Seiple William, Greenstein Vivienne C, Holopigian Karen, Carr Ronald E, Hood Donald C
Department of Ophthalmology, New York University School of Medicine, New York, NY, USA.
Vision Res. 2002 Jan;42(2):257-69. doi: 10.1016/s0042-6989(01)00276-0.
The multifocal electroretinogram (mfERG) has been commonly used as a method for obtaining objective visual fields. Although qualitative comparisons have been good, quantitative comparisons between the results from mfERG and the results from Humphrey Visual Field Analyser (HVFA) have found variable degrees of agreement depending upon the mfERG response parameter examined and/or the disease studied. Lack of agreement may be due to differences in methodology, differences in the sites of response generation, and/or differences derived from comparing suprathreshold versus threshold responses. In addition, the two procedures are performed at different levels of adaptation. We developed an approach for matching stimulus parameters and compared mfERG and psychophysical thresholds to assess the effects of technique and level of adaptation on the two responses. Psychophysical and mfERG thresholds were obtained as a function of the adaptation level (1.5-4.0 log td) and retinal location. The derived increment threshold-versus-intensity functions for both measures were fitted using the equation logT=logT(0)+log((A+A(0))/A(0))(n). We found that the values of A(0) for the mfERG data were one log unit higher than those for the psychophysical data. In addition, the value of the slope (n) for the mfERG data was shallower (0.8) than that of the psychophysical data (1.0). Predictions were made about comparisons of HVFA threshold and mfERG amplitude data in patients with retinal disease based upon a two-site model of adaptation. The data for some groups of patients could be best-fitted with a model of a disease acting at a site distal to all gain changes, whereas data from other patients were best fitted with a model of a disease acting at a site proximal to all retinal gain. The relationship between the Humphrey visual field threshold losses and mfERG amplitude reductions depends upon the site and mechanism of a particular disease process and the model of retinal gain assumed. In no case is a one-to-one relationship between the losses in the two measures predicted.
多焦视网膜电图（mfERG）已被广泛用作获取客观视野的一种方法。尽管定性比较结果良好，但mfERG结果与 Humphrey 视野分析仪（HVFA）结果之间的定量比较发现，根据所检测的 mfERG 反应参数和/或所研究的疾病，一致性程度各不相同。一致性缺乏可能是由于方法学差异、反应产生部位的差异以及/或者比较超阈值与阈值反应所产生的差异。此外，这两种检查是在不同适应水平下进行的。我们开发了一种匹配刺激参数的方法，并比较了 mfERG 和心理物理学阈值以评估技术和适应水平对这两种反应的影响。心理物理学和 mfERG 阈值是作为适应水平（1.5 - 4.0 log td）和视网膜位置的函数而获得的。两种测量方法得出的增量阈值与强度函数均使用方程 logT = logT(0) + log((A + A(0))/A(0))(n)进行拟合。我们发现，mfERG 数据的 A(0)值比心理物理学数据的 A(0)值高一个对数单位。此外，mfERG 数据的斜率（n）值（0.8）比心理物理学数据的斜率值（1.0）更平缓。基于两点适应模型，对视网膜疾病患者的 HVFA 阈值和 mfERG 振幅数据比较进行了预测。某些患者组的数据最适合用一种疾病作用于所有增益变化远端部位的模型来拟合，而其他患者的数据最适合用一种疾病作用于所有视网膜增益近端部位的模型来拟合。Humphrey 视野阈值损失与 mfERG 振幅降低之间的关系取决于特定疾病过程的部位和机制以及所假定的视网膜增益模型。在任何情况下，都无法预测这两种测量方法的损失之间存在一对一的关系。
