急性视神经炎后视神经功能与视觉诱发电位的研究（英文）

Optic nerve functions and visual evoked potential after acute optic neuritis

目的:比较视神经炎患者和正常人的视神经功能与视觉诱发电位。方法:本研究为2011年9月至2013年2月在马来西亚大学眼科医院进行的横断面研究。研究包含在检查前3mo至2y间发生特发性神经炎一次的视神经炎患者20例和10例正常人。眼科检查包括视力、色觉、视觉灵敏度、视野和视觉诱发电位。独立t检验用于比较视神经炎组与对照组视神经功能和VEP参数的差异。在参数非正态分布时,Mann-Whitney试验用于比较两组间的中位数。结果:视神经炎组的平均年龄为30.8岁。在视神经炎发作至评估期间的平均持续时间为6.6个月。视神经炎组视力较差,平均LogM AR值(0.52)明显高于对照组(P=0.001)。色觉下降,视神经炎组的平均值为63%(P=0.001)。视神经炎患者的对比敏感度在四个空间频率上均有所下降[3CPD(P=0.029),6CPD(P=0.026),12CPD(P=0.002)、18CPD(P=0.006)]。视神经炎组的视野下降有统计学意义(P<0.001)。与对照组相比,视神经炎组的VEP P100潜伏期有轻微延长。但使用棋盘格模式1或2时,VEP潜伏期的差异不显著。视神经炎患者的VEP振幅较高,但两组差异无统计学意义。结论:视神经炎急性发作,平均6mo后视神经功能(即视力、色觉、对比敏感度和视野)显著下降。视神经炎组和对照组的VEP振幅和潜伏期无显著差异。VEP可能不是理想的诊断视神经炎既往发作史的试验,尽管VEP参数在浮动后趋于正常。

AIM： To compare the optic nerve function and visual evoked potential（VEP）between optic neuritis patients and normal individuals. METHODS： A cross-sectional study was conducted at the Eye Clinic of Hospital Universiti Sains Malaysia（HUSM）between September 2011 and February 2013. We recruited twenty optic neuritis patients with a single episode of idiopathic optic neuritis occurring between 3mo and 2y prior to examination, and twenty control subjects. Ocular examination included visual acuity, colour vision, contrast sensitivity, visual field and pattern VEP. Independent t-test was conducted to compare the differences in the means of optic nerve function and VEP parameters between the optic neuritis group and control group. In parameters that were not normally distributed, Mann-Whitney test was used to compare the medians between the two groups. RESULTS： In the optic neuritis group, the mean age was 30.8y. The mean duration between the episode of optic neuritis and the time of evaluation was 6.6mo. The visual acuity was poorer in the group with optic neuritis, with the mean LogMAR score（0.52）being significantly higher in this group than in controls（P=0.001）. Colour vision was likewise decreased, with a mean score of 63.0% in the optic neuritis group（P=0.001）. Contrast sensitivity was reduced in all four spatial frequencies; 3CPD（P=0.029）, 6CPD（P=0.026）, 12CPD（P=0.002）and 18CPD（P=0.006）in patients with optic neuritis. There was also a statistically significant loss of visual field in this group（P≤0.001）. Although subjects with optic neuritis had a slightly prolonged VEP P100 latency compared to normal subjects, this difference in VEP latency was not significant using checkerboard pattern 1 or 2. Higher VEP amplitude was observed in optic neuritis subjects, but the difference between groups was not statistically significant. CONCLUSION： There were significant reductions in optic nerve functions（i.e. visual acuity, colour vision, contrast sensitivity and visual field）at a mean of 6mo after an acute attack of optic neuritis. However, no significant differences in VEP amplitude and latency were noted between patients with optic neuritis and the control group. VEP may not be the ideal test to diagnose a previous attack of optic neuritis, as VEP parameters tend to normalize after a variable interval.