Is second-order spatial loss in amblyopia explained by the loss of first-order spatial input?
The purpose of the study was to determine whether amblyopes show detection loss for second-order spatial information, and if present, whether the loss is explained by the loss of first-order spatial input. We psychophysically determined detection thresholds for the amblyopic and non-amblyopic eyes of five adult amblyopes and the dominant eyes of three control observers. We found that four amblyopic eyes and two non-amblyopic eyes showed second-order loss relative to the control eyes. The second-order loss was greater than the first-order loss at the carrier spatial frequency (first-order input). The extra second-order loss indicates an early amplification of cortical neural loss that we speculate is due to deficient binocular input to second-order neurons.
Wong
E H
EH
University of Houston, College of Optometry, The University Eye Institute, 4901 Calhoun Blvd, Houston, TX 77204-6052, USA. ewong@bayou.uh.edu
Levi
D M
DM
McGraw
P V
PV
D000328:Adult; D000550:Amblyopia / Q000150:complications / Q000503:physiopathology*; D015858:Anisometropia / Q000150:complications / Q000503:physiopathology; D016022:Case-Control Studies; D004056:Differential Threshold / Q000502:physiology; D005583:Fourier Analysis; D006801:Humans; D011594:Psychometrics; D011601:Psychophysics; D013028:Space Perception / Q000502:physiology*; D013285:Strabismus / Q000150:complications / Q000503:physiopathology; D014793:Visual Cortex / Q000503:physiopathology