Diabetic Retinopathy

Diabetic retinopathy is a serious eye complication of diabetes that affects blood vessels in the retina and stands as a leading cause of blindness in working-age adults, yet early detection and proper management can significantly protect your vision.

Table of contents

• What is Diabetic Retinopathy?
• Stages of the Disease
• Symptoms and Warning Signs
• Causes and How It Develops
• Who Is at Risk?
• Related Complications
• How It Is Diagnosed
• Treatment Options
• Prevention and Risk Reduction
• Living with Diabetic Retinopathy

What is Diabetic Retinopathy?

Diabetic retinopathy is an eye disease that can cause vision loss and blindness in people who have diabetes^[1]. It affects blood vessels in the retina, which is the light-sensitive layer of tissue at the back of your eye that allows you to see fine detail^[2].

The condition develops when too much sugar in your blood causes damage to the tiny blood vessels that nourish the retina^[1]. Over time, these damaged blood vessels can leak blood and other fluids, causing the retinal tissue to swell and resulting in cloudy or blurred vision^[7].

Diabetic retinopathy is the most common cause of vision loss for people with diabetes and the most common cause of irreversible blindness in working-age Americans^[6]. More than half of people with diabetes will develop diabetic retinopathy at some point in their lives^[2].

• Retina
• Blood vessels of the eye
• Macula
• Vitreous

Stages of the Disease

Diabetic retinopathy develops in stages and usually gets worse gradually over several years^[5]. There are two main stages of the disease, with treatment helping to stop it from progressing to the next stage.

Nonproliferative diabetic retinopathy (NPDR) is the early stage of the disease. During this stage, blood vessels in the retina are weakened and tiny bulges called microaneurysms may form, which can leak fluid into the retina^[7]. At this stage, there may be some signs of damage to blood vessels in your eye, but your vision is typically not affected^[5].

Proliferative diabetic retinopathy (PDR) is the more advanced form of the disease. At this stage, circulation problems deprive the retina of oxygen, causing new, fragile blood vessels to begin growing on the surface of the retina and into the vitreous, the gel-like fluid that fills the back of the eye^[7]. These new blood vessels don’t work as well and can leak blood into the middle of the eye, cause scar tissue formation, pull on the retina causing retinal detachment, or lead to high pressure in the eye^[3].

There is also a condition called diabetic maculopathy or diabetic macular edema (DME). This happens when blood vessels in the retina leak fluid into the macula, which is the part of the retina needed for sharp, central vision^[2]. Over time, about 1 in 15 people with diabetes will develop DME, which causes blurry vision^[2].

Symptoms and Warning Signs

Diabetic retinopathy may not cause any symptoms at first, and you might not have symptoms in the early stages^[2]. It is possible to have diabetic retinopathy for a long time without noticing symptoms until substantial damage has occurred^[6]. This is why the condition is often discovered during routine diabetic eye screening appointments^[5].

Some people notice changes in their vision early on, like trouble reading or seeing faraway objects. These changes may come and go^[2].

As the condition gets worse, people may develop more noticeable symptoms^[1]:

• Spots or dark strings floating in their sight, called floaters
• Blurred or distorted vision
• Changes in vision or difficulty with color perception
• Dark or empty areas in their vision
• Finding it harder to see in the dark or low light
• Vision loss

In later stages of the disease, blood vessels in the retina start to bleed into the vitreous. If this happens, you may see dark, floating spots or streaks that look like cobwebs^[2]. Sometimes, the spots clear up on their own, but it’s important to get treatment right away^[2].

Symptoms can affect one or both eyes^[5]. If your vision changes suddenly or becomes blurry, spotty or hazy, contact a medical professional right away^[1].

Causes and How It Develops

The primary cause of diabetic retinopathy is diabetes—a condition in which the levels of glucose (sugar) in the blood are too high^[6]. Diabetic retinopathy can develop in anyone who has type 1 or type 2 diabetes^[1]. It can also occur in people with gestational diabetes, which is diabetes that develops during pregnancy, or type 3c diabetes^[3].

Over time, elevated sugar levels from diabetes can damage the insides of blood vessels throughout your body^[3]. In the eye, high blood sugar damages the small blood vessels that nourish the retina and may, in some cases, block them completely^[6]. Sugar can block tiny blood vessels in your retina, causing them to bleed or leak fluid^[4].

When damaged blood vessels leak fluid into the retina, it results in swelling. The damaged blood vessels can also leak fluid into the macula, causing macular edema, which leads to blurry vision^[3].

When you have diabetic retinopathy, damaged blood vessels in your retina are trying to repair and reroute to avoid an interruption in blood supply^[3]. Your eyes try to compensate by growing new blood vessels to increase blood flow to undersupplied areas^[3]. However, these new blood vessels are fragile and abnormal. They don’t work as well and can leak blood and fluid into the vitreous^[3]. These blood vessels grow on the surface of your retina, and over time can cause retinal detachments and bleeding, which can lead to blindness^[3].

Who Is at Risk?

Anyone with any kind of diabetes can get diabetic retinopathy—including people with type 1, type 2, and gestational diabetes^[2]. Your risk increases the longer you have diabetes^[1]. Diabetic retinopathy develops in more than half of the people who develop diabetes^[6].

