TY  - CHAP
M1  - Book, Section
TI  - Special Tests of the Eyes
A1  - Kuo, Annie F.
A1  - Karr, Daniel J.
A1  - Levin, Alex V.
A2  - Kline, Mark W.
PY  - 2018
T2  - Rudolph's Pediatrics, 23e
AB  - The  electroretinogram  (also  known  as  full-field  ERG)  is  a  measure  of  retinal  photoreceptor  integrity  and  thus  retina  function.  The  basic  technique  consists  of  measuring  the  action  potential  produced  by  the  retina  when  stimulated  by  light  of  variable  intensity  and  color.  ERG  allows  differentiation  between  the  responses  of  the  retinal  rod  and  cone  systems.  A  contact  lens  with  an  imbedded  electrode  is  placed  on  the  cornea,  or  a  skin  electrode  is  placed  on  the  lower  lid.  A  reference  skin  electrode  is  placed  on  the  forehead.  The  ERG  can  be  performed  awake  in  infancy  and  later  childhood  but  usually  requires  sedation  or  general  anesthesia  between  the  ages  of  1  and  6  years.  The  first  step  of  the  ERG  is  dark  adaptation,  which  is  done  by  patching  both  eyes  for  at  least  20  minutes.  Then,  in  a  completely  dark  environment,  the  test  is  started.  Sleeping  or  awake,  quiet  infants  and  children  under  sedation  or  anesthesia  lie  supine  while  the  bowl-shaped  machine  is  brought  over  their  face.  Older  children  can  sit  upright,  and  their  chin  is  placed  on  a  rest  within  the  bowl.  As  variable  light  stimuli  are  presented  within  the  bowl,  the  electrical  potential  between  electrodes  is  then  measured  and  recorded  as  a  waveform.  In  anxious  children,  dim  light  adaptation  (mesoptic  vision)  can  be  substituted.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/19
UR  - accesspediatrics.mhmedical.com/content.aspx?aid=1182925522
ER  -