Effect of retinopathy of prematurity on scotopic spatial summation

Invest Ophthalmol Vis Sci. 2014 Apr 29;55(5):3311-3. doi: 10.1167/iovs.14-14344.


Purpose: To evaluate scotopic retinal organization in retinopathy of prematurity (ROP) through a study of spatial summation.

Methods: Thresholds for a range of stimulus diameters (0.4°-10°) were measured using a two alternative, spatial, forced choice psychophysical procedure. The critical diameter (DCRIT) for complete summation was estimated in subjects with a history of severe ROP (N = 7) and mild ROP (N = 17). Subjects who were born preterm and never had ROP (N = 16) and term-born subjects (N = 7) were also tested. The subjects ranged in age from 9 to 17 (median 13.5) years.

Results: Critical diameter for complete spatial summation was significantly larger in ROP subjects than in subjects who never had ROP and in term-born control subjects. Critical diameter varied significantly with severity of ROP.

Conclusions: The larger DCRIT values in ROP are consistent with altered organization of the post receptor retina. This may offer the ROP retina a strategy for achieving noise reduction and good dark-adapted visual sensitivity.

Keywords: psychophysics; retinopathy of prematurity; scotopic sensitivity; spatial summation.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Child
  • Dark Adaptation / physiology*
  • Female
  • Humans
  • Male
  • Photic Stimulation
  • Psychophysics
  • Retinal Rod Photoreceptor Cells / physiology*
  • Retinopathy of Prematurity / physiopathology*
  • Sensory Thresholds
  • Visual Perception / physiology*