At one time this was a popular saying: “What you see is what you get.” That statement does not always apply to a person who has diabetes. A diabetic often finds it impossible to detect the subtle changes that could indicate the development of retinopathy.

A patient with retinopathy passes through four distinct stages. In each stage of retinopathy, the eyes undergo a different set of changes. Yet there is no point at which those changes in the eye necessarily set off “alarm bells” in the mind of the diabetic.

Retinopathy results from damage to the blood vessels in the retina. That damage takes place over time. That damage deprives the cells in the retina of needed nourishment. The mal-nourished cells then suffer a reduced sensitivity to light. When the cells of the retina fail to function normally, i.e. when they can not detect light, the cells in the retina stop sending messages to the brain. That in turn can give rise to vision problems.

The subtle and progressive nature of the changes in the retina explains the difficulties experienced by diabetics who strive to detect those changes. Many diabetics are older adults. Almost all aging adults experience vision problems of some sort. Frequently, when a diabetic has failing vision, he or she attributes that failure to his or her age.

Moreover, the changes that take place in the first stage of retinopathy don’t diminish appreciatively the amount of blood that is flowing into and out of the retina. In that first stage of retinopathy—mild, non-proliferative retinopathy—only imperceptible changes take place in the blood vessels of the eye. The swelling of those vessels, the formation within them of tiny “balloons,” initiates the start of the first stage of retinopathy.

After the eye has undergone the changes associated with the first stage of retinopathy, the eye then experiences the second stage of retinopathy. In that second stage, some of the blood vessels that nourish the cells of the retina become blocked. The cells in the retina do not get all of the nutrients that they need. Still, their low level of nourishment fails to initiate any tell-tale symptoms in the eye. At this point, the sight continues to be fine.

The second stage of retinopathy is called moderate non-proliferative retinopathy. The changes that take place during the second stage of retinopathy pave the way for appearance of stage 3—severe non-proliferative retinopathy. In this stage, the brain receives news about the severity of the damage that has been done to the cells in the retina of the eye. That news comes in the form of a protein.

As the blood stops flowing into some vessels in the retina, the cells in the retina cry-out for nourishment. They produce a protein called vascular endothelial factor (VEGF). That protein enters the blood stream and travels to the brain. Cells in the brain detect the VEGF. Those cells know that the VEGF comes from the retina. After detecting the VEGF, the brain orders the formation of more blood vessels in the retina.

As new blood vessels develop in the retina, the eye enters the fourth and final stage of retinopathy. Because new cells are forming at this time, it is called proliferative retinopathy. The new blood vessels do not further diminish the performance of the retina, but they do introduce a source of potential new problems. The new vessels are very thin.

Due to their thin walls, the new blood vessels within the retina are quite fragile. They break easily. They often develop tiny leaks. Fluid from the new blood vessels leaks out onto the retina. That fluid then impairs the ability of the retina to function properly.

Sometimes, a diabetic patient will wake from sleep to find that he or she has spots on one or both eyes. Such spots develop when blood leaks from thin vessels in the retina. While such hemorrhaging can take place at any time, it usually happens at night.

Fortunately, no diabetic needs to accept the inevitability of waking to the sight of a spotted eye. Every diabetic can take important steps to prevent the changes associated with retinopathy. Every diabetic has control over certain elements in his or her life, elements that could either hasten or slow the advancement of retinopathy.

A diabetic can control the amount of blood sugar in his or her bloodstream. High blood sugar levels cause the brain to signal for the production of more insulin. The brain expects the body’s cells to respond to the higher insulin level. A failed response can send the brain into “overdrive,” demanding greater help from the blood vessels.

The signals from the brain only hasten the demise of the blood vessels in the retina. That demise leads to the formation of thin and fragile blood vessels. Those thin vessels allow fluid to leak onto the cells of the retina. Control of the blood sugar level avoids the occurrence of the damaging leaks.

A diabetic should also control his or her blood pressure and cholesterol levels. High blood pressure can damage blood cells. Were such damage to take place in the retina, it would most certainly usher in a period of thin blood vessel formation. That would then lead to the development of leaking blood vessels within the eye.

A diabetic should control his or her cholesterol to prevent the formation of plaques in the blood vessels. Such plaques can block tiny blood vessels. Blockage of blood vessels in the eye could trigger formation of tiny and leaky new vessels.

If all of the above mentioned preventive methods fail, a diabetic can still reverse the effects of retinopathy. Changes caused by retinopathy can be repaired with laser surgery. Still, laser surgery works best, if done before new blood vessels form. For that reason, every diabetic should make a point of seeing an ophthalmologist at least once a year.

A diabetic should also be familiar with the side effects experienced by those who have undergone laser treatment. Such treatments can lower the acuteness of both color and night vision.

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Christopher Berry
Diabetic Discussion