HbA1C and Retinopathy
teamwork helps to
improve diabetic control
Controlling your diabetes can slow down diabetic complications and retinopathy. In practice this means that conditions such as retinopathy may stopped in most people, and good sight maintained. In a few people the retinopathy may still progress, but at a much slower rate. See DCCT and UKPDS.
The progression rate of retinopathy is 37% less for each 10mmol/l (1%) reduction in the HbA1C or 1mmol/l of blood sugar. Teamwork is crucial to good diabetic control: the patient is the focus, but assistance from many health professionals is usually needed to assist good control.
|At the onset of type 2 diabetes||48mmol/mol (6.5%) is the target|
|if well, and diet or tablet controlled||HbA1c less than 48mmol/mol (6.5%)|
|if very ill||higher levels may be accepted|
|if using insulin and keen to control diabetes and able to test glucose 4-6 times day (basal bolus insulin/pump)||HbA1c
48-58 mmol/mol (6.5-7.5%)
(without many hypos)
|if using insulin and keen to control diabetes and able to test glucose <4 times day (basal bolus insulin/pump)..the average patient||HbA1c ~ 58 mmol/mol (7.5%)
(or as low as possible without many hypos)
testing your glucose level is essential for most people with diabetes, especially insulin users
- This means that if your diabetes is controlled (HbA1c less than about 53mmol/mol (7%) retinopathy may never develop, or develop very slowly.
- Such good control is easier to achieve if your have type 2 diabetes and use tablets. Eventually though, the pancreas stops producing any insulin and eventually most people with type 2 diabetes eventually need insulin, and then control is harder.
- Whatever your type of diabetes, if you use insulin, such good control is
harder to achieve. But the lower the better, so if your HbA1c is 53mmol/mol (7%), you
will develop retinopathy at a much slower rate than someone whose level
is 75mmol/mol (9.0%) .
As each percentage point (10mmol/l) of HbA1c translates into a massive 37% difference in progression rate, your retinopathy will be 2 x 37%, = 74% slower, to develop.
- Retinopathy may develop after 14 years of poorly controlled type 1 diabetes (type 2 less than 14 years as it may be diagnosed late).
- Converting HbA1c, table
- If you have well controlled diabetes now, but had a number of years when it was poorly controlled, you are still likely to develop retinopathy (every if the poor control was many years ago). The body seems to have 'memory' of the period with the high glucose levels. This is probably because of the retinal damage produced.
- Sometimes type 2 diabetes is diagnosed late. That is, there were many years of high sugar before the diabetes was discovered. Unfortunately such patients may develop severe retinopathy (even if they immediately control the diabetes very well).
The NHS is trying to screen all at risk patients to detect their diabetes early, but still has to make some progress, as a few patients even in 2020 are diagnosed late develop retinopathy just after the diagnosis has been made. Such a patient will have been diabetic for about 10 years undiagnosed .
Enlarge If your HbA1C is 53mmol/mol (7%) retinopathy may develop, but it is much slower to develop than if it is 75mmol/l (9%) . If your HbA1C is 53mmol/mol (7%) , you will have about 74% less progression after 2 years than if it is 75mmol/l (9%). Blue...no retinopathy; red... retinopathy
What is your HbA1c? Is it below 75mmol/l (9%) ? If not, can you get it lower? Ask your nurse for help.
enlarge The relationship between your sugar level and retinopathy and kidney disease is illustrated here.
If you suddenly improve control and your HbA1C drops the retinopathy may
need laser treatment. The benefits of an HbA1C drop, say from 75 (9%) to 53mmol/l ( 7%), are
long term. The retinopathy may actually deteriorate in the short term, and
so require laser. If this is difficult to understand, ask your ophthalmologist
After two-three years however, assuming you have any laser that may be necessary, you will be better off and the retinopathy will be less active than it would otherwise have been. Retinopathy progression detail.