title: Exploration of multifocal rod electroretinograms recording in human.
abstract: OBJECTIVE
  To test the feasibility of recording rod multifocal electroretinograms (ERG) in humans and observe appropriate recording conditions.
  
  
  METHODS
  Multifocal rod ERG were recorded using a stimulus array of 61 equalsized hexagons in two normal subjects after the dark adaptation. Flashes were blue (W47B). Blank frames between two successive flashes of hexagons varied from 0 to 14. Length of the m-sequence, bandwidth, flash frequency, flash intensities and background intensities were changed to obtain appropriate recording conditions for the clinical use.
  
  
  RESULTS
  Multifocal rod ERG were clearly recordable and well formed. They had an early implicit time, very small negative wave and a late implicit time, large positive wave. The positive wave was bimodal, whose timing and waveform were similar to the full-field rod ERG. The local response amplitudes can be suppressed with increase in flash frequency or background intensity, decrease in flash intensity or the size of stimulus elements.
  
  
  CONCLUSIONS
  Multifocal rod ERG can be recorded in human and can provide topographical maps of retinal function that have clinical usage. 2(12)-1 m-sequence length, 3F blank frames and 3 - 300 Hz bandwidth were suggested to appropriate recording conditions.
authors.affiliation: Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China.
authors.forename: Changzheng
authors.initials: C
authors.lastname: Chen
authors.forename: Lezheng
authors.initials: L
authors.lastname: Wu
authors.forename: De-Zheng
authors.initials: DZ
authors.lastname: Wu
authors.forename: Shixian
authors.initials: S
authors.lastname: Long
authors.forename: Jiongji
authors.initials: J
authors.lastname: Liang
authors.forename: Futian
authors.initials: F
authors.lastname: Jiang
authors.forename: Libing
authors.initials: L
authors.lastname: Jiang
mesh_terms: D000328:Adult; D003623:Dark Adaptation; D004596:Electroretinography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D012160:Retina / Q000033:anatomy & histology; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D014794:Visual Fields