Effect on grating identification of sampling with degenerate arrays.
We have measured observer performance in identifying gratings that were sampled by degenerate-sampling arrays. Grating identification for high-spatial-frequency stimuli fell to threshold levels only after more than 88% of the sampling elements were subtracted. Although several studies with normal observers have shown that foveal visual acuity corresponds to estimates of interphotoreceptor spacing derived from anatomical photoreceptor density, a simple transformation of sampling-element density to mean spacing does not describe the results in our simulation of degenerate-sampling arrays. To the extent that our model simulates the anatomical changes of retinal pathology, our results suggest that grating acuity reflects the normal high-spatial-sampling rate of small regions of preserved anatomy in the degenerate retina rather than the mean density or spacing of foveal receptors after massive degeneration.
Geller
A M
AM
W.K. Kellogg Eye Center, Ann Arbor, Michigan.
Sieving
P A
PA
Green
D G
DG
D000328:Adult; D003198:Computer Simulation; D005556:Form Perception / Q000502:physiology; D006801:Humans; D008433:Mathematics; D010786:Photoreceptor Cells / Q000503:physiopathology*; D012162:Retinal Degeneration / Q000503:physiopathology; D012684:Sensory Thresholds; D014792:Visual Acuity / Q000502:physiology*