Diabetes effect on Eyes, Part II, Diabetic Retinopathy

Why are regular checkups so important?

You must always remember that your retina can be badly damaged before you notice any change in vision. Most people with nonproliferative retinopathy have no symptoms. Even with proliferative retinopathy, the more dangerous form, people sometimes have no symptoms until it is too late to treat them.

And yet, retinopathy is easily diagnosed through an ophthalmoscopic examination. If your doctor sees any evidence of retinal changes, he may then ask you to undergo more tests so that he can treat the problems and prevent further progression to a severe state when vision is seriously affected. There is also some evidence that if diagnosed at an early stage, some of the damage can even be reversible!

For this reason, you MUST have your eyes examined regularly.

Who is most likely to get diabetic retinopathy?

Anyone with diabetes. The longer someone has diabetes, the more likely he or she will get diabetic retinopathy. Nearly half of all people with diabetes will develop some degree of diabetic retinopathy during their lifetime.

You can now check your diabetes at home at just 20 rupees

Several factors influence whether you get retinopathy. These include your blood sugar control, your blood pressure levels, how long you have had diabetes, and your genes.

You can check your blood pressure regularly at home

The longer you’ve had diabetes, the more likely you are to have retinopathy. Almost everyone with Type 1 diabetes will eventually have nonproliferative retinopathy. And most people with Type 2 diabetes will also get it. But the retinopathy that destroys vision, proliferative retinopathy, is far less common.

What can be done to prevent serious eye problems?

There are steps you can take to avoid eye problems.

First and most important, keep your blood sugar levels under good control.

Many studies have shown the importance of a good control of your blood glucose levels. If you do not have diabetic retinopathy and do NOT keep your diabetes under control, your have FOUR times the chances of getting retinopathy as compared to someone who does keep his diabetes well controlled!

In people who already had retinopathy, the condition progresses in those with good control only half as often as those not well controlled.

In fact, it has been shown that for each 1% rise in the HbA1c, ( we have discussed HBA1c or glycoisylated hemoglobin in the section on monitoring control) the retinopathy gets worse at the rate of 32%. So if your HbA1c is 9%, your retina is getting damaged twice as fast as someone with a level of 6% (3 x 32% = 92% additional deterioration).

High blood pressure is fairly common in people with diabetes. Again you should aim for a good control of your blood pressure 130/80 or less [lower still if there is protein in your urine]). With blood pressure, for each 10mmHg rise, the retinopathy gets 11% worse. So if your blood pressure is 150/90, your retina is getting 22% worse that someone whose pressure is 130/80.

Similarly Smoking literally doubles the rate of damage that diabetes causes to the bodies larger arteries, making amputations and heart disease far more likely. Smoking triples the rate of retinopathy progression

These impressive results show that you have a lot of control over what happens to your eyes!

To sum up,

lifestyle 30-60 minutes exercise a day, moderate alcohol consumption only, avoid obesity if possible, balanced diet including 5 portions of vegetables or fruit a day, with the minimal of animal or ‘hard’ vegetable fats, and very low salt.
blood pressure 130/80 or less
125/75 or less if protein in urine present
HbA1c 6.5% or less with very few or preferably no hypos.If hypos develop, see expert advice.ACE inhibitors or AT11 unless young/pregnant/very low blood pressure/poorly tolerated
cholesterol <5.0mmol/l, and statins recommended for most adult patients
Smoking smoking 20 a day triples retinopathy (passive smoking: room-mates inhale at least 25%)

What are the symptoms?

There are usually no symptoms in the early stages of diabetic retinopathy. Vision may not change until the disease becomes severe. An exam is often the only way to diagnose changes in the vessels of your eyes. This is why regular examinations for people with diabetes are so important.

See that your eyes are checked regularly by your doctor for retinopathy.

At the same time, there are some situations which should be considered serious and you should see your doctor at once!

your vision becomes blurry
  • you have trouble reading signs or books
  • you see double
  • one or both of your eyes hurt
  • your eyes get red and stay that way
  • you feel pressure in your eye
  • you see spots or floaters
  • straight lines do not look straight
  • you can’t see things at the side as you used to

But as we said above, there are no signs or symptoms in the early stages of the disease. Vision may not change until the disease becomes severe. Nor is there any pain.

Even in more advanced cases, the disease may progress a long way without symptoms.

But to protect your vision, comprehensive eye exams are needed every year, or as directed by your physician. Remember, the most dangerous threats to vision in diabetes give little or no warning. Only by direct examination with an ophthalmoscope can these early changes be seen and treatment started before sight becomes seriously threatened.

That is why regular eye examinations for people with diabetes are so important.

Although there are quite a few tests which your doctor may carry out, the most important from the viewpoint of diabetic retinopathy detection is an ophthlmoscopic examination of the retina.

Your doctor will use an ophthalmoscope and look at your retina for early signs of the disease, such as:
(1) leaking blood vessels,
(2) retinal swelling, such as macular edema,
(3) pale, fatty deposits on the retina–signs of leaking blood vessels,
(4) damaged nerve tissue, and
(5) any changes in the blood vessels.

During this examination, your doctor may put in some eye drops to dilate your pupils so that he gets a better view of the retina and also to prevent the pupil from contracting when the light from the opthalmoscope falls on the retina. Your vision may be blurred for a few hours after this examination and therefore, please take someone with you when you go for this examination and definitely do not drive to your doctor’s clinic!

Your doctor may ask that you have a test called fluorescein angiography.

Fluorescein angiogram (FA)

Fluorescein angiography is an extremely valuable test that provides information about the circulatory system and the condition of the back of the eye. FAs are useful for evaluating many eye diseases that affect the retina.

