视网膜色素变性的黄斑局部视网膜电图频谱分析

Fourier analysis of macular local electroretinogram in retinitis pigmentosa

目的 通过对黄斑局部视网膜电图 (LERG)的Fourier分析 ,进一步了解视网膜色素变性(RP)患者黄斑部光感受器细胞与光感受器后神经元细胞功能异常的情况。方法 49例RP患者的LERG被记录研究。应用手提眼底镜式局部刺激器通过放大的瞳孔直视眼底监控固视状况 ,闪烁光频率 31Hz。结果 与对照组相比 ,LER的基波 (fundamentalharmonic ,1f)与二次谐波 (secondharmonic ,2f)在RP眼表现振幅降低。 1f的异常率在发病时间 <5年组、5～ 15年组、15～ 2 5年组与 2 5年以上组分别为 6 /11、9/14、10 /12、11/12 ,1f/2f的异常率为 2 /11、5 /14、7/12和 9/12。 1f/2f伴随发病年龄增加而呈升高趋势 ,并与视野的损害程度呈正相关。常染色体隐性与散发性RP患者的 1f与 2f下降程度较常染色体显性型RP明显 ,1f/2f比值明显升高 (P <0 .0 5 )。结论 (1)在视网膜色素变性眼 ,黄斑内层与外层视网膜的损害同时存在 ;(2 )基波与二次谐波的比值变化表明了视网膜内层与外层的相对损害程度 ,随着病情的发展 ,黄斑部内层的损害有加重的趋势 ;(3)不同遗传分型的视网膜黄斑功能受损程度与部位迥异。认为LERG的Fourier分析对RP眼黄斑功能异常的定位诊断具有临床意义。

Objective To understand the sites of macular dysfunction in retinitis pigmentosa (RP) by evaluating local electroretinogram (LERG) and further evaluating fundamental and second harmonic components. Methods LERG were recorded in 98 eyes of 49 patients to a flickered sinusoid of 31Hz and 10Hz with a hand held stimulator with direct visualization of the fundus through dilated pupils. Results Compared to controls, the patients showed losses of both fundamental and second harmonic amplitudes. The abnormality ratios of fundamental amplitudes in RP affected time <5 years,5 15 years,15 25 years and >25 years were 54%, 64%, 83% and 92% respectively; and the abnormality ratios of second harmonic amplitudes were 18%, 36%, 58% and 75% respectively. The fundamental second harmonic ratio was much more higher in the autosomal recessive and sporadic patients than in the autosomal dominant patients ( P <0.01). On average, the fundamental second harmonic ratio in the patients tended to increase with age. Conclusion The results suggest that in the retinitis pigmentosa, both receptoral and postreceptoral sites contribute to macular dysfunction. The level of macular dysfunction in different types of hereditary patients is different. It would be of clinical value to obtain a fundamental second harmonic ratio in order to assess the disturbance in different sites of macular.