What is Diabetic Retinopathy?
Also known as diabetic eye disease, diabetic retinopathy is an eye disease that people with diabetes might develop.
The word “retinopathy” refers to any type of damage to the eye’s retina, which is the light sensitive tissue lining the back of the eye. Carrying visual information about the outside world, light enters the front of the eye through the lens, which focuses the light. The light strikes the retina, which has special photoreceptor cells that absorb the light and the information it carries. The photoreceptor cells convert the light and information into signals that the brain can interpret into visual images.
Diabetic retinopathy, otherwise referred to as DR for short, can damage the blood vessels and tissues in the back of the eye. Diabetic retinopathy can cause significant vision loss and can even lead to blindness if left untreated, according to the American Optometric Association (AOA).
The retina contains a large amount of blood vessels, which supply it with the oxygen and nutrients the photoreceptor cells and retinal tissue needs to function. Damage to these blood vessels can prevent the photoreceptors and retina from working well, resulting in cloudy or blurred vision. Left unchecked, damage to blood vessels can even lead to vision loss.
One small but important spot of retinal tissue, known as the macula, sits at the center of the retina. The macula is responsible for seeing detailed objects straight in front of the eyes and for color vision. Damage to macular tissue can cause loss of center vision, which makes reading, threading a needle and other close-up work difficult. Seepage of blood from the blood vessels can cause the macula to swell, resulting in blurred central vision.
Symptoms of Diabetic Retinopathy
Symptoms of diabetic retinopathy include:
- Spots or “floaters” in the field of vision
- Blurred vision
- Blurred central vision
- Difficulty seeing well at night
- A dark spot at the center of vision
Prevalence of Diabetic Retinopathy
- Diabetic retinopathy affects nearly one-third of all adults over the age of 40 who have diabetes, according to the Centers for Disease Control and Prevention (CDC)
- 4.2 million adults in the U.S. live with diabetic retinopathy
- 655,000 adults in the U.S. have a vision-threatening form of the disease
- From 2010 to 2050, the number of Americans with diabetic retinopathy is expected to nearly double, from 7.7 million to 14.6 million
- Diabetic retinopathy is the most common cause of vision impairment and blindness among working-age adults in the U.S.
How Diabetes Leads to DR
Diabetes is a condition associated with high blood sugar levels. Excessive amounts of sugar in the bloodstream can damage blood vessels within the retina. This damage can cause the blood vessels to swell and leak. Damaged blood vessels can even close off completely to prevent blood from flowing to the retinal tissue. In an effort to supply the retina with the oxygen-rich blood it needs, new blood vessels may form on the surface of the retina. These blood vessels can also leak into the back of the eye to block vision. All of these changes can lead to vision loss.
High blood sugar levels, known as hyperglycemia among medical professionals, can have other negative effects. Long periods of hyperglycemia can cause sugar to accumulate in the eye’s lens, for example, and this accumulation can actually change the curvature of the lens to change vision. As blood sugar levels go down, the lens returns to its normal shape and vision improves.
People with diabetes who maintain good control over their blood sugar levels can slow the onset and progression of diabetic retinopathy. Taking prescribed medications as directed, eating the recommended diet, exercising regularly, controlling blood pressure, and avoiding tobacco use and alcohol consumption can help too.
Types of Diabetic Retinopathy
Diabetic retinopathy is a progressive condition, which means it worsens over time. Eye specialists classify DR according to the stages of the disease and the symptoms. Briefly, there are four stages of diabetic retinopathy:
- Mild nonproliferative retinopathy: microaneurysms (small red dots of dilated capillaries) are often the first sign of diabetic retinopathy and do not affect vision
- Moderate nonproliferative retinopathy: blood vessels in the eye become too swollen to provide nourishment to the retina which causes visible changes to the retina
- Severe nonproliferative retinopathy: large portion of blood vessels in the retina are blocked which decreases blood flow to the retina
- Proliferative retinopathy: new blood vessels begin to grow on the retina which symbolizes the most advanced stage
More on Stage 1
Non-proliferative diabetic retinopathy (NPDR) is the early phase of diabetic retinopathy; symptoms are mild or nonexistent. At this stage of the disease, the blood vessels within the retina are weak, and tiny bulges may appear. These bulges can leak blood into the retina and this can lead to swelling of the macula, a condition known as macular edema. Macular edema is the most common cause of vision loss among people with diabetes. Tiny particles, known as exudates, may form in the retina to affect vision.
More on Stage 4
The most advanced stage of DR is known as proliferative diabetic retinopathy (PDR). As the disease progresses, poor circulation from damaged blood vessels deprive the retina of the oxygen it needs to function well. This triggers the growth of fragile new blood vessels in the retina. The abnormal blood vessels can also grow into the gel-like vitreous fluid that fills the back of the eye, and potentially leak blood into this vitreous fluid to cloud vision. If the blood vessels bleed only a little, they may cause a few dark “floaters” in the visual field. If they bleed a lot, they might block vision completely.
The abnormal growth of blood vessels in PDR can form scar tissue that can cause problems with the macula or even lead to a detached retina, which is a serious emergency that occurs when the retina pulls away from the back of the eye.
Blood vessels can grow near the area of the eye that drains fluid from the eye. These vessels can block drainage and increase pressure inside the eye, and this increased pressure can damage the optic nerve.
Diagnosis of DR
Early detection is important for diabetic retinopathy, so if you have diabetes, you should be having an annual dilated ophthalmologic exam. Those with diabetes who are also pregnant should be examined each trimester. If you have any vision symptoms such as blurred central vision, that can be an indication to visit your eye care specialist soon.
