Cone ERG responses in patients with Smith-Lemli-Opitz Syndrome (SLOS)

Doc Ophthalmol. 2010 Oct;121(2):85-91. doi: 10.1007/s10633-010-9232-3. Epub 2010 May 4.


Purpose: To evaluate cone and cone-driven retinal function in patients with Smith-Lemli-Opitz syndrome (SLOS), a condition characterized by low cholesterol. Rod and rod-driven function in patients with SLOS are known to be abnormal.

Methods: Electroretinographic (ERG) responses to full-field stimuli presented on a steady, rod suppressing background were recorded in 13 patients who had received long-term cholesterol supplementation. Cone photoresponse sensitivity (S(CONE)) and saturated amplitude (R(CONE)) parameters were estimated using a model of the activation of phototransduction, and post-receptor b-wave and 30 Hz flicker responses were analyzed. The responses of the patients were compared to those of control subjects (N = 13).

Results: Although average values of both S(CONE) and R(CONE) were lower than in controls, the differences were not statistically significant. Post-receptor b-wave amplitude and implicit time and flicker responses were normal.

Conclusions: The normal cone function contrasts with the significant abnormalities in rod function that were found previously in these same patients. Possibly, cholesterol supplementation has a greater protective effect on cones than on rods as has been demonstrated in the rat model of SLOS.

Publication types

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

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • Cholesterol / blood
  • Electroretinography*
  • Female
  • Humans
  • Male
  • Retinal Cone Photoreceptor Cells / physiology*
  • Smith-Lemli-Opitz Syndrome / physiopathology*
  • Young Adult


  • Cholesterol