Macular degeneration
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 | |
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Other names | Age-related macular degeneration |
Picture of the back of the eye showing intermediate age-related macular degeneration | |
Specialty | Ophthalmology, optometry |
Symptoms | Blurred or no vision in the center of the visual field |
Complications | Visual hallucinations |
Usual onset | Older people |
Types | Early, intermediate, late |
Causes | Damage to the macula of the retina |
Risk factors | Genetics, smoking |
Diagnostic method | Eye examination |
Prevention | Exercising, eating well, not smoking |
Treatment | Anti-VEGF medication injected into the eye, laser coagulation, photodynamic therapy |
Frequency | 8.7% global prevalence in 2020 |
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.