C wave study in optic neuritis due to demyelinating disease.

The C wave was recorded from 20 eyes suffering from neuritis due to demyelinating disease and in 5 eyes showing optic atrophy due to trauma or to increased intracranial pressure. Our results show that in cases with optic neuritis the C wave amplitude was clearly lower than normal. It is interesting that in the other 'healthy', at least clinically, eye the C wave was subnormal too. On the contrary, in the eyes with optic atrophy the C wave was normal. These findings are against the possibility of an efferent neuronal pathway involvement, which influences the level of the retinal pigment epithelium, and support the view of its involvement during the course of the demyelinating disease that causes the optic neuritis.