Age-related macular degeneration, or ARMD, is a disease of the eye. Specifically, it affects a part of the retina called the macula. The retina is a light-sensitive organ located at the back of the eye. The optic nerve is also in this location. The retina contains special cells called rods and cones, which are responsible for black and white, and color vision, respectively. Rods can function at very low levels of light, while cones require higher levels. That’s why nighttime vision is devoid of color compared to daytime vision. Nocturnal animals have an abundance of rods in their retinas because they must be able to see in low light levels in order to hunt. Your text to link…
The macula is the very center of the retina. It’s where the clearest, sharpest vision is produced. ARMD tends to appear in persons over the age of 60 or so. There is also a form of macular degeneration that can affect younger persons, but that disease is completely genetic in nature, caused by a faulty recessive gene. ARMD probably has some genetic components to it, but its exact cause remains unknown.
Two Types of ARMD
There are two forms of the disease: wet and dry. Both produce vision loss in the central portion of the person’s visual field. At its worst, wet ARMD can cause total loss of central sight. It appears to the patient as though a doughnut hole has been punched out of their vision, right in the middle. It can be impossible to read, work a crossword, recognize faces, or watch TV. Because it affects only the macula, ARMD doesn’t cause total blindness, but it can be extremely debilitating.
The dry form causes damage to the macula by the formation of yellow deposits, called drusen. These drusen can cause distortion in the visual field, which can worsen as the deposits grow in size and number.
The wet form is more severe, affecting only about 10% of persons with ARMD. It’s caused by new blood vessels that form underneath the macula. These vessels aren’t normal and aren’t supposed to be there. They are fragile and they break and bleed. The bleeding causes irritation and damage, leading to vision loss. Additionally, the abnormal blood vessels underneath the macula cause ripples in it to form. For clear vision, the macula and retina must have a flat surface. The ripples cause wavy lines to appear in the patient’s visual field. There is a special vision test to help reveal this defect, which is a hallmark sign of wet ARMD. Your text to link…
ARMD isn’t curable, but there are some promising treatments using biologic drugs such as ranibizumab, which inhibits the formation of the abnormal, damaging blood vessels found in wet ARMD. There is some evidence that vitamin therapy using vitamins A, C and E, along with zinc and a plant substance called lutein, may be protective against the development of ARMD. These preparations are available under various brand names at most drugstores, pharmacies and also online.
Who Gets ARMD?
White people are more likely to have ARMD than black or Hispanic people. Smoking is a strong factor. So is sunlight, so protect your eyes with sunglasses while outside during the day. If you notice sudden blurry vision or wavy lines, see an eye doctor right away. Your normal sight may depend on it.