Macular degeneration

Name(s): 
Age-related macular degeneration
Macular dystrophy
Maculopathy
Nature

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.

Macular degeneration typically occurs in older people, and is caused by damage to the macula of the retina. Genetic factors and smoking may play a role. The condition is diagnosed through a complete eye exam. 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.

The difference between the two forms is categorized by the change in the macula. Those with dry form AMD have drusen, cellular debris in their macula that gradually damages light-sensitive cells and leads to vision loss. In wet form AMD, blood vessels grow under the macula, causing blood and fluid to leak into the retina.

Exercising, eating well, and not smoking may reduce the risk of macular degeneration. There is no cure or treatment that restores the 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. Dietary antioxidant vitamins, minerals, and carotenoids do not appear to affect the onset; 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 the 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 affects males and females equally, 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.

Source: Wikipedia

Incidence 
Macular degeneration is the leading cause of legal blindness in the USA. Macular degeneration is mostly an age-related condition. It is rare among the young, but the incidence is nearly 25% by age 85. A recent estimate is that 13 million Americans over 40 have signs of macular degeneration. This is much higher than a previous estimate of 3.2 +/- 0.5 million people between 55 and 85 years of age, with another 0.9 million of the over-85 age group.

Heredity, race and sex contribute to the risk of macular degeneration; whites are more susceptible than blacks, Hispanics and women are twice as prone as men to develop it.

Lifestyle issues are important risk factors for this disease. A main characteristic of the disease is damage to the macula through oxidation. Oxidation is encouraged smoking, diets deficient in fruits and vegetables, large consumption of alcohol, saturated fats and cholesterol. Exposure to bright sunlight may be a risk factor for early age-related maculopathy. A US study found that people who spend more than five hours daily outside in the summertime have an increased risk of developing early age-related retina damage that can lead to vision loss. The study also linked wearing hats and sunglasses with a slightly - but insignificantly - lower chance of developing age-related maculopathy.

Type 
(G) Very specific problems