Laboratoire de Neuroscience Fonctionnelle et Pathologies, CNRS, université Lille Nord de France, Lille, France.
Invest Ophthalmol Vis Sci. 2011 Mar 1;52(3):1655-60. doi: 10.1167/iovs.10-6003.
To investigate impairment in discriminating a figure from its background and to study its relation to visual acuity and lesion size in patients with neovascular age-related macular degeneration (AMD).
Seventeen patients with neovascular AMD and visual acuity <20/50 were included. Seventeen age-matched healthy subjects participated as controls. Complete ophthalmologic examination was performed on all participants. The stimuli were photographs of scenes containing animals (targets) or other objects (distractors), displayed on a computer monitor screen. Performance was compared in four background conditions: the target in the natural scene; the target isolated on a white background; the target separated by a white space from a structured scene; the target separated by a white space from a nonstructured, shapeless background. Target discriminability (d') was recorded.
Performance was lower for patients than for controls. For the patients, it was easier to detect the target when it was separated from its background (under isolated, structured, and nonstructured conditions) than it was when located in a scene. Performance was improved in patients with increasing exposure time but remained lower in controls. Correlations were found between visual acuity, lesion size, and sensitivity for patients.
Figure/ground segregation is impaired in patients with AMD. A white space surrounding an object is sufficient to improve the object's detection and to facilitate figure/ground segregation. These results may have practical applications to the rehabilitation of the environment in patients with AMD.
研究年龄相关性黄斑变性（AMD）患者辨别图形与背景的能力损伤及其与视力和病变大小的关系。
纳入 17 例新生血管性 AMD 患者，视力<20/50。17 名年龄匹配的健康受试者作为对照组。所有参与者均进行了全面的眼科检查。刺激物是包含动物（目标）或其他物体（干扰物）的场景照片，显示在计算机显示器屏幕上。在四种背景条件下比较了患者和对照组的表现：目标在自然场景中；目标在白色背景上孤立；目标与结构化场景之间有白色空间分隔；目标与非结构化、无形状的背景之间有白色空间分隔。记录目标可辨别性（d'）。
患者的表现低于对照组。对于患者来说，与位于场景中相比，当目标与其背景分离（在孤立、结构化和非结构化条件下）时，更容易检测到目标。随着暴露时间的增加，患者的表现有所提高，但在对照组中仍较低。患者的视力、病变大小和敏感性之间存在相关性。
AMD 患者的图形/背景分离受损。物体周围的白色空间足以提高物体的检测能力，并促进图形/背景分离。这些结果可能对 AMD 患者环境康复具有实际应用价值。
