Pattern electroretinography in routine clinical diagnosis of open angle glaucoma

: According to current opinion, the pattern electroretinogram (ERG) is generated in the retinal ganglion cells. Therefore, the amplitude is expected to be reduced in diseases of the optic nerve. This leads to the conclusion that the pattern ERG might be applied in detecting ganglion cell loss in the routine clinical diagnosis of chronic open-angle glaucoma. Pattern ERGs were recorded in 15 patients with defined chronic open-angle glaucoma and 21 control individuals using a DTL fiber electrode at two different check sizes. A Fourier analysis of the ERG results reduces the subjectivity when analysing the amplitudes on screen and implies the possibility of multicentric comparability. The reliability of coordinating a value of a future patient to the correct group was estimated to 82% for the Fourier data by the bivariate discriminant analysis, based on the amplitudes of both check sizes. In this way, the relatively high interindividual variability will be partly overcome. The ability of the ERG amplitudes to separate glaucoma patients from healthy persons was determined by the AUC value, using a combination of sensitivity and specificity extracted from the ROC curves. The AUC value has its maximum at 1.0. We found an AUC value of 0.8, which confirmed the information given by the pattern ERG amplitudes. Healthy individuals and glaucoma patients cannot be separated completely by the procedure but, combined with additional clinical parameters, further validation can be achieved.