Division of Optometry & Visual Science, City University London, London, United Kingdom.
Moorfields Eye Hospital, London, United Kingdom.
Invest Ophthalmol Vis Sci. 2014 Aug 5;55(9):5687-57015. doi: 10.1167/iovs.14-14745.
To examine factors contributing to eye-hand coordination deficits in children with amblyopia and impaired stereovision.
Participants were 55 anisometropic or strabismic children aged 5.0 to 9.25 years with different degrees of amblyopia and abnormal binocularity, along with 28 age-matched visually-normal controls. Pilot data were obtained from four additional patients studied longitudinally at different treatment stages. Movements of the preferred hand were recorded using a 3D motion-capture system while subjects reached-to-precision grasp objects (two sizes, three locations) under binocular, dominant eye, and amblyopic/nonsighting eye conditions. Kinematic and "error" performance measures were quantified and compared by viewing condition and subject group using ANOVA, stepwise regression, and correlation analyses.
Movements of the younger amblyopes (age 5-6 years; n = 30) were much slower, particularly in the final approach to the objects, and contained more spatial errors in reaching (∼×1.25-1.75) and grasping (∼×1.75-2.25) under all three views (P < 0.05) than their age-matched controls (n = 13). Amblyopia severity was the main contributor to their slower movements with absent stereovision a secondary factor and the unique determinant of their increased error-rates. Older amblyopes (age 7-9 years; n = 25) spent longer contacting the objects before lifting them (P = 0.015) compared with their matched controls (n = 15), with absence of stereovision still solely related to increases in reach and grasp errors, although these occurred less frequently than in younger patients. Pilot prospective data supported these findings by showing positive treatment-related associations between improved stereovision and reach-to-grasp performance.
Strategies that children with amblyopia and abnormal binocularity use for reach-to-precision grasping change with age, from emphasis on visual feedback during the "in-flight" approach at ages 5 to 6 years to more reliance on tactile/kinesthetic feedback from object contact at ages 7 to 9 years. However, recovery of binocularity confers increasing benefits for eye-hand coordination speed and accuracy with age, and is a better predictor of these fundamental performance measures than the degree of visual acuity loss.
研究导致弱视和立体视觉障碍儿童手眼协调能力缺陷的因素。
参与者为 55 名屈光不正或斜视的儿童，年龄 5.0 至 9.25 岁，存在不同程度的弱视和双眼视异常，以及 28 名年龄匹配的视力正常对照者。来自 4 名不同治疗阶段的纵向研究的额外患者的初步数据。使用 3D 运动捕捉系统记录优势手的运动，当受试者在双眼、主导眼和弱视/非注视眼状态下到达并精确抓取物体（两种大小，三个位置）时。使用方差分析、逐步回归和相关分析，根据观察条件和受试者组，对运动学和“误差”性能指标进行量化和比较。
年龄较小的弱视儿童（5-6 岁；n=30）的动作速度较慢，尤其是在最后接近物体时，在所有三种观察条件下（P <0.05），在到达（约×1.25-1.75）和抓取（约×1.75-2.25）方面的空间误差更多，与年龄匹配的对照组（n=13）相比。弱视严重程度是导致他们动作较慢的主要因素，立体视觉缺失是次要因素，也是增加错误率的唯一决定因素。年龄较大的弱视儿童（7-9 岁；n=25）在提起物体之前接触物体的时间更长（P=0.015）与他们匹配的对照组（n=15）相比，立体视觉缺失仍然仅与到达和抓取误差的增加有关，尽管这些错误比年龄较小的患者发生的频率更低。前瞻性初步数据支持这些发现，表明改善的立体视觉与到达抓取性能之间存在积极的治疗相关关联。
患有弱视和双眼视异常的儿童在 5 至 6 岁时使用视觉反馈在“飞行中”接近，7 至 9 岁时更多地依赖于物体接触时的触觉/运动觉反馈，用于精确抓握的策略会随年龄而变化。然而，双眼视的恢复随着年龄的增长，对手眼协调速度和准确性的益处越来越大，并且是这些基本性能指标的更好预测因素，而不是视力丧失的程度。
