Phenotypic subtypes of Stargardt macular dystrophy-fundus flavimaculatus.
OBJECTIVE
To determine if phenotypic subtypes exist in Stargardt macular dystrophy-fundus flavimaculatus (SMD-FFM).


METHODS
A cross-sectional study of 63 patients with autosomal recessive SMD-FFM was undertaken. The age of onset, duration of symptoms, visual acuity, and clinical features on fundus examination, color fundus photographs, and fundus autofluorescence images were recorded. Electrophysiological tests, including pattern, focal, and full-field electroretinogram (ERG), electro-oculogram, and color-contrast sensitivity measurement, were also performed.


RESULTS
Based on electrophysiological attributes (ERG), patients with SMD-FFM could be classified into 3 groups. In group 1, there was severe pattern ERG abnormality with normal scotopic and full-field ERGs. In group 2, there was additional loss of photopic function, and in group 3, there was loss of both photopic and scotopic function. Differences in scotopic or photopic function among groups were not explained on the basis of differences in age of onset or duration of disease.


CONCLUSIONS
Patients with SMD-FFM can be classified into 3 groups based on the absence or presence of generalized loss of either photopic or photopic and scotopic function. It appears that these 3 groups may represent distinct phenotypic subtypes in SMD-FFM.
Medical Retina Service, Moorfields Eye Hospital, City Road, London EC1V 2PD, England.
N
N
Lois
G E
GE
Holder
C
C
Bunce
F W
FW
Fitzke
A C
AC
Bird
D000328:Adult; D017668:Age of Onset; D000368:Aged; D003119:Color Perception Tests; D015350:Contrast Sensitivity; D003430:Cross-Sectional Studies; D004585:Electrooculography; D004596:Electroretinography; D005260:Female; D005453:Fluorescence; D005654:Fundus Oculi; D006801:Humans; D008266:Macula Lutea / Q000473:pathology* / Q000503:physiopathology; D008268:Macular Degeneration / Q000145:classification* / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D014792:Visual Acuity