Macular Degeneration, Age-Related

BASICS

DESCRIPTION

  • Age-related macular degeneration (AMD) is the leading cause of central vision loss in older adults.
  • Loss of reading, driving at night, recognizing faces or expressions
  • Classified as:
    • “Dry”/Nonexudative or atrophic, such as drusen or macular pigmentary changes
    • “Wet”/Exudative or neovascular age-related macular degeneration (nAMD)

EPIDEMIOLOGY

  • nAMD form is more common in White people.
  • Predominant sex: female

Incidence

  • “Dry”/Nonexudative: 80–85% of cases; favorable prognosis
  • “Wet”/Exudative: 15–20% of cases; accounts for 80% of severe vision loss

Prevalence

  • People 65 to 74 years old: 11%
  • People ≥75 years old: 27.9%

ETIOLOGY AND PATHOPHYSIOLOGY

  • Atrophic/nonexudative
    • Drusen and/or pigmentary changes in the macula is “hallmark.” Drusen are deposits of hyaline material between the retinal pigment epithelium (RPE) (a pigment layer underneath the retina that normally helps remove metabolic by-products from the retina) and Bruch membrane (the limiting membrane between the RPE and the choroid).
    • Visible light can result in the formation and accumulation of metabolic by-products in the RPE, a pigment layer underneath the retina that normally helps remove metabolic by-products from the retina. Excess accumulation of these metabolic by-products interferes with the normal metabolic activity of the RPE and can lead to the formation of drusen.
  • nAMD
    • nAMD stage generally arises from the atrophic stage.
      • In type 1 neovascularization, breaks in Bruch membrane allow choroidal neovascular membranes (CNVMs) to grow into the sub-RPE space. This corresponds to occult CNVMs. Fluid leakage and bleeding can produce a vascularized serous or fibrovascular RPE detachment.
      • In type 2 neovascularization, the CNVM passes through the RPE and is located in the subretinal space; typically appears as a lacy or gray-green lesion. This corresponds to classic CNVM.
      • Type 3 neovascularization, also known as retinal angiomatous proliferations (RAPS), the neovascularization develops from the deep capillary plexus of the retina and grows downward toward the RPE.
      • Polypoidal choroidal vasculopathy (PCV) is a subtype of nAMD and often presents with multiple, recurrent serosanguineous RPE detachments. An RPE detachment is also known as a pigment epithelial detachment (PED). Optical coherence tomography (OCT) features of PCV include multiple PEDs, sharply peaked PED, notched or multilobulated PED, and a hyperreflective ring surrounding an internal hyporeflective lumen beneath a PED.

Genetics

Complement factor H (CFH) and age-related maculopathy susceptibility 2 genotypes are important susceptibility genes for AMD.

RISK FACTORS

  • Advanced age
  • Obesity
  • Hypertension
  • Hyperlipidemia
  • Cigarette smoking
  • Chlamydia pneumoniae infection
  • Family history
  • Excess sunlight exposure
  • Blue or light iris color
  • Hyperopia
  • Short stature

GENERAL PREVENTION

  • Omega-3 and Omega-6 fatty acids
  • Ultraviolet (UV) protection for eyes
  • Routine ophthalmologic visits

There's more to see -- the rest of this topic is available only to subscribers.

© 2000–2025 Unbound Medicine, Inc. All rights reserved
All content is protected by copyright and may not be used for AI model training or other unauthorized purposes.