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).
This page summarises our current knowledge. Age-related macular degeneration is explained in more detail on other
web-sites, such as the RNIB.
An excellent animation: www.eyesight.org.
Contributing factors: aging, genes, diet, smoking,
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 is the main factor.
||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. Ophth 20
||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
||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.
progression to neovascular ARMD by 70% AJO17
||~50% is directly due to the genes we inherit Gene
||a high fat diet 10% (2010)
||This causes cardiovascular
disease, and will contribute to macular disease.
In urban environments, ~8% of deaths are generally attributed to pollution BMJ 14
||Excess alcohol is also related to ARMD, see
||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
CRP, dental caries, each contribute
|| 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
||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
A healthy lifestyle
A healthy lifestyle helps to prevent
age related macular degeneration. This is important for the younger relations
of age related macular degeneration sufferers:
- 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.
report and 2003
study . Lithuania Japanese China Ophth 20
- 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%.
Blood Pressure & Exercise
- 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
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
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
D reduces risk, (Vitamin D increases with sunlight) Archives
- 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.
Oily fish twice a week reduces ARMD by 40%, especially
oily fish such as tuna, mackerel, sardines, herring, and salmon. A Japanese
diet may be helpful as above. Other omega 3 fats are helpful. See
Cholesterol & statins, patient and relatives
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
Cataract surgery and Vitreous changes
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
The retinal changes in ARMD
These are the different layers of the retina:
the different retinal layers
As we get older, changes develop in the retina. The bruchs membrane
thickens and the choroidal blood vessels change. diagram. The thickened bruchs membrane prevents waste products leaving the retina
and also prevents nutrients entering. Lipofuscin (type of fat) accumulates in the retinal
pigment epithelium (RPE); this damages the pigment cells which eventually
die. The choroidal circulation changes...the blood vessels become larger. This is probably mainly due to a 'hardening of the arteries'
that happens particularly with a Western diet.
Unfortunately these invisible changes tend progress, and this process is called 'dry ARMD' Eye 2013, leading to
- basal linear deposit (a thin layer),
- deposits of waste products 'drusen',
- the drusen lead to geographic atrophy,
- or the dry changes may convert to 'wet ARMD' ,
In this process
- Pigment changes
develop; pseudodrusen / reticular drusen. develop in the choroid.
- Drusen contain inflammaory proteins, complement, fibrin, fibrin products, lipids, lipoproteins, glycoaminoglycans, amyloid, Eye 2013 Inflammation Eye 2013.
- Patches of extra thin retina develop, just as though the retina is
'worn out'. These patches enlarge
reducing sight (geographic atrophy),.
- <50% drusen patients develop AMD Eye 2013.
What does a person notice with very early dry ARMD?
- You may notice difficult seeing in dim light, needing to read with extra light, difficult seeing in bright light, slow recovery in bright light, difficutly adjusting to different lighting, and poor central vision when you wake up.
- If you notice these problems then you are probably at risk and need
a check from an optometrist or ophthalmologist. A healthy lifestylewill delay or prevent AMD and other health problems.
Types of 'dry' macular degeneration
As the dry changes progress, sight is affected. Detailed vision is worse, so it becomes harder to read, hard to see details on television, and later harder to drive. Optometrist are able to detect the macula changes, which are described here:
look like little white spots in the retina. tiny drusen. These
are accumulations of material, probably some waste products of the
retinal cells. These are common, and do not usually affect the sight.
The accumulation occurs as bruch's membrane becomes thicker and
prevents the flow of chemicals to and from the photoreceptors
Also, the retinal pigment cells accumulate lipofuscin. This
pigment will also slow down the passage of chemicals to and from the
People with a lot of
drusen in the central retina have slightly reduced sight. If there
are a few drusen you may be said to have very early 'dry' macular degeneration.
See diagram types of drusen after Eye 17
Hard and soft drusen:
If they are well defined
with a sharp edge, the sight is likely to stay good for a long time.
