What is diabetic retinopathy?
Diabetic retinopathy is a complication that occurs in diabetics that affects the light sensitive tissue in the back of the eye (the retina). There are many stages of diabetic retinopathy ranging from mild to severe, but the two main classes are Non-Proliferative Diabetic Retinopathy (NPDR) and Proliferative Diabetic Retinopathy (PDR).
Non-Proliferative Diabetic Retinopathy (NPDR) is considered early diabetic retinopathy and is the most common type. Having too much sugar in the bloodstream can cause blockages of tiny vessels in the retina. These blockages cause the blood vessels to bulge and break, allowing blood and fluid to leak into the retinal tissue. Patients in this stage may have no noticeable symptoms.
If fluid begins to build up in the macula (an area of the retina responsible for sharp, central vision), patients may begin to notice a change in vision. This is called diabetic macular edema (DME), and affects 1 out of every 15 diabetics. If DME is left untreated, it can cause permanent vision loss.
Proliferative Diabetic Retinopathy (PDR) is known as the advanced stage. Once the retinal vessels become damaged enough they will begin to close off. The retina will try to compensate for this by growing (proliferating) new blood vessels. However, these new vessels are very fragile and easily leak even more blood into the back of the eye.
The growth of these new blood vessels can also create scar tissue which can make the retinal tissue detach from the back of the eye. These vessels can also interfere with normal fluid outflow of the eye, which can increase the pressure inside of it and damage the optic nerve, causing glaucoma.
Who is at risk for diabetic retinopathy?
Anyone with diabetes is at risk for developing diabetic retinopathy, including type 1, type 2, and gestational (diabetes that develops during pregnancy). The less controlled your blood sugar levels are and the longer you’ve had diabetes, the more likely you are to develop retinopathy.
Additional risk factors for developing diabetic retinopathy include tobacco use, being of Black, Hispanic or Native American descent, and having high blood pressure or high cholesterol in addition to diabetes.
What are the symptoms of diabetic retinopathy?
In the early stages of diabetic retinopathy, you may experience no symptoms at all. That is why it is essential to have routine eye exams to monitor for any findings of diabetic retinopathy.
As the condition progresses, you may start to notice any of the following symptoms:
- Blurred or fluctuating vision
- New floaters in vision (dark spots, strings or cobwebs)
- Dark or missing areas of vision
- Complete vision loss
How is diabetic retinopathy diagnosed?
Diabetic retinopathy is diagnosed through a full retinal exam. This can be performed either with the use of dilation drops or with imaging that allows a wide angle view into the back of the eye.
Our doctors perform retinal imaging on all diabetics using our Optomap instrument. The Optomap photographs allow for a side by side comparison of retinal health over time. This imaging is taken each year at their routine eye exam, or more frequently if complications are found.
What are the dangers of diabetic retinopathy?
When caught early enough, most cases of diabetic retinopathy can be treated prior to any permanent impact on vision. However, when left untreated, diabetic retinopathy can lead to any of the following conditions:
- Glaucoma: Abnormal blood vessel growth can interfere with normal fluid outflow of the eye, which can increase the pressure inside of it and damage the optic nerve, causing glaucoma. If left untreated, this can cause permanent loss of peripheral vision.
- Retinal Detachment: As new blood vessels grow, scar tissue forms which can cause the retinal tissue to detach from the back of the eye. If left untreated, this can cause permanent and complete vision loss.
- Vitreous hemorrhage: The vitreous is the clear, jellylike substance inside of the eye. Bleeds (hemorrhages) can leak into the vitreous, causing floaters or total vision loss. On their own, vitreous hemorrhages typically don’t cause permanent vision reduction.
- Permanent blindness: Diabetic retinopathy can result in permanent blindness (both central and peripheral vision) from either DME or a combination of the above conditions.
- Other systemic complications: The reason it is essential for diabetic patients to have routine eye examinations is because the retina is the only place in the body that doctors can non-invasively examine blood vessels. Diabetic retinopathy is an indicator that blood vessel changes are occurring throughout the entire body, making you more likely to develop other complications, such as neuropathy.
How do you treat diabetic retinopathy?
Treatment of diabetic retinopathy depends on the severity of it. In all cases, the most important goal is to get the blood sugar level under control again. Our doctors will communicate their findings and plan with your endocrinologist to help achieve this.
Patients who have early, non-proliferative diabetic retinopathy may only require more frequent retinal examination and imaging. Their endocrinologist may or may not need to make changes to their medication or dosage.
Patients who have advanced, proliferative diabetic retinopathy may require more aggressive treatments to prevent permanent vision loss. These treatments are performed by an ophthalmologist and may include:
- Medicated injections into the eye that stops proliferation (blood vessel growth).
- Laser treatments to help reduce swelling and prevent blood vessel leakage.
- Vitrectomy, a surgery in which the clear, jellylike substance inside of the eye (the vitreous) is removed and replaced with a clear, artificial fluid. This may be necessary in cases of dense vitreous hemorrhages.
“I haven’t been diagnosed with diabetes but I think I might have it. Can you tell this from an eye exam?”
The short answer to this is no. The longer answer is that no, our doctors cannot definitively diagnose diabetes from an eye exam. However, there may be findings that could indicate a strong possibility of diabetes, especially in severe cases with highly fluctuating blood sugar levels. In these cases, it will be recommended to have blood work performed. If you are concerned that you might have diabetes, you should see your general doctor immediately for blood work and additional testing.
“Is diabetic retinopathy reversible?”
Early, mild cases of diabetic retinopathy can be reversible with adequate blood sugar control. More severe cases may be reversible with appropriate treatment. Some cases may be too severe for treatment to return vision to normal.
“My vision is very blurry because of my diabetes, why won’t my Optometrist prescribe me glasses to help?”
Fluctuating or uncontrolled blood sugar can cause a temporary shift in vision and prescription. Any prescription that is found at this time is highly inaccurate and will likely shift again before your glasses even arrive! Although it may be inconvenient, it is essential for your blood sugar to be stable prior to ordering glasses.
“I was just diagnosed with diabetes, what should I do for my eye health next?”
Your diabetic doctor will surely recommend a baseline eye exam to monitor your retinal health. Depending on those findings, our doctors will recommend a schedule for follow up that may range from a few months to 1 year. It is never recommended for a diabetic to go more than 1 year without a retinal examination, even once their levels are stable.
“I’m a diabetic but my vision is fine, why do I need a diabetic eye exam?”
Our doctors can detect diabetic retinopathy long before you notice any symptoms. Although your vision is clear, your retinal tissue may show signs of sickness that can only be reversed with appropriate treatment. If you wait until your vision is blurry from your diabetes, the damage may be too severe to reverse, causing permanent vision loss.
If you are a diabetic and have not had an eye exam within the last year, or if you are noticing any changes in your vision, contact us to schedule an exam. The sooner we can evaluate your retina, the better chance you have of continuing with a lifetime of healthy eyes and clear vision!