Pigmentary paravenous chorioretinal degeneration: fundus appearance and retinal functions

A case of pigmentary paravenous chorioretinal degeneration initially diagnosed as retinitis pigmentosa is presented. The focal macular visual evoked response (VER) was normal. Both rod and cone components in the electroretinogram showed reduced amplitude with normal peak time. The psychophysical threshold in the dark adaptation was nearly normal in some parts of the retina and extremely elevated in other parts of the retina. Fundus appearance and retinal function studies suggest that the impaired area in the retina and choroid is localized in this disease.