Development of rod function in term born and former preterm subjects

Optom Vis Sci. 2009 Jun;86(6):E653-8. doi: 10.1097/OPX.0b013e3181a6a237.


Purpose: To provide an overview of some of our electroretinographic (ERG) and psychophysical studies of normal development of rod function and their application to retinopathy of prematurity (ROP).

Methods: ERG responses to full-field stimuli were recorded from dark adapted subjects. Rod photoreceptor sensitivity (SROD) was calculated by fit of a biochemical model of the activation of phototransduction to the ERG a-wave. Dark adapted psychophysical thresholds for detecting 2 degrees spots in parafoveal (10 degrees eccentric) and peripheral (30 degrees eccentric) retina were measured and the difference between the thresholds, Delta10-30, was examined as a function of age. SROD and Delta10-30 in term born and former preterm subjects were compared.

Results: In term born infants, (1) the normal developmental increase in SROD changes proportionately with the amount of rod visual pigment, rhodopsin, and (2) rod-mediated function in central retina is immature compared with that in peripheral retina. In subjects born prematurely, deficits in SROD persist long after active ROP has resolved. Maturation of rod-mediated thresholds in the central retina is prolonged by mild ROP.

Conclusions: Characterization of the development of normal rod and rod-mediated function provides a foundation for understanding ROP.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Child Development*
  • Dark Adaptation
  • Electroretinography
  • Humans
  • Infant, Newborn
  • Infant, Premature*
  • Psychophysics
  • Recovery of Function
  • Retina / physiology
  • Retina / physiopathology
  • Retinal Rod Photoreceptor Cells / physiology*
  • Retinopathy of Prematurity / physiopathology
  • Rhodopsin / metabolism
  • Sensory Thresholds
  • Term Birth*
  • Vision, Ocular


  • Rhodopsin