According to the Centers for Disease Control (CDC), one out of every three persons living with diabetes eventually develops diabetic retinopathy. This makes diabetic retinopathy the leading cause of blindness for adults who also have diabetes.
How Does Diabetes Trigger Diabetic Retinopathy?
Diabetic retinopathy is a disease that damages the retina, the part of the eye that senses light. Researchers believe it is the blood sugar elevation associated with diabetes that initially gives rise to diabetic retinopathy.
Blood sugar elevation can damage the tiny blood vessels within and around the retina. These damaged vessels begin to swell and leak fluid and blood into the retina itself. This damages the retina, causing it to swell in turn. Lesions can form on the retinal surface as the retina tries to repair itself. In time, ischemia (reduced oxygen flow into the tissues) can set in, causing more extensive damage to the retina and surrounding eye tissues.
In the later stages of diabetic retinopathy, as ischemia worsens, new blood vessels can develop in an abnormal way on the retina surface, causing more damage to the retina. Blindness will result if diabetic retinopathy is left untreated.
I have Type 1 Diabetes – Am I at Risk?
Unfortunately, yes. Both Type 1 and Type 2 diabetic patients can eventually cause diabetic retinopathy.
Because in the early stages of diabetic retinopathy most people don’t even know they have it, routine diabetic retinopathy eye exams are vital. The earlier diabetic retinopathy is caught and treated, the less you are at risk for eventual blindness.
Early warning signs of diabetic retinopathy can include the presence of eye floaters or spots, blurry vision, reduced night vision, or feeling like you have a blind spot in the center of your vision.
There are two main stages of Diabetic Retinopathy.
NPDR: Non-proliferative Diabetic Retinopathy
With non-proliferative diabetic retinopathy, which is the earlier stage of diabetic retinopathy, the tiny blood vessels leading to the retina begin to experience damage as a result of extended blood sugar elevation. This causes the vessels to swell and hemorrhage (burst), which then causes fluid and blood to leak into the retina.
As the fluids and blood seeps into the sensitive retinal tissues, the retina itself starts to swell. This is called DME, or diabetic macular edema.
As non-proliferative diabetic retinopathy continues unchecked, the most sensitive part of the retina, the macula, may receive a diminished supply of blood and oxygen (ischemia) and begin to lose function. As the eye tissues scramble to try to form new blood vessels, these new vessels themselves may grow in such a way as to interfere with the eye’s functioning.
This leads to the second and more severe stage of diabetic retinopathy.
PDF: Proliferative Diabetic Retinopathy
If diabetic retinopathy is still not caught and treated, the second stage of the disease is initiated. The oxygen and blood-deprived retina begins to send out frantic SOS messages, which speeds the formation of abnormal blood vessel networks across its own tissues (called neo-vascularization).
Frequently the new vessels perform poorly, hemorrhaging and leaking more blood and fluid into the retina. At this point, the retina is compromised in multiple ways and can begin to form scar tissue and even detach from the eye.
Neo-vascular glaucoma is a secondary complication of severe diabetic retinopathy, where the continual formation and hemorrhage of new blood vessels leads to intensely high pressure within the eye. This then damages the optic nerve, leading to permanent blindness.
Treating Diabetic Retinopathy
The better care you receive for your underlying diabetes mellitus (Type 1 or Type 2), the less risk you bear of eventually developing diabetic retinopathy.
The most important treatment aspects for minimizing your risk of diabetic retinopathy include monitoring your blood sugar levels, blood pressure levels, and cholesterol levels.
Since diabetic retinopathy is notoriously difficult to detect in its earliest stages, you may not discover you have it until you begin to develop noticeable symptoms. The earlier you are diagnosed and receive appropriate treatment, the more likely you will be able to retain and regain full vision.
You have a variety of treatment options for diabetic retinopathy depending on how far your disease has progressed.
AAII: Anti-angiogenic intravitreal injections: injections can help to stop the formation of abnormal blood vessels (neo-vascularization) on the surface of the retina. These injections are called anti-angiogenic intravitreal injections. The injections deliver medication directly to the vitreal cavity near the retina to help stop retinal swelling (diabetic macular edema). You may need several injections over your treatment period to maintain progress and recovery.
Laser treatments: Laser treatments (focal or laser grid) are often prescribed as a complement to anti-angiogenic intravitreal injections. Laser treatments can help seal off damaged blood vessels so they will not leak further fluid into the retinal area.
At the later stages of diabetic retinopathy or in the presence of secondary symptoms such as a detached retinal, neo-vascular glaucoma or ongoing vitreous hemorrhage (blood leaking into the vitreal cavity), injections and laser treatments are typically prescribed together.
PRP: Pan-retinal laser photocoagulation treatment. Later-stage non-proliferative diabetic retinopathy and any level of proliferative diabetic retinopathy may also respond positively to panretinal laser photocoagulation, a type of laser treatment that targets the peripheral retina. The good news here is that, by shrinking new blood vessel cells and preventing the formation of new blood vessels at the edges of the retina, PRP is successful at preventing blindness in the majority of patients.
ISI: Intraocular steroid injections are yet another treatment option that can be especially beneficial if you are unable to tolerate or do not respond well to other treatments. Sometimes ISI is prescribed in concert with anti-angiogenic intravitreal injections, laser treatments and pan-retinal laser photocoagulation treatment to help the eye heal faster without interference from the body’s immune system. Since use of steroids can cause cataracts or increased eye pressure in some patients, this treatment is only recommended when the potential benefits outweigh its risks.