Drusen were initially described by Franciscus Donders who called them "Colloidkugeln" (colloid spheres). Later, Heinrich Müller named them for the German word for geode, based on their glittering appearance. In view of their location between the retinal pigment epithelium (RPE) and its vascular supply, the choriocapillaris, it is possible that drusen deprive the RPE and photoreceptor cells of oxygen and nutrients. In some cases, drusen develop above the so-called pillars of the choriocapillaris that is the area between two micro vessels; although important variations are observed between different subtypes of AMD.