title: Positional loss in strabismic amblyopia: inter-relationship of alignment threshold, bias, spatial scale and eccentricity.
abstract: In order to understand the spatial loss in strabismic amblyopia and its relationship to the contrast sensitivity deficit, we measured alignment performance for a three element vertical alignment task in which the elements were equi-visible, spatial Gabors. We derived the threshold and bias and compared these for stimuli of different spatial scale and eccentricity. Our results suggest that: (1) the deficits for alignment thresholds and bias are uncorrelated; (2) in the majority of strabismic amblyopes, both deficits are scale invariant; (3) the form of the regional distribution depends on the spatial measure used and the scale at which it is measured; and (4) there is a poor correlation between the deficit for either spatial measure and the contrast sensitivity loss.
authors.affiliation: McGill Vision Research, Department of Ophthalmology, McGill University, Montreal, Quebec, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Demanins
authors.forename: R F
authors.initials: RF
authors.lastname: Hess
mesh_terms: D000550:Amblyopia / Q000503:physiopathology*; D015350:Contrast Sensitivity / Q000502:physiology; D006801:Humans; D010364:Pattern Recognition, Visual / Q000502:physiology; D011601:Psychophysics; D012684:Sensory Thresholds / Q000502:physiology; D013285:Strabismus / Q000503:physiopathology; D014794:Visual Fields