by Dr Natasha Lim
Dr Natasha Lim Eye Centre
Age-Related Macular Degeneration (AMD) is a chronic irreversible disease where you lose central vision due to degenerative changes of the central retinal cells.
AMD used to be a rare condition in Singapore and was prevalent only in the western world. However, in recent years, we see a change in local diets towards a heavier consumption of calorie-rich food and more meat.
This means it's not surprising to see an increase in the incidence of AMD in both women and men in the local population. AMD normally affects people from the age of 50 onwards.
If you’re unlucky, disease progression can become severe, leading to potential blinding.
While macular degeneration can be progressive in some and stationary in others, it is always recommended to see your ophthalmologist, or eye doctor, directly.
What is Age-Related Macular Degeneration (AMD)?
There are a few different types of macular diseases, but age-related macular degeneration is the most common form of macular disease. 
The macula is small, but extremely important. It is located at the centre of the retina, the light-sensing tissue that lines the back of the eye, and is responsible for seeing fine details clearly.
If you have AMD, you lose the ability to see fine details, both close-up and at a distance. This affects only your central vision. Your side, or peripheral vision usually remains normal.
For example, when people with AMD look at a face, they can see the face’s outline, but cannot see the facial features clearly; they then gradually lose the ability to recognise people’s faces.
What is the difference between Dry and Wet Age-Related Macular Degeneration?
There are two types of AMD, namely “dry” and “wet” Age-related Macular Degeneration.
Most people ( > 75%) have a form called “early” or “dry” AMD, which develops as a result of a build-up of waste materials under the macula, causing thinning of the retina at the macula. Dry AMD sufferers have near normal vision or milder sight loss. 
A minority of patients with early (dry) AMD can progress to the vision-threatening forms of AMD called late AMD.
The most common form of late AMD is “wet” AMD. Wet AMD occurs when abnormal blood vessels grow underneath the retina. These unhealthy vessels leak blood and fluid, which can prevent the retina from working properly.
Eventually, scarring occurs at the site of the bleed, leading to permanent loss of central vision. The eye is not usually at risk of losing all vision (total blindness) as the peripheral retinal cells are not affected, thus the ability to see in the periphery remains.
There is a rarer form of late AMD called geographic atrophy, where vision is lost through severe thinning or even loss of the macula tissue without any leaking blood vessels.
Dry AMD develops slowly and gradually over months and years. There is currently no treatment for dry AMD.
However, dry AMD can develop into wet AMD, and it is important that this transition is discovered early and treated as soon as possible to mitigate irreversible loss of vision.
If you suffer from wet AMD, you would experience a sudden deterioration in your vision.
There is only a small window of opportunity for you to successfully treat it. The treatment should ideally be administered within 2 weeks after identification.
Wet AMD starts by leaking blood at the macula. The area of the bleed can result in scar tissue formation. It is scarring that results in permanent visual loss.
What causes Age-related Macular Degeneration in Singapore?
In Singapore, it is not uncommon to see people above 55 years old developing age-related macular degeneration, even though it usually affects people above 65 years old.
Changes in lifestyle leading to more westernized diets in our local population have increased the risk of developing AMD at an earlier age, meaning you should start worrying about this condition and go for regular eye examinations in your 50s.
Macular degeneration typically affects both eyes.
In the event where only one eye is affected, you may find it hard to detect any changes in your overall vision. This is because your good eye may compensate for the affected eye.
It’s best to cover one eye and test your other eye alone to detect any visual changes.
What are the symptoms of Age-Related Macular Degeneration?
1. Visual distortions.
The first sign of AMD would be that straight lines seem to curve or look wavy. When you are looking at straight objects such as the edge of a table and if the line appears a bit wonky, it is a symptom of AMD. 
2. Inability to see in the centre of your vision
Unlike cataracts (another common age-related eye disease which causes blurred vision for both central and peripheral vision), macular degeneration only affects your central vision.
In advanced stages, the centre of your vision may appear to be dark, blurry or completely white out, or simply put there would be a loss of vision.
