Diabetic retinopathy is the result of damage to the blood vessels in the eye due to chronic elevations in blood sugar, or diabetes. The retina is responsible for detecting light and visual cues and sending them via your optic nerve into your brain to tell you what you just saw.
Uncontrolled sugar levels leads to damage to the small blood vessels in the eye, allowing them to leak. Over time, this leaking leads to swelling in the eye. The end effect is a lack of blood flow and nutrients to the retina, resulting in loss of vision. The body attempts to repair this damage by building new blood vessels, which are even more fragile and likely to leak. All of this bleeding and blood vessel growth causes scar tissue to form, and as scars tend to do, they contract away from the surrounding tissue. This pulling away can actually pull the retina off, leading to permanent visual loss.
Unfortunately, there are often no symptoms of diabetic retinopathy. Later symptoms may include visual floaters, increased visual difficulty, dark spots or difficulty with night vision.
This is why it is vital that people with diabetes get annual eye exams by an optometrist or ophthalmologist. Since there are usually no symptoms, it is important to get a visual of your retina and its blood vessels to ensure there are no abnormal blood vessels.
The best way to prevent diabetic retinopathy is to control your blood sugar. Long term sugar control is measured via hemoglobin A1C, which can tell you how your sugar has been over the last 3 months. An A1C of less than 8.0 can reduce your risk of developing diabetic retinopathy by more than 75%. Don’t be discouraged if your A1C is not at that goal yet – studies show that for every 1 point reduction in A1C, there is a 35% reduction in retinopathy development. So, small improvements can help while you are working toward your diabetic control goals.
There are some treatment options for diabetic retinopathy, depending on the severity of the disease.
An ophthalmologist may inject a medication directly into the eye. One type of medication is to block a protein that stimulates blood vessel growth and leakage, vascular endothelial growth factor (VEGF). Another is a steroid, which is used to reduce inflammation and can be an injection or implant.
There are two different types of laser eye treatments used for treatment: focal laser surgery and panretinal photocoagulation. Focal laser surgery uses a spot laser to concentrate in an area that is already leaking fluid into the macula, the central area of the retina. Panretinal photocoagulation utilizes multiple laser spots to diminish current blood vessels and prevent new blood vessels from forming, thus preventing leaking in the future.
If there is severe bleeding, a vitrectomy may be needed. This is removal of the gel in the center of the eye. It is replaced with a salt solution. Or a terminator eye, if you have a billion dollars to spare.
We are fortunate to have these treatments available, but they usually don’t return vision after it’s been compromised by diabetes. Our best hope is to slow the progression of further retinopathy once it has started. If you do have diabetes, make sure you follow up with your ophthalmologist or optometrist for regular exam. And, even more importantly, make sure you follow up with your health care provider to ensure you have optimal sugar control!