title: Improvement of retinal function in L-ORD after prolonged dark adaptation.
abstract: OBJECTIVE
  To describe the changes in dark-adapted (DA) retinal electrophysiological function after prolonged dark adaptation in a cohort of patients with late-onset retinal degeneration (L-ORD).
  
  
  METHODS
  Prospective case series.
  
  
  METHODS
  Nine patients with either stage 2 or 3 L-ORD.
  
  
  METHODS
  International Society for Clinical Electrophysiology of Vision standard DA electroretinograms (ERGs) were performed before and after a period of extended dark adaptation (16 hours) in a cohort of patients heterozygous for the Ser163Arg mutation in C1QTNF5.
  
  
  RESULTS
  Rod function was abnormal in 8 of 9 patients after standard (20 min) of dark adaptation. After extended dark adaptation, rod function normalized in 4 patients and there was a mean improvement in the DA 0.01 rod-specific ERG b-wave amplitude of 310% (p = 0.004). A significant improvement in DA 3.0 a-wave ERG amplitude localized the improvement in rod function at the level of the photoreceptor.
  
  
  CONCLUSIONS
  This study demonstrates that a significant proportion of rod dysfunction in L-ORD can be reversed by extended dark adaptation and suggests that an abnormality of the visual cycle contributes to the pathogenesis of the disease. These findings would suggest that some retinal function could be restored, even in advanced cases of the disease if a suitable treatment is found.
authors: Newcastle Eye Centre.
authors: Vasileios T
authors: VT
authors: Papastavrou
authors: Regional Medical Physics Department, Royal Victoria Infirmary.
authors: Karen R
authors: KR
authors: Bradshaw
authors: Newcastle Eye Centre.
authors: Kyaw H
authors: KH
authors: Aye
authors: Regional Medical Physics Department, Royal Victoria Infirmary.
authors: Clare
authors: C
authors: Turney
authors: Newcastle Eye Centre; Institute of Genetic Medicine, International Centre for Life, Newcastle University, Newcastle upon Tyne, United Kingdom.. Electronic address: andrew.browning@nuth.nhs.uk.
authors: Andrew C
authors: AC
authors: Browning
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003094:Collagen / Q000235:genetics; D017931:DNA Primers / Q000737:chemistry; D003623:Dark Adaptation / Q000502:physiology*; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061848:Optical Imaging; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012162:Retinal Degeneration / Q000235:genetics / Q000503:physiopathology*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology
chemical_list: C487851:C1QTNF5 protein, human; D017931:DNA Primers; D003094:Collagen