Macular Degeneration (AMD) – Risk Factors and Preventing Blindness
Not only is age-related macular degeneration very common, but its potential to damage sight permanently means it’s important to understand the condition and how we can all reduce our risk of vision loss.
Also known as AMD, the World Health Organisation (WHO) ranks the condition as the main cause of visual deficiency in industrialised countries, and third overall worldwide. Here in Australia, AMD is the most common cause of blindness in people over the age of 50.
The macula is the central and most sensitive part of the retina, and is responsible for central and fine-detail vision; in the advanced stages of AMD it is this area that is damaged. that’s why maintaining the health of the macula is very important as good central vision is vital to a number of everyday tasks; driving, watching television, reading, face recognition, and even pouring a cup of tea rely on macular function. Not being able to do these tasks has an enormous effect on a person’s mental health, risk of falls and social independence.
Whilst there is currently no cure for macular degeneration, treatment is available for the advanced ‘wet’ form of AMD; early diagnosis and treatment helps ensure the best possible visual outcome. The treatment involves injections, is effective in controlling the condition, and in 2 out of 5 people improves the vision significantly.
The treatment of ‘dry’ AMD is the subject of ongoing research; we’ve been involved in a multi-centre worldwide trial of such a treatment at the Box Hill clinic, with preliminary results expected to become available in 2017.
Regular eye checks by your optometrist, particularly if you have any associated risk factors, helps ensure macular changes are monitored and diagnosed earlier. Whilst early diagnosis and treatment of the condition remains essential to limiting the damaging effects of AMD, prevention is always better.
What are the risk factors for macular degeneration?
There are five factors that are known to increase a person’s risk of developing AMD:
- Family history of AMD
With the exception of age and family history, we can all take steps to address these factors and reduce the risk of development of AMD.
Is it because I’m getting older?
Age is the most significant risk factor in the development of AMD, as prevalence increases with age. 2% of people over the age of 50 suffer from late stage AMD, and this rises to 14% in people over the age of 80 and 25% of people over 90.
Whilst age is a known risk factor, just because you’re getting older doesn’t mean that you’ll develop AMD. Whether you have any other risk factors, and the severity of each, can influence the onset and development of AMD.
Is macular degeneration hereditary?
There is a macular degeneration genetic predisposition in people who have a family history of the condition.
If one (or both) of your parents have AMD, the risk of you developing the condition is suggested to be 50% (or possibly higher).
There are a number of genes that have been identified and are being researched, and they can have differing effects (and interactions) on the development of AMD. And whilst you can’t do anything about your genes, reducing other risk factors, particularly diet modification, can help reduce the influence that genetic predisposition has upon the development of AMD.
Is macular degeneration caused by smoking?
Tobacco smoking is the main, modifiable risk factor in the development of AMD. Smokers are 4 times more likely to develop advanced AMD, and on average 5-10 years earlier than non-smokers.
The longer, and the more,that you have smoked in your lifetime, the more significant the effect.
And whilst ex-smokers still have a greater chance of developing AMD compared with non-smokers, research suggests that stopping smoking could delay the onset of advanced AMD and the associated vision problems. Aside from AMD, smoking has other effects on the eyes and body, so quitting can benefit your health in general.
Will my diet make any difference?
If you’ve never smoked and you’re not obese, you can possibly eat away your risk of developing advanced macular degeneration. This is very important for any blood-relatives of people with AMD -you can’t blame your parents for developing AMD if you haven’t followed this advice.
In the clinic, for AMD patients and their relatives I’m always recommending a diet of “fish green and gold”. This includes consuming:
- Oily fish at least three times a week, such as salmon, sardines, herring, trout (and tuna to a lesser extent) and can be fresh, frozen or tinned. These fish are rich in Omega 3
- Green leafy vegetables daily such as spinach, kale, cabbage, brussel sprouts, which are good sources of lutein and zeaxanthin
- Bright yellow or ‘gold’ coloured vegetables such as pumpkin, squash, yellow capsicum, and sweet potatoes; these include betacarotene, Vitamin C, A, niacin, lutein and amino acids
These foods are not only good for the eyes, but are also good for the body.
Should I lose weight?
The relationship between obesity and AMD has involved research exploring areas such as body mass index (BMI), obesity, interactions with nutrient absorption, and its effects on AMD.
Studies have shown BMI and waist size being linked to a higher risk of progression to advanced AMD; the higher your BMI, or the larger your waistline, the more likely it is that you’ll develop late stage AMD.
The evidence for weight loss varies in its strength, but reducing your weight and waistline could reduce your risk of AMD and its visual consequences, regardless of all the other benefits.
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