This 14YO female presented with difficulty distinguishing colors and seeing the yellow softball when batting. Vision was 20/30 OD and 20/25 OS.
Her fundus examinations were normal. However, OCT scanning shows a pathognomonic loss of the photoreceptor layers outer to the external limiting membrane.
Fundus autofluorescence shows foveal hypofluorescence corresponding to the angiographic bull’s-eye lesions.
This patient tested positive for the ABCA4 gene, which is associated with both cone-rod dystrophy and Stargardt’s disease.
Four years later, vision and the clinical findings remain stable, but the OCT outer retinal defects have collapsed with increased outer retinal atrophy.
Learning Points:
Stargardt disease is an autosomal recessive disorder caused by a mutation in the ABCA4 gene. The ABCA4 protein is located in the photoreceptor outer segments and is involved in the recycling of 11-cis-retinal.
Mutation of this gene causes the accumulation of lipofuscin in the RPE, which eventually leads to photoreceptor and RPE degeneration. Other ABCA4 disorders include fundus flavimaculatus and cone-rod dystrophy.
