Evaluation of the central retina and optic nerve function in media opacities

Conventional electroretinogram (ERG) and pattern VECP (or visual evoked cortical potential) are of limited value in estimating visual function in eyes with media opacities. We used a method consisting of flicker ERG and flicker VECP to successfully overcome this limitation. Three of 25 eyes with cataract had a reduced flicker VECP. These 3 patients also had a history of glaucomatous optic nerve damage. Normal flicker VECP was found in some patients with reduced flicker ERG or reduced scotopic and photopic a-wave. Analysis of the results showed that the flicker VECP is independent of the ERG and flicker ERG. Utilizing this method we could rule out maculopathy and optic nerve damage in patients with media opacities as well as recognize optic nerve damage in patients with coexisting maculopathy.