Background

Electroretinogram (ERG) plays an essential role in the diagnosis of retinal disease. Choosing appropriate methods could extract valuable information from ERG. In this study, a new criterion based on time–frequency domain analysis was proposed to investigate the retina in retinitis pigmentosa (RP) patients.

Materials and methods

The total number of 16 eyes from eight RP patients and 20 eyes from age-matched healthy subjects were assessed. The signals included photopic and scotopic ERGs. Continuous wavelet transform was applied to ERGs. Dominant frequencies were extracted, and the contours related to these dominant frequencies were selected. As a new criterion, the areas related to dominant frequency contours were considered a feature to differentiate the RP and normal groups. To better evaluate the proposed criterion results, the time-domain analysis characteristics of ERG were also considered.

Results

The results showed an increase in implicit time and reduced amplitude in RP patients (P < 0.05). A significant decrease of dominant frequencies and increasing their occurrence time were seen in ERG of RP patients. Also, in RP patients, the third dominant frequency was disappeared from the three main frequencies observed in photopic ERGs of normal subjects. The area criterion showed a significant decrease in RP groups (P < 0.05).

Conclusion

RP can cause changes in the time and time–frequency components of the ERG. The area index could represent a new view of the characteristics of the ERG in the time–frequency domain. This criterion can help the ophthalmologist to have a better evaluation of retinal disease.

中文翻译：

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视网膜色素变性患者视网膜电图评价新标准

背景

视网膜电图 (ERG) 在视网膜疾病的诊断中起着至关重要的作用。选择合适的方法可以从 ERG 中提取有价值的信息。在这项研究中，提出了一种基于时频域分析的新标准来研究视网膜色素变性 (RP) 患者的视网膜。

材料和方法

评估了来自 8 名 RP 患者的 16 只眼睛和来自年龄匹配的健康受试者的 20 只眼睛的总数。信号包括明视和暗视 ERG。连续小波变换应用于 ERG。提取主导频率，并选择与这些主导频率相关的轮廓。作为一个新标准，与主频率轮廓相关的区域被认为是区分 RP 和正常组的一个特征。为了更好地评估所提出的标准结果，还考虑了 ERG 的时域分析特性。

结果

结果显示RP患者的隐性时间增加，幅度降低（P  < 0.05）。在 RP 患者的 ERG 中观察到显性频率的显着降低和它们的发生时间的增加。此外，在 RP 患者中，第三个主频率从正常受试者的明视 ERG 中观察到的三个主要频率中消失。面积标准显示 RP 组显着减少（P  < 0.05）。

结论

RP 会导致 ERG 的时间和时频分量发生变化。面积指数可以代表 ERG 在时频域中的特征的新视图。这个标准可以帮助眼科医生更好地评估视网膜疾病。