Bergamin Oliver, Bizzarri Sandra, Straumann Dominik
Department of Neurology, Zurich University Hospital, Zurich, Switzerland.
Invest Ophthalmol Vis Sci. 2002 Nov;43(11):3438-43.
Most studies on blink-induced eye movements have been restricted to rotations about the horizontal and vertical axes. By additionally measuring rotation about the torsional axis, the authors investigated whether the three-dimensional rotation of the eye during the early phase of eyelid closure could be assigned to the action of a single extraocular muscle.
In five healthy human subjects, eye movements about all principal axes of rotation (horizontal, vertical, and torsional) were recorded during voluntary blinks of different durations (as short as possible, 0.83 seconds, and 1.67 seconds) in straight-ahead gaze. Original dual search coils frequently rotate about the line of sight, because the upper eyelid touches the nasally exiting wire leads. Therefore, the search coils were modified so that the wires left the silicon annulus from its inner border at 6 o'clock.
The earliest eye movement during blinks consisted of a pulselike trajectory in a direction that was always extorsional, downward, and inward, regardless of the duration of eyelid closure. The beginning of all three movement components preceded the beginning of eyelid movement; thus, a coil artifact is unlikely. On eyelid opening, a consistent pulselike movement in the intorsional, upward, and outward direction occurred.
During the initial phase of voluntary eyelid closure, the eyes move in a three-dimensional direction that is consistent with a pulselike innervation of the inferior rectus muscle. To obtain reliable measurement of torsional eye movements with dual search coils during blinks, modification of the annulus is indispensable.
大多数关于眨眼诱发眼动的研究都局限于绕水平轴和垂直轴的旋转。通过额外测量绕扭转轴的旋转，作者研究了在眼睑闭合早期眼睛的三维旋转是否可归因于单一眼外肌的作用。
在五名健康人类受试者中，记录了他们在向前直视时不同持续时间（尽可能短、0.83秒和1.67秒）的随意眨眼过程中绕所有主要旋转轴（水平、垂直和扭转）的眼动。原始的双搜索线圈经常绕视线旋转，因为上眼睑会碰到从鼻腔穿出的导线。因此，对搜索线圈进行了改进，使导线从6点位置的硅环内边界离开。
眨眼过程中最早出现的眼动由一个脉冲状轨迹组成，其方向始终是外旋、向下和向内，与眼睑闭合的持续时间无关。所有三个运动成分的开始都早于眼睑运动的开始；因此，不太可能是线圈伪影。在眼睑睁开时，出现了内旋、向上和向外方向的一致脉冲状运动。
在随意眼睑闭合的初始阶段，眼睛在三维方向上移动，这与下直肌的脉冲状神经支配一致。为了在眨眼过程中用双搜索线圈获得可靠的扭转眼动测量，对环进行改进是必不可少的。
