Age-related macular degeneration (AMD) is a medical condition which usually affects older adults and results in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It occurs in “dry” and “wet” forms. It is a major cause of blindness and visual impairment in older adults (>50 years). Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life.
Starting from the inside of the eye and going towards the back, the three main layers at the back of the eye are the retina, which contains the nerves; the choroid, which contains the blood supply; and the sclera, which is the white of the eye.
The macula is the central area of the retina, which provides the most detailed central vision.
In the dry (nonexudative) form, cellular debris called drusen accumulate between the retina and the choroid, and the retina can become detached. In the wet (exudative) form, which is more severe, blood vessels grow up from the choroid behind the retina, and the retina can also become detached. It can be treated with laser coagulation, and with medication that stops and sometimes reverses the growth of blood vessels.
Although some macular dystrophies affecting younger individuals are sometimes referred to as macular degeneration, the term generally refers to age-related macular degeneration (AMD or ARMD).
Age-related macular degeneration begins with characteristic yellow deposits (drusen) in the macula, between the retinal pigment epithelium and the underlying choroid. Most people with these early changes (referred to as age-related maculopathy) have good vision. People with drusen can go on to develop advanced AMD. The risk is considerably higher when the drusen are large and numerous and associated with disturbance in the pigmented cell layer under the macula. Recent research suggests that large and soft drusen are related to elevated cholesterol deposits and may respond to cholesterol-lowering agents.
This text uses material from Wikipedia
licensed under CC BY-SA
Whether to screen? How often? At what age? At what cost?—seem to readily breed conflicting opinions and public confusion. What's needed is rigorously produced evidence. That's where Constantine Gatsonis, chair of the Department ...
Physicians and patients like to believe that early detection of cancer extends life, and quality of life. If a cancer is present, you want to know early, right? Not so fast.
Patients who complain they can't hear their friends at a noisy restaurant, but pass a hearing test in their doctor's office, may be describing hidden hearing loss.
Even infants can have conversations with mom or dad. Their turn just tends to involve a smile or some gibberish instead of words. That's a key lesson from programs that are coaching parents to talk more with their babies—and ...
New imaging techniques enable exploration of the brain in much more detail than ever before, opening the door to greater understanding of neurological problems and possibly new treatments, researchers say.
Contact tracing, combined with targeted, indoor residual spraying of insecticide, can greatly reduce the spread of the mosquito-borne dengue virus, finds a study led by Emory University.
For most vaccines to work the body needs two cell types - B cells and T helper cells - to make antibodies. B cells are the antibody factories and the T helper cells refine the strength and accuracy of antibodies to home and ...
Vaccine developers have successfully protected mice against Zika by injecting synthetic messenger RNA that encodes for virus proteins into the animals. The cells of the mice then build parts of the virus, training the immune ...
The community of microorganisms that resides in the gut, known as the microbiome, has been shown to work in tandem with the genes of a host organism to regulate insulin secretion, a key variable in the onset of the metabolic ...
In 1932 T.S. Eliot famously argued, "Genuine poetry can communicate before it is understood."