This 58YO female recently noticed difficulties with depth perception. There was no family history of eye disease. Vision was 20/50 OD and 20/80 OS. Genetic testing revealed two heterozygous pathogenic ABCA4 mutations.
Optos color RG imaging shows multiple yellow fleck-like lesions throughout each posterior pole. Fundus autofluorescence (FAF) of these flecks shows variable hyper-FAF, with patches of paracentral hypo-FAF.
Triton swept-source OCT shows variable outer retinal atrophy and disorganization. Some hyperreflective spots are noted above the RPE.
Learning Points:
Fundus flavimaculatus is a genetic disorder, usually transmitted as an autosomal recessive trait, that is caused by mutations involving the ABCA4 gene. This gene encodes one of a family of ATP-binding cassette (ABC) transmembrane proteins that mediate the active transport of various substrates across cellular membranes. The ABCA4 protein is present in the photoreceptor outer segment disc membranes, where it is involved in recycling 11-cis-retinal.
Stargardt disease is believed to be fundus flavimaculatus without peripheral findings. Vision in fundus flavimaculatus is often better than that in Stargardt due to later disease onset and less macular involvement. Both likely represent an RPE lipofuscin storage disease. The RPE cells become engorged with lipofuscin, causing a dark choroid on fluorescein angiography.