If the white spots look a
little like cotton wool, they are termed soft drusen. these are more of a problem as they may lead to
geographic atrophy (thin retina) or wet AMRD.
enlarge...hard drusen with atrophic patches
enlarge...white arrow is pointing to one of the large soft drusen
(Soft drusen, 6/6. vision slight distortion, patient born 1936)
drusen (in between hard and soft)
Drusen are slightly related
to cholesterol levels. It is logical that reducing the cholesterol
will slow down drusen development and therefore slow macular degeneration. Retina11 UK cholesterol target is 4.5mmol/l, and the World
Health Organisation recommends less than 3.5 as ideal, although risks
increase above 2.5.
DK therefore advises patients with drusen to try and reach these
targets, even if that means using statins (as long as the patient can
find a statin that without side effects).
Pseudodrusen / reticular drusen / basallaminar: subretinal drusenoid deposits and no drusen
enlarge drusen & reticular pseudodrusen
Reticular drusen/ pseudodrusen are vascular changes in the choroid, which appear as RPE changes on the OCT. However, this is an artefact...the changes are in the choroid risk. Features BJO 2012See Photo Autofluorescence is helpful.
Geographic atrophy (GA)
Geographic atrophy (GA): patchy areas of thin retina (atrophy) in the macula area
Separate page. GA is very common indeed. Patches of thin retina develop, like the patterns of countries
of the world. The areas get bigger over years, slowly causing more
damage to the sight, with very patchy central vision.
GA is the main type of dry ARMD. See a photo
Geographic atrophy (GA) accounts for a third of ARMD, with new 12,000
cases a year in the UK. It is caused by retinal
pigment epithelial atrophy leading to cell death. It is best examined
with autofluorescence Retina
2010. There is no
treatment available yet, although trials are in place. FAF photo. Atrophic myopic macular degeneration is
usually similar. We now know here that
the risk of passive smoking (doubles the risk) and personal smoking
(3-4x the risk) of both GA and wet ARMD. Genes and here.
enlarge...white arrow is pointing to the geographic change. This progressed over 7 years. Just recently, sight deteriorated, and there are cnv (wet ARMD) which has just begun (blue arrow). Patient male, born 1932. (Only 7% of GA leads to cnv).
GA small print
This is a more rapidly progressing form, with basal laminar deposits. So GA is not one disease...it is the end stage of many different types of 'dry' ARMD, and an intermediate type in others. It is still not known whether the primary problem is in the retinal pigment epithelium, choroid, or photoreceptors. GA
- see Retina 19 classification
- affects 1/3 people >75y.
- causes 26% of uk blindness
- Incidence quadruples each decade
- Autofluorescence can be used to predict the progression rate.
Lipofuscin deposits demonstrate autofluorescence, with the stressed affected retina showing up white, the atrophic retina black. Crystalline and soft drusen may turn into areas of GA.
- Night vision, age, smoking, blood pressure etc can be used to predict progression. Rods tend to be affected first, then cones. New treatment
- Eye 17.. link with renal function
- different types with different progression rates BJO 18
Concerning the change for GA dry arm to wwet
- Bilateral ga less likely than unilateral to get cnv
- cnv are more likely if the GA has an irregular outline ('lobulated').
Mixed type of dry AMD: drusen, pigmentation, and atrophic patches.
Changes may include thinning of the retina, drusen, pigmentation,
or thickening of the retina. There is a variable outcome. 'Prevention' may
help. photo photo photo. Thickening of the retina is termed 'retinal pigment hypertrophy'.
previously termed Adult
onset foveomacular vitelliform dystrophy (AOFVD),
A pale are develops in the central retina (the fovea) is affected,
leading to problems with central vision.
This is a type of dry macular degeneration
(ARMD), now know as adult onset Bests disease. The damage is confined to the centre of the macula, the fovea.
This is a very small central area, and has been described by Gass,
Generally the prognosis is good. However, the retina does become thin in the
affected area, and the sight may get slightly worse with age.
