Bach M, Birkner-Binder D, Pfeiffer N
Universitäts-Augenklinik Freiburg.
Ophthalmologe. 1993 Apr;90(2):128-31.
The pattern electroretinogram (PERG), a noninvasive tool to measure the activity of retinal ganglion cells, shows changes in early glaucoma. We wanted to investigate whether or not the PERG is preferentially affected when the Bjerrum area is stimulated. We recorded the PERG from 17 eyes in 17 patients with initial stages of visual field defects due to open-angle glaucoma and from 10 eyes in 10 normal subjects. Counter-phasing checkerboard patterns were used as visual stimuli with a check size of 0.8 degrees at 16 reversals/s and 98% contrast. Three visual field extents were stimulated: (1) full screen (31 degrees x 27 degrees), (2) central stimulation with a diameter of 14 degrees, (3) peripheral stimulation = full screen with central mask of 14 degrees in diameter. The latter stimulus covers the regions where traditionally glaucomatous defects are expected early. In glaucoma patients, there was a significant decrease in the PERG amplitude compared to normals. This reduction was very similar for all three stimuli (42%, 52% and 47%, respectively). Thus, the PERG amplitude is reduced to a similar degree both in regions of the visual field where early damage is found (Bjerrum area) and in the central area. This result suggests that in early glaucoma there is focal as well as diffuse retinal damage.
图形视网膜电图（PERG）是一种用于测量视网膜神经节细胞活动的非侵入性工具，它在早期青光眼时会出现变化。我们想要研究当刺激 Bjerrum 区时，PERG 是否会受到优先影响。我们记录了 17 例开角型青光眼所致视野缺损初始阶段患者的 17 只眼睛以及 10 名正常受试者的 10 只眼睛的 PERG。使用反相棋盘格图案作为视觉刺激，方格大小为 0.8 度，翻转频率为 16 次/秒，对比度为 98%。刺激了三种视野范围：（1）全屏（31 度×27 度），（2）直径为 14 度的中央刺激，（3）周边刺激 = 全屏减去直径为 14 度的中央遮挡。后一种刺激覆盖了传统上预期早期会出现青光眼性缺损的区域。与正常受试者相比，青光眼患者的 PERG 振幅显著降低。对于所有三种刺激，这种降低非常相似（分别为 42%、52%和 47%）。因此，在视野中早期发现损伤的区域（Bjerrum 区）和中央区域，PERG 振幅降低的程度相似。这一结果表明，在早期青光眼中存在局灶性以及弥漫性视网膜损伤。
