title: Silent substitution S-cone electroretinogram in subjects with diabetes mellitus.
abstract: A defect in the blue sensitive mechanism has been reported in certain ocular and systemic diseases. For example, tritanopic colour vision defects and changes to the S-cone electroretinogram (ERG) have been demonstrated in glaucoma and diabetes mellitus. Electrophysiological methods of eliciting the S-cone ERG, however, often result in considerable L- and M-cone intrusion. We report the findings of a study employing the silent substitution S-cone ERG technique, which is thought to represent an almost pure S-cone signal, and the L'Anthony desaturated D15 colour vision test in subjects with Type 1 or 2 diabetes mellitus with no or minimal background retinopathy. The results of this study show a significantly increased S-cone ERG b-wave implicit time and significantly worse colour vision in those with background retinopathy compared with those with no diabetic retinopathy. This suggests that S-cone pathway dysfunction may be responsible for the deterioration in colour vision found in diabetes mellitus.
authors.affiliation: School of Optometry and Vision Sciences, Cardiff University, Redwood Building, King Edward VII Avenue, Cathays Park, Cardiff, CF10 3NB, UK.
authors.forename: Katharine E
authors.initials: KE
authors.lastname: Mortlock
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Chiti
authors.forename: Neville
authors.initials: N
authors.lastname: Drasdo
authors.forename: David R
authors.initials: DR
authors.lastname: Owens
authors.forename: Rachel V
authors.initials: RV
authors.lastname: North
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003117:Color Vision Defects / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000150:complications / Q000503:physiopathology; D004596:Electroretinography / Q000379:methods; D006801:Humans; D008875:Middle Aged; D017949:Retinal Cone Photoreceptor Cells / Q000503:physiopathology*; D014787:Vision Tests / Q000379:methods