The pattern electroretinogram in patients with optic nerve disease

We analyzed the electroretinogram elicited by pattern stimuli (PERG) in 29 patients with unilateral optic nerve disease. The normal fellow eyes served as a control. When the normal fellow eye was covered and the patient was asked to watch the center of the pattern stimuli with the affected eye, the poor fixation often caused irregular eye movements which resulted in a poor reproducibility of the response. In such instance we opened the normal fellow eye for fixation, which helped to stabilize the affected eye being examined even when visual acuity was extremely poor. The cross-talk phenomenon of the ERG and the reflection of the VER from the normal fellow eye were proved negligible in this recording condition. We analyzed PERGs in comparison with the visual acuity and the degree of optic atrophy. Unlike the results of many previous authors, little correlation was observed between PERG and these two factors. Most patient showed normal or only slightly abnormal PERG, even when the visual acuity was extremely poor and the optic disc was completely atrophic. Our results suggest that, at least with our method, PERG has extremely limited value in detection of optic nerve disease.