Retinal function in carriers of Bardet-Biedl syndrome
Retinal function in carriers of Bardet-Biedl syndrome
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DOI：
10.1001/archopht.121.6.804
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发表时间：
2003-06-01
影响因子：
--
通讯作者：
Fulton, AB
中科院分区：
文献类型：
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作者：
Cox, GF;Hansen, RM;Fulton, AB
目的：为了验证Bardet-Biedl综合征携带者具有异常视杆介导反应的假设。方法：Bardet-Biedl综合征（BBS）儿童的父母（n=26），他们是BBS的专性携带者，同意进行暗视、全场视网膜电图（ERG）。在4至5个对数单位范围内记录反应，最大刺激约为+3.6 log暗视troland秒。研究了视杆细胞光反应激活参数S。（敏感性参数）和R-mp3（饱和视杆反应的振幅）通过将转导模型拟合到ERG a波而导出。对于b波，确定产生半最大响应（log sigma）和饱和振幅（V-max）的刺激。从完整的ERG中减去视杆细胞光反应模型，以证明角膜正电位（P-2），并确定log k（P2）和P-2 max。结果：所有父母的P-2敏感性降低，其中15例（60%）b波敏感性降低。视杆光反应敏感性和视杆细胞反应的饱和振幅，b波和P-2，没有显着差异载体和controls.Conclusions：减少P-2敏感性是BBS的载体的特点。BBS视杆通路中的原发性缺陷的位点似乎接近外节，最有可能在视杆-双极细胞突触之前。
Objective: To test the hypothesis that carriers of Bardet-Biedl syndrome have abnormal rod-mediated responses.Methods: Parents (n=26) of children with Bardet-Biedl syndrome (BBS), who are obligate carriers of BBS, consented to scotopic, full-field electroretinography (ERG). Responses were recorded over a 4 to 5 log unit range, up to a maximum stimulus of approximately +3.6 log scotopic troland seconds. The parameters of activation of the rod photoresponse, S.(sensitivity parameter) and R-mp3 (amplitude of the saturated rod response), were derived by fitting a transduction model to the ERG a-waves. For the b-wave, the stimulus producing a half maximum response (log sigma) and the saturated amplitude (V-max) were determined. The model of the rod photoresponse was subtracted from the intact ERG to demonstrate a corneal positive potential (P-2), and log k(P2) and P-2max were determined. The carriers' ERG responses were compared with those of healthy control subjects (n = 26).Main Outcome Measures: Sensitivity (S, log sigma, and log k(P2)) and saturated amplitude (R-mp3, V-max, and P-2max) of receptoral and postreceptoral response components.Results: All parents had decreased P-2 sensitivity, and most (15 [60%] of 26) had decreased b-wave sensitivity. The rod photoresponse sensitivity and the saturated amplitudes of the rod cell response, b-wave and P-2, did not differ significantly between carriers and controls.Conclusions: Diminished P-2 sensitivity is characteristic of the carriers of BBS. The site of the primary defect in the BBS rod pathway appears to be proximal to the outer segments, most likely before the rod-bipolar cell synapse.