Drusen associated with aging and age-related macular degeneration contain proteins common to extracellular deposits associated with atherosclerosis, elastosis, amyloidosis, and dense deposit disease

Age-related macular degeneration (AMD), a blinding disorder that compromise s central vision, is characterized by the accumulation of extracellular dep osits, termed drusen, between the retinal pigmented epithelium and the chor oid. Recent studies in this laboratory revealed that vitronectin is a major component of drusen. Because vitronectin is also a constituent of abnormal deposits associated with a variety of diseases, drusen from human donor ey es were examined for compositional similarities with other extracellular di sease deposits. Thirty-four antibodies to 29 different proteins or protein complexes were tested for immunoreactivity with hard and soft drusen phenot ypes. These analyses provide a partial profile of the molecular composition of drusen. Serum amyloid P component, apolipoprotein E, immunoglobulin lig ht chains, Factor X, and complement proteins (C5 and C5b-9 complex) were id entified in all drusen phenotypes. Transcripts encoding some of these molec ules were also found to be synthesized by the retina, retinal pigmented epi thelium, and/or choroid. The compositional similarity between drusen and ot her disease deposits may be significant in view of the recently established correlation between AMD and atherosclerosis. This study suggests that simi lar pathways may be involved in the etiologies of AMD and other age-related diseases.