(DME, diabetic macular oedema)
The fovea: this is the view of your eye a doctor sees looking, just like a map. The central area of the retina is the 'macula', shown by the dotted black ring. Light focuses here, so any damage may affect your sight. The very central area, the yellow dot, is the the fovea.
The macula is the central area of your retina. It is responsible for all your sharp vision, such as used for watching TV or reading. It can become damaged in diabetes, with leaks developing (oedema).
Generally, if the diabetes is not well controlled, without treaetment, this a progressive condition, as described below.
But now new anti-VEGF eye injections can be very effective in reducing the leakage (oedema) and keeping good sight, and nearly all patients will keep good sight.
- good diabetic control (blood pressure, glucose etc as below)
- anti-VEGF drugs (injections into the eye itself)
- and rarely, steroid injections into the eye itself
Side view of the eye:
light enters the eye from the left and focuses on the macula, the
central area of the retina. Damage to the macula affects your
By keeping to these levels as much as possible (or lower still) you will be doing your best to stop your eyes getting worse. Occasionally by sticking to these targets your retinopathy will improve, even without laser. Review BMJ17
- 30-120 minutes exercise a day ,
- moderate alcohol consumption only,
- avoid obesity if possible,
- balanced diet including
- 9 portions of vegetables or fruit a day (9 for men, 7 for women), Lowers BP
- minimal of animal or 'hard' vegetable fats,
salt, see the evidence
Alcohol should be limited to one drink or unit a day, six days a week (Mukamal 2004). More than this leads to brain damage.
- Oily fish such as sardine, salmon, tuna, trout, at least twice a week (small amounts are fine...not a whole salmon!).
- Fibre and healthy fats in the diet slows down retinopathy. No transfats and minimal saturated fat.
- generally 130/80 (see graph) or preferably less BMJ 16. Even less if well <120 BMJ17
- (120/75 ..home monitoring)
- 125/75 or less if protein in urine present (115/70.. home monitor)
- ACE inhibitors or Angiotensin Receptor Antagonists unless young/pregnant/very low blood pressure/poorly tolerated
- The lower the better in macular oedema, as long as you feel well.
- An ideal pressure is below 115 (systolic, first number) for healthy people. <120 is is only suitable for new/well diabetes patients 2012. Otherwise slightly higher as above.
- Home monitoring blood pressures should be 10mmHg (systolic) and 5mmHg (diastolic) lower see than these 'clinic' pressures.
- Depression & anxiety increase BP.
- 48-58 mmol/mol (6.5%-7.5%) or less (see graph) with very few or preferably no hypos. These (or slightly lower) levels are the best to prevent complications
- <58 mmol/mol (7.5%) for insulin users; <48 mmol/mol (6.5%) if not using insulin and have good health. Problems with intensive control. Target should be adjusted according to health and age. If you are a type 1 patient and cannot achieve good control, you need to checked for other conditions such as coeliac disease (anti-TTG antibodies), addisons, and thyroid.
- If hypos develop, seek expert advice from your diabetes nurse/doctor.
- if your HbA1c is high (say 97mmol/mol / 11%), then the next step may be to achieve 75 (9%)....in other words, and any improvement is helpful, gradually reaching lower levels above.
sudden decrease in HbA1c
- A sudden improvement in control (HbA1c drop of 33 mmol/mol/3% ) will lead to a temporary rapid increase in progression of retinopathy: laser may be needed.
- Good control is important in the longer term, that is after about 2 years. When people who control their diabetes well will be better off after this period. See
- A temporary increase in retinopathy is most common when starting insulin for the first time, especially if the diabetes is very badly controlled when you start the insulin.
- Individual targets Nice 16
- <4.0mmol/l, and statins recommended for most adult patients with diabetes whatever the cholesterol.
- statins are recommended whatever the cholesterol, if well tolerated age>40y
- A fibrate such as fenofibrate is advisable in nearly every person with retinopathy. They reduce retinopathy progression 40% (Fenofibrate 200mg od) Field Study. We now recommend these for all adult patients, and they can be used in addition to a statin.
