Change Text Size : Normal Text Medium Text Large Text
 
 
Age-related Macular Degeneration (AMD)
Age-related Macular Degeneration (AMD) is the number one cause of vision loss in people over age 65 years in the U.S. The macula is the part of the retina that is responsible for central vision. Proper macular function is essential for reading and driving. There are two types of AMD: Dry (non-exudative) and Wet (exudative).

Dry AMD is the most common type. In the macula there are characteristic deposits called Drusen. It is believed that drusen may lead to loss, or "atrophy," of the layer beneath the retina (the RPE) which provides nutrients to the retina. Once an area atrophies the overlying retina does not function well and may lead to a blind spot (Scotoma.) If the blind spot is directly in the center it could interfere with reading, recognizing faces, or driving. If it causes a severe loss of vision to worse than 20/200 line on the eye chart, the person is considered legally blind.

Most people diagnosed with AMD have the dry form. Dry AMD progresses slowly. However, it can go onto to the Wet form.

Leaking Blood vessels in an eye with Wet AMD
Wet AMD accounts for most of the vision loss from AMD. In the wet form, abnormal blood vessels grow under the retina and leak or bleed. This causes a sudden change in vision. Sometimes the patient notices that straight lines have a bend in them. Other times a person may notice a blank spot or blurring in vision.

The traditional treatment for Wet AMD has been laser treatment. Laser treatment works for lesions that are not in the direct center. There is a possibility of recurrence with laser treatment and close follow-up and repeated treatment may be needed. Another proven treatment is Photodynamic Therapy with Visudyne. Visudyne is injected in a vein (usually the arm) and then travels to the eye. It is then activated by a special "cold" laser light which activates the drug, which then selectively damages the abnormal blood vessels. This treatment is less destructive to the normal retina. It may be repeated every 6 weeks to 3 months. On average patients require 3 treatments within the first year of diagnosis.

Type of treatment used depends on the location of the lesion within the macula and the nature of the lesion based on fluorescein angiography.
 
 
 
Copyright 2009 Retina Institute of the Carolinas & The Macular Degeneration Center. All Rights Reserved.