[Familial drusen of the macula]

Hereditary drusen are an autosomal dominant inherited disease that shows complete penetrance and variable expression. The disease is caused by an unclear metabolic defect of the retinal pigment epithelium, which leads to an accumulation of metabolic break-down deposits from the retina and from the retinal pigment epithelium within the inner collagenous layer of Bruch's membrane. The most important factor in making a differential diagnosis is age-related so-called typical drusen. Apart from the genetics and family history, familial drusen are characterized by the earlier appearance of drusen (at 20 to 30 years of age), a different distribution pattern for the drusen within the fundus (drusen situated in the nasal half of the fundus) and a distinctly earlier reduction in visual acuity (50 years of age). Because of the possibility of loss of vision in the younger years, an early diagnosis of familial drusen in necessary to be able to perform thorough family and job counseling.