3. Decrease in colour intensity/brightness
Colours can seem to be less bright than they used to, making your vision seem dull. You may also experience difficulty adapting to a change in light in the environment, making it hard to see clearly when entering a dim room from the bright outdoors.
How do doctors diagnose Age-related Macular Degeneration?
Mild AMD, which refers to the early stages of AMD, is usually asymptomatic and typically requires a comprehensive eye check to detect such early onset AMD. This allows for early treatment before the symptoms worsen.
The small white or yellow deposits on the retina are called drusen. A detailed dilated eye examination can detect the presence of drusen, an early sign of AMD.
If drusens are detected, your ophthalmologist will use an Amsler grid to detect any visual distortions, a clinical sign of AMD.
As well as the standard tests (vision charts, examination of the eye, etc), additional techniques are employed to examine the eye blood vessels and tissues.
Fluorescein angiography is a technique used to visualise the blood vessels at the back of the eye:
First, your pupils will be dilated with some eye drops
Next, a yellow dye will be injected into your arm (this makes the blood vessels in your eyes glow brightly when a certain type of light is shone on them)
A series of photographs are taken
A complete eye examination for AMD would also include an Optical Coherence Tomography (OCT) scan of the macula. OCT produces cross-sectional images of the back of the eye, measuring the thickness of the retina and helps determine if there are any fluids being accumulated due to the underlying growth of abnormal blood vessels.
The OCT test costs around $100 per eye and is non-radioactive.
What are the risks of me getting Age-related Macular Degeneration?
Although there is no exact cause of AMD, there are a number of risk factors that you should take note of that puts you at higher risk of developing AMD. Other than age, this is a list of risk factors that will contribute to the development of AMD :
Ethnicity. Studies have shown that Caucasians are more likely to develop AMD as compared to other ethnic groups.
Genetics and Family History. AMD has a hereditary possibility. Genetic factors play a significant role in AMD alongside other modifiable risks factors such as smoking, diet and UV exposure.
An estimated 15-20% of people who suffer from AMD have a close relative that also suffers from the condition.
Smoking. Smoking is the single most modifiable risk factor for AMD. Long-term smokers, or regularly being exposed to smoke, can double the risk of AMD as compared to non-smokers. Smokers are also four times more likely to develop the “wet” form of AMD than non-smokers. Cessation of smoking is important to prevent the progression of AMD.
UV Exposure. While this risk factor has not been completely proven yet, it is better to be safe than sorry! I will always recommend that you wear sunglasses to protect yourself from UV light.
Obesity. Obesity and its linked factors, like high blood pressure and high cholesterol, may increase the chances of early macular degeneration and the chance of it progressing to a more severe form of the disease.
Reducing fat intake. Dietary modifications to reduce intake of saturated fats and increase omega 3 fatty acids. Reducing the consumption of red meat and dairy products such as whole milk, cheese and butter which are high in saturated fats. Higher red meat intake has been positively associated with early AMD.
How can I stop Age-Related Macular Degeneration development?
There is currently no treatment for dry AMD. Published clinical research shows people at high risk of developing advanced AMD (by 25%) can prevent disease progression by taking an oral supplement, Lutein 10 mg, daily.
You might wish to consider taking Lutein supplements if you have either large drusen or vision loss from AMD in one eye (either wet or dry form)
Self-medication with high doses of vitamins and minerals is not recommended. It is important to speak to your eye specialist before taking large doses of supplements, and to follow daily dosage recommendations.
Besides that, there are some things to take note of:
Food and Diet. A super antioxidant, Lutein, can be used to prevent the progression of AMD. While this may sound too good to be true, Lutein has been medically-proven to slow down or stop the development of AMD.
Unfortunately, this antioxidant does not come naturally in fruits or vegetables. They come in the form of supplement pills, but are not drugs and hence will not have any drug effects.
You can buy Lutein supplements over-the-counter and costs around $40 per bottle of supplement.
