Age related macular degeneration (AMD)
The part of your eye that controls your central vision (seeing what is directly in front of you) is called the macula. Macular degeneration occurs when the macula is damaged.
Reviewed by: Mr Jong Min Ong
What is age-related macular degeneration (AMD)?
Age-related macular degeneration (AMD) is a common eye condition and a leading cause of vision loss among people aged 60 years and older. It causes damage to the macular, which is a small area of the centre of the retina and the part of the eye needed for sharp, central vision. It allows us to see objects that are straight ahead, such as when reading or watching TV.
Different types of age-related macular degeneration (AMD)
There are two main types of age-related macular degeneration; dry AMD and wet AMD.
Dry AMD: Around 80% of patients have dry AMD, which develops when the cells of the macula become damaged by a build-up of deposits called drusen. Dry AMD develops slowly and generally progresses over years. At its worst, late dry AMD can cause a black patch in the centre of the vision.
Wet AMD: Wet AMD affects around 15-20% of patients and occurs when abnormal blood vessels grow underneath the retina. This tends to progress quickly, over weeks or months, and can eventually result in scarring and severe permanent loss of central vision.
Patients with dry AMD are at risk of converting to wet AMD. Nevertheless, severe visual loss may occur in both conditions.
What are the risk factors for age-related macular degeneration (AMD)?
Age is the major risk in AMD, and it most commonly occurs after the age of 60.
The risk is doubled in smokers and is greater among Caucasians and those with a family history. A great number of genes have been found to affect the possibility of developing AMD with many more genetic risk factors also suspected. However, because it is influenced by so many genes and environmental factors, there are currently no genetic tests that can diagnose AMD, or predict with certainty who will develop it.
What are the symptoms of age-related macular degeneration (AMD)?
AMD is a painless condition that can cause loss of central vision, and usually affects both eyes but not necessarily to the same degree.
In the early stages of AMD, patients might notice blurred central vision. Distortion in vision where straight lines, such as window frames or lamp posts appear bent or words appear wavy, are common symptoms. Patients may also complain of difficulty reading, watching TV, driving or recognising faces.
AMD doesn’t affect your peripheral vision (side vision), which means it will not cause complete blindness.
How can I tell if I have age-related macular degeneration (AMD)?
Early AMD may not cause any symptoms, so it’s important to have your eyes checked regularly. It is equally important to perform regular self-checks by closing one eye at a time and to use an Amsler grid to detect any change in vision, especially if it is blurred or distorted. Monitoring by looking at a door, window frame or clock can also be a good alternative. Always see your optician or an eye specialist if you have any changes or concerns.
How is age-related macular degeneration (AMD) diagnosed?
A full eye examination should be carried out to make a diagnosis. Retinal photography and imaging such as Optical Coherence Tomography scans are also helpful. A Fundus Fluorescein Angiogram, where a dye (Fluorescein) is injected into the arm and a series of images are taken of retinal circulation, is usually performed when wet AMD is suspected.
How is age-related macular degeneration (AMD) treated?
There is currently no treatment for dry AMD. Cessation of smoking is important. A healthy diet high in antioxidants, including lutein and zeaxanthin, (eg kale, spinach and broccoli) is beneficial. Some patients may also benefit from vitamins and supplements. Visual aids such as magnifiers can be helpful in optimising vision.
Wet AMD is treated with Anti-Vascular Endothelial Growth Factor injections to help reduce the growth of abnormal blood vessels. With early diagnosis and treatment, the outcome is good with 90% chance of stabilising vision and up to 30% chance of improvement in vision. During an outpatient appointment, your specialist consultant ophthalmologist will inject Anti-VEGF drugs into the clear jelly within the eye, called the vitreous. Eye drops are used to numb the eye, and this procedure is typically pain-free.