Duchenne muscular dystrophy: negative scotopic bright-flash electroretinogram and normal dark adaptation.
Recent reports indicate that most subjects with Duchenne muscular dystrophy (DMD) have a negative scotopic bright-flash electroretinogram (ERG). We performed dark adaptometry in seven patients with the DMD phenotype. Three patients had the negative bright-flash response combined with severely reduced rod-related activity; their mean psychophysical dark-adapted threshold was -5.5 +/- 0.3 (normally -5.4 +/- 0.3) cd.m-2. Two of the three patients were able to sit through the complete test: the profile of their dark adaptation curve was normal. The four other patients had a normal scotopic ERG, and their mean psychophysical dark-adapted threshold was -5.3 +/- 0.3 cd.m-2. One of the four was able to complete the entire procedure, and a normal profile was found. In patients with DMD the dark adaptation measurements are normal despite abnormalities in rod-related ERG activity.
Tremblay
F
F
Department of Ophthalmology, Dalhousie University, Halifax, NS.
De Becker
I
I
Riddell
D C
DC
Dooley
J M
JM
D000293:Adolescent; D000328:Adult; D003623:Dark Adaptation / Q000502:physiology*; D004596:Electroretinography; D006801:Humans; D009136:Muscular Dystrophies / Q000503:physiopathology*; D010775:Photic Stimulation; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D014796:Visual Perception / Q000502:physiology