Anti-VEGF Injections. You can get intravitreal injections into the eye for wet AMD using a medicine containing anti-VEGF (Vascular Endothelial Growth Factor).
It can help improve vision in about 30% of the people who use the injection and help stabilise vision in up to 90% of the people who use the injection. When injected into the eye on a regular basis, anti-VEGF medicines can stop abnormal growth of new blood vessels in the eye, which can in turn, help stop leakage and vision loss.
What anti-VEGF does is to restrict the production of VEGF, which reduces the abnormal blood vessel growth in your eye. Most people with wet AMD require an estimate of 3-8 injections per year.
Some people may need this injection for life, while others can discontinue the injections if the treatment is successful in stopping the progression of wet AMD totally.
The injection is available in public hospitals but can still be pricey since the drug is still in patency. Luckily, the injection is covered by both Medisave and insurance. Under the Medisave subsidy, 50% of patients are charged below $313 for the injection.
Other Intravitreal Injections. Although there aren’t any known drugs that can have the same effect as the injection, some medication can help with slowing down the development of AMD.
Avastin is an off-licensed FDA-approved treatment for large bowel colon cancer, but can be injected in the eye to block VEGF activity. However, there is a slight chance that you may suffer from stroke as a side effect. Other drugs, like Lucentis and Eylea, have a lower risk of stroke as a side effect.
While there are a few alternatives in medicine to choose from, it is always best to consult your doctor on which medication to take or if you should be taking supplements along with the recommended medicine. Alternatively, you may ask a doctor here.
What are other common ageing eye diseases in Singapore?
If you have read this far and are not convinced that you are suffering from Age-related Macular Degeneration, you may be suffering from other eye diseases! Listed below are some other common ageing eye diseases in Singapore.
1. Presbyopia (“Lao Hua”)
Presbyopia is a condition where the lens of your eye loses its elasticity. This leads to a gradual loss in your ability to focus on objects near you. People usually notice this in their early 40s and it continues to worsen until around their mid-60s.
A common sign of presbyopia is when you start holding your phone or newspapers at a distance to be able to read the words clearly. At a normal reading distance, vision is blurred and continuously doing so can lead to eye strain or headaches.
Glaucoma is a condition surrounding the optic nerve, usually affected by the presence of abnormally high pressure in the eye. It is especially prevalent in people over the age of 60 and is one of the leading causes of blindness in older people.
The development of glaucoma is very subtle and signs of the disease are hardly noticed until it has reached the advanced stage. The symptoms of glaucoma vary depending on different factors such as type and stage of the disease.
For open-angle glaucoma, the symptoms include:
- Blind spots in the peripheral or central vision
- Tunnel vision (in later stages)
For acute angle-closure glaucoma, symptoms that may present are:
- Severe headache, nausea and vomiting
- Eye pains, redness and/or blurred vision
- Halos appearing around lights
You may read more about glaucoma and glaucoma treatments here.
Cataracts is a condition related to the lenses in your eyes. It occurs when your natural lenses are clouded, making your vision seem foggy and making it harder to continue with daily activities like reading and driving.
The onset of cataracts comes slowly and doesn’t hinder much of the eyesight in the early stages.
However, when it worsens, stronger lighting and glasses would not be sufficient in dealing with cataracts anymore.
Some symptoms of cataracts are:
- Clouded, blurry or dim vision
- Increased difficulty in seeing at night
- Double vision in a single eye
- Fading or yellowing of colours
- Sensitivity to light and glares
What is the cost of Age-Related Macular Degeneration treatment?
Screening Tool (or Test) / Diagnosis
Optical Coherence Tomography (OCT) scan
Prevention is better than cure. Ensure that you make the right lifestyle choices now to prevent the development of age-related eye disease when you grow older.
Although we cannot stop these diseases from developing completely, we can reduce the effects and severity of these diseases on our lives.
Eye health is often neglected but that should not be the case.
Consult the right doctors for your eye problems and here’s a reminder to go for regular eye tests! I hope you have enjoyed this article and have learnt Age-related Macular Degeneration!