Contributing factors

• genes
• healthy lifestyle & exercise
• smoking
• blood pressure & exercise & weight
• diet
• Vitamin supplements
• Oily fish
• cholesterol
• statins

pathology

'Wet' or neovascular types of ARMD

• Fibrovascular Pigment Epithelial Detachment:
  occult type 1..this page               (separate page)
• Type 2 Occult CNV..this page     (separate page)
• Classic CNV..this page                (separate page)
• Polypoidal choroidal vasculopathy
  
  
• laser
• PDT (photodynamic therapy)
• scarring
• distortion of Vision
• Amsler grid test
• the other eye                               (separate page)
  
  
• Feeder vessel laser
• 'Rip'
  

Further details

• abbreviations
• BMJ article   a slide show
  

Age-related macular degeneration (ARMD) is one of the commonest causes of poor sight in developed countries.

The main factor is age.  Whilst the causes are different in different people, other factors contribute.

cholesterol

a high fat diet is probably directly related to this condition

alcohol

We now know that alcohol excess is also related to ARMD, see 

Sunlight exposure, especially the summer sun, contributes to ARMD; and sunglasses protect, see.  Some sunlight exposure is important...gentle sun exposure increases vitamin D production, and this will reduce the risk of many conditions such as diabetes, osteoporosis, and prostate cancer. It is probably very bight sunlight that contributes to ARMD, not gentle exposure.

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) in our diet, the lack of protective fats (omega 3s, from fish), and salt (by increasing blood pressure) increases the number of people with ARMD.

click here for full size image

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. This paper suggests that we will soon be able to work out who is at risk...the main genes have been found.

See Gene page   The genes that may cause macular degeneration probably control the way used-up chemicals are removed from the eye.

Being long-sighted (hyperopic) is also a risk factor

Diagram copyright.

• Smoking, accounts for 32% of ARMD
  
• regular exercise,
  
• alcohol,
  
• a healthy diet
  

• 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 body receives 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 data    Japanese   Germany
  
  
  
• A new report here describes the risk of passive smoking (doubles the risk) and personal smoking (triples the risk) of both types of ARMD, that is geographic atrophy and neovascular.
  
  
  
• Each cigarette probably increases the progression rate or ARMD ~15%

larger

• 30 minutes a day at least, walking, or more active exercise for younger people,  reduces risk by 70%  : a 2006 study. Exercise may help by preventing hardening of the arteries.
  30 minutes walking a day for example...regular walking, for example, three times a week will result in less than a third of the amount of neovascular ARMD 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.
  
  
• 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     May be red wine (in small amounts) is healthier.

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, if drunk every day, will put the systolic blood pressure up (16 x 0.25=) 4mmHg.

enlarge

Experts recommend a healthy diet.

• This should include a variety of vegetables and fruit
  (at least 5-9 x 100gm portions/day),
• low fat only dairy food
• the minimum of trans and saturated fat
• the minimum of red meat, as part of a balanced diet
• oily fish ...2 small portions a week
• 1-2 hours exercise a day
• A low salt diet is important
• Vitamin D reduces risk, as in milk
• a Mediterranean or Japanese diet (as was 20years ago) will almost certainly protect. 

Fruit/vegetables prevent 36-50% of ARMD see, see and see (fruit & vegetables lower homocysteine levels, and this improves blood flow).

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).

5-9 portions of fruit/vegetables a day, with portions of different colours
5 is a minimum..best 9 for men, 7 women, 5 children, see.

The Guardian (2005) reviewed healthy diets etc, here, here , here , here and so on.

See some epidemiology

If you are unable to eat this many vegetables, low dose multivitamin tablets may help, but too many vitamins may be harmful.   Lack of vitamins has been linked to macular degeneration

Some research suggests that the pigments in vegetables, lutein, and two types of zeoxanthin might be helpful, as these are the pigments found in the healthy macula.

Against. See AREDS. BMJ

Lutein is in most fruits and vegetables, one type of zeaxanthine is in corn, nectarines and oranges (and other yellow/orange fruits/vegetable), but one type is not normally present in the diet. However, some supplements include doses that are too high, so once again, these are probably best as part of a healthy diet.

