Abstract：
CONCLUSIONS: Visual midline shifts are thought to occur post-stroke and be a risk factor for falls. This study investigates a new method for quantifying visual midline shifts, a first step toward developing greater understanding of visual midline shift.
OBJECTIVE: This study standardized the parameters of a novel visual midline gauge, compared the results with the current clinical method, and presents normative data and repeatability of both methods.
METHODS: Ninety-three participants without neurological or ocular problems were recruited in Canada and Hong Kong. In experiment 1, horizontal and vertical visual midlines were measured using the gauge for two speeds and two repositioning methods. In experiment 2, visual midline was measured for three distances using a target speed and repositioning method chosen based on the first experiment. Visual midlines were also measured using the current clinical method during both visits.
RESULTS: There were no significant effects of age, speed, study location, or repositioning method on visual midline positions (all p>0.05). For the horizontal direction, measurements at 25 cm were different from those at 50 (p=0.03) and 100 cm (p=0.001). For the vertical direction, there was no such effect. The measurements were found to be repeatable to within approximately 3°. In both visits, there were significant correlations between measurements using the visual midline gauge and the clinical method for the vertical direction (all p<.001) but not for the horizontal direction (all p>0.05).
CONCLUSIONS: The measurement of visual midline is tolerant of differences in target speed, testing method, and age of the participants, and the visual midline gauge measurements are repeatable.
OBJECTIVE: This study standardized the parameters of a novel visual midline gauge, compared the results with the current clinical method, and presents normative data and repeatability of both methods.
METHODS: Ninety-three participants without neurological or ocular problems were recruited in Canada and Hong Kong. In experiment 1, horizontal and vertical visual midlines were measured using the gauge for two speeds and two repositioning methods. In experiment 2, visual midline was measured for three distances using a target speed and repositioning method chosen based on the first experiment. Visual midlines were also measured using the current clinical method during both visits.
RESULTS: There were no significant effects of age, speed, study location, or repositioning method on visual midline positions (all p>0.05). For the horizontal direction, measurements at 25 cm were different from those at 50 (p=0.03) and 100 cm (p=0.001). For the vertical direction, there was no such effect. The measurements were found to be repeatable to within approximately 3°. In both visits, there were significant correlations between measurements using the visual midline gauge and the clinical method for the vertical direction (all p<.001) but not for the horizontal direction (all p>0.05).
CONCLUSIONS: The measurement of visual midline is tolerant of differences in target speed, testing method, and age of the participants, and the visual midline gauge measurements are repeatable.
摘要：
结论：视觉中线偏移被认为是卒中后发生的，并且是跌倒的危险因素。本研究探讨了一种量化视觉中线偏移的新方法，对视觉中线移位有更多理解的第一步。
目的：这项研究标准化了一种新型视觉中线仪表的参数，将结果与目前的临床方法进行比较，并介绍了两种方法的规范性数据和可重复性。
方法：在加拿大和香港招募了93名无神经或眼部问题的参与者。在实验1中，使用仪表以两种速度和两种重新定位方法测量了水平和垂直视觉中线。在实验2中，使用基于第一个实验选择的目标速度和重新定位方法测量了三个距离的视觉中线。在两次访问期间还使用当前的临床方法测量视觉中线。
结果：年龄没有显著影响，速度,研究地点,或视觉中线位置上的重新定位方法(所有p>0.05)。对于水平方向，25厘米处的测量值与50厘米（p=0.03）和100厘米（p=0.001）处的测量值不同。对于垂直方向，没有这样的效果。发现测量在大约3°内是可重复的。在这两次访问中，在垂直方向(所有p<.001),而在水平方向(所有p>0.05),使用视觉中线测量仪和临床方法的测量结果之间存在显著相关性.
结论：视觉中线的测量可以容忍目标速度的差异，测试方法,和参与者的年龄，视觉中线仪表测量是可重复的。
目的：这项研究标准化了一种新型视觉中线仪表的参数，将结果与目前的临床方法进行比较，并介绍了两种方法的规范性数据和可重复性。
方法：在加拿大和香港招募了93名无神经或眼部问题的参与者。在实验1中，使用仪表以两种速度和两种重新定位方法测量了水平和垂直视觉中线。在实验2中，使用基于第一个实验选择的目标速度和重新定位方法测量了三个距离的视觉中线。在两次访问期间还使用当前的临床方法测量视觉中线。
结果：年龄没有显著影响，速度,研究地点,或视觉中线位置上的重新定位方法(所有p>0.05)。对于水平方向，25厘米处的测量值与50厘米（p=0.03）和100厘米（p=0.001）处的测量值不同。对于垂直方向，没有这样的效果。发现测量在大约3°内是可重复的。在这两次访问中，在垂直方向(所有p<.001),而在水平方向(所有p>0.05),使用视觉中线测量仪和临床方法的测量结果之间存在显著相关性.
结论：视觉中线的测量可以容忍目标速度的差异，测试方法,和参与者的年龄，视觉中线仪表测量是可重复的。
