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Known as ‘Age-Related Macular Degeneration (AMD)’, AMD is the leading cause of blindness in Australia.
Roughly 6.5% of those over the age of 40 have some degree of AMD. This rises to 15% for 50 and above. Prevalence continues to increase with age.
What is AMD? (American Macular Degeneration Foundation)
Early signs of AMD include vision that is fuzzy or distorted, a loss of light sensitivity, difficulty distinguishing colours, and shadowing or dark patches in your central view.
Vision loss is typically slow and painless though in some instances it can occur rapidly.
The risk factors, as outlined by the Australian 'Macular Disease Foundation' are as follows.
There is a strong genetic correlation for the disease. Those with a known family history have a 50% chance of developing it so if you fall into this category it is critical that you see your doctor to discuss lifestyle and diet changes to reduce your risk.
AMD can also develop in the absence of both prior family history or commonly known risk factors.
There is a direct correlation between age and the prevalence of AMD. One in seven Australians over the age of 50 will show symptoms.
Smoking both significantly increases the chance of AMD developing as well as when. It can cause the disease to develop upwards of a decade earlier!
Poor Diet and Lack of Exercise
Poor health habits can significantly increase your risk. This is further exacerbated by diabetes which increases your long term risk.
Regular and extended periods of sunlight exposure are speculated to cause long term eye damage increasing the risk of developing AMD.
So now that we know what the symptoms are let's look at the simple home tests you can use to determine if you need to go to a doctor.
'Straight Line' Eye Test
A quick rough test that can be performed at home is to look at straight edges such as a door and see if there are any distortions or parts missing. Test each eye individually by covering the other.
If there is a concern, consider the next test which can also be done at home.
An Amsler Test is a simple printed out check that can be performed at home.
Under normal light, wearing reading glasses if you regularly use them, and testing one eye at a time, keep your focus on the central dot.
You will be looking to see if any of the lines are wavy, blurred or distorted. Also, check to see if there is any distortion of the grids or any areas are missing.
Test your eyesight with our AMD Tool.
Amsler Test: The right image shows how an AMD sufferer may see the grid.
If you have any problem areas, mark them on the grid. If need be, use two grids, one for each eye. Take the grid(s) to your doctor as soon as possible.
The Macular Disease Foundation of Australia can also provide you with a home kit that includes the Amsler Test, an information guide and some disease management recommendations.
Amsler Test from the Australian 'Macular Disease Foundation'
There are smartphone apps now that can test eye function and replicate physical exams such as the Amsler grid.
CentralVisionTest Mobile App (Healthcare4mobile)
Just note that these tests can sometimes provide false positives. If you get a positive result, double-check with the Straight Line test a physical test and a printed Amsler test before heading to the doctor.
If any of the above tests have given you cause for concern then it is definitely time to see a doctor or optometrist.
They will perform a retinal exam involving a number of tests that could include a pupil dilation test, a visual acuity test, an Amsler test, and an Ophthalmoscopy.
If the results are positive the doctor will likely refer you to an ophthalmologist who can perform more specialised tests to confirm a diagnosis.
There are two genes closely associated with AMD, though their capacity to do harm is not well understood. The two genes are complement factor H (CFH) and ARMS2/HTRA.
While there are genetic tests available to test for these, there is currently no supporting evidence to guide a specialist in tailoring medications for them.
At best, knowing that you have the genes could encourage you to reduce your risk factors. However, adopting the recommended healthy habits such as not smoking and eating a diet rich in vegetables and fruits applies for general health anyway!
It's Worth Knowing Early!
While there is no cure for AMD, spotting it early can make a huge difference in managing the disease.
Interventions include dietary and behavioral modifications, medications, augmented vision support (wearables), and surgery. There is even gene and stem cell therapies in clinical trials now that are aiming to cure the disease entirely.
Managing AMD can lead to many more years of functional vision and the earlier it’s picked up the better the treatment outcomes.
AMD is a progressive disease without any cure. It can begin as early as the age of 40 and results in progressive vision loss. Untreated it will eventually result in blindness.
If identified early there is a wide range of treatments that can significantly reduce the rate of deterioration. The near future promises biotech therapies, in clinical trials now, which aim to cure the disease entirely.
The sooner the disease is identified the sooner these treatments can begin and the greater their resulting effect will have.
Start with the home tests which are both easy and free. If you’re concerned than definitely see your doctor or optometrist.
Early intervention can mean the difference between managing the disease and total blindness.
Don’t leave it until it’s too late!
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