'Ocuvite-Lutein' is one preparation that may help. One paper suggested zinc may be helpful, but only in low dose, and is probably best as part of a healthy diet.
ICap (Alcon), is available in pharmacies and optometrists. This has lutein and other vitamins in, and had been recommended by some ophthalmologists. Beta-carotene supplements are not recommended for smokers, as they may contribute to lung cancer. I Cap is similar to the AREDS vitamins that reduced ARMD risk by 28%. See Ocular nutrition part 1 pdf & part 2 pdf.

These supplements may not help (see), as some experts advise that people with a healthy diet may be harmed by taking vitamin supplements. A review (2006, Drug and Therapeutics Bulletin, not free online) recommmeded a healthy diet including green vegetables diet was preferable to supplements.
If you have a healthy diet, ophthalmologists disagree.

The AREDS vitamins reduce ARMD by 25% if diet is not discussed. It is not known whether or not they help patients who have a healthy diet.

Ocuvite-Lutein has the most logical formulation...but a healthy diet may be better still.

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. See    see,   Although statin tablets are not yet formally recommended by all agencies, this author would recommend them for people with ARMD.  
This paper & another found no benefit, so it is difficult to be certain.

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.

Age-related macular degeneration (ARMD) is usually a progressive condition.It explained in more detail on other web-sites, such as the RNIB and NIH. This is an excellent animation: www.eyesight.org. Below is a brief description.

Dry ARMD progresses over many years, with areas of thin retina (atophy), and pigment changes, described here. 

Dry ARMD may progress to the 'wet type' (4%/year). Occasionally wet ARMD develops without any previous dry ARMD, although usually there is an area of retinal damage that triggers the process.

Wet ARMD  begins as new vessels growth in the macular area. This causes retinal leakage and swelling. The condition progresses to cause a scar in the macular area. If the scar is small, sight is reasonable; if large, the sight can be very poor.

Wet ARMD progresses 4 times faster (a 400% increase in progression rate) in smokers. It is very difficult to predict whose dry ARMD will progress, but in addition to smoking, soft drusen, high blood pressure, smoking, poor diet, lack of exercise increase the likelihood of progression.

New vessels growing under the central retina in a 'classic' pattern: PDT treatment may help

There are 3 main types of wet ARMD

• Fibrovascular pigment Epithelial Detachment: occult type 1
• Type 2 Occult CNV
• Classic CNV

endstage

• rip
• scarring

Some dry types of macular degeneration progress to form this type of wet ARMD.

It is very difficult to predict whose dry ARMD will progress, but the risk factors include those mentioned above (soft drusen, high blood pressure, smoking, poor diet, lack of exercise).

When blood vessels grow under the macula, this is termed choroidal neovascularisation (CNV or CCNV).

When the new vessels are seen easily on a fluorescein angiogram, they are called 'classic CNV': They look like a net of blood vessels.

See a photo,   another , another , another (case 12) and a healthy fluorescein for comparison.

When a doctor looks in the retina looks elevated, there may be tiny haemorrhages, a grey area, or exudates. This photo is a severe case. In milder cases vision may still be good.

The condition may develop over days or weeks, with increasing distortion or blurred central vision. If this process is mild you can still read, but if it becomes severe reading with any magnifier is impossible.

Treatment, if possible, will be include new ant-VEGF drugs.

Laser  may help (see details of the Verteporfin treatment program) but is becoming less important as it is not effective as the new drugs.

If you notice the symptoms (central vision becoming distorted or blurred, sometimes like looking through water) you should have your eye checked: see distortion below.

This is usually a very serious type of macular degeneration, serious because it can cause very poor sight. It never blinds in the sense that you cannot see light and dark, but in its serious form it can damage the central vision so you can only see fingers or even the movements of hands. Once again, the side vision will normally be good, so you should always be able to walk around the house.

Surgery has not proved very helpful.

The CNV grow at 20microns/day, reaching 3000 microns in 6 months. They can be extremely difficult to see in early stages. Small membranes gain, on average, 5 lines of vision with the Lucentis.
The biggest problem is detecting them early, and much work ('Replacing the Amsler Grid")   is being carried out to detect early membranres.

