POSITIONAL ACUITY IN AMBLYOPIA - DOES A PERCEPTUAL CONSEQUENCE OF NEURAL RECRUITMENT EXIST

Animal models of amblyopia have shown that visual deprivation for even brief periods can result in dramatic changes in cortical architecture . Active neural recruitment mechanisms present the possibility that th e non-deprived eye of amblyopes may show enhanced visual capacity. Thi s idea was tested by measuring a form of positional acuity which we ha ve termed alignment threshold. Three subject groups were examined, adu lts, visually normal children, and children with amblyopia in which th e non-deprived eye was tested. Alignment thresholds in adults were sig nificantly better (similar to 0.3 log unit) than the thresholds for vi sually normal children. No significant difference was found in thresho lds between the visually normal children and the non-deprived eye of t he amblyopic children. The results of this study suggest that subjects with unilateral amblyopia do not show enhanced visual alignment perfo rmance in their non-deprived eye, (C) 1998 The College of Optometrists , Published by Elsevier Science Ltd. All rights reserved.