Retinal photograph of a patient complaining of decreased vision.

Fluorescein angiogram indicating fluid leakage within the retina

The test is performed by injecting a special dye, called fluorescein, into a vein in the arm. In just seconds, the dye travels to the blood vessels inside the eye. A camera equipped with special filters that highlight the dye is used to photograph the fluorescein as it circulates though the blood vessels in the back of the eye. If there are any circulation problems, swelling, leaking or abnormal blood vessels, the dye and its patterns will reveal these in the photographs. The doctor can then make a determination as to the diagnosis, and possible treatments.

How is it treated?

There are two treatments for diabetic retinopathy. They are very effective in reducing vision loss from this disease. In fact, even people with advanced retinopathy have a 90 percent chance of keeping their vision when they get treatment before the retina is severely damaged.

This again shows the importance of regular eye checkups!

These two treatments are laser surgery and vitrectomy. It is important to note that although these treatments are very successful, they do not cure diabetic retinopathy.

Laser Surgery

Laser surgery is performed in a doctor’s office or eye clinic. Before the surgery, your ophthalmologist will: (1) dilate your pupil and (2) apply drops to numb the eye. In some cases, the doctor also may numb the area behind the eye to prevent any discomfort.

The lights in the office will be dim. As you sit facing the laser machine, your doctor will hold a special lens to your eye. During the procedure, you may see flashes of light. These flashes may eventually create a stinging sensation that makes you feel a little uncomfortable.

In laser treatment, the doctor makes tiny burns on the retina with a special laser. These burns seal the blood vessels and stop them from growing and leaking.

In scatter photocoagulation (also called panretinal photocoagulation), the doctor makes hundreds of burns in a polka-dot pattern on two or more occasions. Scatter photocoagulation reduces the risk of blindness from vitreous hemorrhage or detachment of the retina — but it only works before bleeding or detachment has progressed very far.

Side effects of scatter photocoagulation are usually minor. They include several days of blurred vision after each treatment and possible loss of side (peripheral) vision.

In focal photocoagulation, the eye care professional aims the laser precisely at leaking blood vessels in the macula. This procedure does not cure blurry vision caused by macular edema. But it does keep it from getting worse.

For the rest of the day, your vision will probably be a little blurry. If your eye hurts a bit, your doctor can suggest a way to control this.

You may leave the office once the treatment is done, but you will need someone to drive you home. Because your pupils will remain dilated for a few hours, you also should bring a pair of sunglasses.

laser for proliferative retinopathy (white for illustration) a common type of laser for maculopathy (burns are shown white for illustration)

When the retina has already detached or a lot of blood has leaked into the eye, photocoagulation is no longer useful.

Vitrectomy

The next option is vitrectomy, which is surgery to remove scar tissue and cloudy fluid from inside the eye. The earlier the operation occurs, the more likely it is to be successful. When the goal of the operation is to remove blood from the eye, it usually works. Reattaching a retina to the eye is much harder and works in only about half the cases.

How Common Are the Other Diabetic Eye Diseases?
If you have diabetes, you are also at risk for other diabetic eye diseases. Studies show that you are twice as likely to get a cataract as a person who does not have the disease. Also, cataracts develop at an earlier age in people with diabetes. Cataracts can usually be treated by surgery.Glaucoma may also become a problem. A person with diabetes is nearly twice as likely to get glaucoma as other adults. And, as with diabetic retinopathy, the longer you have had diabetes, the greater your risk of getting glaucoma. Glaucoma may be treated with medications, laser, or other forms of surgery.
Self-Testing The Eye
At times, someone who has diabetes can detect changes in their vision that warn of problems. These changes can be found using a simple Amsler grid. Testing with an Amsler grid helps to detect vision changes caused by poor control, macular edema, or a detached retina. The grid is used by doctors to detect eye problems, but it only detects problems in the macula and cannot check other regions of the eye.Your doctor may ask you to test yourself with an Amsler’s Chart.Anyone who has been told they have significant eye changes caused by diabetes should test each eye daily. If you notice any changes in your vision, see your eye doctor immediately.
Instructions for the test using the Amsler grid:


1. Look at the square (grid).
2. Wear your reading glasses (if you use one) and cover one eye.
3. Focus on the center dot for one full minute.
4. While looking directly at the center, be sure that all the lines are straight and clear, and all the small squares are the same size.
5. Repeat the test in the other eye.
6. If any lines or squares appear distorted, wavy, blurred, discolored, or otherwise abnormal, call your eye doctor right away.
7. In healthy eyes the lines are straight.

The Amsler’s chart is very useful for early detection of macular problems and thus is very important as this may be an early sign of macular problems and lead to a loss of central vision! But one must know its limitations.The Amsler grid will NOT detect proliferative diabetic retinopathy, most preproliferative changes and other types of damage that may threaten vision, nor is it useful for detecting any of the early changes. Remember: a normal Amsler grid test does not rule out the presence of retinopathy that can threaten your vision.It cannot replace routine eye exams. Only regular eye exams can do this.

Finally,

You will realize that protecting yourself against serious diabetes eye complications is in your hands.

Even if one cannot “see” INTO the future, at least one can “see” in the future!!

www.healthsewak.com

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About Anuj Agarwal

I am a professional with varied working experience of more than 18 years in India, USA and Middle East. My areas of work and interest are Information Technology, Corporate Social Responsibility, Health and Wellness. Please feel free to contact me through the blog or write me at agarwalanuj@yahoo.com
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One Response to Diabetes effect on Eyes, Part II, Diabetic Retinopathy

  1. Pingback: Diabetes effect on Eyes, Part II, Diabetic Retinopathy « healthsewak.com

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