Age related macular degeneration:
ARMD is an aging change or wearing out of the central retina. It causes loss of central vision. This makes reading and driving difficult. Later, if it gets more severe, it becomes difficult seeing faces, crossing roads, and cooking. The peripheral or side vision always remains, so even if the central vision is poor, it is always possible to see and get round the house and see to the side.
Dry ARMD is usually a progressive condition. Invisible early changes occur, with drusen , pigmentary changes, and slight thinning of the retina Later, the dry changes may progress, usually slowly, to cause geographic atrophy and more thinning of central retina. These are all termed part of 'dry' ARMD. There is no tretment for dry ARMD.
A secondary change may then develop in some people, as the body tries to 'heal' the changes. Blood vessels may start to grow in the dmaged centre of the retina in the macula area. The blood vessel growth causes leakage and scarring, and is termed 'wet' ARMD. These wet changes can be slowed down with anti-VEGF eye injections (wet ARMD page).
Age-related macular degeneration (ARMD) is one of the commonest causes of poor sight in developed countries. Whilst the causes are different in different people, certain factors may contribute. The main factor is age.
"By age 85, 57.4% of [people have] AMD. Age, smoking, plasma HDL cholesterol, BMI, and female sex are associated with AMD. Elevated HDL cholesterol is associated with GA development." .Oph 14
|age||Age is the main factor.|
|smoking||Contributes 32% overall, even passive
smoking. BJO 17.
'Just one cigarette a day seriously elevates cardiovascular risk ' BMJ18, so it is best to stop completely.
|diet||related up to ~30%; a high cholesterol from an unhealthy diet or genes Klein (2010); Toothbrushing helps. (tooth decay promotes conditions such as rheumatoid arthritis) summary BJO16|
|blood pressure||High blood pressure damages the circulation...target is 140 systolic in clinic, 10 lower for diabetes. 10 lower at home. 120 at home for diabetes at home. Best below 120 2 medications often required.|
|genes||~50% is directly due to the genes we inherit Gene page|
|cholesterol||a high fat diet 10% (2010)|
|airbourne pollution||This causes cardiovascular disease, and will contribute to macular disease. In urban environments, ~8% of deaths are generally attributed to pollution BMJ 14|
|alcohol||Excess alcohol is also related to ARMD, see|
|sunlight||Strong sunlight contributes to ARMD; and sunglasses protect, see. But gentle sun exposure increases vitamin D production, and this will reduce the risk of many conditions such as diabetes, osteoporosis, and prostate cancer. Retina16|
|inflammation||Chlamydia high CRP, dental caries, each contribute|
|macular pigment||Light skin increases risk Eye 2012.|
|obstructive sleep apnoea||Untreated obstructive sleep apnea hinders response to bevacizumab in age-related macular degeneration Retina 16 BJO 17|
|Oral Bisphosphonates||AJO 16 2-4x risk|
Some communities in Japan did not develop macular degeneration as people aged, but as soon as they started eating Western food the condition started to occur. Similarly, when Japanese people move to Western countries, they develop the condition more frequently.
These observations suggest that the high fat, and type of fats, such as saturated and trans-fats, the lack of protective fats (omega 3s, from fish), and salt (by increasing blood pressure) increases ARMD. Lack of exercise as we drive everywhere in Western countries will contribute.
We inherit these from our parents. Genes are the genetic information that tells our body what chemicals to make. Overall, our genes may contribute to more than 50% of ARMD. The main genes have been found. Gene page. For example, these genes control the way used-up chemicals are removed from the eye. Being long-sighted (hyperopic) is also a risk factor
A healthy lifestyle helps to prevent age related macular degeneration. This is important for the younger relations of age related macular degeneration sufferers:
- Smoking, accounts for 32% of ARMD regular exercise, alcohol,
- a healthy diet reduces risk 70% (diet,exercise, not smoking) Archives 2011
- Overall smoking accounts for 32% of ARMD. Even stopping at the age of 80 will reduce the risk of developing the disease. So if you have a relation with macular degeneration, try and stop as smoking may make it develop earlier.
- Smoking increases the risk of macular degeneration about 3 times. Macular degeneration occurs 10 years earlier in smokers.
- If you have macular degeneration, do try and stop. Even if you are 90 years old stopping smoking will help your eyes considerably.
- Passive smoking is also harmful: for instance, if your partner smokes cigarettes a day, you receive 25% of the smoke, so that is equivalent to you smoking 5 cigarettes a day. 28000 cases a year in the UK. See 2002 report and 2003 study . Lithuania Japanese China
- Passive smoking doubles the risk , personal smoking triples the risk of both geographic atrophy and neovascular ARMD.
- Each cigarette increases the ARMD progression rate ~15%.
- 30 minutes a day at least, walking, or more active exercise for younger people, reduces risk by 70%: 2006
- Exercise may help by preventing hardening of the arteries. 30 minutes walking a day (regular walking) three times a week will reduce ARMD risk by one third, compared to people who don't walk or exercise and who drive everywhere.
