Histopathologic findings in Best's vitelliform macular dystrophy.

Postmortem donor eyes from a 69-year-old man with Best's vitelliform macular dystrophy showed retinal pigment epithelial cells across the entire fundus that had accumulated an excessive amount of lipofuscin as defined by ultrastructural appearance, autofluorescence studies, and staining properties. Lipofuscin accumulation was particularly notable in some pigment epithelial cells in the fovea. An accumulation of heterogeneous material located between Bruch's membrane and the pigment epithelium in the fovea was believed to represent the location of a previtelliform lesion. This material appeared to be derived from degenerating pigment epithelial cells and contained few intact lipofuscin granules. Foveal photoreceptor loss occurred above the lesion and in midperipheral sites where the subretinal space contained collections of outer segment debris and phagocytic cells. Best's vitelliform macular dystrophy appears to be a generalized disorder of the pigment epithelium that secondarily affects focal areas of the retina.