儿童外斜视手术前后多焦视觉诱发电位的变化

目的　研究儿童外斜视手术前后多焦视觉诱发电位（ｍｕｌｔｉｆｏｃａｌｖｉｓｕａｌｅｖｏｋｅｄｐｏ-ｔｅｎｔｉａｌ，ｍＶＥＰ）特征峰的变化。方法　采用德国Ｒｏｌａｎｄ多焦视觉电生理仪，对２０例外斜视力正常组和６０例外斜伴不同程度（轻度、中度、重度）弱视组患者进行ｍＶＥＰ的检测，并进行视网膜不同区域的斜视矫正术术前及术后１个月、３个月、６个月的比较。结果　外斜伴轻、中度弱视患者的ｍＶＥＰ特征峰振幅反应密度在第一、二、三环术后与术前相比均升高，术后３个月、６个月与术前相比差异均有统计学意义（均为Ｐ＜０．０５）。外斜伴轻、中度弱视组上下半侧视网膜的ｍＶＥＰ特征峰的振幅反应密度较术前提高，差异均有统计学意义（均为Ｐ＜０．０５）；潜伏期缩短，但差异均无统计学意义（均为Ｐ＞０．０５）。外斜伴中、重度弱视患者术后各组鼻侧视网膜ｍＶＥＰ特征峰的振幅反应密度与颞侧相比差异均有统计学意义（均为Ｐ＜０．０５）。结论　外斜伴弱视患者鼻颞侧视网膜的视觉传导通路均有不同程度损害，且鼻侧视网膜的视觉传导通路损害均重于颞侧视网膜。外斜伴轻度弱视患者术后ｍＶＥＰ特征峰振幅反应密度可有不同程度提高，提高程度鼻侧视网膜要高于颞侧，鼻颞侧视网膜特征峰振幅反应密度达到平衡；外斜伴中、重度患者术后鼻侧与颞侧视网膜特征峰振幅反应密度提高程度相近，鼻颞侧视网膜特征峰振幅反应密度仍未达到平衡。

Changes of multifocal visual evoked potential before and after exotropia surgery in children

Objective To study the characteristic changes of multifocal visual evoked potential ( mVEP) before and after exotropia surgery in children. Methods Eighty exotropic children including 20 exotropic children with normal visual and 60 exotropias children with amblyopia were chosen. All subjects were checked by Roland Retiscan multifocal visual evoked response imaging system which made by Germany Roland company. The different retinal areas were checked at pre-operation, postoperative I month.3 months and 6 months. Results The amplitudes density in the exotropic light-amblyopia group and exotropic mid-amblyopia group were improved at the first. second.third eccentricity after surgery at postoperative 3 months and 6 months, and there were statistical sigruficances compared with pre-operation ( all P < 0. 05 ) . The amplitudes density in upper and lower retinal hemifields of the exotropic light-amblyopia group and exotropic mid-amblyopia group were markedly improved , and there were statistical significances compared with pre-operation ( all P < 0. 05 ) , and the latencies were shorted,but there was no statistical significance ( all P > 0. 05 ) . The amplitudes density in the nasal retinal henufields were improved more than temporal retinal hemifields in exotropic mid-amblyopia group and weight-amblyopia group , there were statistical significance s( all P < 0. 05 ) . Conclusion In the exotropic amblyopia, compared with the temporal retinal hemifields .the contanunate in the nasal retinal hemifields are more serious at the visual transmission path. The amplitudes density and latencies in nasal retinal hemifields are improved more than temporal retinal hemifields. The nasal and temporal retinal hemifields keep balance in exotropic light-amblyopia, while there is unbalance in mid-amblyopia and weight-amblyopia.