 ms in duration. The frequency-doubling stimulus was a sinusoidal grating (0.5 cyc/deg) tem