Visual evoked potential-based acuity assessment in normal vision, artificially degraded vision, and in patients
Visual evoked potential-based acuity assessment in normal vision, artificially degraded vision, and in patients
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DOI：
10.1136/bjo.2007.130245
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发表时间：
2008-03-01
影响因子：
4.1
通讯作者：
Wolf, M. E.
中科院分区：
文献类型：
--
作者：
Bach, M.;Maurer, J. P.;Wolf, M. E.
目的：目的：采用视觉诱发电位（VEP）客观评价视力，避免主观痕迹评价，提供一种具有相关置信限的视力估计值。方法：40例正常人和24例角膜和视网膜疾病患者（视力范围为0.15-1.1（=0.8（logMAR）~-0.04（logMAR）参加了本研究。在7.5 Hz下，以闪烁起始模式（开40 ms，关93 ms）呈现具有6个检查大小的棋盘刺激，覆盖0.05-0.4度（或对于视力低于0.35（=0.46（logMAR））为0.09-0.8度）。在正常受试者中，磨砂封堵器也使刺激发生光学降解，导致十进制VA范围为0.13-2.8（=0.9（logMAR）至-0.45（logMAR））。共记录了108个稳态VEP，采用Laplacian导联（2xOz-（RO+LO））。傅立叶分析产生刺激频率处的幅度（A），以及两个相邻频率的平均值作为噪声估计（N）。A和N确定响应的显著性水平p，并且从它们的比率可以计算非噪声污染响应（A*）。调谐曲线通过绘制A* 与相应棋盘格的主空间频率的关系而获得。全自动算法使用显著性水平（p
Aims: To assess visual acuity (VA) objectively using visual evoked potentials (VEPs), avoiding subjective trace evaluation and providing an acuity estimate with associated confidence limits.Methods: 40 normal subjects and 24 patients (with corneal and retinal diseases, decimal VA range 0.15-1.1 (=0.8(logMAR) to -0.04(logMAR))) participated in the study. Checkerboard stimuli with six check sizes covering 0.05-0.4 degrees (or 0.09-0.8 degrees for visual acuities below 0.35 (=0.46(logMAR)) were presented in brief-onset mode (40 ms on, 93 ms off) at 7.5 Hz. In normal subjects, the stimuli were also optically degraded by frosted occluders resulting in a decimal VA range of 0.13-2.8 (=0.9(logMAR) to -0.45(logMAR)). Altogether, 108 steady-state VEPs were recorded with a Laplacian montage (2xOz-(RO+LO)). Fourier analysis yielded the magnitude (A) at the stimulus frequency, and the average of the two neighboring frequencies as noise estimate (N). A and N determine the significance level p of the response, and from their ratio the non-noise-contaminated response (A*) can be calculated. Tuning curves were obtained by plotting A* vs the dominant spatial frequency of the corresponding checkerboard. A fully automatic algorithm used the significance level (p