What Is Age-related Macular Degeneration (AMD)?
Age-related macular degeneration (AMD) is a degenerative eye disease that causes damage to the macula, the central part of the retina at the back of the eye that allows us to see fine details clearly. AMD can impair central vision. People who are affected by AMD may have problems reading, driving, and performing activities that require clear central vision. In severe cases, AMD makes close work like threading a needle or reading a book difficult or impossible. When the macula does not function correctly, we experience blurriness or darkness in the center of our vision. Although AMD reduces vision in the central part of the retina, it does not tend to affect peripheral vision. AMD alone does not usually result in total blindness. Most people continue to have some useful vision and are able to live independently. AMD is the leading cause of irreversible vision loss in our senior population.
Stages of Age-related Macular Degeneration
The Dry Stage
This is the more common form. In this type of AMD, the delicate tissues of the macula become thinned and slowly lose function over a period of years to decades.
The Wet Stage
This is less common, but is typically more damaging. The wet type of AMD is caused by the growth of abnormal blood vessels behind the macula. The abnormal blood vessels tend to hemorrhage or leak fluid, resulting in the formation of scar tissue if left untreated. In most instances, the wet stage develops in addition to the dry stage of AMD.
AMD develops differently in each person and the symptoms tend to vary. AMD may cause a progressive loss of central sight; however, it does not usually cause total blindness. Peripheral vision is unaffected, allowing a certain amount of mobility in normal surroundings. If left untreated, the wet type of AMD may progress rapidly.
Straight lines appear wavy
Objects may appear as the wrong shape or size
The loss of clear, correct colors
A dark, empty area in the center of vision
The symptoms described above may not necessarily mean that you have AMD. However, if you experience one or more of these symptoms, contact your eye doctor for a complete exam.
Treatment and Drugs
Currently, there is no known cure for AMD. There are, however, new therapies emerging. For individuals with AMD , it is recommended that a regular schedule of eye examinations be maintained. During these examinations, detailed documentation may be performed. With this information, your eye doctor is better able to monitor the condition, note any changes that may occur, and determine the most appropriate therapy.
Treatment for Dry Macular Degeneration
Supplementation with specific anti-oxidant vitamins and minerals has been shown to significantly slow the progression of dry AMD. For details on the dosage and side-effects, please see your ophthalmologist.
Treatment for Wet Macular Degeneration
Since approximately 2005, ophthalmologists have used a class of drugs called vascular endothelial growth factor (VEGF) inhibitors as the primary treatment for wet macular degeneration. These drugs inhibit the growth and leakage of abnormal blood vessels and are the first treatments that have been shown to improve vision in some eyes rather than simply slowing the rate of vision loss. VEGF inhibitors are delivered through tiny injections in the eye periodically.
Other treatments include laser treatments and photodynamic therapy. These treatments are designed to seal the leaking blood vessels, halting the damage they can inflict upon the retina. These treatments may be effective in slowing the progression of wet macular degeneration and are sometimes used in combination with VEGF inhibitors. Research is underway to find new and more effective treatments for this condition.