Tang Jessica, Hui Flora, Coote Michael, Crowston Jonathan G, Hadoux Xavier
Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.
Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
Transl Vis Sci Technol. 2018 Sep 21;7(5):9. doi: 10.1167/tvst.7.5.9. eCollection 2018 Sep.
The photopic negative response (PhNR) of the light-adapted electroretinogram (ERG) holds promise as an objective marker of retinal ganglion cell function. We compared baseline detrending methods to improve PhNR repeatability without compromising its diagnostic ability in glaucoma.
Photopic ERGs were recorded in 20 glaucoma and 18 age-matched control participants. A total of 50 brief, red-flashes (1.6 cd.s/m) on a blue background (10 photopic cd/m) were delivered using the RETeval device. Detrending methods compared were: (1) increasing the high-pass filter from 1 to 10 Hz and (2) estimating and removing the trend with an increasing polynomial (order from 1-10) applied to the prestimulus interval, prestimulus and postsignal interval, or the whole ERG signal. Coefficient of repeatability (COR%), unpaired Student's -test, and area under the receiver operating characteristic curve (AUC) were used to compare the detrending methods.
Most detrending methods improved PhNR test-retest repeatability compared to the International Society for Clinical Electrophysiology of Vision (ISCEV) recommended 0.3 to 300 Hz band-pass filter (COR% ± 200%). In particular, detrending with a polynomial (order 3) applied to the whole signal performed the best (COR% ± 44%) while achieving similar diagnostic ability as ISCEV band-pass (AUC 0.74 vs. 0.75, respectively). However, over-correcting with higher orders of processing can cause waveform distortion and reduce diagnostic ability.
Baseline detrending can improve the PhNR repeatability without compromising its clinical use in glaucoma. Further studies exploring more complex processing methods are encouraged.
Baseline detrending can significantly improve the quality of the PhNR.
明适应视网膜电图（ERG）的明视负反应（PhNR）有望成为视网膜神经节细胞功能的客观标志物。我们比较了基线去趋势方法，以提高PhNR的可重复性，同时不损害其在青光眼诊断中的能力。
对20名青光眼患者和18名年龄匹配的对照参与者进行了明视ERG记录。使用RETeval设备在蓝色背景（10明视cd/m²）上总共发送50次短暂的红色闪光（1.6 cd·s/m²）。比较的去趋势方法有：（1）将高通滤波器从1 Hz增加到10 Hz；（2）使用应用于刺激前间隔、刺激前和信号后间隔或整个ERG信号的递增多项式（阶数从1到10）估计并去除趋势。使用重复性系数（COR%）、未配对学生t检验和受试者操作特征曲线下面积（AUC）来比较去趋势方法。
与国际临床视觉电生理学会（ISCEV）推荐的0.3至300 Hz带通滤波器相比，大多数去趋势方法提高了PhNR的重测可重复性（COR%±200%）。特别是，对整个信号应用多项式（3阶）去趋势表现最佳（COR%±44%），同时实现了与ISCEV带通相似的诊断能力（AUC分别为0.74和0.75）。然而，更高阶的处理过度校正会导致波形失真并降低诊断能力。
基线去趋势可以提高PhNR的可重复性，同时不损害其在青光眼临床中的应用。鼓励进一步研究探索更复杂的处理方法。
基线去趋势可以显著提高PhNR的质量。
