Frishman L J, Shen F F, Du L, Robson J G, Harwerth R S, Smith E L, Carter-Dawson L, Crawford M L
College of Optometry, University of Houston, Texas 77204-6052, USA.
Invest Ophthalmol Vis Sci. 1996 Jan;37(1):125-41.
This study describes the dark-adapted electroretinograms (ERGs) of macaque monkeys with severe visual field defects and substantial retinal ganglion cell loss as a consequence of long-standing ocular hypertension.
Monocular experimental glaucoma was produced by argon laser trabeculoplasty, and visual fields were assessed with behavioral static perimetry. Electroretinographic responses to brief ganzfeld flashes under fully dark-adapted conditions were recorded using DTL fiber electrodes in anesthetized animals. The authors quantified retinal layer thickness and cell loss in 1-micron radial sections and inspected optic nervous under the light microscope.
At the lowest intensities, a sensitive negative component of the scotopic ERG, which normally peaks approximately 200 msec after stimulus onset, was present in the control eyes but was reduced greatly or was virtually absent in the experimental eyes of monkeys with severe visual field loss. A previously unreported sensitive positive component of the scotopic ERG remained in both eyes. In the control eyes, the positive component gave rise to a sharp peak approximately 120 msec after stimulus onset, but in the experimental eyes, because of the absence of the more delayed sensitive negative potential, it was sustained, lasting as long as 700 msec. Scotopic a- and b-waves and oscillatory potentials in the experimental eyes were not consistently different from control eyes. Ganglion cell and optic nerve loss in the experimental eyes was substantial, and there was little other obvious retinal damage.
A sensitive negative component is reduced or absent from the dark-adapted ERGs of macaque monkeys with severe visual field defects and substantial retinal ganglion cell loss as a consequence of long-standing ocular hypertension.
本研究描述了因长期高眼压导致严重视野缺损和大量视网膜神经节细胞丢失的猕猴的暗适应视网膜电图（ERG）。
通过氩激光小梁成形术制造单眼实验性青光眼，并用行为静态视野计评估视野。在麻醉动物中使用DTL纤维电极记录在完全暗适应条件下对短暂全视野闪光的视网膜电图反应。作者在1微米径向切片中量化视网膜层厚度和细胞丢失，并在光学显微镜下检查视神经。
在最低强度下，暗视ERG的一个敏感负成分，通常在刺激开始后约200毫秒达到峰值，在对照眼中存在，但在严重视野缺损的猴子的实验眼中大大降低或几乎不存在。暗视ERG中一个先前未报道的敏感正成分在两只眼中均保留。在对照眼中，正成分在刺激开始后约120毫秒产生一个尖锐峰值，但在实验眼中，由于没有更延迟的敏感负电位，它持续存在，持续长达700毫秒。实验眼中的暗视a波和b波以及振荡电位与对照眼没有一致的差异。实验眼中的神经节细胞和视神经丢失严重，几乎没有其他明显的视网膜损伤。
因长期高眼压导致严重视野缺损和大量视网膜神经节细胞丢失的猕猴的暗适应ERG中，敏感负成分减少或缺失。
