Our patient shows classic findings for adult-onset foveomacular vitelliform dystrophy (Adult Best’s) including small, round, symmetrical subfoveal yellow spots, which is seen on OCT as subretinal hyperreflective material between the RPE and outer retina.
Additionally, the vitelliform lesions provide a great example of shadowing of the underlying choroid. Shadowing occurs when a hyperreflective structure prevents the OCT laser from penetrating to illuminate deeper structures.
A bonus finding in the left eye is focal nasal vitreofoveal traction lifting the retina, splitting the outer plexiform layer and forming a partial tractional lamellar macular hole.
Learning Points:
There are numerous causes for the subfoveal accumulation of yellow material (acquired vitelliform lesions. Adult-onset foveomacular vitelliform dystrophy (Adult Best’s) is associated with a mutation in the BEST1 gene, which encodes for the bestrophin-1 protein.
Bestrophin-1, a calcium-activated chloride channel, is primarily found in the basolateral plasma membrane of the RPE. BEST1 mutations cause a variety of varied phenotypes, also including autosomal recessive bestrophinopathy, best vitelliform macular dystrophy, and autosomal dominant vitreoretinochoroidopathy.
These patients tend to maintain fairly good vision. Outer retinal and RPE atrophy can cause central vision loss, as can the rare development of macular neovascularization. Patients should therefore regularly monitor their vision with an Amsler grid.
