title: Alteration of rod and cone function in children with Usher syndrome.
abstract: OBJECTIVE
  To evaluate the retinal function, with emphasis on phenotype and rate of progression, in infants and children with different genotypes of Usher syndrome.
  
  
  METHODS
  Fourteen children (2-10 years of age) with retinitis pigmentosa and hearing impairment were examined with full-field electroretinography (ERG) during general anesthesia, ophthalmologic examination, and genetic analysis. Five children were repeatedly examined (follow-up 5-10 years) with full-field ERG under local anesthesia and in 2 children multifocal ERG and optical coherence tomography (OCT) were performed. These results were compared to full-field ERG data from 58 children without retinal eye disorder.
  
  
  RESULTS
  Six children were genotyped as Usher 1B, 2A, and 3A. Full-field ERG demonstrated early alterations corresponding to a rod-cone dystrophy in all children. A remaining rod function could be verified in the majority of the children up to 4 years of age. After 4 years of age, there was a further deterioration of the rod function; the progress was severe in Usher types 1 and 2 and moderate in Usher type 3. In all children, the cone function was moderately reduced, in a few cases almost normal. The results from the 58 children without retinal disorder confirm that full-field ERG during general anesthesia is reliable. Multifocal ERG confirmed a preserved central cone function and in OCT there were discrete structural alterations.
  
  
  CONCLUSIONS
  Full-field ERG during general anesthesia in children with Usher syndrome demonstrates variable phenotypes and different degrees in rate of progression during childhood.
authors.affiliation: Department of Ophthalmology, Lund University Hospital, Lund, Sweden. eva.malm@med.lu.se
authors.forename: Eva
authors.initials: E
authors.lastname: Malm
authors.forename: Vesna
authors.initials: V
authors.lastname: Ponjavic
authors.forename: Claes
authors.initials: C
authors.lastname: Möller
authors.forename: William J
authors.initials: WJ
authors.lastname: Kimberling
authors.forename: Edwin S
authors.initials: ES
authors.lastname: Stone
authors.forename: Sten
authors.initials: S
authors.lastname: Andréasson
mesh_terms: D000768:Anesthesia, General; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D004596:Electroretinography; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D010641:Phenotype; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D012042:Registries; D012174:Retinitis Pigmentosa / Q000503:physiopathology; D041623:Tomography, Optical Coherence; D052245:Usher Syndromes / Q000235:genetics / Q000503:physiopathology*