title: A basic investigation of multifocal electroretinogram: reproducibility and effect of luminance.
abstract: OBJECTIVE
  To investigate the reproducibility as well as the effect of luminance in multifocal electroretinogram (mERG).
  
  
  METHODS
  Multifocal electroretinogram recordings were repeated on different days in 6 normal subjects using the Veris III system. The mean luminance of the monitor displaying the stimuli was randomly varied by five kinds of neutral density (ND) filters.
  
  
  RESULTS
  The standard deviation of mERG amplitude from the macular region was approximately 10% of the mean value for each normal subject. Reproducibility largely depended on the condition of the subject and placement of the contact lens electrode. With decreases in the mean luminance of the monitor, the amplitude of mERG decreased exponentially, whereas the peak latency increased linearly. mERGs elicited from a patient with mild cortical cataract resembled the mERGs obtained from the control group using an ND filter between -0.30 and -0.52 log, whereas two patients with typical retinitis pigmentosa showed much lower response densities in mERGs.
  
  
  CONCLUSIONS
  It is necessary to pay attention to the reproducibility and the luminance effect to obtain reliable mERGs.
authors.affiliation: Department of Ophthalmology, National Defense Medical College, Tokorozawa-shi, Saitama-ken, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yoshii
authors.forename: K
authors.initials: K
authors.lastname: Yanashima
authors.forename: T
authors.initials: T
authors.lastname: Wakaguri
authors.forename: F
authors.initials: F
authors.lastname: Sakemi
authors.forename: Y
authors.initials: Y
authors.lastname: Kikuchi
authors.forename: S
authors.initials: S
authors.lastname: Suzuki
authors.forename: S
authors.initials: S
authors.lastname: Okisaka
mesh_terms: D000328:Adult; D000368:Aged; D002386:Cataract / Q000175:diagnosis; D003936:Diagnosis, Computer-Assisted; D004596:Electroretinography / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D008027:Light; D008875:Middle Aged; D011930:Reaction Time; D012016:Reference Values; D015203:Reproducibility of Results; D012174:Retinitis Pigmentosa / Q000175:diagnosis; D014786:Vision Disorders / Q000175:diagnosis; D014794:Visual Fields