Macula Month is an initiative of Macular Disease Foundation Australia and runs for the month of May to raise awareness of macular disease. This includes age-related macular degeneration (AMD).
Causes of macular degeneration
Macular degeneration, as it sounds, is a degeneration of the macula. It’s also known as age-related macular degeneration, as it commonly occurs in those over 50 years old. The macula is the part of the eye which is responsible for central vision (straight ahead) in the direction you look.
The early stages of macular degeneration typically show waste product build up within the retina, these are yellow spots called drusen. Small amounts of drusen at the macular may not cause visual symptoms, however it does mean there is more risk of vision loss from ARD.
The later stages will result in some visual loss or distortion. This is due to the death of retinal-pigment epithelium cells or RPE. The death of the cells results in patches called retinal atrophy.
Types of AMD
There are two types of macular degeneration:
- Dry AMD is the most common, it is a painless, slow and progressive deterioration of the macular.
- Wet AMD is much more severe and sudden, it is due to the growth of new vessels under the RPE which are leaky. These vessels leak fluid and blood underneath the macula which then leads to scar tissue and vision loss.
Although there is no cure, treatment aims to prevent any further decline for as long as possible. In some cases, treatment can restore vision.
Risk factors
One obvious risk factor is in the name of AMD – age. Anyone over the age of 50 years is at a higher risk of macular degeneration.
Family history is also a big influence as a risk factor of macular degeneration. Approximately 70 per cent of cases have a genetic link. Smoking has been shown to increase your risk of AMD by three to four times and the disease may affect you 5-10 years earlier as well.
Signs and symptoms
The obvious sign that AMD may be occurring is the loss or distortion of your central vision in one or both eyes. A common example of this is that straight lines in your vision appear to bend or distort.
It’s important to never ignore any of these signs, as early diagnosis and detection is imperative for treatment of macular degeneration.
Diagnosis and Detection
Common tests that your optemtrist will perform will include a check for visual acuity (how well you can see), retinal photos to image the retina and track changes in the future. Optical coherence tomography or OCT uses light to look at the different layers of the retina to check for fluid, blood vessels or drusen. The optometrist will typically refer you to an ophthalmologist for further investigation, if required.
Lastly, your optometrist or ophthalmologist will recommend using an Amsler Grid. It’s a grid with a central target to fixate on. The purpose of the grid is to monitor your vision for further changes at home – again early detection of changes can be the difference between saving your vision or losing your sight.
Prevention and treatment
Treatment will depend whether you have been diagnosed with the wet or dry form of macular degeneration.
While you can’t control your age or family history, there are some things you can do to help in the prevention of macular degeneration. Quitting smoking is a good place to start to try to reduce the likelihood of macular degeneration. It is also important that you protect your eyes from UV light. Other recommendations include a healthy diet which consists of fresh fruit, leafy greens, fish (omega 3) and nuts.
Treatment will vary depending on your situation and the type of macular degeneration you have. Unfortunately, dry macular degeneration has no treatments available. All that can be done in the way of treatment is to try and slow down the progression of the disease. Wet macular degeneration is also not curable. The treatment lies with ocular injections to stabilise the retina, reduce the fluid build-up and maintain vision.
It’s important to regularly see your local optometrist for check-ups and to speak to them if you would like further information.
