Diabetic retinopathy is damage to your eye caused by diabetes. It can result in blurred vision or indeed complete blindness. So, as a diabetic, how can you hold on to your vision?
Your retina consists of millions of tiny light-sensitive nerves at the back of your eye. These nerves convert the rays of light that enter the front of your eye into electrical impulses that travel along the optic nerve to your brain where you see them as a dynamic image.
Without the retina, vision would be impossible.
What is diabetic retinopathy?
The nerves of the retina are supported by tiny blood vessels in the back of the eye. These blood vessels can be destroyed over time by continuous high levels of glucose in your blood and/or high blood pressure (hypertension).
Destroying the tiny blood vessels prevents the retina from receiving the nutrients it needs to maintain vision. This medical condition is known as diabetic retinopathy.
In the early stages of diabetic retinopathy, which is called non-proliferative retinopathy, these blood vessels will leak fluid and this will distort your sight.
In later stages, called proliferative retinopathy, new blood vessels grow around the retina and in the vitreous humour (a clear substance that fills the eye). These blood vessels are very fragile and may bleed, clouding your vision or creating a scar that detaches the retina.
Diabetic retinopathy can cause macular oedema or swelling of the inner part of the retina (the macula). The macula is the part that allows you to see detail. The swelling happens when fluid from the blood vessels leaks into the macula. The swelling blurs your vision.
In addition, contraction of the new blood vessels can cause scar tissue to form on the back of the retina. This scarring can cause the retina to pull away from the back of the eye. This is known as retinal detachment, and if it is not treated it can cause permanent blindness.
What are the treatments for retinopathy?
In most cases of diabetic retinopathy, laser surgery can prevent significant loss of vision.
Laser photocoagulation is a fairly pain-free surgical procedure that is used to seal or destroy leaking or growing blood vessels in the retina. Unfortunately it can also reduce your ability to see colour and lower your night vision.
Where fragile blood vessels in the retina are leaking into the vitreous humour and are clouding your vision, a surgical procedure called a vitrectomy, performed under anaesthesia, can be used to remove the blood by suction.
Risks of getting retinopathy
Anyone with diabetes, whether type 1 or type 2, is at risk of developing retinopathy.
This risk however will vary according to the type of diabetes you have, how widely your blood glucose fluctuates, how well you are controlling your diabetes, and how long you have had the disease.
The only way to lower your risk of developing diabetic neuropathy is to control your blood glucose levels rigorously. And if you are hypertensive, you also need to control your blood pressure.
Diabetic retinopathy is the most common cause of blindness in the working population of the United States and of the European Union.
Indeed, the National Eye Institute in the USA estimates that nearly 45% of Americans who have diabetes are affected to varying degrees by diabetic retinopathy, and that 24,000 of them go blind each year. Statistics for the European Union are similar.
So the odds that you will develop retinopathy due to your diabetes are only a little better than 50:50.
However, if you are diagnosed in time and even if you have late-state diabetic retinopathy, you have a 90% chance of being saved from blindness.
Symptoms and diagnosis
There are no early signs of diabetic retinopathy. Indeed you sight may not be affected at all until your condition has become severe.
However if you experience a loss of central vision when driving or reading, or you lose the ability to see colour, or find things look blurry, you should suspect that you have retinopathy.
Floaters, small blackish specks that float across your eye may indicate leaking blood vessels even if they clear up in a few days or weeks.
Thus you should contact your doctor for a complete eye examination without delay and ask for a complete eye examination if you:
- Have black spots in your vision
- See flashes of light
- Have ‘holes’ in your vision
- Experience blurred vision
How to prevent diabetic retinopathy
Retinopathy does not have any symptoms when it starts, so by the time you experience the symptoms mentioned above the condition may be fairly well advanced.
Thus it is essential to have your eyes checked regularly … at least once a year.
However, the changes caused by retinopathy cannot be detected by an ordinary eye examination using an ophthalmoscope (which a doctor would use) or by a regular sight-test (an optometric examination) by an optician.
You should be examined by an ophthalmologist, who will dilate your eyes so that he can see into the retina at the back of the eye and look for changes in blood vessels, new blood vessel growth, swelling of the retina and retinal detachment.
This is the only way to catch the disease early enough to save you from significant loss of vision.
The only way to prevent diabetic retinopathy from developing is to be rigorous in keeping your diabetes under control by maintaining the correct levels for you blood glucose, blood pressure and cholesterol.