title: Electroretinographic characteristics in children with infantile nystagmus syndrome and early-onset retinal dystrophies.
abstract: OBJECTIVE
  To differentiate early-onset retinal dystrophies on the basis of electroretinogram (ERG) characteristics in children with infantile nystagmus syndrome (INS).
  
  
  METHODS
  Thirty-seven children with INS and early-onset retinal dystrophies were included, with diagnosis according to clinical and ERG findings. Three ERG protocols were used according to the child's age and 17 children were followed with 2 protocols: 27 (mean 2.1 years) were recorded with skin electrodes to flash stimulation, 16 (mean 6.5 years) with skin electrodes to full-field stimulation, and 11 (mean 12.2 years) with HK electrodes to full-field stimulation. The ERGs were compared to those of age-matched controls, with differences significant if p&lt;0.05.
  
  
  RESULTS
  Clinical and electrophysiologic findings were in agreement across all of the children. In nine children with Leber congenital amaurosis, the scotopic and photopic ERGs were not recordable under all protocols. Six children with congenital stationary night blindness (CSNB) had electronegative scotopic ERG under all protocols, those with complete CSNB had absent rod ERG, and those with incomplete CSNB had reduced rod ERG. Eight children with achromatopsia had nonrecordable photopic and subnormal scotopic ERG under all protocols. The implicit times of the scotopic b-waves were prolonged. One child had blue-cone monochromatism and reduced photopic and normal S-cone ERG. Six children with cone-rod dystrophy without systemic disorder, and seven children with systemic disorder, had affected photopic and scotopic ERGs under all protocols.
  
  
  CONCLUSIONS
  In children with INS, some early-onset retinal dystrophies can be differentiated through ERGs, also with skin electrodes.
authors.affiliation: Eye Hospital, University Medical Centre Ljubljana, Ljubljana - Slovenia.
authors.forename: Alma
authors.initials: A
authors.lastname: Kurent
authors.forename: Branka
authors.initials: B
authors.lastname: Stirn-Kranjc
authors.forename: Jelka
authors.initials: J
authors.lastname: Brecelj
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004596:Electroretinography; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D020417:Nystagmus, Congenital / Q000175:diagnosis* / Q000503:physiopathology; D010775:Photic Stimulation; D012160:Retina / Q000503:physiopathology; D058499:Retinal Dystrophies / Q000175:diagnosis* / Q000503:physiopathology; D055815:Young Adult