Ioannis S Dimopoulos1, Paul R Freund1, Tanner Redel1, Blake Dornstauder1, Gregory Gilmour2, Yves Sauvé3. 1. Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada. 2. Department of Internal Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. 3. Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada Department of Physiology, University of Alberta, Edmonton, Alberta, Canada.
Abstract
PURPOSE: We recorded oscillatory potentials (OPs) to document how age impacts on rod- and cone-driven inner retina function. METHODS: Dark- and light-adapted electroretinogram (ERG) luminance-response functions were recorded in healthy human subjects aged 20 to 39, 40 to 59, and 60 to 82 years. Raw ERG traces (0.1-300 Hz) were filtered (75-300 Hz) to measure OPs trough-to-peak in the time-amplitude domain. Morlet wavelet transform (MWT) allowed documenting OPs time-amplitude-frequency distribution from raw traces. RESULTS: Under dark adaptation, both methods revealed reduced OP amplitudes and prolonged implicit times by 40 years of age. The MWT identified a high-frequency band as the main oscillator, which frequency (150-155 Hz) was unaffected by age. Under light adaptation, most OP peaks were delayed by 40 years of age. Peak-trough measures yielded inconsistent results in relation to luminance. Contrastingly, MWT distinguished two frequency bands at all luminances: high frequency (135 ± 6 Hz) time locked to the onset of early OPs and low frequency (82 ± 7 Hz), giving rise to early and late OPs. By 60 years, there was a consistent power reduction specific to the low-frequency band. CONCLUSIONS: Age-related OP changes precede those seen with a- (photoreceptoral) and b-waves (postphotoreceptoral). In addition, MWT allows quantifying distinct low- and high-frequency oscillators in the human retina, which complement traditional OP analysis methods. The identification of an age-independent OP marker (light-adapted high frequency band) opens a new dimension for the screening of retinal degenerations and their impact on inner retina function. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
PURPOSE: We recorded oscillatory potentials (OPs) to document how age impacts on rod- and cone-driven inner retina function. METHODS: Dark- and light-adapted electroretinogram (ERG) luminance-response functions were recorded in healthy human subjects aged 20 to 39, 40 to 59, and 60 to 82 years. Raw ERG traces (0.1-300 Hz) were filtered (75-300 Hz) to measure OPs trough-to-peak in the time-amplitude domain. Morlet wavelet transform (MWT) allowed documenting OPs time-amplitude-frequency distribution from raw traces. RESULTS: Under dark adaptation, both methods revealed reduced OP amplitudes and prolonged implicit times by 40 years of age. The MWT identified a high-frequency band as the main oscillator, which frequency (150-155 Hz) was unaffected by age. Under light adaptation, most OP peaks were delayed by 40 years of age. Peak-trough measures yielded inconsistent results in relation to luminance. Contrastingly, MWT distinguished two frequency bands at all luminances: high frequency (135 ± 6 Hz) time locked to the onset of early OPs and low frequency (82 ± 7 Hz), giving rise to early and late OPs. By 60 years, there was a consistent power reduction specific to the low-frequency band. CONCLUSIONS: Age-related OP changes precede those seen with a- (photoreceptoral) and b-waves (postphotoreceptoral). In addition, MWT allows quantifying distinct low- and high-frequency oscillators in the human retina, which complement traditional OP analysis methods. The identification of an age-independent OP marker (light-adapted high frequency band) opens a new dimension for the screening of retinal degenerations and their impact on inner retina function. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.
Authors: Pantea Moghimi; Nathalia Torres Jimenez; Linda K McLoon; Theoden I Netoff; Michael S Lee; Angus MacDonald; Robert F Miller Journal: Schizophr Res Date: 2019-10-12 Impact factor: 4.939
Authors: Paul A Constable; Sebastian B Gaigg; Dermot M Bowler; Herbert Jägle; Dorothy A Thompson Journal: Doc Ophthalmol Date: 2016-02-11 Impact factor: 2.379