Adult onset foveomacular dystrophy or adult onset pseudovitelliform dystrophy is the presence of a yellowish deposit under the macula, often noted in patients in their 40s and 50s. Patients may have no symptoms or may have reduced or distorted vision.
In some patients, foveomacular dystrophy may has a genetic component. The RDS gene codes a protein in the retina known as peripherin. Patients with a mutation in this protein may develop foveomacular dystrophy. Gene testing is available from the University of Michigan Kellogg Eye Center.
Over many years the yellow deposit may “collapse” leaving thinning and altered pigmentation in the macula, often resembling a patient with dry macular degeneration. Sometimes distinguishing a foveomacular dystrophy patient from a dry macular degeneration patient is difficult. For practical purposes, I counsel patients the same: I advise taking the AREDS antioxidant vitamins and self monitoring with an Amsler grid. Both types of patients may develop choroidal neovascularization or “wet macular degeneration.”
Scientific article from Molecular Vision: the point of this article is that not all patients with foveomacular dystrophy have a mutation in the RDS gene. Probably other, as yet unknown genes contribute to foveomacular dystrophy in many patients.