title: Retinal dysfunction in carriers of bardet-biedl syndrome.
abstract: OBJECTIVE
  To determine whether retinal dysfunction in obligate carriers of the Bardet-Biedl syndrome (BBS) could be observed in local electroretinographic responses obtained with the multifocal electroretinogram (mfERG).
  
  
  METHODS
  Six obligate carriers of the BBS were examined for the study. Examination of each carrier included an ocular examination and mfERG testing of one eye. For the mfERG, we used a 103-scaled hexagonal stimulus array that subtended a retinal area of approximately 40 degrees in diameter. The amplitudes and implicit times in each location for the mfERG were compared with the corresponding values determined for a group of 34 normally sighted, age-similar control subjects.
  
  
  RESULTS
  Mapping of 103 local electroretinographic response amplitudes within a central 40 degrees area with the mfERG showed regions of reduced mfERG amplitudes in three of six carriers. Implicit time measurements in the 6 carriers were all normal except for those locations associated with abnormal amplitude reductions in 3 of the carriers. When present, retinal dysfunction was evident in the presence of a normal-appearing fundus.
  
  
  CONCLUSIONS
  Multifocal ERG testing can demonstrate areas of retinal dysfunction in carriers of the BBS. This test may therefore be useful for identifying some heterozygous carriers of this disease.
authors: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.
authors: Linda S
authors: LS
authors: Kim
authors: Gerald A
authors: GA
authors: Fishman
authors: William H
authors: WH
authors: Seiple
authors: Janet P
authors: JP
authors: Szlyk
authors: Edwin M
authors: EM
authors: Stone
mesh_terms: D000328:Adult; D020788:Bardet-Biedl Syndrome / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology*; D004596:Electroretinography / Q000379:methods; D006579:Heterozygote; D006801:Humans; D008875:Middle Aged; D012160:Retina / Q000503:physiopathology*; D014792:Visual Acuity