IOVS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

(Investigative Ophthalmology and Visual Science. 2007;48:3622-3631.)
© 2007 by The Association for Research in Vision and Ophthalmology, Inc.
DOI:  10.1167/iovs.06-1207
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via ISI Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Zele, A. J.
Right arrow Articles by Ireland, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Zele, A. J.
Right arrow Articles by Ireland, D.

Anisometropic Amblyopia: Spatial Contrast Sensitivity Deficits in Inferred Magnocellular and Parvocellular Vision

Andrew J. Zele,1,2 Joel Pokorny,1 David Y. Lee,3 and Dennis Ireland3

1From the Department of Ophthalmology and Visual Science, The University of Chicago, Chicago, Illinois; the 2School of Optometry, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia; and the 3Illinois College of Optometry, Chicago, Illinois.

PURPOSE. To measure achromatic spatial contrast sensitivity in patients with anisometropic amblyopia under conditions favoring inferred parvocellular (PC) or magnocellular (MC) pathway mediation.

METHODS. Fourteen anisometropic amblyopes (VA amblyopic eye 6/12 or lower; better eye greater than 6/7.5) and 10 age-matched, nonamplyopic controls (VA 6/6) participated. Foveal spatial contrast sensitivity was measured using localized, spatially narrow band targets (0.25–8.0 cpd) presented in the center of a steady pedestal (favoring MC detection) or a pulsed pedestal (favoring PC detection) that was set within a uniform surround.

RESULTS. Spatial contrast sensitivity functions were bandpass for the steady-pedestal and lowpass for the pulsed-pedestal. Under steady-pedestal adaptation, the amblyopes showed reduced spatial contrast sensitivity at intermediate frequencies (1–2 cpd), consistent with MC sensitivity loss. For the pulsed-pedestal condition, a generalized loss of sensitivity was observed across all spatial frequencies (0.5–4 cpd), consistent with PC sensitivity loss. The magnitudes of inferred MC and PC loss were similar. In the steady- and pulsed-pedestal paradigms, results for the better eye of greater than 75% of the amblyopes were normal or near normal at low and intermediate spatial frequencies.

CONCLUSIONS. Anisometropic amblyopia produces spatial contrast sensitivity losses in inferred PC- and MC-mediated vision, suggesting there may be anomalous processing of MC and PC signals in higher visual areas, including those with orientation and spatial frequency selective cells in the visual cortex. With spatially localized stimuli and a paradigm designed to distinguish between MC and PC vision under conditions that differ only in the interstimulus adaptation, the better eye of the amblyopes was normal or near normal.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2007 by the Association for Research in Vision and Ophthalmology