Macular Degeneration

Patient Education >> Macular Degeneration

retinaMacular Degeneration is one of the primary causes of central vision loss in older Americans. This condition results from changes in the back of the eye which lead to blurring or loss of the center of your vision. This may make reading or doing close-up work more difficult or impossible. There are two forms of macular degeneration: Dry and Wet.

Dry macular degeneration
In the "dry" type of macular degeneration, the deterioration of the retina is associated with the formation of small yellow deposits, known as drusen, under the macula. This phenomena leads to a thinning and drying out of the macula, causing the macula to lose its function. The amount of central vision loss is directly related to the location and amount of retinal thinning caused by the drusen. The early stage of age-related macular degeneration is associated with minimal visual impairment and is characterized by large drusen and pigmentary abnormalities in the macula. Drusen are accumulations of acellular, amorphous debris subjacent to the basement membrane of the retinal pigment epithelium. Nearly all people over the age of 50 years have at least one small druse in one or buth eyes. Only eyes with large drusen are at risk for late age-related macular degeneration. This form of macular degeneration is much more common that the "wet" type of macular degeneration and it tends to progress more slowly than the "wet" type. However, a certain percentage of the "dry" type of macular degeneration turns to "wet" with the passage of time. There is no known cure for the "dry" type of macular degeneration. Center vision may appear blurry because parts of the macula have begun to die, leaving blank spots in vision. Straight lines may look wavy. Side or "peripheral" vision is rarely affected.

Web macular degeneration
In the "wet" type of macular degeneration, abnormal blood vessels (known as choroidal neovascularization or CNV) grow under the retina and macula. These new blood vessels may then bleed and leak fluid, causing the macula to bor lift up from its normally flat position, thus distorting or destroying central vision. Under these circumstances, vision loss may be rapid and severe. With the "Wet" type, the patient may see a dark spot (or spots) in the center of their vision due to blood or fluid under the macula. Straight lines may look wavy because the macula is no longer smooth. Side or "peripheral" vision is rarely affected. However, some patients do not notice any such changes, despite the onset of neovascularization. Therefor periodic eye examinations are still very important for patients at high risk.

Signs and Symptoms

  • Decreaased visual acuity
  • Loss of central vision
  • Visual distortion of size, shape, or inclination of objects

Treatment and Maintenance

  • AREDS vitamin
  • Monitor any vision changes using the Amsler Grid - see below
  • For web macular degeneration: Intravitreal Injections

Click this link to test your vision using the Amsler Grid