视网膜电图明视负向反应对外伤性视神经萎缩的诊断意义

目的研究外伤性视神经萎缩的视网膜电图（ERG）各成分及其明视负向反应（PhNR）的变化特点，并进行PhNR与视网膜神经纤维层厚度（RNFLT）、视野平均缺损值（MD），以及杯盘比（C／D）的相关性研究，探索在外伤性视神经萎缩中PhNR的变化规律。方法选取外伤性视神经萎缩的患者21例（25眼）和与其性别年龄相匹配的正常人25例（25眼）。分别对两组进行ERG、视野、眼底照相和光学相干断层扫描（OCT）检查，比较两组视网膜电图，并将外伤性视神经萎缩组的PhNR振幅分别与MD、C／D和RNFLT进行相关性分析。结果外伤性视神经萎缩组的PhNR振幅比对照组明显下降（P〈0．01），而外伤性视神经萎缩组和对照组的ERG中暗视反应、最大反应、30Hz震荡电位的振幅差异无统计学意义，视神经萎缩组明视反应a波和b波振幅差异也无统计学意义。PhNR的振幅与视神经损伤情况如RNFLT（r=0．665）、MD（r=0．564）、杯盘比（r=0．686）等相关，且相关关系有统计学意义（P〈0．01）。结论视网膜电图PhNR振幅在外伤性视神经萎缩眼明显地下降甚至消失，PhNR可作为外伤性视神经萎缩的诊断和神经节细胞及其轴突功能评价的良好指标。

The photopic negative response of the flash electroretinogram in traumatic ocular nerve atrophy

Objective To study the wave form of the photopic negative response(PhNR) in electroretiongram(ERG),and the relationship between PhNR and retina nerve fibre layer thickness(RNFLT),visual field mean defect(MD),and cup/disc ratio(C/D).Investigate the function of PhNR in diagnosis of traumatic ocular nerve atrophy and evaluation of ocular nerve ganglion cells. Methods Twenty five normal cases(25 eyes) and twenty one traumatic ocular nerve atrophy cases(25 eyes) were taken into this study.They accepted the ERG,vsual fields,fundus photographs and optic coherence tomography(OCT) examination.Compared the PhNR amplitudes between two groups.Investigated the correlation between the amplitudes of the PhNR and RNFLT,MD and C/D. Results The amplitudes of the rod,maximum,and 30Hz flicker ERG between two groups were not different(P>0.05).The amplitudes of a,b wave in cone ERG between were not different,but the amplitudes of the PhNR were significantly reduced in group of traumatic ocular nerve atrophy(P<0.01).PhNR amplitude was significantly correlated with RNFLT(r=0.665,P<0.01),MD(r=0.564,P<0.01) and C/D(r=0.686,r=0.564). Conclusions(The amplitudes) of the PhNT were significantly reduced or disappeared in traumatic ocular nerve atrophy eyes,so it can be used to diagnose traumatic ocular nerve atrophy and evaluate the function of ganglion cells or their axons.