November 1988
Volume 29, Issue 11
Articles  |   November 1988
Scotopic threshold response (STR) of the human electroretinogram.
Author Affiliations
  • P A Sieving
    Department of Ophthalmology, W. K. Kellogg Eye Center, University of Michigan, Ann Arbor 48105.
  • C Nino
    Department of Ophthalmology, W. K. Kellogg Eye Center, University of Michigan, Ann Arbor 48105.
Investigative Ophthalmology & Visual Science November 1988, Vol.29, 1608-1614. doi:
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      P A Sieving, C Nino; Scotopic threshold response (STR) of the human electroretinogram.. Invest. Ophthalmol. Vis. Sci. 1988;29(11):1608-1614.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements
This content is PDF only. Please click on the PDF icon to access.

We recorded the human ERG using full-field stimuli at light intensities near absolute threshold to examine characteristics of the scotopic threshold response (STR). The human STR was seen below PII threshold and was the only component of the ERG evident near absolute rod psychophysical threshold. The human STR was detectable in the corneal ERG at stimulus intensities 0.6-1.0 log units above psychophysical threshold and had about a 2 log unit range to apparent saturation. Maximum STR amplitude was 12-20 microV. The STR latency ranged from 100-185 msec, depending on stimulus duration and intensity. The STR returned to baseline by 300 msec after onset, for very brief flashes, but it was prolonged with longer flashes. The spectral characteristics of the human STR matched rods and not cones. The STR followed Bloch's law and exhibited temporal integration for at least 80 msec. At 2.5-3 log units above visual threshold, corneal positive PII (b-wave and d.c. component) progressively obscured the negative STR. We propose that the human STR reflects post receptor processing in the retina. This is based on the similarity of the human STR to the STR of the cat and monkey, both of which originate at postreceptoral sites. Thus the human STR may find clinical use to evaluate the rod pathway in the proximal retina.


This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.