Abnormality in the external limiting membrane in early Stargardt disease.

Stargardt disease (STGD1) is caused by mutations in the ABCA4 gene. It has previously been reported that abnormalities in STGD1 may be detectable in the photoreceptors using spectral domain-optical coherence tomography (SD-OCT) prior to the detection of retinal pigment epithelium abnormalities. We present a 5-year-old asymptomatic girl with normal appearing fundi who possessed pathogenic ABCA4 variants on both chromosomes and where thickening of the external limiting membrane was the only abnormality detected on SD-OCT.