The condition is occasionally unresponsive to treatment. Macugen is probably the least effective of the new anti-VEGF drugs, and even combined with laser may give a poor response.

New vessels growing under the central retina in a 'classic' pattern: PDT treatment may help

Until recently the only treatment was laser treatment.

If the classic new vessels (CNV) are not in the very centre of the retina, regular laser can help. (Laser is a very bright light that makes tiny burns at the back of the eye.)

This appearance is called classic extra-foveal CNV.

If the CNV were away from the fovea, regular laser may help. However, over the years laser burns expand and this can reduce central vision years later. This treatment is only suitable if the CNV are well away from the fovea.

If the area of neovascular ARMD (CNV), shown as the red area, is not under the very centre (the yellow spot, called the fovea), regular laser may help.

Most people with neovascular ARMD have CNV in the centre of the retina. Regular laser cannot be used as it itself would destroy the central vision, so photo-dynamic laser (PDT) laser may help. But even with this treatment many people lose vision.

Now Anti-VEGF drugs are being used, and success rates are much higher. They may be used in addition to PDT. This is discussed here. See a case..  The drugs are given by injections in the eye itself about 8 times a year.

Traditionally after laser the CNV often return, and this may be the case with new drugs. We have to await further research results. Here is an up to date treatment plan, if the new anti-VEGF drug Lucentis is available  see.

There are other treatments for neovascular ARMD (CNV), such as surgery or transthermal laser, but these are not very successful and not in general use:

If the area of CNV is under the very centre PDT laser may help. This appearance is called classic sub-foveal CNV.

See a photo (angiogram)      See PDT

Many types of macular degeneration progress to cause scarring. 'Dry' types usually progress more slowly, but occasionally can cause very poor central vision, but this is commoner in the 'wet types'.

If your conditions is severe wet (example) scarring is likely.

See a scar ,  another. another large

After anti-VEGF treatment for wet CNV central vision may still get worse

• the CNV may enlarge and not respond
• the underlying geographic atrophy may progress

How would you know if you have the 'neovascular' type of age related macular degeneration?

Some symptoms suggest you may be developing the problem

• distortion of vision, where straight lines such as window frames appear bent as shown below
• a feeling as though you are looking through water

If you do develop distortion of vision you usually need to see your ophthalmologist reasonably soon. In the UK you may need to discuss this with your GP, or in a large city attend the Eye Emergency department.

Your ophthalmologist may recommend tests such as a fluorescein angiogram. The angiogram tells the doctor if there are new vessels, where they are, what type they are, and what type of treatment if any will help.

Patients are given a grid, told to look at the central spot with their reading glasses on, using one eye at a time. If any of the adjacent lines become bent or wiggly or distorted, then CNV (blood vessels growing under the macula) may be present, and patients should see their ophthalmologist (in Birmingham attend the Eye Centre Casualty, City Hospital).

The test is explained well here .

Distortion of straight lines which may start to appear crooked over a few weeks usually means the ARMD is progressing. Sometimes this is due to the 'neovascular' ARMD developing, and you are advised to be checked in case laser may help.

• The atrophic or dry type usually does occur in both eyes, but remember this generally gets only slowly worse.
  
• There may be a gap of years before the process begins in the second eye.

Concerning neovascular or wet type ARMD....

• The neovascular or wet type can also affect the other eye, at an overall rate of 90% over the next 5 years.
  
• High blood pressure, one large drusen near the fovea, 5 drusen in the macular area, and retinal pigment epithelial changes each contribute to this 90%.
  
• So if you have only one of these risk factors, such as 5 drusen and a low blood pressure and don't smoke, then the progression rate is 90/4, that is about 23% over a 5 year period . If you have 2 risk factors, 45%.
  
• But if you have 2 risk factors (45% 5 year risk) and your partner smokes 20/day, your risk is 45 x2 = 90% over 5 years...see immediately below.
  
• The figure is 4 times higher for smokers, and twice as high for passive smokers. (If smoking at 20 cigarettes/day.)
  
• the active phase may last 3-12 months, with the sight deteriorating during this time, and after that they may be little change. Treatment (laser & drugs) is needed during the active phase, and is of no help later. Anti-VEGF treatment may be needed for 2 years.