Kocher L, Perenin M T
J Fr Ophtalmol. 1983;6(10):843-51.
Visual deprivation during the first few months of life is known to result in a severe and irreversible visual deficit. Animal models of amblyopia developed during the past 20 years has considerably increased our knowledge of the "sensitive period" during which deprivation can lead to irreversible effects, and of the anatomical and physiological changes underlying this visual deficit. However precise data regarding either the duration of the sensitive period or the nature of the amblyopic deficit are still mostly lacking in humans. Preliminary results on the latter topic are reported in the present paper. Contrast sensitivity function (CSF) has been studied using stationary sinusoidal gratings in three patients with deprivation amblyopia resulting from bilateral congenital cataracts and in nine normal emmetropic subjects. Compared with these control subjects, the three amblyopic patients showed a dramatic decrease of their CSF with a maximal drop in the high and medium spatial frequency range and a relative sparing at low spatial frequencies. Within the framework of current theories of parallel processing of visual information through the geniculostriate pathway, these results indicate that early visual deprivation in man severely affects development of "sustained" channels involved in form perception. Further studies are underway to explore "transcient" channels in similar cases.
众所周知，出生后头几个月的视觉剥夺会导致严重且不可逆的视力缺陷。在过去20年中建立的弱视动物模型极大地增加了我们对“敏感期”的认识，在这个时期，剥夺会导致不可逆的影响，以及对这种视力缺陷背后的解剖学和生理学变化的认识。然而，关于敏感期的持续时间或弱视缺陷的性质的精确数据在人类中仍然大多缺乏。本文报道了关于后一主题的初步结果。使用静态正弦光栅对三名因双侧先天性白内障导致剥夺性弱视的患者和九名正常正视眼受试者进行了对比敏感度函数（CSF）研究。与这些对照受试者相比，三名弱视患者的CSF显著下降，在高空间频率和中空间频率范围内下降最大，而在低空间频率处相对保留。在当前通过膝状体纹状体通路对视觉信息进行并行处理的理论框架内，这些结果表明，人类早期视觉剥夺严重影响参与形状感知的“持续”通道的发育。正在进行进一步的研究以探索类似病例中的“瞬态”通道。
