Post-illumination pupil response in subjects without ocular disease

Invest Ophthalmol Vis Sci. 2010 May;51(5):2764-9. doi: 10.1167/iovs.09-4717. Epub 2009 Dec 10.


Purpose: A sustained pupilloconstriction is often observed after the cessation of a bright visual stimulus. This post-illumination pupil response (PIPR) is produced by the intrinsically photosensitive retinal ganglion cells (ipRGCs). The present study was designed to examine the characteristics of the PIPR in a normal population without ocular disease.

Methods: Thirty-seven subjects (mean age, 48.6 years) were tested by presenting a 60 degrees, 10-second light stimulus (13 log quanta/cm(2)/s retinal irradiance) and recording pupillary responses for 50 seconds after light cessation. The light stimuli (470 [blue] and 623 [red] nm) were presented by an optical system to one eye after dilation, while the consensual pupil response of the fellow, undilated eye was recorded by infrared pupillometry.

Results: A positive PIPR was seen in all subjects tested. The population average of the PIPR for 470-nm light was 1.5 mm (SEM 0.10, P < 0.05) and the net PIPR (blue PIPR minus red PIPR) was 1.4 mm (SEM 0.09, P < 0.0001). The net PIPR correlated positively with baseline pupil diameter (P < 0.05), but not significantly with age, race, or sex (P > 0.05) in the test population.

Conclusions: All normal subjects displayed a significant PIPR for a 10-second, 470-nm light stimulus, but not a 623-nm stimulus, which is consistent with the proposed melanopsin-mediated response. In most normal individuals, the amplitude of the PIPR was substantial. This test has the potential to be used as a tool in evaluating subjects with inner retinal dysfunction or melanopsin-related disorders.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Humans
  • Light*
  • Male
  • Middle Aged
  • Photoreceptor Cells, Vertebrate / metabolism
  • Pupil / physiology*
  • Reflex, Pupillary / radiation effects*
  • Retinal Diseases / diagnosis
  • Retinal Diseases / metabolism
  • Retinal Ganglion Cells / metabolism
  • Rod Opsins / metabolism


  • Rod Opsins
  • melanopsin