title: The S-cone electroretinogram: a comparison of techniques, normative data and age-related variation.
abstract: The blue sensitive mechanism in human colour vision is highly susceptible to damage in ocular disease. There is a need for objective methods to assess this and several methods of recording the blue cone (S-cone) electroretinogram (ERG) have been described. We therefore compared a silent substitution technique (SST) and a selective adaptation technique (SAT) using a novel combination of optical filters, on 24 normal subjects. The age-related variation in the S-cone ERG was also investigated in a further 73 normal subjects. S-cone ERGs elicited by SAT were of higher amplitude, (p < 0.001) with smaller coefficients of variation than those elicited with SST. The SST method has already been shown to be highly sensitive in primary open angle glaucoma and, unlike SAT, has no significant age related variation. However, the results of this study suggest that the new, SAT method may prove to be more convenient and effective in clinical practice, provided that age norms are applied.
authors.affiliation: Department of Optometry and Vision Sciences, Cardiff University, Cardiff, UK. z.chiti@bristol.ac.uk
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Chiti
authors.forename: Rachel V
authors.initials: RV
authors.lastname: North
authors.forename: Katharine E
authors.initials: KE
authors.lastname: Mortlock
authors.forename: Neville
authors.initials: N
authors.lastname: Drasdo
mesh_terms: D000221:Adaptation, Ocular; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003118:Color Perception / Q000502:physiology*; D004596:Electroretinography / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*