Age-related macular degeneration (AMD) Home A-Z Health Information Health Library A-Z Age-related Macular Degeneration (AMD) Overview Age-related macular degeneration (AMD) refers to the ageing-induced damage of the macula, which is the central part of the retina. The macula, which consists of light-sensing tissues that line the back of the eye, is responsible for sharp, clear central vision. In AMD, the central vision is blurred, while the peripheral (side) vision is not affected. This common condition is the most prominent cause of vision impairment in people aged > 50 years.The visual precision required for daily activities is greatly impaired by AMD. The progression of this disease interferes with several activities, including facial recognition, driving, and viewing details up close (for example, telling the time) or from afar (for example, trying to view a bus number), or reading.Early diagnosis and timely treatment can impede the progression of AMD. Regular eye checkups, knowledge regarding risk factors, and prompt medical attention to alterations in vision are crucial for the preservation of eyesight. With proper eyecare and management, vision can be effectively maintained in patients with AMD. Two primary types of AMD Dry AMD: About 75%–80% of AMD cases represent the dry form. Genetic and environmental factors are thought to cause dry AMD although an exact cause has not yet been identified. Dry AMD involves the gradual degradation of the light-sensitive cells in the macula (generally, one eye at a time). The loss of vision is usually slow and gradual. Most patients experience near-normal vision or only slight vision loss. The ageing-induced deterioration of an important support membrane under the retina has been theorised to cause dry AMD.Wet AMD: Although wet AMD is a less common type of AMD, it is the most common cause of severe loss of vision. Usually, vision loss after wet AMD is more severe than that after dry AMD. The occurrence of wet AMD occurs is attributed to the growth of abnormal blood vessels beneath the retina. This causes a leakage of fluid and blood (giving rise to the term ‘wet AMD’), which prevents the light-sensitive cells in the retina from functioning properly. Ultimately, due to the bleeding and scarring, a large blind spot is created in the centre of the visual field. This causes the permanent loss of central vision. However, as the peripheral (side) vision is not affected, complete vision loss is unlikely. Regular eye exams are recommended to diagnose wet AMD as it progresses more rapidly than dry AMD, preventing extensive vision loss. Geographic atrophy, a less common form of wet AMD, represents a condition involving the severe thinning or loss of the macula. However, there is an absence of leaking blood vessels. Antiangiogenic medicines are not effective against geographic atrophy. Causes The exact causes of AMD are unknown. However, certain patient groups have been reported to be at a higher risk of developing this condition. Such groups include subjects who are smokers and/or overweight and subjects with hypertension. A family history of AMD may also be a risk factor. Diagnosis It is diagnosed by an ophthalmologist and confirmed with the help of additional imaging tests, such as:Retinal scan to evaluate AMD severity.Optical coherence tomography (OCT) of the macula. In this non-invasive imaging test, light waves are used to capture cross-section pictures of the retina.Regular comprehensive eye exams, even in the absence of changes in vision, are advised for the early detection of AMD before major vision loss. Early detection and timely treatment are crucial to counter the impairment of vision caused by AMD progression. Treatment Preventive measures for AMD include:Cessation of smoking, consuming a well-balanced diet (to maintain a healthy weight), and following a healthy lifestyle, including regular exercise regimens.Certain antioxidant-based and zinc-based supplements may halt the progression of AMD although their benefits have not been proven.Treatment options for AMD include:Wet AMD: Wet AMD is treated by injecting anti-vascular endothelial growth factor (VEGF) drugs, also known as anti-angiogenic medicines, into the eye. They prevent the growth and leakage of abnormal blood vessels and bleeding under the retina. In most cases, repeated injections are required several times per year to control wet AMD.Dry AMD: No treatment options are currently available for dry AMD.