Mansouri Behzad, Hansen Bruce C, Hess Robert F
McGill Vision Research Unit, Ophthalmology Department, McGill University, Montreal, Quebec, Canada.
Invest Ophthalmol Vis Sci. 2009 Jul;50(7):3218-25. doi: 10.1167/iovs.08-2914. Epub 2009 Feb 28.
The amblyopic visual system exhibits both positional inaccuracy (uncertainty) and systematic biases (distortion). The fidelity of the retinotopic representation of the visual field driven by the amblyopic eye was studied for each of these aspects of position coding by using a dichoptic position-matching task.
Fifteen patients with amblyopia and five normal subjects were tested. The stimuli were luminance-defined Gaussian blobs that were presented within a circle of 15 degrees diameter. Each Gaussian blob was seen only by the amblyopic eye. Moving a mouse marker seen only by the fellow fixing eye (perceptual matching measure), each subject had to localize the position of previously presented targets.
The results confirm previous findings that there is significant distortion in the maps of the central visual field in amblyopic subjects. However, the uncertainty measure did not correlate with the measured distortion in amblyopic maps nor with the visual acuity. Also, regional analysis of the data showed that the distortion occurred heterogeneously in different parts of the visual field and had no relationship to the associated strabismus.
The underlying explanations for these three visual deficits-inaccuracy, distortion, and acuity loss-may be different.
弱视视觉系统表现出位置不准确（不确定性）和系统性偏差（失真）。通过使用双眼分视位置匹配任务，针对位置编码的这些方面，研究了弱视眼驱动的视野视网膜定位表征的保真度。
测试了15名弱视患者和5名正常受试者。刺激物是在直径15度的圆内呈现的由亮度定义的高斯斑点。每个高斯斑点仅由弱视眼看到。通过移动仅由健侧注视眼看到的鼠标标记（感知匹配测量），每个受试者必须定位先前呈现目标的位置。
结果证实了先前的发现，即弱视受试者中央视野图中存在明显失真。然而，不确定性测量与弱视图中测量的失真以及视力均无相关性。此外，对数据的区域分析表明，失真在视野的不同部分不均匀发生，且与相关斜视无关。
这三种视觉缺陷——不准确、失真和视力丧失——的潜在解释可能不同。
