Diabetes is a disease in which the body does not produce or properly use insulin. Insulin is a hormone that is needed to convert sugar, starches and other food into energy needed for daily life. Consequently, when a patient has diabetes there is an increase in the amount of “sugar” in the blood stream. Over time, this leads to a multitude of health problems including kidney failure, nerve damage, increased chance of heart attack or stroke, and blindness.
In fact, diabetes is the number one cause of preventable blindness among people ages 20-64 years old. When people have diabetes, the small blood vessels in the body become damaged and begin to leak a plasma-like fluid into the area surrounding the blood vessel. Initially, in most parts of the body, this small amount of leakage is without much consequence, and patients do not experience changes in their daily functioning. However, in the eye, this small amount of leakage can create considerable disruption of the performance of someone’s vision. This leakage surrounding the blood vessel leads to swelling of the retinal tissue (macular edema). The retina is responsible for obtaining images that are transferred to the brain (via the optic nerve). When this retinal tissue is swollen it obtains “blurred” images that can no longer be focused by the eye. These “blurred” images progressively worsen and lead to the type of blindness that diabetic patients experience. When patients have vision loss due to diabetes, it is called “diabetic retinopathy”.
Diabetes also causes other forms of damage to the eye. In advanced stages, diabetes causes the eye to become deprived of oxygen. The eye responds to this “oxygen deprived” state by producing new blood vessels as a means of providing more blood (and oxygen) to itself. This process is called “neovascularization”. These new blood vessels are not like the ones we were born with. The too are very leaky. Additionally, as these new blood vessels grow, they destroy the architecture of the retina, much in the way that growing roots from a tree destroy the nearby sidewalk, causing it to crumble. This also leads to blindness in the form of retinal detachments and hemorrhage inside the eye (vitreous hemorrhage).
In most instances, blindness caused by diabetes is not in the form of “total darkness”. However, it can be so severe that a patient may not even be able to recognize his/her own face in a mirror six inches away.
There are 20.8 million children and adults in the United States, or 7% of the population, who have diabetes. While an estimated 14.6 million have been diagnosed with diabetes, unfortunately, 6.2 million people (or nearly one-third) are unaware that they have the disease.
Prevention & Treatment
The standard of care in the United States is for all diabetic patients to have a dilated eye exam every year or sooner as directed by their eye doctor. The purpose of this exam is to check for areas of leakage that may lead to retinal swelling. The eye doctor will also check for new blood vessel growth.
If retinal swelling is detected, only your eye doctor can determine if treatment is indicated at that time. Additionally, if new blood vessels are detected, the doctor will need to determine if treatment is indicated. In either instance (retinal swelling or new blood vessel growth) your ophthalmologist will be able to perform LASER surgery to reduce the chances of vision loss due to the diabetic changes.
The best way to reduce your chances of developing blindness due to diabetic retinopathy is to control your blood sugar levels. They should remain around 120 or as directed by your physician. Additionally, having your eyes examined once a year by a qualified eye doctor will reduce your chances of losing vision due to diabetes.
To find out more about diabetes and diabetic retinopathy please visit the following links:
– National Eye Institute: www.nei.nih.gov/health/diabetic/retinopathy.asp
– American Diabetes Association: www.diabetes.org