Threshold suprachoroidal–transretinal stimulation current resulting in retinal damage in rabbits
Threshold suprachoroidal–transretinal stimulation current resulting in retinal damage in rabbits
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DOI：
10.1088/1741-2560/4/1/s07
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发表时间：
2007-02
影响因子：
4
通讯作者：
K. Nakauchi;T. Fujikado;H. Kanda;S. Kusaka;M. Ozawa;H. Sakaguchi;Y. Ikuno;M. Kamei;Y. Tano
中科院分区：
文献类型：
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作者：
K. Nakauchi;T. Fujikado;H. Kanda;S. Kusaka;M. Ozawa;H. Sakaguchi;Y. Ikuno;M. Kamei;Y. Tano
本研究的目的是确定阈值脉络膜上-跨视网膜刺激（STS）电流，导致视网膜损伤的兔子。使用100 µm直径的铂丝电极，使用双相STS脉冲（先阳极，频率20 Hz）连续刺激有色家兔（n = 18）的视网膜1 h。1 h后，通过检眼镜或荧光素血管造影（FA）独立测定诱导视网膜损伤的STS电流。研究了脉冲宽度对阈值电流的影响。在电刺激实验后进行组织学研究。视网膜安全电流阈值为0.6 mA，持续时间为0.5 ms。安全充电阈值随着刺激持续时间的增加而近似线性增加，但安全电流阈值随着刺激持续时间的增加而呈对数下降。安全电能的阈值在所有持续时间内几乎保持不变。组织学检查显示，当电流超过阈值时，视网膜严重损伤，与视网膜外层相比，内层损伤更严重。安全电流的阈值高于直接刺激神经组织的阈值，表明STS方法是安全的，能够与视网膜假体一起使用。由于安全充电的阈值在较短的脉冲持续时间下较低，因此应小心使用短持续时间的脉冲。
The purpose of this study is to determine the threshold suprachoroidal–transretinal stimulation (STS) current that results in retinal damage in rabbits. Biphasic STS pulses (anodic first, frequency 20 Hz) were used to stimulate the retina of pigmented rabbits (n = 18) continuously for 1 h using a 100 µm diameter platinum wire electrode. The STS current that induced retinal damage after 1 h was determined by ophthalmoscopy or by fluorescein angiography (FA) independently. The effect of the pulse duration on the threshold current was investigated. Histological studies were performed after electrical stimulation experiments. The threshold for a safe current to the retina was 0.6 mA for a duration of 0.5 ms. The threshold for a safe charge increased approximately linearly with an increase of stimulus duration but the threshold for a safe current decreased logarithmically with an increase of duration. The threshold for a safe electrical energy remained almost constant for all durations. Histological examination showed severe retinal damage when the current exceeded the threshold, with more damage in the inner layers compared with the outer layers of the retina. The threshold for the safe current was higher than that reported for direct stimulation of neural tissues, suggesting that the STS method was safe and able to be used with a retinal prosthesis. Because the threshold for the safe charge was lower with shorter pulse durations, care should be taken using pulses of short durations.