Blue and green cone mechanisms in retinitis pigmentosa.
Blue and green cone mechanisms in retinitis pigmentosa.
复制标题
色素性视网膜炎中的蓝色和绿色视锥细胞机制。
DOI：
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发表时间：
1977
影响因子：
4.4
通讯作者：
E. Berson
中科院分区：
文献类型：
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作者：
M. Sandberg;E. Berson
在不同遗传类型的视网膜色素变性中，在2.5度刺激下，发现仅在中央凹上方10度处，并且在某些情况下在中央凹中，蓝色和绿色锥体机制的增量阈值曲线明显异常。当视锥阈值异常时，由蓝色视锥机制确定的阈值（pi1和pi3）比由绿色视锥机制确定的阈值（pi4）更高。由绿色锥机制确定的保留值在低背景强度下比在中间和高背景强度下一致地更升高。在用2.5度刺激测试的给定患者中，蓝色和绿色视锥机制在中央凹周围相对于彼此的阈值升高可以在用单个小刺激测试的正常观察者中模拟。这些发现支持了这样一种观点，即在视网膜色素变性中，至少在中央凹周围，蓝色和绿色视锥细胞机制的总和池成比例地降低到低于正常水平，并且与这两种机制在光感受器水平上都是间接参与的这一观点相一致。
Pronounced abnormalities in the increment threshold curves for the blue and green cone mechanisms only 10 degrees above the fovea, and in some cases in the fovea as well, have been found with a 2.5 degrees stimulus in different genetic types of retinitis pigmentosa. Whenever cone thresholds were abnormal, thresholds determined by the blue cone mechanism (pi1 and pi3) were more elevated than those determined by the green cone mechanism (pi4). Thresholds determined by the green cone mechanism were consistently more elevated at low background intensities than at intermediate and high background intensities. Threshold elevations for the blue and green cone mechanisms relative to each other in the perifovea in a given patient tested with the 2.5 degrees stimulus could be simulated in normal observers tested with a single small stimulus. These findings support the idea that the summation pools for blue and green cone mechanisms are proportionally reduced below normal in retinitis pigmentosa, at least in the perifovea, and are compatible with the idea that both mechanisms are comparably involved at the photoreceptor level.