Many people can be in the early stages of macular degeneration yet not realise it, believing that they simply need a new glasses prescription. This is because the initial signs of macular degeneration can come on gradually.
However, when a blurring or distortion of the central vision becomes obvious, the disorder has already set in and vision may be permanently lost. This is why early diagnosis is essential.
There are a number of ways to diagnose macular degeneration.
As part of your regular eye examination, your optometrist will check your eyes for any signs of macular degeneration and glaucoma. If there is any indication of macular degeneration or you are in a high-risk group, are a smoker or have diabetes, you may be recommended to have digital retinal imaging to allow your condition to be monitored over time. You may also be referred to an ophthalmologist for further assessment of the retina (the back of the eye) if change is detected.
If you’re over the age of 40 – particularly if you have any history of macular degeneration in your family – you can be proactive and self-test. This is an extremely simple process that will take 10 seconds once a week.
Self-testing involves using a printed card or piece of paper that has a series of horizontal and vertical lines and a dot in the middle. This is called an Amsler Grid, named after Swiss ophthalmologist Marc Amsler.
To test your sight, use your spectacles if you require any, then place your hand over one eye and use the other to look at the small dot that is located in the centre of the grid, then test the other eye in the same way.
If the straight lines become in any way wavy or if any of the lines are missing, make an appointment with your optometrist or ophthalmologist immediately.
A fluorescein angiography (sometimes called retinal photography or eye angiography) is a medical test, during which a fluorescent dye is injected into the bloodstream, usually via the arm. This test is used because macular degeneration can cause blockages in the blood vessels, or cause them to leak – any signs of this can be picked up via this examination.
The dye flows through the system, highlighting in detail the blood vessels in the back of the eye so they can be easily seen. The back of the eye is then photographed using a special camera. This will allow your ophthalmologist to detect any signs of macular degeneration.
Your ophthalmologist will be looking for any dye that is leaking or blocked from moving through the blood vessels. Your vision will be blurred for up to 12 hours after the test.
Optical coherence tomography – commonly called an OCT scan – is a non-invasive test that can detect the presence of macular degeneration and be used to monitor the condition over time.
This test provides detailed cross sectional images of the retina. Once eyes are dilated, patients sit in front of the machine and stay as still as possible while the OCT scans the eyes without actually touching them. An OCT scan takes less than 10 minutes, yet is able to identify areas of retinal thinning, thickening, or even swelling caused by fluid build up and leaking blood vessels.
OCT scans produce detailed imaging of the surface below the retina itself, allowing detection of any changes or any areas of concern.
Regular check-ups with your optometrist, usually every two years, are a must. Remember, macular degeneration can initially have no obvious symptoms at all.
If there are any concerns with your vision, please see your optometrist or GP as soon as possible. The Amsler Grid is an excellent way to self-test at home.
Please ask your optometrist or GP about your risk factors and ensure you are reviewed appropriately