title: Early detection of central visual function decline in cone-rod dystrophy by the use of macular focal cone electroretinogram.
abstract: OBJECTIVE
  To evaluate macular focal cone ERG (fERG) as a tool for reliable and early detection of central retinal function decay in cone-rod dystrophy (CRD).
  
  
  METHODS
  A retrospective study of the time course of fERG amplitude and its relation to visual acuity alterations was performed in 47 CRD patients followed yearly for 6.0 ± 3.1 years. Macular focal cone ERG was evoked by a flickering uniform red field overlaying the central 18° of visual field.
  
  
  RESULTS
  Macular focal cone ERG follow-up allowed a clear-cut identification of CRD patients as stationary or progressive, in agreement with visual acuity follow-up. In all progressive patients, fERG declined whenever visual acuity declined, and--in 50% of the cases--fERG loss anticipated acuity loss of several years.
  
  
  CONCLUSIONS
  Macular focal cone ERG represents a sensitive assay to detect, categorize, and follow the progression of central retinal dysfunction in CRD. Its use as a diagnostic tool in CRD may help anticipate, for an individual patient, the likelihood and rate of further disease progression before visual acuity loss has occurred.
authors.affiliation: Istituto di Neuroscienze Consiglio Nazionale delle Ricerche (CNR), Pisa, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Galli-Resta
authors.forename: Marco
authors.initials: M
authors.lastname: Piccardi
authors.forename: Lucia
authors.initials: L
authors.lastname: Ziccardi
authors.forename: Antonello
authors.initials: A
authors.lastname: Fadda
authors.forename: Angelo
authors.initials: A
authors.lastname: Minnella
authors.forename: Dario
authors.initials: D
authors.lastname: Marangoni
authors.forename: Giorgio
authors.initials: G
authors.lastname: Placidi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Resta
authors.forename: Benedetto
authors.initials: B
authors.lastname: Falsini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D042241:Early Diagnosis; D004596:Electroretinography / Q000379:methods*; D005260:Female; D006801:Humans; D008266:Macula Lutea; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D015203:Reproducibility of Results; D012174:Retinitis Pigmentosa / Q000175:diagnosis / Q000503:physiopathology*; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology; D055815:Young Adult
keywords: cone–rod dystrophy; focal ERG; visual acuity