Stereopsis-dependent deficits in maximum motion displacement in strabismic and anisometropic amblyopia

Vision Res. 2007 Sep;47(21):2778-85. doi: 10.1016/j.visres.2007.07.008. Epub 2007 Sep 4.

Abstract

Direction discrimination thresholds for maximum motion displacement (D(max)) have been previously reported to be abnormal in amblyopic children [Ho, C. S., Giaschi, D. E., Boden, C., Dougherty, R., Cline, R., & Lyons, C. (2005). Deficient motion perception in the fellow eye of amblyopic children. Vision Research, 45, 1615-1627; Ho, C. S., & Giaschi, D. E. (2006). Deficient maximum motion displacement in amblyopia. Vision Research, 46, 4595-4603]. We looked at D(max) thresholds for random dot kinematograms (RDKs) biased toward low- or high-level motion mechanisms. D(max) is thought to be limited, for high-level motion mechanisms, by the efficiency of object feature tracking and probability of false matches. To reduce the influence of low-level mechanisms, we determined thresholds also for a high-pass filtered version of the RDKs. Performance did not significantly differ between strabismic and anisometropic groups with amblyopia, although both groups performed significantly worse than the age-matched control group. D(max) thresholds were higher for children with poor stereoacuity. This was significant in both anisometropic and strabismic groups, and more robust for high-pass filtered RDKs than for unfiltered RDKs. The results imply that impairment of the extra-striate dorsal stream is a likely part of the neural deficit underlying both strabismic and anisometropic amblyopia. This deficit appears to be more dependent on extent of binocularity than etiology. Our findings suggest a possible relationship between fine stereopsis, coarse stereopsis, and motion correspondence mechanisms.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Analysis of Variance
  • Anisometropia / psychology*
  • Child
  • Depth Perception / physiology*
  • Female
  • Humans
  • Male
  • Motion Perception / physiology*
  • Perceptual Disorders / psychology*
  • Photic Stimulation
  • Psychophysics
  • Sensory Thresholds
  • Strabismus / psychology*