弱视治愈儿童多导视觉诱发电位地形图研究

目的：研究弱视基本治愈儿童多导视觉诱发电位地形图的变化特征。方法：选取13．7′、27．5′及55′共3种空间频率对正常儿童及弱视基本治愈儿童进行多导视觉诱发电位地形图的研究，分析13个导联位的P1潜时及N1P1振幅，并对每一例地形图进行观察。结果：(1)仅在13．7′及27．5′方格，弱视眼的P1潜时同正常组相比显著延迟，而在55′方格两组间P1潜时差异无统计学意义；3种空间频率N1P1振幅在两组间的差异无统计学意义。(2)N1P1振幅的分布同正常组改变。(3)地形图：枕区高电位活动无类似半视野刺激现象。结论：弱视基本治愈儿童视力恢复正常，但视皮层的功能仅有部分恢复．另外振幅及潜时的恢复不平行，前者的改变早于后者，弱视的视觉中枢具有一定程度的可塑性。

Investigation of multi-channel visual evoked potentials in cured amblvopia

Objective: To investigate multi channel visual evoked potentials with different spatial frequencies in cured amblyopia. Methods: 44 controls (88 eyes) and 18 cured cases (33 eyes) were studied. Visual evoked potentials to 13.7, 27.5 and 55 check sizes were recorded from 13 scalp derivations, and P1 latency and N1P1 amplitude in all leads were analysed. The VEP topography of each subject was also analysed. Results: There were significant differences of P1 latency at all leads (P<0.05) at a check size of 13.7 and 27.5 between cured and normal group, being longer in the former. The N1P1 amplitude of cured amblyopic amblyopia did not have significant difference from normal group in large parts of leads at all spatial frequencies, and as were P1 latencies at 55 check size. The cured group also showed similarities in topography and N1P1 amplitude distribution as normal group. Entirely asymmetric responses were not found in this group. Conclusions: It is assumed that although the visual acuity reaches normal after treatment, the function of visual cortex may be only partially recovered. The changes of P1 latency and N1P1 amplitude may be not matched. It is considered that visual cortex still has plasticity to some extent in amblyoia and multi channel VEPs is of some value in observing the effect of treatment.