RT Book, Section
A1 Singh, Manpreet
A1 Whitfield, Denise
A2 Knoop, Kevin J.
A2 Stack, Lawrence B.
A2 Storrow, Alan B.
A2 Thurman, R. Jason
SR Print(0)
ID 1181038452
T1 Afferent Pupillary Defect
T2 The Atlas of Emergency Medicine, 5e
YR 2021
FD 2021
PB McGraw-Hill
PP New York, NY
SN 9781260134940
LK accessemergencymedicine.mhmedical.com/content.aspx?aid=1181038452
RD 2024/04/24
AB Pupil  size  is  controlled  in  the  midbrain,  from  which  efferent  nerves  travel  to  both  pupils,  resulting  in  symmetric  pupils,  even  with  a  unilateral  light  stimulus.  The  perception  of  the  light  stimulus,  however,  may  be  decreased  by  disease  within  anterior  visual  structures  such  as  the  retina,  optic  nerve,  chiasm,  optic  tract,  and  midbrain  pathways.  With  diminished  afferent  stimulation,  less  light  is  “perceived,”  and  pupil  contraction  diminishes  (ie,  dilates)  as  a  result.  In  this  situation,  the  affected  side  is  said  to  demonstrate  an  afferent  pupillary  defect  (APD).