Only a few patients
do eventually develop wet ARMD, or other problems.
OCT: drusenoid PED..vision 6/24, very little change in the last 2 years
Summary; progression of
'dry' macular degeneration, but staying dry
phagocytosis of tips ...normally tips of photoreceptors (rod outer segments) are repaired every night
phagocytosis of tips of photoreceptors (rod outer segments).
phagocytosis efficiency of RPE reduces
debris accumulates, such as drusen & thickened basement membrane
VEGF > wet
After the invisible changes
above develop, dry changes may develop.
- Drusen develop. These are deposits of various types of fatty (lipids)
- The drusen may may small and hard...in which case
progression is slow
- Alternatively the drusen may soft, in which case
the condition usually progresses
- The soft drusen cause thinning of the retina and loss of sight
- the degree of sight loss is very variable...depending on the amount
of retina that becomes thin. If the very centre of the macula is affected
(the fovea) the reading becomes a problem. Sometimes the fovea appears
healthy, but the fovea is surrounded by thin 'atrophic' retina....reading
may still be a problem as the images of letters that are being read
fall on the damaged non-seeing retina...so you can only see part
of words at any one time.
- The thinning of the retina is called 'geographic atrophy'.
Atrophic changes are present in most of the of the 'dry' types of ARMD.
- A number of patients with the dry geographic atrophy or soft drusen
also develop wet macular degeneration.
Wet ARMD occurs when blood vessels grow under the macula, and leak
But in some ways it is best to consider wet and dry as different
conditions, with different genetic and environmental 'causes'.
2011...risks should be addressed.
atrophic patches see photo
Patchy vision in atrophic macular degeneration
The retina becomes very thin, just as though it is worn out. The patches
of such thin retina do not 'see', so the central vision becomes patchy.
Essentially it is a type of wear and tear.
Dry types of macular degeneration can get very slowly worse, but only
affect the macular area. The rest of the retina, which helps you see
at the sides so you can walk round the house, always stays good.
The progression is a usually a very slow process taking years.
If this wear and tear is mild you may be able to read and even drive,
although it takes a little longer to adjust to different lighting.
Often it is a little more severe, and reading is difficult, and driving
is impossible. TV is not too bad if you sit close: this is discussed
in Hints & coping.
Some types of dry ARMD are
none progressive, and not discussed here in detail (such as old macular
holes). Every person is different, and often it is very difficult for your doctor
to predict what will happen to your sight. Sometimes changes can occur more rapidly, and this would
suggest that you are also developing the 'wet' type of
ARMD as below. www.macula.org
The appearance of the retina may be same in different patients (phenotype).
But in fact each person's condition (even though it looks the same
to the doctor) s may have different causes such
as different genes (genotype).
This is one of the reasons it is so difficult how each person's condition
may progress to wet
Dry ARMD progresses slowly to give areas of atrophy. These areas may enlarge to cause GA In some types of dry ARMD progression
may be very slow. Sight
does deteriorate, but most people manage to cope well, although reading
is difficult and life may be different and a lot harder.
However, occasionally dry ARMD may progress to the 'wet type' : essentially the body tries to 'heal' the damaged area, and a network of blood vessels starts to grow in the central retina (Wet
- it may help to consider wet
and dry macular degeneration as 'different' conditions.
- whilst wet usually follows dry ARMD, only one third of
dry ARMD patients develop wet
- by addressing all the risk factors, especially smoking,
the progress of dry to wet may be stopped
- increasing drusen size Eye 19
Wet ARMD (exudative/leaky)
(vascular endothelial growth factor)
blood vessel growth
leakage..blood and fluid
give anti-VEGF drug
leakage stops for a while
In wet ARMD, new vessels grow under the central retina
in the macular area, causing retinal leakage and swelling. (CNV..choroidal neovascularisation). The blood vessel growth seems to be part of the eye's 'healiing' response to ack of oxggen and damage. The damaged retina releases a chemical VEGF (Vascular
endothelial growth factor). The VEGF
stimulates blood vessel growth, to produce the different types of wet
ARMD. In addition, the new blood vessels leak, causing fluid under the
retina in these condition.
