Accommodative stimulus/response function in human amblyopia

Abstract

Three parameters are essential to describe static accommodative behavior in a comprehensive, quantitative manner: the slope of the stimulus/response curve, the depth of focus, and the tonic response. These parameters were obtained in amblyopes, former amblyopes, strabismus without amblyopia, and normals. Results showed that the accommodative response in the amblyopic eye was characterized by a reduction in the slope of the stimulus/response curve and increased depth of focus. Similar abnormalities but of lesser magnitude were found in the non-dominant eye of some former amblyopes and some strabismus without amblyopia. Orthoptic therapy always increased the slope of the stimulus/response curve in the amblyopic eye. We believe that the reduced accommodative responses found in amblyopic eyes reflect a primary sensory loss over the central retinal region that occurs as a result of prolonged, early, abnormal visual experience associated with the presence of strabismus and/or anisometropia.

Accommodative Performance of Children With Unilateral Amblyopia

“…Several studies have directly shown that the DOF of an amblyopic eye is larger than that of its fellow nonamblyopic eye. 22,41,42 The sensory DOF hypothesis would predict that accommodative performance should be correlated with the magnitude of vision deficits. Studies have found that adults with unilateral amblyopia have both reduced contrast sensitivity and higher accommodative lags over the entire spatial frequency spectrum when viewing with their amblyopic eye.…”

On the Age-Related Prevalence of Anisometropia

“…The binocular accommodative control via the 3rd nucleus may not be absolute. Amblyopes are liable to exhibit weaker accommodation in the amblyopic than in the normal eye [31][32][33]. Since the amblyopic eye has the greater depth of focus, it needs less accommodative power.…”

Accommodative ability in exotropia: Predictive value of surgical success

“…This reduced accommodative performance could be attributed to a primary sensory loss over the retinal region as a result of prolonged, abnormal visual experience due to the presence of strabismus, resulting in abnormal binocular interactions and monocular contrast deprivation. [12][13][14][15] Reduced sensitivity to either a focused or …”