title: Temporal response properties of the macular cone system: effect of normal aging and age-related maculopathy.
abstract: OBJECTIVE
  To evaluate the influence of aging and age-related maculopathy (ARM) on the temporal frequency response function (TFR) of macular focal electroretinography.
  
  
  METHODS
  Macular (18 degrees ) focal electroretinograms (FERGs) in response to sinusoidal flicker, modulated at TFs between 3.7 and 52 Hz, were recorded from 13 young (age range, 14-29 years) and 9 old (age range, 55-80 years) healthy subjects and from 18 patients with ARM (stage 2 disease; age range, 55-80 years; visual acuity >/=0.4). Amplitude and phase of the Fourier-analyzed response fundamental (1F) and seconnd harmonic (2F) were measured.
  
  
  RESULTS
  In young healthy subjects, mean 1F TFR showed a maximum amplitude at 41 Hz, a secondary peak at 3.7 Hz, a minimum at 8 Hz, and a high TF (32-52 Hz) roll-off. Mean 1F TFR of old, compared with young, healthy subjects showed amplitude enhancement at 10 to 14 Hz and a small loss at high TF. Mean 2F TFR of young and old healthy subjects had a maximum at 5.7 to 8 Hz and an attenuation beyond 10 Hz. Mean 1F and 2F TFRs of ARM patients were similar to those of old healthy subjects but were depressed in mean amplitude. FERG TFR changes of old healthy subjects and ARM patients were not mimicked by reducing stimulus retinal illuminance or modulation depth in young healthy subjects.
  
  
  CONCLUSIONS
  FERG temporal properties are affected by normal aging and ARM. Because FERG TFR is shaped mainly by postreceptoral activity, the findings suggest that photoreceptor and postsynaptic dysfunction underlie aging- and ARM-related FERG changes.
authors: Institute of Ophthalmology, Catholic University, Rome, Italy. md0571@mckink.it
authors: Benedetto
authors: B
authors: Falsini
authors: Lucia
authors: L
authors: Ziccardi
authors: Giovanna
authors: G
authors: Stifano
authors: Giancarlo
authors: G
authors: Iarossi
authors: Erasmo
authors: E
authors: Merendino
authors: Angelo M
authors: AM
authors: Minnella
authors: Antonello
authors: A
authors: Fadda
authors: Emilio
authors: E
authors: Balestrazzi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D004596:Electroretinography; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008268:Macular Degeneration / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D017949:Retinal Cone Photoreceptor Cells / Q000503:physiopathology*; D009435:Synaptic Transmission / Q000502:physiology