Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred or no vision in the center of the visual field. Early on there are often no symptoms. Over time, however, some people experience a gradual worsening of vision that may affect one or both eyes. While it does not result in complete blindness, loss of central vision can make it hard to recognize faces, drive, read, or perform other activities of daily life. Visual hallucinations may also occur but these do not represent a mental illness. Macular degeneration typically occurs in older people. Genetic factors and smoking also play a role. It is due to damage to the macula of the retina. Diagnosis is by a complete eye exam. The severity is divided into early, intermediate, and late types. The late type is additionally divided into "dry" and "wet" forms with the dry form making up 90% of cases.
Preventive efforts include exercising, eating well, and not smoking. There is no cure or treatment that returns vision already lost. In the wet form, anti-VEGF medication injected into the eye or less commonly laser coagulation or photodynamic therapy may slow worsening. Antioxidant vitamins and minerals do not appear to be useful for prevention. However, dietary supplements may slow the progression in those who already have the disease. Age-related macular degeneration is a main cause of central blindness among working aged population worldwide. As of 2020, it affects more than 190 million people globally with the prevalence expected to increase to 288 million people by 2040 as the proportion of elderly persons in the population increases. It is equally seen in males and females and it is more common in those of European or North American ancestry. In 2013 it was the fourth most common cause of blindness after cataracts, preterm birth, and glaucoma. It most commonly occurs in people over the age of fifty and in the United States is the most common cause of vision loss in this age group. About 0.4% of people between 50 and 60 have the disease, while it occurs in 0.7% of people 60 to 70, 2.3% of those 70 to 80, and nearly 12% of people over 80 years old.
Early or intermediate AMD may be asymptomatic, or it may present with blurred or decreased vision in one or both eyes. This may manifest initially as difficulty with reading or driving (especially in poorly lit areas).Other symptoms of AMD include distortion of vision and blind spots (especially in and around the central visual field.
Other signs and symptoms of macular degeneration include:
Distorted vision in the form of metamorphopsia, in which a grid of straight lines appears wavy and parts of the grid may appear blank: Patients often first notice this when looking at things like miniblinds in their home or telephone poles while driving. There may also be central scotomas, shadows or missing areas of visionBlurred vision: Those with no exudative macular degeneration may be asymptomatic or notice a gradual loss of central vision, whereas those with exudative macular degeneration often notice a rapid onset of vision loss (often caused by leakage and bleeding of abnormal blood vessels).Formed visual hallucinations and flashing lights have also been associated with severe visual loss secondary to wet AMD Macular degeneration by itself will not lead to total blindness. For that matter, only a small number of people with visual impairment are totally blind. In almost all cases, some vision remains, mainly peripheral. Other complicating conditions may lead to such an acute condition (severe stroke or trauma, untreated glaucoma, etc. but few macular degeneration patients experience total visual loss.
The area of the macula comprises only about 2.1% of the retina, and the remaining 97.9% (the peripheral field) remains unaffected by the disease. Even though the macula provides such a small fraction of the visual field, almost half of the visual cortex is devoted to processing macular information. In addition, people with dry macular degeneration often do not experience any symptoms but can experience gradual onset of blurry vision in one or both eyes. People with wet macular degeneration may experience acute onset of visual symptoms.
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American Journal of Pharmacology and Pharmacotherapeutics