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The electroretinogram
A Harden1, G G Adams, D S Taylor
1Department of Clinical Neurophysiology, Hospital for Sick Children, London.
Insights
Electroretinogram (ERG) testing in children, combined with visual evoked potentials, helps diagnose various conditions. This non-sedated method is reliable for identifying ocular and neurodegenerative disorders.
Area of Science:
- Ophthalmology
- Neuroscience
- Genetics
Background:
- The electroretinogram (ERG) is a diagnostic tool for retinal function.
- Combining ERG with visual evoked potentials (VEPs) can enhance diagnostic capabilities.
- Non-invasive methods are crucial for pediatric assessments.
Purpose of the Study:
- To establish normal electroretinogram parameters in infants and children.
- To evaluate the utility of ERG, combined with VEPs, in diagnosing pediatric disorders.
- To assess the feasibility of routine, non-sedated ERG recordings in young patients.
Main Methods:
- Recorded flash electroretinograms (fERG) using a skin electrode on the nose in 4465 children over 10 years.
- Combined fERG with flash visual evoked potentials (fVEP).
- Defined normal fERG parameters using 240 control patients aged 1 day to 17 years with normal fVEP and no suspected retinal pathology.
Main Results:
- Established age-specific normal electroretinogram parameters.
- Identified 332 patients with absent or significantly reduced ERG amplitudes.
- Categorized these patients into ocular disorders (195), neurodegenerative disorders (94), and various syndromes (43).
- Noted that fundus examination did not always reveal abnormalities in affected patients.
Conclusions:
- Non-sedated electroretinogram recordings are feasible and reliable in infants and uncooperative children.
- ERG, particularly when combined with VEPs and sometimes EEG, aids in diagnosing diverse pediatric conditions.
- These electrophysiological studies have significant implications for identifying genetic disorders.
Abstract:
The electroretinogram, findings, in response to a flash stimulus, was recorded from a skin electrode placed on the bridge of the nose in 4465 infants and children seen over a 10 year period. The electroretinogram was combined with a flash visual evoked potential. From this total, the electroretinographic findings in 240 patients, aged 1 day to 17 years, without suspected retinal pathology and with a normal visual evoked potential, were used as controls and normal electroretinographic parameters of different age groups defined. There were 332 patients who showed an absent or very reduced amplitude electroretinogram. They were divided into primarily ocular disorders (n = 195), neurodegenerative disorders (n = 94), and various syndromes (n = 43). Fundus examination did not always show any obvious abnormalities. The use of this simple and reliable technique for recording the electroretinogram made it possible to include this investigation as a routine procedure without the need for sedation in infants and uncooperative children. Electroretinographic studies, especially when combined with visual evoked potentials, and in some cases electroencephalography, may aid diagnosis in a wide variety of paediatric conditions, many of which have genetic implications.