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Updated: Aug 29, 2026
Electroretinogram Recording for Infants and Children under Anesthesia to Achieve Optimal Dark Adaptation and International Standards
Published on: September 3, 2020
Alteration of electroretinographic recordings when performed under sedation or halogenate anesthesia in a pediatric
François Tremblay1, Joan E Parkinson
1Department of Ophthalmology, Dalhousie University, Halifax, Nova Scotia, Canada. ftrembla@dal.ca
Insights
Sedation and anesthesia impact electroretinography (ERG) by altering retinal responses. These effects vary between sedation and anesthesia, influencing both scotopic and photopic vision, and must be considered during ERG interpretation.
Area of Science:
- Ophthalmology
- Neuroscience
- Anesthesiology
Background:
- Electroretinography (ERG) assesses retinal function.
- Sedation and anesthesia can potentially alter ERG recordings.
- Understanding these effects is crucial for accurate interpretation.
Purpose of the Study:
- To investigate the differential effects of sedation and halogenate anesthesia on electroretinographic (ERG) recordings.
- To compare ERG responses in conscious, sedated, and anesthetized patients.
Main Methods:
- Retrospective chart review of 27 patients diagnosed without retinal disease.
- Standard ERG protocol applied to three groups: conscious (n=9), sedated (n=9), and anesthetized (n=9).
- Analysis of scotopic bright-flash and photopic responses.
Main Results:
- Sedation reduced scotopic a- and b-wave amplitudes but did not affect implicit times.
- Anesthesia spared the scotopic a-wave but more severely decreased the b-wave amplitude.
- Anesthesia reduced photopic response amplitude and prolonged implicit times, impacting glutamate-dependent OFF components.
Conclusions:
- Sedation and anesthesia affect normal retinal physiology through distinct mechanisms.
- Alterations in ERG recordings under sedation/anesthesia necessitate careful consideration during interpretation.
- Further research is needed to fully elucidate the mechanisms underlying these observed effects.
Abstract:
Fran The effects of sedation and of halogenate anesthesia on electroretinographic recordings were investigated by reviewing the hospital charts of 27 patients who were eventually diagnosed free of retinal disease. The same ERG protocol was performed in conscious (n=9), sedated (chloral hydrate or pentobarbital sodium, n=9) and anesthetized (halothane or isoflurane, in combination with N2O, n=9) young patients. Sedation decreased the a- and b-wave amplitude of the scotopic bright-flash response, without affecting implicit times. ERG recordings performed in photopic conditions showed minimal disturbances. Anesthesia spared the a-wave of the scotopic bright-flash response but decreased more severely the b-wave. In addition, anesthesia reduced the amplitude and prolonged the implicit time of the photopic responses, affecting predominantly the ionotropic glutamate dependent OFF components (peak of b-wave, 0P4 and 0P5). The normal retinal physiology is affected by sedation and anesthesia through different mechanisms that still remain to be fully elucidated. These alterations in electroretinographic recordings must be considered when evaluating ERGs obtained under similar sedation/anesthetized conditions.
