Visual cycle modulation in neurovascular retinopathy

Exp Eye Res. 2010 Aug;91(2):153-61. doi: 10.1016/j.exer.2010.04.008. Epub 2010 Apr 27.


Rats with oxygen-induced retinopathy (OIR) model the pediatric retinal disease retinopathy of prematurity (ROP). Recent findings in OIR rats imply a causal role for the rods in the ROP disease process, although only experimental manipulation of rod function can establish this role conclusively. Accordingly, a visual cycle modulator (VCM) - with no known direct effect on retinal vasculature - was administered to "50/10 model" OIR Sprague-Dawley rats to test the hypotheses that it would 1) alter rod function and 2) consequently alter vascular outcome. Four litters of pups (N=46) were studied. For two weeks, beginning on postnatal day (P) 7, the first and fourth litters were administered 6 mg kg(-1) N-retinylacetamide (the VCM) intraperitoneally; the second and third litters received vehicle (DMSO) alone. Following a longitudinal design, retinal function was assessed by electroretinography (ERG) and the status of the retinal vessels was monitored using computerized fundus photograph analysis. Rod photoreceptor and post-receptor response amplitudes were significantly higher in VCM-treated than in vehicle-treated rats; deactivation of phototransduction was also significantly more rapid. Notably, the arterioles of VCM-treated rats showed significantly greater recovery from OIR. Presuming that the VCM did not directly affect the retinal vessels, a causal role for the neural retina - particularly the rod photoreceptors - in OIR was confirmed. There was no evidence of negative alteration of photoreceptor function consequent to VCM treatment. This finding implicates the rods as a possible therapeutic target in neurovascular diseases such as ROP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetamides / pharmacology
  • Animals
  • Animals, Newborn
  • Dark Adaptation
  • Disease Models, Animal
  • Electroretinography
  • Humans
  • Infant, Newborn
  • Injections, Intraperitoneal
  • Oxygen / toxicity
  • Photic Stimulation
  • Rats
  • Rats, Sprague-Dawley
  • Retinal Neovascularization / physiopathology*
  • Retinal Pigment Epithelium / drug effects
  • Retinal Pigment Epithelium / physiology
  • Retinal Rod Photoreceptor Cells / drug effects
  • Retinal Rod Photoreceptor Cells / physiology
  • Retinal Vessels / pathology
  • Retinopathy of Prematurity / physiopathology*
  • Vision, Ocular / drug effects
  • Vision, Ocular / physiology*


  • Acetamides
  • N-((2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohex-1-enyl)nona-2,4,6,8-tetraenyl)acetamide
  • Oxygen