Age-related Macular Degeneration (AMD)
What is AMD?
Age-related macular degeneration (AMD) is an acquired degeneration of the retina that causes significant central visual impairment and progressive visual loss.
It is thought to be due to a combination of genetic and environmental factors. AMD is the leading cause of blindness in Australians over 60 years old. It is estimated there are over 1 million Australians with signs of AMD, and this may rise to 1.7 million over the next 15 years.
Types of AMD
There are two main types of age-related macular degeneration:
1. Dry AMD
Dry AMD is the more common (approx 80-90% cases) of the two types, and can be thought of as a gradual "wear and tear" ageing process of the retina.
Dry AMD is characterised by the deposition of waste material under the retinal pigment epithelium, known as “drusen”, which become more common as people get older. It usually affects both eyes, and slowly may worsen over many years.
Dry AMD may lead to gradual worn down patches in the central vision over many years, known as "geographic atrophy". It can also transform into wet AMD (see below)
2. Wet AMD
Wet (neovascular) AMD usually causes a sudden blurry patch in the central vision of one eye, often associated with distortion of straight lines such as a doorway or bathroom tiles.
Wet AMD is the more severe form of AMD, and if left untreated, can lead to permanent loss of central vision within a few weeks or months. In wet AMD, a new blood vessel grows through the base of the retina and can leak fluid or bleed into the retina. This can cause permanent scar tissue.
Diagnosis of AMD
Diagnosis of wet AMD is made through a combination of clinical examination, optical coherence tomography imaging (OCT) and fundus fluorescein angiograph (FFA).
For wet macular degeneration in particular, it is important you see an ophthalmologist experienced in the treatment of retinal diseases as quickly as possible to confirm the diagnosis and commence appropriate treatment. If you have noticed a sudden change in your vision or new onset distortion, do not leave it too long to be seen.
What you can do
AMD is thought to occur due to a combination of genetic and environmental factors. While we cannot change the genes we are born with, there are a number of measures patients can undertake to reduce the risk of vision impairment from macular degeneration.
1. Routine eye exams: Regular eye checks can help to detect early stages of AMD, and increase your awareness of the warning symptoms of this condition. Amsler grid monitoring (see Amsler Chart below) is a very useful tool to detect early distortion associated with wet AMD.
2. Stop smoking: People who smoke are more likely to develop macular degeneration and experience more severe visual impairment from this condition. Discuss ways to help stop smoking with your general practitioner, pharmacist or the Quit Helpline.
3. Healthy macular diet: Choose a healthy diet full of a variety of green leafy vegetables, fish, fresh fruit and a handful of nuts. These foods contain antioxidants and vitamins that may reduce your risk of macular degeneration. In particular, vegetables such as kale, spinach, broccoli, and peas have high levels of antioxidants, including lutein and zeaxanthin.
4. Maintain a healthy weight and exercise regularly. If you need to lose weight, reduce the number of calories you eat and increase the amount of exercise you get each day.
5. Manage your other diseases. For example, if you have cardiovascular disease or high blood pressure, take your medication and follow your doctor’s instructions for controlling the condition.
Treatment for Wet AMD
Intravitreal anti-VEGF (vascular endothelial growth factor) injection therapy has revolutionised the treatment of wet AMD, and has led to much better outcomes for patients with this condition. Over 90% of patients should stabilise their vision with treatment, and about 1 in 3 patients will notice an improvement in their vision.
The injections are performed using a sterile technique by our highly experienced eye specialists. The injection is conducted in the procedure room in our clinic. There is very little pain felt during or after the injection. Our specialists will discuss this with you in detail should you require this treatment.