During the ophthalmologic exam, the doctor will place eyedrops in your eyes to dilate your pupils, which helps them inspect for any damage potentially caused by retinopathy. They could also conduct one of two common diagnostic tests:
- Fluorescein angiography: taking pictures of the inside of your dilated eyes, then injecting a special dye into your arm to help identify which blood vessels have blockages and which blood vessels leak blood
- Optical coherence tomography (OCT): providing a cross-section image of your eye to see the thickness of your retina and where fluid could leak from damaged blood vessels
Preparing for an Appointment
When preparing for an appointment, make sure you have the following pieces of information prepared (along with anything else your healthcare provider may have asked for):
- Symptoms you are experiencing
- When your symptoms occur, and what your blood glucose levels are like at the time
- Any other health issues you are experiencing, when they occur, and what you think makes them stop
- Any other relevant information to your eye health
- List of any questions you have for your healthcare provider
Other Conditions Caused by Diabetic Retinopathy
Diabetic retinopathy can lead to other eye conditions such as neovascular glaucoma, diabetic macular edema (DME), and retinal detachment.
- Neovascular glaucoma: a type of secondary glaucoma where the angle of the eye is closed by new blood vessels
- DME: accumulation of fluid in the macula due to leaking blood vessels
- Retinal detachment: occurs when the retina pulls away from its normal position at the back of the eye; separates retinal cells from the blood vessels that provide oxygen and nourishment
Who is at Risk for Diabetic Retinopathy?
Anyone with any type of diabetes (type 1, type 2, and gestational) can develop diabetic retinopathy. The longer you have diabetes, the higher your risk becomes. You can lower your risk by controlling your diabetes and following advice from your healthcare professional. Those at highest risk for developing diabetic retinopathy are women with diabetes who become pregnant, or women who develop gestational diabetes.
Preventing Diabetic Retinopathy
- Experts recommend to eat healthy and keep active to help control your blood pressure, blood sugar, and cholesterol, which can reduce your risk for developing diabetic retinopathy
- Quit smoking, as it increases your risk of developing diabetic retinopathy
- Schedule an annual comprehensive dilated eye exam to catch any potential issues early, and contact your eye specialist immediately if you notice any vision changes
- Follow your healthcare provider’s recommendations on keeping your blood sugar low
Community Resources and Support Groups
Developing diabetic retinopathy can be difficult to go through, but there are support groups and resources available to help you during this time.
- FB – Diabetic Retinopathy Support Group: supports those who have or have been recently diagnosed with diabetic retinopathy
- FB – Diabetic Retinopathy & DME Explained: doctors and artists make medical information easy to understand and connects you to those with the same condition
- AccessWorld: free monthly online technology magazine that reviews accessibility for various technologies and assistive devices
- American Diabetes Association – eNewsletters: provides information on living with diabetes, food, fitness, and advocacy initiatives
- Tudiabetes: online support forum for those affected by diabetes
Scientists are continually researching on how to best address and treat vision loss in people with diabetes.
- NEI-supported diabetic research: diabetic eye disease research done by NEI scientists and grantees.
- Harvard Medical School’s Department of Ophthalmology: news feed for recent updates in diabetic eye disease research
- News Medical: news articles about diabetic retinopathy research and advancements
Treatment depends largely on the extent of the disease. Laser surgery can seal leaking blood vessels and prevent other blood vessels from leaking. Injection of medications into the eye can decrease inflammation or stop the formation of abnormal blood vessels. Certain surgical procedures can remove and replace the vitreous fluid in the eye; other surgical procedures can repair retinal detachment.
Available Assistive Technology
For those with diabetic retinopathy who may be going through vision loss, eSight is an option. eSight is a low vision eyewear device that stimulates synaptic activity from the remaining photoreceptor function of its users’ eyes. Many successful eSight users live with central vision loss commonly caused by diabetic retinopathy. DR can damage the blood vessels and tissues in the back of the eye, which can prevent the photoreceptors and retina from working well which often results in cloudy or blurred vision.
Fortunately, eSight can stimulate synaptic activity from the remaining photoreceptor function of the user’s eyes. As a result, eSight makes clearer vision possible, resulting in enhanced vision of up to 7 lines on a doctor’s eye chart. It uses a cutting edge camera, smart algorithms and high resolution screens, and provides the flexibility to read books up close with the same ease as seeing a crosswalk sign from a distance.
Users have been able to see their family’s faces for the first time in decades, resume their hobbies and jobs, and regain their confidence and independence in their daily lives. Although there are other options for vision-enhancing technology on the market, eSight is one of the only ones that can boast substantial mobility for its users.
Can I develop diabetic retinopathy without having diabetes?
No, diabetic retinopathy only affects those with diabetes.
Is there anything I can use to help improve my vision if I have diabetic retinopathy?
eSight is a form of electronic eyewear that has been clinically validated to enhance vision for people living with visual impairments and legal blindness, and has improved the vision of many users who live with diabetic retinopathy.
Can you reverse vision loss caused by diabetic retinopathy?
This varies for each person, but controlling blood sugar and blood pressure can slow the disease from progressing. It is best to speak to your healthcare provider about your options.
Can diabetic retinopathy cause headaches?
Yes, this can be one of the symptoms along with blurry vision and black spots.
What is the difference between hypertensive retinopathy and diabetic retinopathy?
Hypertensive retinopathy occurs in those who have high blood pressure, and typically there are no symptoms in the early stages as opposed to diabetic retinopathy.
What is background diabetic retinopathy?
This is another name for stage 1 of diabetic retinopathy, mild non proliferative retinopathy, when microaneurysms develop.
Does diabetic retinopathy affect both eyes?
Yes, typically the clouded/blurry vision will occur in both eyes.