Age-Related Macular Degeneration

Age-Related Macular Degeneration

Useful Terms

Macula = small, central portion of the retina with more sensitivity than the rest of the retina and is

responsible for central vision

Peripheral retina = the area of the retina that does not contain the macula and is responsible for

peripheral (side) vision

Common Symptoms

  • Dim and blurry spot in the central vision (first sign)
  • Blurriness
  • Darkened areas
  • Distortion in central vision

Risk Factors

  • Hereditary = can be passed on to children and future descendants
  • Smoking
  • High Blood Pressure
  • High cholesterol
  • Obesity
  • Light skinned females with light eye colors

Causes

Dry Form

  • Formation of yellow deposits called drusen under the retina
  • As the size and number of the drusen increase, central vision becomes dimmer and moredistorted
  • Loss of vision is gradual process as the increase presence of drusen degrades the macula into astate of atrophy
  • The atrophic state leads to blind spots in the central vision before it is eventually completelylost

Wet Form

  • About 10% of those who experience the dry form will also experience the wet form
  • Abnormal blood vessels grow in the choroid, a layer underneath the retina
  • They leak fluids and blood that blur and distort central vision
  • The process of vision less is quickened and more apparent
  • As time passes and the leakage continues, it may spread to both eyes and permanent loss of thecentral vision

Diagnosis

  • Drusen can be detected in a routine eye exam
  • If one looks at an Amsler grid and sees wavy lines or missing lines, then he/she has the dryform
  • In angiography, a dye is injected into the vein of the arm and reaches the eye and retina.
  • Photographs are taken while the dye travels to look for the abnormal blood vessels of the wetform
  • An OCT can also be used to look for these blood vessels by using light waves to take cross-sectionpictures of the retina

Treatment

  • There is no cure for the disease
  • Anti-angiogenesis drugs (Avastin, Eyelea, Lucentis, Macugen) block the growth of the abnormal bloodvessels and their leakage
    • Repeated treatment sessions can lead to a recovery of vision that was lost or evencomplete reversal of the damage
  • Photodynamic laser therapy
    • The light-sensitive drug Visudyne is injected into the bloodstream to be absorbedby the abnormal blood vessels
    • Then a cold laser is used to activate the drug and weaken the blood vessels or evendestroy them
  • Low vision aids help people make the most of the vision they have left through the use of speciallenses or systems to enlarge images of objects or people nearby