- LDL <2
- Avoid if pregnant, GFR <15, pancreatitis
- If GFR low but still >15, need a lower dose.
- smoking 20 a day triples/quadruples retinopathy
- passive smoking may double retinopathy: room-mates inhale at least 25%
- electronic cigarettes are much much safer and probably have a negligible effect on retinopathy
- multiple dose insulin, using a protocol such as using lantus (long acting) and rapid acting (novarapid/humalog) is normally superior to twice daily. (This is controversial.)
- Insulin pumps generally produce better control still, but are harder to use.
- everyone with diabetes should attend an education course, such as DAFNE (insulin) , DESMOND (type 2 at diagnosis), or XPERT (type 2). Primary Care Trusts are obliged to send you on such a course, but very few patients have ever attended one. If you have not been on one, discuss this with your diabetic team. Get a diabetes buddy.
- this contributes to macular oedema and loss of sight (Schwartz, 2006), and many serious problems.
- It is common in diabetes, particularly if you are overweight. Do you have sleep apnoea?
- see 15
- 5.0-7.2 mmol/l before meals
- <10.0 mmol/l after meals
- no serious hypos
- for patients who test their glucose levels and adjust insulin doses, the new glucose sensor is highly recommended and has transformed the lives of many patients. The cost is about £30/week).
- Rosiglitazone and pioglitazone should not be used if there is significant retinopathy, and certainly not if macular oedema is present, as they increase macular oedema and fluid retention. Case 49. Lirglutadite and Exenatide are drugs that can be used instead low also lower weight (they are injections.)
- insulin users need to avoid serious hypoglycaemia. Expert help is usually needed if episodes are severe/frequent. See
- many patients receive totally inadequate care BMJ 11. Some call this 'institutionalised neglect'.
- 10% compliance if multiple treatment,
? 60% one tablets
type 2 at diagnosis
- need a test for Haemochromatosis
Enlarge A small area of leakage developing in the macula, near to the central area, as indicated by the black pointer. Laser is needed to prevent the leakage spreading out, like a growing tree trunk. As the fovea is not affected, sight will be good. But without laser the leak will spread to the fovea and reduce sight.
Areas of leakage develop in retina, and the retina can become boggy like a sponge. The leak can progress, causing more and more damage. If there is a small area of leakage, laser can seal or reduce the leakage and prevent it going on to cause more damage. Your ophthalmologist can see the leaks by examining your eye on a 'slit lamp' in the clinic or using an OCT.
Laser is a very bright light that is very focused so it makes tiny burns on the retina. The burns are so tiny they cause very little damage when treating this type of maculopathy. Once again, controlling your blood pressure, sugar, and fat levels (see Prevention) can help to stop this condition getting worse. Laser for this type of retinopathy is not painful, and is moderately effective (see evidence).
The leaks in the macular area can be sealed with laser treatment.
These leaks are called 'macular oedema', that is areas of thickened spongy retina. Most patients with macular oedema need laser.
Mild oedema may settle without laser AJO 08. On the other hand, an OCT may measure an increase in oedema and vision may deteriorate. The leakage is much more likely to reduce if glucose, blood pressure, and cholesterol levels etc are controlled.
Macula is thickened an all diabetic retinopathy patients (Retina 14).
Laser shown as black specs.
Moderate Maculopathy (macular oedema) and anti-VEGF drugs such as Avastin and Lucentis and Eylea (aflibercept)
an OCT scan showing macula oedema
As leaky areas develop, they need to be lasered, otherwise the condition will become severe (Severe Maculopathy). See photo tour.The water logging takes 4-6 months to disappear. Because of this, you may not know whether the treatment has been successful until then. As long as the very centre of the macular area remains healthy, the fovea, your vision will remain good. Remember a low blood pressure is helpful, as in the table above. See photo. Control of diabetes and 'statins' to lower their cholesterol, providing there are no side effects, helps a great deal. See.
Many patients need extra treatment in addition to laser or even instead of laser. The anti-VEGF are Lucentis, Avastin, or Eylea.
