Differential effects of refractive errors and receptive field organization of central and peripheral ganglion cells.

Abstract Microelectrode recordings were made from retinal ganglion cells in cats, and the receptive field organization of these cells was investigated with particular reference to the effect of defocusing the retinal image. Cells within 5° of the area centralis were critically affected by defocusing the stimulus spot, while peripheral cells continued to respond to defocused stimuli. These differences have been related to differences in the receptive field organization of central and peripheral ganglion cells in respect of the spatial distribution of excitation and inhibition, and the “sustained” and “transient” response types. These results form the basis of a hypothesis about the causation of various forms of amblyopia. For instance, it is suggested that amblyopia which follows long-standing squint of early onset may be a functional degeneration resulting from the habitual exposure of the fovea of the squinting eye to defocused images of low constrast and detail, which are shown here to be inadequate stimuli for central retinal ganglion cells.