Temporal response properties of the macular cone system: Effect of normal aging and age-related maculopathy

Benedetto Falsini, Lucia Ziccardi, Giovanna Stifano, Giancarlo Iarossi, Erasmo Merendino, Angelo M. Minnella, Antonello Fadda, Emilio Balestrazzi

Research output: Contribution to journalArticlepeer-review

Abstract

PURPOSE. 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°) 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 37 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.

Original languageEnglish
Pages (from-to)4811-4817
Number of pages7
JournalInvestigative Ophthalmology and Visual Science
Volume48
Issue number10
DOIs
Publication statusPublished - Oct 2007

ASJC Scopus subject areas

  • Ophthalmology

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