The network of blood vessels usually progresses to cause a scar in the macular area. If the scar
is small, sight is reasonable; but if large, the sight can be very poor. 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). This is described below.
There are different types of wet ARMD
Mixed: classic CNV (formally termed 'classic CNV') wet armd
New vessels growing under the central retina in a 'classic' pattern:
Anti-VEGF treatment needed. enlarge Photo (case 12)
When blood vessels grow under the macula, this is termed choroidal
neovascularisation (CNV). When the new vessels are seen easily on a fluorescein angiogram, they
are called 'classic CNV': they look like a net of blood vessels.
When a doctor looks in the retina looks elevated, there may be tiny
haemorrhages, a grey area, or exudates. Severe . 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 early you can still read,
but if it becomes severe reading with any magnifier is impossible. Treatment is based on anti-VEGF drugs, although other treatment are available
This is usually a serious type of macular degeneration, serious
because it can cause very poor central vision. 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.
|ARMD progression rate
and relative risk of smoking
'Occult', no PED, = Mixed (predominantly or minimally classic CNV with occult CNV) wet armd
type 1 cnv
In this type of ARMD, there
are new blood vessels, but they are not clearly seen with the angiogram. 'Occult' CNV
is the term given to a specific 'blotchy' appearance of the
angiogram. This is probably an early phase of classic, see .
Occult and classic patterns can occur together. Anti-VEGF drugs generally help. The symptoms of this type of CNV are the same as 'classic
CNV', except the condition takes longer to develop. Without treatment, this usually turns into classic CNV over the next months
or years, to cause poor central vision.
- Large CNV membranes can develop haemorrhages with anti-VEGF treatment
- photo another another..occult/mixed another flash another large diagram
- The term occult is not really used now: the condition is a subtype of wet armd sometimes termed type 1 cnv.
- Sometimes there is a hyper-reflective material which is related to prognosis, and to pachychoroidopathy (= thickened choroid).
- Sometimes there is fluid, but if the fluid is stable injections don't seem to help.
CNV vascularised PED =fibrovascular PED and serous PED with neovascularisation wet armd
In this type of CNV there is a PED (pigment epithelial detachment)
PED..pigment epithelial detachment, with CNV (choroidal
neovascularisation): with a PED. This condition usually progresses,
but progression rates are very variable.
In this type of wet ARMD the damaged area looks like a dome, but in addition fluid leaks under
the retina, hence the term 'wet'.
Anti-VEGF drugs generally help. The PED may reduce in size with treatment, and treatment will reduce intraretinal and subretinal fluid. Retina 2011. Occasionally
may 'rip', causing more loss of sight Eye 2011. Overall, 15% of PEDs rip, but the risk is proportional to the PED size, so a large PED is much more likely to rip. About of 8% of patients may develop worse sight with treatment Retina 17. The rip typically occurs 2 months after starting treatment. The rip may not cause that much visual loss initially, but central vision may get worse over time.
November, 7 months later, a PED has developed, with a retinal haemorrhage. Also, intraretinal and subretinal fluid.
Patient, age 86, April, reasonable vision
Photo / OCT show drusen, hard and soft enlarge
A wrinkled PED
This probably represents CNV without subretnal fluid, and needs treatment Retina18:
Polypoidal choroidal vasculopathy
This is another type of CNV. The condition is seen as a branching choroidal network of vessels with vascular dilatation.
- Types Retina 19 "Typical polypoidal choroidal vasculopathy was defined as eyes with polypoidal changes to neovascular tissue, accompanied by increased choroidal thickness and/or the presence of pachyvessels, in the absence of drusen, characteristic pigmentary abnormalities, and geographic atrophy. Polypoidal choroidal neovascularization was defined as polypoidal changes to neovascular tissue that did not meet the definition of T-PCV as described above. Polyps in P-CNV typically represented only a small portion at the end of a much larger Type 1 neovascularization on ICGA."
