Effects of experimental glaucoma in macaques on the multifocal ERG: Multifocal ERG in laser-induced glaucoma
Effects of experimental glaucoma in macaques on the multifocal ERG: Multifocal ERG in laser-induced glaucoma
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DOI：
10.1023/a:1002735804029
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发表时间：
2000-01-01
影响因子：
1.4
通讯作者：
Barnes, George
中科院分区：
文献类型：
--
作者：
Frishman, Laura J.;Saszik, Shannon;Barnes, George
本文对5只激光诱发青光眼的视网膜内层缺损的成年猕猴和3只视网膜内层活动受抑制的猕猴的多焦视网膜电图（MERG）进行了比较。用DTL纤维电极记录麻醉猴的MERG。刺激物由103个大小相等的六边形组成，位于中心凹的17度范围内。每个位置的刺激都经过典型的VERIS m序列的白色（200 cd/m2）和黑色（12 cd/m2）呈现。在激光诱导青光眼的动物中，使用Humphrey C24-2全阈值程序通过静态视野检查评估视野敏感度，该程序针对动物行为进行了修改。玻璃体内注射TTX（4.7-7.6 μ M）和NMDA（1.6-5 mM）可抑制视网膜内层（无长突细胞和神经节细胞）的活性。在正常眼中，一阶响应（一阶核）更大且更复杂，在中央比在周边位置具有更明显的振荡（>60 Hz）。二阶内核也是由振荡活动为主。两个内核都有鼻时变化。药物抑制内视网膜活动减少或消除了振荡行为和鼻颞变化。一阶核振幅增加最多，在中心凹处最大。移除的内层视网膜反应在中央凹处也最大。二阶核在所有位置都大大减少。在患有晚期青光眼的眼睛中，效果类似于通过抑制内部视网膜活动产生的效果，但是第一阶内核波形的后部分不同，在大的正波之后缺乏下降。视敏度丧失和MERG变化均随青光眼的时间进程而增加，其中MERG的变化在整个视野中更弥散地分布。我们的结论是，第一和第二阶反应的灵长类动物MERG可以确定，起源于视网膜内层，是敏感的指标青光眼性神经病变。
Multifocal ERGs (MERGs) of 5 adult monkeys (Macaca mulatta) with inner retinal defects caused by laser-induced glaucoma were compared to MERGs from 3 monkeys with inner retinal activity suppressed pharmacologically. MERGs were recorded with DTL fiber electrodes from anesthetized monkeys. Stimuli consisted of 103 equal size hexagons within 17degree of the fovea. Stimuli at each location passed through a typical VERIS m-sequence of white (200 cd/m2) and black (12 cd/m2) presentations. In animals with laser-induced glaucoma, visual field sensitivity was assessed by static perimetry using the Humphrey C24-2 full-threshold program modified for animal behavior. Inner retinal (amacrine and ganglion cell) activity was suppressed by intravitreal injection of TTX (4.7-7.6 muM) and NMDA (1.6-5 mM). In normal eyes the first order response (1st order kernel) was larger and more complex, with more distinct oscillations (>60 Hz) in central than in peripheral locations. The 2nd order kernel also was dominated by oscillatory activity. There were naso-temporal variations in both kernels. Pharmacological suppression of inner retinal activity reduced or eliminated the oscillatory behavior, and naso-temporal variations. The 1st order kernel amplitude was increased most and was largest at the fovea. Removed inner retinal responses also were largest at the fovea. The 2nd order kernel was greatly reduced at all locations. In eyes with advanced glaucoma, the effects were similar to those produced by suppressing inner retinal activity, but the later portion of the 1st order kernel waveform was different, lacking a dip after the large positive wave. Visual sensitivity losses and MERG changes both increased over the timecourse of glaucoma, with changes in the MERG being more diffusely distributed across the visual field. We conclude that 1st and 2nd order responses of the primate MERG can be identified that originate from inner retina and are sensitive indicators of glaucomatous neuropathy.