Is amblyopia spatial frequency or retinal locus specific?

The visual deficit associated with amblyopia is thought to be both spatial frequency and retinal locus dependent. However, most data that have been obtained can be accounted for by either of these factors or by a combination of both. We have tried to distinguish between these three possibilities by measuring contrast sensitivity at different retinal loci using discrete localized patches of grating. For five of nine amblyopes, we find the contrast sensitivity deficit to be constant across the retina for a given spatial frequency. In only two cases were there substantial changes as a function of retinal eccentricity. Therefore, most of our data suggest that the visual deficit in amblyopia is primarily spatial frequency and not retinal locus specific.