[Electrophysiological examination methods in glaucoma diagnostics].

The two currently used most successful techniques for early detection of glaucoma are described. (1) The pattern electroretinogram (PERG) allows detection of incipient glaucomatous damage in eyes with ocular hypertension up to 4 years ahead of manifest glaucoma with a sensitivity and specificity of approximately 75%. This is achieved by selecting optimized stimulation (check size and stimulation frequency) and analysis protocols (amplitude ratio to different check sizes). The major disadvantage is the requirement for best corrected visual acuity to be at least 0.8(decimal) to avoid false positive results. (2) The photopic negative response (PhNR), a component of the Ganzfeld ERG, does not suffer from optical factors reducing visual acuity. It is also affected in early glaucoma but so far has not achieved the same sensitivity and specificity as the PERG.