Diabetic Eye Disease
Diabetes mellitus is one of the leading causes of irreversible blindness worldwide, and, is the most common cause of blindness in people younger than 65 in Pakistan.
In addition to being a leading cause of blindness, diabetic eye disease encompasses a wide range of problems that can affect the eye such as a reversible, temporary blurring of the vision, to sever permanent loss of vision. It also increases the risk of developing cataracts and glaucoma.
Some people may not realize they have had diabetes mellitus for several years until they begin to experience problems with their eyes or vision. Severe diabetic eye disease most commonly develops in people who have had diabetes mellitus for many years, but they have had little or poor control of their blood sugar / blood glucose over that period of time.
If you have fairly large, rapid shifts in your blood sugar levels, you may notice that your vision becomes blurry. This may occur prior to the diagnosis of diabetes mellitus, or it may develop after the initiation of treatment or a change in the treatment of diabetes mellitus. The sugar in the blood can diffuse into (or out of) the lens of the eye and cause it to swell (or shrink) resulting in blurring vision. This difficulty with vision or focusing will disappear once blood sugar levels have been stable for a few days.
If you watch your diet, exercise, monitor your blood sugars, and take your diabetic medications, the chances of developing serious problems from diabetes decrease dramatically. The most important method of preventing eye disease related to diabetes is to maintain strict control of your blood sugar. High Blood pressure and high lipid or cholesterol levels must also be treated to decrease damage to the blood vessels within the eye.
When to Seek Medical Care
Even if you are not experiencing any symptoms due to your diabetes mellitus, you should have an annual eye examination. If you note any significant changes in your vision, other than a mild temporary blurring, you should contact an eye specialist immediately.
Diabetic Eye Disease Treatment
Medical treatment of diabetic eye disease is generally directed at the underlying problem – the diabetes itself. The better control you have of your diabetes, the fewer problems you will have in the long run.
Currently, effective medications do not exist to directly treat diabetic retinopathy and surgery (i.e. laser) is the treatment of choice.
Surgical treatment of diabetic eye disease most commonly involves treatment of the retina with an argon laser.
Difference Between mmol/L and mg/dL?
Both sets of units are used to measure blood sugar levels and both give a measurement of the concentration of glucose in the blood, albeit in slightly different ways.
mmol/L (Millimoles per litre) gives the molarity, which is the number of molecules of a substance within a specified volume, in this case within 1 litre. mg/dL (Milligrams per 100 millilitres) gives the concentration by the ratio of weight to volume, in this case milligrams per decilitre.
mmol/L is the most common measurement used in United Kingdom with mg/dL predominantly used in the USA and continental Europe.
Blood glucose typically varies from 4 mmol/L to 6 mmol/L for people without diabetes.
Recommended Target Blood Glucose Level Ranges
|2 hours after meals
|Non-diabetic||4.0 to 5.9 mmol/L||under 7.8 mmol/L|
|Type 2 diabetes||4 to 7 mmol/L||under 8.5 mmol/L|
|Type 1 diabetes||4 to 7 mmol/L||under 9 mmol/L|
|Children w/ type 1 diabetes||4 to 8 mmol/L||under 10 mmol/L|
NB: There are differing opinions about the ideal blood glucose level range.
You should discuss your own individual needs with your healthcare specialist.
What is HbA1c?
The term HbA1c refers to glycated haemoglobin. It develops when haemoglobin, a protein within red blood cells that carries oxygen throughout your body, joins with glucose in the blood, becoming ‘glycated’ (chemically bonded with glucose).
By measuring glycated haemoglobin (HbA1c), we get a longer-term trend, similar to an average, of how high your blood sugar levels have been over a period of 3 months.
For people with diabetes this is important as the higher the HbA1c, the greater the risk of developing diabetes-related complications.
The HbA1c units (mmol/mol) looks similar to the units used for blood glucose tests (mmol/l) but they are measuring two different values. As stated earlier, HbA1c provides a longer-term trend, similar to an average, of how high your blood sugar levels have been over a period of time whilst blood glucose level is the concentration of glucose in your blood at a single point in time, i.e. the very moment of the test.
Research has also shown that people with type 2 diabetes who reduce their HbA1c level by 1% are:
- 19% less likely to suffer cataracts
- 16% less likely to suffer heart failure
- 43% less likely to suffer amputation or death due to peripheral vascular disease