Erkelens C J, Collewijn H, Steinman R M
Department of Physiology I, Erasmus University, Rotterdam, The Netherlands.
Invest Ophthalmol Vis Sci. 1989 Jun;30(6):1132-45.
We report the extent to which effective asymmetrical saccadic adaptation was achieved by a myopic subject, who was exposed to "long-term" adaptation as he wore anisometropic corrective spectacles for about 40 years and also the extent of "short-term" adaptation in this subject and two other subjects, who initially made conjugate saccades, when they wore newly fitted anisometropic spectacles for about 8 hr. Two-dimensional binocular eye positions were measured with an accurate and precise revolving magnetic field-sensor coil technique. We found that long-term adaptation of vertical saccades was virtually perfect (almost 100% of the asymmetry introduced by the spectacles was corrected). Long-term adaptation of horizontal saccades was less complete and increased with target separation from about 40% for saccadic amplitudes of 5 degrees to about 75% for amplitudes of 60 degrees. Short-term adaptation of vertical saccades was virtually complete (100%) in one newly fitted subject and only partially complete (40%) in the other two subjects. The persistence of the adaptive asymmetry of saccades during monocular viewing showed that adaptation derived from plasticity in the programming of saccades and not from modification of vergence responses. Without the anisometropic spectacles, 30 min of self-paced, one per second changes in binocular fixation between two targets, which required a version change of 45 degrees in combination with a vergence change of 11 degrees, did not induce any asymmetrical adaptation. This result shows that a specific repeated association of version and vergence eye movements was not sufficient to induce asymmetrical adaptation, leading us to suggest that the transient fixation disparities at saccade-offset might be the necessary stimulus for the asymmetrical saccadic adaptation we observed.
我们报告了一名近视受试者实现有效不对称扫视适应的程度，该受试者佩戴屈光参差矫正眼镜约40年，经历了“长期”适应，还报告了该受试者以及另外两名最初进行共轭扫视的受试者在佩戴新配的屈光参差眼镜约8小时后的“短期”适应程度。使用精确的旋转磁场传感器线圈技术测量二维双眼眼位。我们发现，垂直扫视的长期适应几乎是完美的（眼镜引入的不对称性几乎100%得到纠正）。水平扫视的长期适应不太完全，并且随着目标间距的增加而增加，对于5度的扫视幅度，适应率约为40%，对于60度的幅度，适应率约为75%。一名新配镜受试者的垂直扫视短期适应几乎完全（100%），另外两名受试者仅部分完成（40%）。单眼注视期间扫视适应性不对称的持续性表明，适应源于扫视编程中的可塑性，而非聚散反应的改变。不佩戴屈光参差眼镜时，在两个目标之间以每秒一次的自定节奏进行30分钟的双眼注视变化，这需要45度的转位变化与11度的聚散变化相结合，并未引起任何不对称适应。这一结果表明，特定的重复转位和聚散眼球运动关联不足以诱导不对称适应，这使我们认为扫视偏移时的短暂注视差异可能是我们观察到的不对称扫视适应的必要刺激。
