Age-related macular degeneration and the role of the complement system

Mol Immunol. 2015 Sep;67(1):43-50. doi: 10.1016/j.molimm.2015.02.032. Epub 2015 Mar 21.


Age-related macular degeneration (AMD) is a leading cause of visual impairment. It is characterised by damage to a tissue complex composed of the retinal pigment epithelium, Bruch's membrane and choriocapillaris. In early AMD extracellular debris including drusen accumulates in Bruch's membrane and then in late AMD geographic atrophy and/or neovascularisation develop. Variants in genes encoding components of the alternative pathway of the complement cascade have a major influence on AMD risk, especially at the RCA locus on chromosome 1, which contains CFH and the CFHR genes. Immunohistochemical studies have demonstrated complement components in unaffected and AMD macular tissue. Whilst other factors, including oxidative stress, play important roles in AMD pathogenesis, evidence for the central role played by complement dysregulation is discussed in this review.

Keywords: Age-related macular degeneration; Alternative pathway; Complement system.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bruch Membrane / chemistry
  • Bruch Membrane / immunology
  • Bruch Membrane / pathology*
  • Chromosomes, Human, Pair 1
  • Complement Activation
  • Complement C3b Inactivator Proteins / genetics
  • Complement C3b Inactivator Proteins / immunology*
  • Complement Factor H / genetics
  • Complement Factor H / immunology
  • Gene Expression Regulation
  • Genetic Loci
  • Humans
  • Macular Degeneration / genetics
  • Macular Degeneration / immunology
  • Macular Degeneration / pathology*
  • Oxidative Stress
  • Retinal Pigment Epithelium / chemistry
  • Retinal Pigment Epithelium / immunology
  • Retinal Pigment Epithelium / pathology*


  • CFH protein, human
  • Complement C3b Inactivator Proteins
  • Complement Factor H