eye disorders
Age Related Macular Degeneration (AMD or ARMD)
Causes of AMD
The following are risk factors for age-related macular degeneration: Age Family history Smoking Certain genetic abnormalities Cardiovascular disease (such as Atherosclerosis ) High Blood Pressure None Obesity None Sun exposure A diet low in omega-3 fatty acids (for example, in certain fish) and dark green leafy vegetables There are two types of AMD: Dry (nonexudative or atrophic) Wet (neovascular or exudative) All AMD starts as the dry type. Some people (around 10%) go on to develop wet AMD. About 85% of people with AMD have only the dry type. Although relatively few people have the wet type, 80 to 90% of the severe vision loss caused by AMD results from the wet type. Dry AMDcauses the tissues of the macula to thin as cells disappear. Accumulated waste products from the rods and cones may produce deposits in the retina (the transparent, light-sensitive structure at the back of the eye) called drusen (yellow spots). Both eyes may be affected simultaneously in the dry form. There appears to be no scarring or bleeding or other fluid leakage in the macula. Wet AMDdevelops when abnormal blood vessels grow in from the choroid (the layer of blood vessels that lies between the retina and the outer white layer of the eye called the sclera) under the macula and leak blood and fluid (hence the description as "wet"). Eventually, a mound of scar tissue develops under the macula. The wet form develops in one eye first but eventually may affect both eyes. 