Abel L A, Williams I M, Levi L
Department of Ophthalmology, Indiana University Medical Center, Indianapolis 46202-5175.
Invest Ophthalmol Vis Sci. 1991 Nov;32(12):3104-8.
Spontaneous reports of oscillopsia are rare in cases of congenital nystagmus (CN). We examined the relationship between nystagmus waveform characteristics and oscillopsia in one such case. To reduce the patient's nystagmus, she was fitted with contact lenses. We examined the effects of tactile feedback by applying local anesthetic while she wore the lenses. When she was without lenses, we provided tactile feedback by applying gentle finger pressure to one eyelid. She was also asked to look at a peripheral afterimage. Nystagmus was analyzed for frequency, amplitude, foveation duration, and drift velocity, if foveation was not perfectly stable. Perceived target stability was recorded. The patient noted oscillopsia during the initial baseline recording and with lid pressure. The image was stable with contact lenses with and without anesthesia and during the second session baseline; at these times, drift velocity was less than 4 degrees/sec and foveation duration was greater than 100 msec. No oscillopsia of the afterimage in dark was noted; she perceived it moving with her gaze as she attempted to look at it. It appears that in some CN patients, the suppression of oscillopsia operates only within fixed limits of foveation stability and duration. When, because of internal or external factors, their nystagmus exceeds these, oscillopsia results.
在先天性眼球震颤（CN）病例中，关于视振荡的自发报告很少见。我们在一个这样的病例中研究了眼球震颤波形特征与视振荡之间的关系。为了减轻患者的眼球震颤，给她佩戴了隐形眼镜。在她佩戴隐形眼镜时，我们通过局部麻醉来研究触觉反馈的效果。当她不戴隐形眼镜时，我们通过轻轻按压一只眼睑来提供触觉反馈。我们还让她注视一个周边后像。如果注视点不稳定，则分析眼球震颤的频率、幅度、注视持续时间和漂移速度。记录感知到的目标稳定性。患者在初始基线记录期间和眼睑受压时表示有视振荡。在佩戴或不佩戴麻醉剂的隐形眼镜期间以及第二次基线记录期间，图像是稳定的；此时，漂移速度小于4度/秒，注视持续时间大于100毫秒。在黑暗中未观察到后像的视振荡；当她试图注视后像时，她感觉后像随着她的注视而移动。似乎在一些CN患者中，视振荡的抑制仅在注视稳定性和持续时间的固定范围内起作用。当由于内部或外部因素导致他们的眼球震颤超过这些范围时，就会出现视振荡。
