原发性视神经萎缩患者视网膜电图明视负向反应振幅异常

目的研究视网膜电图(ERG)明视负向反应(PhNR)在原发性视神经萎缩进展中的变化特点以及与视网膜神经纤维层厚度(RNFLT)的关系。设计前瞻性、对照性研究。研究对象正常健康者18例(18眼)和原发性视神经萎缩稳定期患者15例(18眼)及7例(7眼)视神经挫伤导致视神经萎缩的患者。方法对正常健康者和原发性视神经萎缩者进行ERG和相干光断层扫描(OCT)检查,比较两组PhNR振幅,并将原发性视神经萎缩者的PhNR振幅与RNFLT进行相关分析;另对视神经挫伤导致视神经萎缩者随访半年,研究其PhNR振幅与RNFLT变化规律。主要指标PhNR振幅与RNFLT。结果稳定期原发性视神经萎缩组和对照组的ERG中暗视反应、最大反应、30Hz震荡电位的振幅及明视反应a波和b波振幅差异均无显著性意义,但原发性视神经萎缩组的PhNR振幅比对照组明显下降(P<0.01),而且PhNR的振幅与RNFLT显著相关(r=0.688,P<0.01)。视神经挫伤导致视神经萎缩的患者随访第1~3个月,PhNR振幅下降先于RNFLT的变薄。结论原发性视神经萎缩眼ERGPhNR振幅明显下降甚至消失,且PhNR振幅下降早于RNFLT变薄。

The significance of photopic negative response in early diagnosis of primary optic nerve atrophy

Objective To study the waveform of the photopic negative response (PhNR) in electroretinogram(ERG), the relationship between PhNR and retina nerve fiber layer thickness(RNFLT), and to determine how the PhNR and RNFLT altered after onset of symptom. Design Prospective, comparative case series. Participants Eighteen cases (18 eyes) of normal subjects, fifteen cases (18 eyes) of primary optic nerve atrophy and seven cases (7 eyes) of secondary optic nerve atrophy. Methods The normal group and primary optic nerve atrophy group were performed with ERG and optic coherence tomography (OCT)examination. Compare the PhNR amplitudes between these two groups, and investigate the correlation between the amplitudes of the PhNR and RNFLT. Another seven cases (7 eyes) were taken into the follow up study, investigate how the PhNR and RNFLT are altered after onset of symptom. Main Outcome Measures PhNR and RNFLT. Results There are no difference between the amplitudes of the rod, maximum, 30Hz flicker ERG, and a, b wave in cone ERG of two groups(P>0.05). But the amplitudes of the PhNR were significantly reduced in group of primary optic nerve atrophy (P<0.01), and the PhNR amplitude was significantly correlated with RNFLT(r=0.688, P<0.01). During the first 3 months after symptom onset, the PhNR dropped earlier than RNFLT. Conclusion In primary optic nerve atrophy eyes the amplitudes of the PhNR were significantly reduced or disappeared, and dropped earlier than RNFLT change.