title: Multifocal electroretinography as a function of age: the importance of normative values for older adults.
abstract: OBJECTIVE
  To determine the influence of age on local electroretinographic responses in humans.
  
  
  METHODS
  Multifocal electroretinograms (mfERGs) were obtained from 62 normally sighted subjects ranging in age from 21 to 81 years. A stimulus array of 103 scaled hexagons was used to measure electrical signals within a retinal area approximately 46 degrees in diameter. Commonly reported mfERG methods were used to quantify the responses: peak-to-peak amplitudes and implicit times, scalar product amplitude, and amplitude and time scales derived from the algorithm of Hood and Li, published in 1997.
  
  
  RESULTS
  Regression analysis showed significant linear relationships of amplitude and timing measures with age. The rates of losses were 10.5% per decade for peak-to-peak amplitude, 11.7% per decade for scalar product amplitude, and 9.5% per decade for a-scale. The rate of amplitude reduction was highest in the central 3 degrees. Age had less influence on implicit time measures. The rates of timing losses were 1.4% per decade for the N1 component and 1.0% per decade for both the P1 component and the t-scale measure. Using predicted interval ranges, the age was calculated at which 50% of the expected values would fall below the lower 95% prediction interval band of younger subjects.
  
  
  CONCLUSIONS
  The age-associated mfERG alterations are presented to emphasize the importance of appropriate normative data in interpretation of mfERGs.
authors.affiliation: Department of Ophthalmology, New York University School of Medicine, New York, New York 10016, USA. whs4@nyu.edu
authors.forename: William
authors.initials: W
authors.lastname: Seiple
authors.forename: Thasarat S
authors.initials: TS
authors.lastname: Vajaranant
authors.forename: Janet P
authors.initials: JP
authors.lastname: Szlyk
authors.forename: Colleen
authors.initials: C
authors.lastname: Clemens
authors.forename: Karen
authors.initials: K
authors.lastname: Holopigian
authors.forename: Jennifer
authors.initials: J
authors.lastname: Paliga
authors.forename: David
authors.initials: D
authors.lastname: Badawi
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Carr
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D004596:Electroretinography; D006801:Humans; D008875:Middle Aged; D012016:Reference Values; D012160:Retina / Q000502:physiology*