- Excellent review TAO 19
- more common
in Chinese and
- The choroidal neovascularisation often occurs with a serous haemorrhagic PED.
- Polypoidal choroidal vasculopathy page.
- multiple PEDS, subretinal haemorrhages, visible polyps: deep orange lesions
- lipid exudates, subretinal fluid, RPE atrophy, peripapillary lesions
- classic & occult cnv, peripheral lesions: Features see
- distinguishing polypoidal choroidal vasculopathy from typical neovascular age-related macular degeneration based on spectral domain optical coherence tomography Retina16
- type 1 and type 2 IOVS; this depends on the presence or absence of feeder vessels Retina 18
- CNV in PCV respond slightly better to Eyela, and intervals can be extended to 16 weeks (2019)
Other types of wet ARMD
Pigment epithelial detachments
PEDs are present in different types of ARMD, but the caues are slighty different. The treatment depends on the cause. The PED is a dome of fluid under the pigment layer of the retina.
Hereare the different types of PED, some of which were discussed above:
Serous (avascular) PED
This is another type of PED, without any vascular element. In younger
patients this is usually part of Central Serous
Retinopathy. In older patients this is usually part of 'dry' ARMD, and
there may have been obvious 'dry' changes visible before this develops. Anti-VEGF treatment is not helpful (Eye
2010). Perhaps a serous PED in an older patient is better thought of as half way between dry and wet ARMD.
However, if the other eye has had wet ARMD, then such an eye is at very high risk of wet ARMD itself. Eye 2012 . It is probably safer for such a patient to have regular OCT examinations, perhaps every 3 months: as yet there is no evidence to prove that this will help, but logically it will help by detecting very early disease that is much easier to treat.
The PED is a dome of fluid under the pigment layer of the retina. there is a 'PED' only, no leak
'PED', with a leak under the retina (shown here) or in the retina
of vision and other symptoms:
dry ARMD changing into wet ARMD
How would you know if you have the 'neovascular' type of age related
macular degeneration? Some symptoms suggest you may be developing the problem:
- if one is is 'wet' , 3 monthly octs for fellow eye and home monitoring Retina 20
- distortion of vision, where straight lines such as window frames
appear bent as shown below
- a feeling as though you are looking through water
- distortion only occurs in 10-50% of patients
- 7/8 patients have no symptoms in the early stages BJO 2011
- amsler helps with training Eye 2012, Eye14 ,
- early detection CO14 , BJO 16
If you do develop distortion of vision you usually need to see your
optometrist and have an OCT scan within a few days. See the amsler test below. Your optmerist or ophthalmologist will recommend an OCT scan, and this shows the wet ARMD immediately.
Wet ARMD progresses 4 times faster (a 400% increase in progression
rate) in smokers.
Dry ARMD may develop into 'wet' ARMD (4%/year).
In wet ARMD, leaks develop,
and new vessels start to grow right through the retina.
Occasionally wet ARMD develops without dry changes, although usually
there is an area of retinal damage that triggers the process. photos
There may be a trigger factor such as inflammation, that triggers the conversion of dry to wet. (For example. teeth decay bacteria have been implicated.)
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.
should be given the Amsler Grid test to use every day, or at
least once a week, at home. These
authors recommend this test, although personally I have found that
patients may still present late (this is a major problem). 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 optometrist, ophthalmologist
(or in Birmingham attend the Eye Centre Casualty, City Hospital). The test is explained well here . home device another Ophth14
Unfortunately visual changes follow changes that can be detected by OCT scans BJO 2011 CNV are detected
- 1/8 when the patient notices changes generally
- 1/3 when there are changes in the amsler grid
- 1/3 by reduced vision acuity reading a chart as compared with OCT. Monthly OCTs are necessary to detect recurrences!