VEGF (vascular endothelial growth factor) is the chemical released by a damaged retina, and this chemical makes nearby parts of the retina leak more. Anti-VEGF drugs such as Lucentis and Avastin 'block' the effect of VEGF, and often reduce leakage. (See College statement: & Lucentis/Avastin are equally effective.)
At worse levels of initial visual acuity, aflibercept is more effective at improving vision NEJM 16.
The anti-VEGF drugs:
- Lucentis (Avastin would be equally effective and 10% the cost) has been approved by NICE if oedema >400µ: monthly injections until oedema stable, and then continuing monitoring offering injections if oedema increases again. They reduce macular oedema but will not improve sight if there is no oedema. Very occasional patients will notice a deterioration in vision, and such eyes are more likely to have more macular ischaemia than the eyes that benefit .
- treatment needs to be OCT monitored: treat if there in increase in oedema.
- treatment will be needed with monthly injections until oedema has resolved, until there is no improvement in the oedema, and after that injections are continued to maintain that level.
- So if there is 400µ central macular thickness, injections are carried out monthly until there is no extra response. In such a patient oedema may reduce to 250µ. If a further injection does not reduce the oedema, then 250µ would be considered the best that can be achieved. After that injections would be restarted if the thickness increases again. So if the thickness increases, perhaps to 300µ, injections would be restarted again so as to maintain 250µ.
- Aflibercept marginally more effective NEJM15
- combination treatment? Eye 15
- Long-term outcomes with intravitreal fluocinolone acetonide (FAc) implants Eye 15
Intravitreal steroid injections
- Triamcinolone. This is for short term use only, and is very useful for macular oedema after cataract surgery.
- Long term, Iluvien
subretinal fluid..little improvement in vision
spongy /diffuse oedema...best result, some improvement in vision often
cystoid oedema..poor response...little improvement in vision
different types of diabetic macular oedema respond differently to anti-VEGF enlarge
Circinate retinopathy..exudates are in a 'ring' or partial ring.
If the exudate forms a ring this is termed 'circinate' retinopathy as opposite. Laser to the central area of the ring is very helpful, see case 42. and case 54. Usually the leakage dries up after the laser.
Laser cannot be carried out if the centre is the fovea, as otherwise vision would be lost.
Enlarge Here there is oedema (leakage), shown as the grey patch here. The very centre of the vision can be affected as the fovea is affected (the yellow spot).
Here the waterlogging affects the very central of the vision, and will reduce sight. In the very early stages your sight may be good, but usually, without laser, the leakage increases and your sight will be reduced so reading and watching TV may become more difficult. See photo. Recent reports indicate that Avastin or Lucentis help most patients, and should be standard treatment.
Laser is may help needed, and may need to be repeated several times.
A 'C' pattern of laser is often applied as above (shown in black).
Enlarge There is considerable water logging in the central area of the retina, and your vision may be very poor.
Your sight can be badly affected. Your doctors will have tried to have prevented this severe condition developing, but sometimes this is not possible even with the best treatment. See photo. As medicine advances we hope fewer and fewer people will reach this stage. Sometimes the tiny capillaries are permanently damaged and treatment will not restore your sight. See Coping with Poor Vision if this has happened to you.
If the macular oedema has not been present long, intravitreal steroids or Avastin may help, as below. Laser is usually needed also. The leak is shown as a dark area in the centre of the macula with a fluorescein angiogram. This is called 'ischaemia' or 'ischemia' or 'ischaemic maculopathy'.
Glitazones may increase macular oedema. If there is retinopathy they drugs should be stopped, and may be replaced in some patients with Exenatide or Sitagliptin. Case 49. If there is no retinopathy they will not have an effect on the retina so are safe from the eye point of view.
left eye, mild macular oedema, good vision
right eye, foveal oedema, good vision. The oedema resolved when the pioglitazone was stopped enlarge
It particularly helps:
- with unexplained visual loss
- helps plan treatment and particularly re-treatment
- can detect early proliferative disease
- identifies post-cataract macular oedema