How Diabetic Macular Edema Causes Vision Loss
For our Mini Med School video series, we break down how damaged blood vessels in the eye lead to DME.
Diabetic macular edema (DME) is the most common cause of vision loss for people with diabetes. Learn how high blood sugar levels can do damage to your eyes, and what to do to prevent as well as treat this condition.
What's the connection between high blood sugar levels and your eyesight? If you or someone you love, has diabetes, you want to understand the risks of diabetic macular edema. It's the leading cause of vision loss in people with Type 1 or Type 2 diabetes.
Diabetics are at risk for damage to the small blood vessels in the eyes' light sensing layer, called the retina. DME occurs when fluid from these damaged vessels leaks into the macula, causing swelling. The macula helps us see objects directly ahead, as well as make out fine detail, color and faraway objects.
As fluid builds up over time, often without noticeable symptoms, the macula loses its ability to focus. Vision can be distorted and colors may appear washed out and faded. You may even have total blind spots.
Here's how DME develops in the eye. Over a long period of time, high blood sugar levels, a hallmark of uncontrolled diabetes, damage the blood vessels throughout your body. In the retina, sugar damaged blood vessels develop balloon like bulges inside.
This swelling increases the surface area of the blood vessel. So it's thinner and not as watertight. The cells that wrap around the blood vessels and seal them off called parasites, also begin to retract and can die off.
As a result, fluid, blood and lipids can leak into the macula, causing more swelling. This prevents cells from sending accurate messages to the brain. So images become distorted.
When damage to the retinas blood vessels is at its worst stage from a related condition called proliferative diabetic retinopathy, or PDR, the damaged blood vessels close off, depriving the retina of oxygen and resulting in the growth of new but abnormal blood vessels. Because these new blood vessels are very fragile, they may leak even more or even bleed inside the eye in what is called a vitreous hemorrhage.
Scar tissue from the growth of the new blood vessels may also cause the retina to detach. Eventually, complete vision loss can occur. Once your vision is affected, you may not regain all of your site.
How can you prevent or slow DME? Keep your blood sugar levels under control. It's one of the most important things you can do. If you're diabetic is crucial to see an ophthalmologist regularly. The first line of treatment is Anti-VEGF medications. Given as eye injections, they act like spot welders, plugging damaging leakage and preventing problematic new vessels from forming. As a result of this treatment, fewer people today lose vision due to diabetic eye disease.