Ruether K, Kellner U
Charité-Virchow Eye Hospital, Berlin, Germany.
Acta Anat (Basel). 1998;162(2-3):169-77. doi: 10.1159/000046483.
Hereditary retinal dystrophies are most often disorders of photoreceptors and/or the retinal pigment epithelium. Structures secondary to the photoreceptor layer such as bipolar, horizontal, amacrine and ganglion cells are secondarily involved. In later stages of the disease a mild to moderate loss of inner retina occurs, but the second and third neurons remain surprisingly viable even in late and severe stages of retinal dystrophies. The function of the inner retina in patients suffering from hereditary retinal dystrophies is not easy to determine because it depends on the input of photoreceptors. The electroretinogram (ERG) offers several possibilities in this respect: b-wave, off-response (off-ERG), oscillatory potentials, scotopic threshold response of the flash ERG and the pattern ERG (PERG). We looked at two ERG tests: the PERG and the off-ERG. The PERG is an indicator of ganglion cell function. Its amplitude is related to the photoreceptor input determined by the flash ERG and visual field testing. But in cases of an undetectable flash ERG response the PERG can be recorded in some patients, but not in others. This may be an indication of a different effect on inner retinal function in different groups of patients. On- and off-responses are related to the function of depolarizing and hyperpolarizing bipolar cells. Evaluation of 301 patients with various retinal dystrophies revealed that most hereditary disorders primarily affect the photoreceptors or the pigment epithelium. In some patients, alterations of the on- and off-response amplitudes or implicit times were indicative of inner retinal disorders and different pathophysiologic mechanisms. However, interpretation has to be made carefully, as on- and off-responses may be influenced by dysfunction of photoreceptor synapses to bipolar cells, bipolar cells, Müller cells and intercellular matrix.
遗传性视网膜营养不良通常是光感受器和/或视网膜色素上皮的疾病。光感受器层的继发结构，如双极细胞、水平细胞、无长突细胞和神经节细胞，会继发受累。在疾病的后期，视网膜内层会出现轻度至中度的丧失，但即使在视网膜营养不良的晚期和严重阶段，第二和第三神经元仍出人意料地保持存活。遗传性视网膜营养不良患者的视网膜内层功能不易确定，因为它取决于光感受器的输入。视网膜电图（ERG）在这方面提供了几种可能性：b波、离反应（离ERG）、振荡电位、闪光ERG的暗视阈值反应和图形ERG（PERG）。我们研究了两种ERG测试：PERG和离ERG。PERG是神经节细胞功能的指标。其振幅与由闪光ERG和视野测试确定的光感受器输入有关。但在闪光ERG反应无法检测到的情况下，一些患者可以记录到PERG，但另一些患者则不能。这可能表明不同组患者对视网膜内层功能有不同影响。开反应和关反应与去极化和超极化双极细胞的功能有关。对301例各种视网膜营养不良患者的评估显示，大多数遗传性疾病主要影响光感受器或色素上皮。在一些患者中，开反应和关反应振幅或隐含时间的改变表明视网膜内层疾病和不同的病理生理机制。然而，由于开反应和关反应可能受光感受器与双极细胞、双极细胞、米勒细胞和细胞间基质功能障碍的影响，因此必须谨慎解释。