- A low blood pressure helps. A level of 140/85 or below is likely to be best. Blood pressure is written as '140/85', with the systolic/diastolic. Above 115 (systolic) the risk of heart disease increases. See the evidence and more. Macular haemorrhages are more likely with high blood pressure. More evidence Eye.
- Obesity is also a risk factor see.
- A low salt diet is important Salt and more than 2 units of alcohol a day may cause blood pressure to rise.
Too much may contribute indirectly by increasing blood pressure, and is related to ARMD, see.
Blood pressure rises after drinking (opposite...drinking 4 pints/bottle of wine).
Each gram of alcohol puts systolic blood pressure up 0.24mmmHg, diastolic 0.16 mmHg. This means 1 pint of beer (2 units, each unit 8g alcohol) with 16gm of alcohol, drunk every day, will put the systolic blood pressure up (16 x 0.25=) 4mmHg.
Experts recommend a healthy diet.
- This should include a variety of vegetables and fruit,
- 5-9 portions of fruit/vegetables a day, 100gm portions (2008) see.
- low fat only dairy food
- the minimum of trans and saturated fat Solid fats are harmful Eye 2011
- the minimum of red meat (and no processed meat), as part of a balanced diet
- oily fish ...2 small portions a week, Blue Mountain 2009, Australia 09 reduces aging Fish and soya contains DHA Retina17
- low salt
- Vitamin D reduces risk, (Vitamin D increases with sunlight) Archives 2011 See
- a Mediterranean or Japanese diet (as was 20years ago) will almost certainly protect.
- plants sterols lower cholesterol food.gov.uk, which foods
- Losing weight (if overweight) reduces risk
- BMJ 18 Minimally processed food is prefered (vegetables, fruit, nuts, seeds, beans, vegetables, whole grains, plant oils, live yoghurt): avoid ultraprocessed foods rich in refined starch and sugars, and industrial additives such as trans-fats and salt.
7 portions of vegetables a day and 2 portins of fruit, with portions of different colours
Fruit/vegetables prevent 36-50% of ARMD see, see and see (fruit & vegetables lower homocysteine levels, and this improves blood flow) BMJ 15. Pulses like beans are fine. Bread, pasta, rice and potatoes provide 'energy'. Vegetarians have lower blood pressures and healthier lipid levels, see . A healthy diet reduces homocysteine levels, which are associated with ARMD. Certainly saturated fats increase the risk of ARMD; and fish and polyunsaturated fats halve the risk. Avoiding certain fats helps, with strong evidence here (explained more clearly here for heart disease). Nuts may help prevent ARMD (small amounts...they are fattening).
Lutein and Zeoxanthin supplements slow down progression on average 10%, AREDS 2, 20% if diet is poor.
2020 As the macula is the most chemically active area in the body, with the greatest oxygen demand, it has been thought that antioxidants such as vitamins may play a critical role. The retina contains the pigments carotenoids lutein, xeaxanthin, mesoxanthin.
Lutein is in dark green leaves such as kale and spinach, and most of us do not eat enough. Xeaxanthin is in orange peppers, corn, nectarines and oranges (and other yellow/orange fruits/vegetable). "Higher dietary intake of lutein/zeaxanthin was independently associated with decreased likelihood of having neovascular AMD, geographic atrophy, and large or extensive intermediate drusen" Seddon. No need Cochrane 2017.
- Lack of vitamins and ARMD, Micronurients 2013 , BMJ, BJO 17.
- Beta-carotene not for smokers (risk of lung cancer)
- I Cap is similar to the AREDS vitamins Against May not help
- Lutein and Xeoxanthin supplements at too higher dose: retinal crystal
- Lutein and Zeoxanthin are in the 'AREDS2' supplements, including ICap (Alcon), available in pharmacies and optometrists. Very helpful JAMA 2015
ARMD is commoner in people with higher cholesterol levels. Atherosclerosis, caused by a high cholesterol, does contribute to ARMD, see . Statin treatment reduces macular degeneration. DK recommends them for people with ARMD. Naturally all relatives of ARMD patients should address this issue of fat levels in the blood, sticking to a low fat diet with plenty of exercise, avoiding obesity, just as described on this page for ARMD patients. Statins may not help
Macular pigment density is inversely related to ARMD: the thicker the pigment the less likely the condition.
- this explains why the condition is much commoner in Caucasians with blond hair and lighter coloured retina
- increasing the pigment with lutein may delay the condition Acta 2012 Eye 2012
- ARMD is unusual in Afro-Caribbeans, and this may be because the 'elastin' layer is thicker.
- Especially in wet ARMD with CNV, the elastin layer acts as a barrier to the growing CNV (new vessels). Elastin is part of Bruchs membrane link.
One paper suggests cataract surgery leads to an extra 4-5 times risk of developing neovascular macular changes or dry ARMD. Another states this is not so AREDS 25. Certainly patients with early ARMD undergoing cataract surgery should be warned of symptoms, that is distortion or changes in central vision, and attention should be sought in a few days. Also.
If the vitreous is separated from the macular the risk of CNV is significantly reduced AMJO 09.