Retinal cone dysfunction of supernormal rod ERG type. Five new cases

Acta Ophthalmol (Copenh). 1993 Apr;71(2):246-55. doi: 10.1111/j.1755-3768.1993.tb04998.x.


Five patients, not related to each other, showed clinical signs, including electroretinograms, of a retinal dysfunction which mainly affected the cone system, but also involved the rod responses in a peculiar way. ERG b-wave threshold under dark adapted conditions was elevated. In contrast, rod b-wave sensitivity was enhanced with medium to high intensity flash stimulation. Furthermore, all patients had a severe reduction of the oscillatory potentials. The findings are discussed with special emphasis on a hypothetical disturbance in the cyclic guanosine monophosphate metabolism, involving both photoreceptors and cells of the inner plexiform layer responsible for retinal feedback mechanisms.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Child
  • Dark Adaptation
  • Electroretinography*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Oscillometry
  • Photic Stimulation
  • Photoreceptor Cells / physiopathology*
  • Retinal Diseases / physiopathology*
  • Sensory Thresholds