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Time courses for maturation of electroretinogram responses from infancy to adulthood
C A Westall1, C M Panton, A V Levin
1Department of Ophthalolology, University of Toronto and The Hospital for Sick Children, and the Research Institiute, Ontatrio, Canada. Carol@sickkids.on.ca
Insights
Human electroretinogram (ERG) responses mature at different rates during childhood. Rod-mediated responses mature slower than cone-mediated responses, with most ERG components reaching adult levels by age five.
Area of Science:
- Ophthalmology
- Neuroscience
- Developmental Biology
Background:
- The human electroretinogram (ERG) is a key diagnostic tool for assessing retinal function.
- Understanding the developmental trajectory of ERG responses is crucial for interpreting pediatric ophthalmological findings.
Purpose of the Study:
- To investigate age-related changes in normal human electroretinogram (ERG) responses.
- To establish normative data for ERG development across different age groups.
Main Methods:
- Studied 62 children (10 days-15 years) and 30 adults (15-37 years) using the International Society for Clinical Electrophysiology of Vision (ISCEV) standard protocol.
- Utilized Burian-Allen bipolar contact-lens electrodes to measure rod response, maximal response, oscillatory potentials (OPs), cone response, flicker response, and b-wave amplitude/log intensity (V/log I) curves.
- Employed logistic growth curves to model developmental changes.
Main Results:
- Dark- and light-adapted ERG a- and b-wave amplitudes reached adult levels by 3-5 years of age.
- Scotopic rod-mediated b-wave amplitudes matured more slowly than mixed rod-cone responses.
- Oscillatory potentials (OPs) showed the slowest initial development but reached adult levels by age two.
- ERG response amplitudes in sedated vs. non-sedated children did not differ significantly.
Conclusions:
- ERG responses develop at varying rates, reflecting distinct maturation timelines for photoreceptors and retinal neural pathways.
- These findings provide normative developmental data for the human ERG.
- ERG maturation highlights the complex, layered development of the human retina.
Abstract:
The purpose of this study was to determine how responses in the normal human electroretinogram (ERG) change with subject age. We studied 62 children, 10 days to 15 years old, and 30 subjects 15-37 years old, using the standard protocol established by the International Society for Clinical Electrophysiology of Vision, with Burian-Allen bipolar contact-lens electrodes. We measured rod response, maximal response, oscillatory potentials (OPs), cone response, flicker response, and b-wave amplitude/log intensity (V/log I) curve. A logistic growth curve was used to describe the developmental changes. Dark- and light-adapted ERG a- and b-wave amplitudes reached adult levels by three to five years of age. although b-wave amplitudes of scotopic rod-mediated responses were slower to reach maturity than mixed rod-cone mediated responses. In early infancy OPs were the most immature of the ERG responses, although the rate of development thereafter exceeded that of the other responses such that OP amplitudes were within adult levels by two years of age. Amplitudes of the ERG responses in 21 children sedated with chloral hydrate did not differ significantly from 21 who had not been sedated. ERG responses developed at varying rates, reflecting different developmental stages in photoreceptors, middle retinal layers and more proximal retina.