What is Age-Related Macular Degeneration?
Age-related macular degeneration (AMD) is a condition that affects the macula – the central part of the retina responsible for detailed straight-ahead vision – and AMD causes loss of this central vision.
As its name suggests, AMD tends to occur later in life, although it can affect people in their late 40s. AMD is the leading cause of permanent visual loss in people aged over 60 in developed countries, and is a growing problem for Singapore as our population ages.
“It is estimated that the number of people affected by AMD in developed countries will increase by around 30% in the next 10 years and by around 59% in the next 20 years.”
There are two types of AMD: wet and dry. The wet form is caused by the growth of abnormal blood vessels under the retina, which bleed and leak into the macula causing distorted or wavy vision and blind spots. Ultimately, this leads to a scar which causes permanent loss of central vision. Currently, the wet form of AMD can be slowed down with eye injections or laser, but there is no cure.
The dry form of AMD is due to a gradual accumulation of deposits called drusen under the macula, and the important retinal cells in this area slowly die off. Dry AMD causes a progressive loss of central vision and there is currently no cure.
Prevention is always better than cure, especially for eye problems, so the following 8 health tips can reduce your chances of losing vision from AMD:
Tip 1: Know your family eye history
While the causes of AMD are not yet fully understood, we know that certain genes contribute to the development of AMD. So individuals with a parent, brother or sister with AMD have a greater risk of developing it themselves. If AMD runs in your family, you should be more vigilant for the symptoms of AMD and seek advice from an eye doctor (ophthalmologist) even if you do not yet have symptoms. If you start to have difficulty seeing letters and numbers, difficulty recognising faces or seeing distortion of straight lines, see an eye doctor immediately.
Tip 2: Stop smoking
Overall, smokers are 3-4 times more likely to develop AMD compared to non-smokers. The reason is that cigarette smoke contains numerous toxins that damage the delicate cells in the retina as well as the blood vessels that nourish the retina.
Smoking causes blindness
Tip 3: Eat a healthy diet with plenty of leafy green vegetables and oily fish
Research has shown that certain nutrients are very beneficial for eye health and two types in particular can reduce the risk of developing AMD. Lutein and zeaxanthin are part of the carotenoid group of nutrients, which are yellow-red pigment produced by plants, that have antioxidant properties. Antioxidants are substances which protect your body against toxins. Lutein and zeaxanthin are found in high concentrations in the macula where they have an important role in protecting the retina from damage. Leafy green vegetables such as spinach, kale, broccoli and, red and orange peppers are great sources of lutein and zeaxanthin. In addition, Fructus lycii, commonly known as goji berry, is also an excellent source of lutein and zeaxanthin. Frutus lycii is also known as wolfberry in English, kei tze in Cantonese, and gou qi zi in Mandarin.
Oily fish such as salmon and mackerel are high in omega-3 fatty acids, which have also been shown in scientific studies to reduce the incidence of advanced AMD, as well as having a myriad of other health benefits.
Tip 4: Consider nutritional supplements
If you have a strong family history of AMD or you struggle to get enough vegetables and fish in your diet, it’s worth considering antioxidant supplements to boost your intake of these important nutrients. Research from the large-scale Age-Related Eye Disease Study 2 (AREDS2) found that taking a daily dose of vitamin C, vitamin E, zinc, lutein and zeaxanthin caused a significant reduction in the progression to advanced age-related macular degeneration.
Omega-3 supplements are produced in various forms, and it’s best to look for the “natural triglyceride”, “re-esterified triglyceride”, “free fatty acid” or “phospholipid” forms of omega-3 as these tend to be more easily absorbed and used by the body, compared to the more commonly sold ethyl ester form of omega-3.
Tip 5: Wear sunglasses during sunny weather
Intense ultraviolet (UV) rays from the sun can damage the delicate retinal cells and accelerate ageing of the macula. If you are outside for any length of time in bright and sunny conditions, it is important to protect your eyes from harmful UV rays by wearing adequate sun protection. Your optometrist can help you find a suitable pair of sunglasses that offer good protection from the sun.
Tip 6: Good cardiovascular health
High blood pressure and high cholesterol can damage the blood vessels that supply the retina, reducing its blood flow which accelerates ageing of the delicate cells in the macula. Looking after your heart by maintaining a healthy weight, exercising and controlling blood pressure will also reduce your risk of developing AMD.
Tip 7: Check your vision regularly with an Amsler grid
Two of the earliest symptoms of AMD are distortion of straight lines and blind spots in the central visual field. An Amsler grid is a simple chart made up of horizontal and vertical lines. Use it by covering one eye and looking at the dot in the centre of the grid. The lines should appear straight with no dark spots in the way. Repeat for each eye in turn.
If you notice that the lines are wavy or there are dark spots in one eye, then you should seek help from an eye doctor immediately. A good tip is to keep your Amsler chart somewhere where you will remember to view it regularly, such as on the front of your fridge. Eye doctors recommend checking each eye every 2-4 weeks on the Amsler chart.
The Amsler chart as it appears when viewed through a healthy eye (left), and as it may appear through an eye with wet macular degeneration (right)
Tip 8: Visit your ophthalmologist regularly for an eye health check
AMD, as well as many other eye conditions, often have no symptoms or warning signs in the early stages. Seeing an eye doctor regularly for an eye check can catch AMD at an early stage when it can still be treated. Ophthalmologists can examine your retina using specialised equipment and can detect AMD at an early stage using the latest technology such as OCT retinal scans.
Remember that it is important to follow these tips even as a young adult, especially if you have a relative with AMD, as doing so can reduce or delay the development of AMD later in life and give you many more years of good vision.