- late presentation is common and linked to social deprivation BJO14
- a home device may be best Eye 16 see
the other eye, risks
Unfortunately age related macular
degeneration can affect the other eye. See healthy
lifestyle above: this may help. If you do notice a change in your sight,
see distortion above. Risk
- The atrophic or dry type usually does occur in both
eyes, but remember this generally gets only worse slowly.
- There may be a gap of years before the process begins in the second
- If one eye has had wet ARMD, and the other eye has a PED, then screening with regular OCTs may help.
- If you notice the symptoms (central vision becoming distorted or blurred,
sometimes like looking through water) you should have your eye checked with an OCT scan:
Concerning neovascular or wet type ARMD:
- The neovascular or wet type can also affect the other
eye, at an overall rate of ~50% over the next 5 years. BJO 17
- 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
about 23% over a 5 year period . If you have 2 risk factors,
- 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
- 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.
Aspirin and anticoagulants
- aspirin and anticoagulants can lead to more bleeding from wet AMD
- but their benefits usually outweigh the risks
- Primary prevention: risks and benefits. In patients who, under current guidelines, are eligible for treatment because of their 10-year risk of myocardial infarction or stroke, "the presence or absence of strong risk factors for neovascular AMD might tilt treatment decisions in one direction or the other."
Some other features of ARMD
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 scarring is likely.
Sometimes retina in the macula area can tear and shrink. This
is call a 'rip' or a 'tear' of the pigment epithelium. It may occur spontaneously
as part of wet ARMD, but can occur after PDT or anti-VEGF treatment, particularly if there is a large PED.
A rip may cause significant loss of central vision see. but the risks are only slightly
The chances of rip depend on how elevated
the PED is (the retinal
pigment epithelial detachment). For instance, an 840μ elevation
has a 50% chance of ripping. A 500μ elevation
has a 10% chance of ripping. Gelsiken
Case. Rip: separate page for printing.
Here is a summary of some of the abbreviations ophthalmologists use
in this condition:
|anti-VEGF / injection
||drugs that reduce growth and leaking from the new blood vessels under the retina in ARMD, or on the retina in diabetes etc. They are given by injection into the eye. Avastin, Lucentis, Eyela.
||age-related macular disease = age-related macular degeneration = ARMD
||age-related macular degeneration
||easy-to-see neovascular ARMD (based
on angiogram) blood vessels growing under the retina and leaking
||choroidal new vessels (i.e. neovascular
macular degeneration, or 'wet'). Blood vessels growing through the retina
under the macula.
Also called CCNV.
|CNVM or CNVm
||a choroidal neovascular membrane, that is a network of CNV,
although in practice this means the same thing as CNV
||central serous chorio-retinopathy
||a type of aging change of the retina...tiny white spots/areas
||thinning (and other changes)
of the central retina
||the very centre of the macula
||indocyanine green angiography
||intraretinal fluid (an OCT scan finding)
||the centre of the retina that sees detailed vision like faces and reading
||similar meaning to wet armd
|OCT / scans
||optical coherence tomogram: a 3 dimensional photograph of the macula, called a scan
||hard-to-see neovascular ARMD (based
blood vessels growing under the retina and leaking (but the leakage is late) (type 1 CNV)
||Polypoidal choroidal vasculopathy
therapy (for classic sub-foveal neovascular ARMD )
||pigment epithelial detachment,
a type of wet ARMD
||retinal angiomatous proliferation (type 3 cnv)
||a pigment epithelial rip or tear
||subretinal fluid (not subretinal fibrosis)
||fluid under the retina typically type 2 cnv (or part of other types)
||Vascular endothelial growth factor...the main chemical that
makes blood vessels grow in ARMD
||Virtual macular clinic..patients attend for an OCT and the scan is interpreted later, and the patient contact if another anti-vegf injection is needed
||wet age-related macular degeneration, with CNV as above (blood vessels growing and leaking under the retina, usually under the macula)