Cone ERG responses in patients with Smith-Lemli-Opitz Syndrome (SLOS).
OBJECTIVE
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.
Garry
Deirdre
D
Department of Ophthalmology, Children's Hospital Boston, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
Hansen
Ronald M
RM
Moskowitz
Anne
A
Elias
Ellen R
ER
Irons
Mira
M
Fulton
Anne B
AB
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002784:Cholesterol / Q000097:blood; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D019082:Smith-Lemli-Opitz Syndrome / Q000503:physiopathology*; D055815:Young Adult
D002784:Cholesterol