title: Multifocal pattern electroretinogram does not demonstrate localised field defects in glaucoma.
abstract: OBJECTIVE
  To determine if a multifocal PERG could be recorded in normals, and to examine changes in the multifocal PERG in glaucoma patients. To compare the ability of multifocal PERG and multifocal VEP responses in the same individuals to identify localised field defects in glaucoma.
  
  
  METHODS
  Using the VERIS Scientific system multifocal PERGs were recorded from 19 sites of the visual field according to pseudo-random binary m-sequence. Twenty normals and 15 glaucoma subjects were tested. Multifocal pattern VEPs were also recorded in the glaucoma cases using a cortically scaled stimulus.
  
  
  RESULTS
  The second order kernel of the PERG shows a consistent signal. The overall PERG amplitude decreases with age in normals. In glaucoma the PERG amplitude was reduced across the field, but reductions did not correspond to the area of the scotoma. The VEP showed localised signal reductions in all 15 cases of glaucoma.
  
  
  CONCLUSIONS
  A multifocal PERG can be recorded in normals. However it did not reflect localised ganglion cell losses, whereas the multifocal pattern VEP recorded to a very similar stimulus in the same individual did show losses in the scotoma area.
authors.affiliation: Save Sight Institute, Department of Ophthalmology, Sydney University, Australia. sasha@eye.usyd.edu.au
authors.forename: A I
authors.initials: AI
authors.lastname: Klistorner
authors.forename: S L
authors.initials: SL
authors.lastname: Graham
authors.forename: A
authors.initials: A
authors.lastname: Martins
mesh_terms: D000328:Adult; D000368:Aged; D004596:Electroretinography / Q000379:methods*; D005074:Evoked Potentials, Visual; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D008875:Middle Aged; D012165:Retinal Ganglion Cells / Q000473:pathology; D012607:Scotoma / Q000473:pathology; D014786:Vision Disorders / Q000175:diagnosis*; D014794:Visual Fields