Several factors can increase the risk of developing diabetic retinopathy^[3][6]:

• Disease duration—the longer someone has diabetes, the greater the risk
• Poor control of blood sugar levels over time
• High blood pressure (hypertension)
• High cholesterol levels
• Heart-specific cardiovascular diseases, like heart disease and coronary artery disease
• Chronic kidney disease and kidney failure
• Pregnancy

Women with diabetes who become pregnant, or women who develop gestational diabetes, can increase their risk of diabetic retinopathy^[1]. The good news is that you can lower your risk of developing diabetic retinopathy by controlling your diabetes^[2].

Related Complications

Diabetic retinopathy can lead to other serious eye conditions. Without treatment, scars can form in the back of the eye, and blood vessels may start to bleed again, or the bleeding may get worse^[2].

Diabetic macular edema (DME) happens when blood vessels in the retina leak fluid into the macula, the part of the retina needed for sharp, central vision. This causes blurry vision^[2].

Neovascular glaucoma can develop when diabetic retinopathy causes abnormal blood vessels to grow out of the retina and block fluid from draining out of the eye. This causes a type of glaucoma, which is a group of eye diseases that can cause vision loss and blindness^[2].

Retinal detachment occurs when diabetic retinopathy causes scars to form in the back of your eye. When the scars pull your retina away from the back of your eye, it’s called tractional retinal detachment^[2].

Diabetic retinopathy can eventually lead to blindness^[4]. Diabetes can also make you more likely to develop several other eye conditions. Having diabetes makes you 2 to 5 times more likely to develop cataracts and nearly doubles your risk of developing open-angle glaucoma^[2].

How It Is Diagnosed

Diabetic retinopathy is usually found during a diabetic eye screening appointment, which involves taking photographs of the back of your eye^[5]. The best way to diagnose diabetic retinopathy is a dilated eye exam^[6].

During a comprehensive dilated eye exam, an eye care professional places drops in your eyes that widen your pupils to give a better view inside your eyes^[9]. The drops can cause your near vision to blur for several hours^[9]. During the exam, the eye care professional looks for irregularities in the inside and outside parts of your eyes^[9].

The physician will look for^[6]:

• Swelling in the retina that threatens vision (diabetic macular edema)
• Evidence of poor retina blood vessel circulation
• Abnormal blood vessels that may predict an increased risk of developing new blood vessels
• New blood vessels or scar tissue on the surface of the retina

Other tests that may be used include^[9]:

Optical coherence tomography (OCT) provides highly detailed cross-sectional images of the retina that show its thickness. This test helps determine whether fluid has leaked into retinal tissue. The images show the anatomy and thickness of the retina, helping to determine how much fluid, if any, has leaked into retinal tissue^[9].

Fluorescein angiography involves injecting a dye into a vein in your arm after your eyes are dilated. Then pictures are taken as the dye circulates through blood vessels in your eyes. The pictures can pinpoint blood vessels that are closed, broken or leaking^[9].

If you have diabetes, it’s important to get a comprehensive dilated eye exam at least once a year^[2]. If you’re pregnant and have diabetes, your healthcare professional might recommend additional eye exams throughout your pregnancy^[1].

Treatment Options

Treatment depends largely on the type of diabetic retinopathy you have and how severe it is^[9]. The aim of treatment is to help stop your vision from getting worse^[5]. It’s not possible to cure sight loss that has already occurred^[5].

If you have mild or moderate nonproliferative diabetic retinopathy, you might not need treatment right away^[9]. Your eye care professional will closely watch your eyes to decide if and when you might need treatment. When diabetic retinopathy is mild or moderate, good blood sugar control can usually slow the worsening of symptoms^[9].

If you have proliferative diabetic retinopathy, you’ll need treatment and will be referred to an eye specialist^[5]. The main treatments include:

Laser treatment (photocoagulation) usually works very well to prevent vision loss if it’s done before the retina has been severely damaged^[11]. A more aggressive laser therapy called scatter (pan-retinal) photocoagulation may be used for severe proliferative retinopathy. It allows your doctor to limit the growth of new blood vessels across the back of the retina^[11].

Regular eye injections of a medicine called anti-VEGF (vascular endothelial growth factor) reduce damage to blood vessels^[5]. Anti-VEGF medicines slow the growth of abnormal blood vessels in the retina by blocking the effects of a protein that triggers this growth^[11]. Medicines such as aflibercept (Eyelea) or ranibizumab (Lucentis) might be used if the macula has been damaged by macular edema^[11].

Steroid implants in your eye gradually release steroid medicine to reduce swelling^[5]. Sometimes steroids may be injected into the eye, or an implant such as Iluvien may be placed in the eye, which releases a small amount of corticosteroid over time^[11].

Eye surgery, such as vitrectomy, involves surgical removal of the vitreous gel. This surgery may help improve vision if the retina hasn’t been severely damaged and is done when there is bleeding or retinal detachment^[11]. Vitrectomy can also be used to treat macular edema and to remove scar tissue^[11].

Many people with diabetic retinopathy need to be treated more than once as the condition gets worse^[9].

Prevention and Risk Reduction

Diabetic retinopathy happens when high blood glucose (sugar) damages the blood vessels in your retina^[5]. It’s more likely to happen if you’ve had diabetes for a long time, and if you have high blood pressure or high cholesterol^[5].

If you have diabetes, you can reduce the risk of diabetic retinopathy by^[5]:

• Managing your blood glucose as well as possible—you can learn how to do this by attending a diabetes course
• Making healthy lifestyle changes to lower high blood pressure and high cholesterol
• Eating a healthy diet and exercising regularly
• Taking your medicine as prescribed

Proper treatment of diabetes is the best way to prevent vision loss^[1]. Managing your diabetes by staying physically active, eating healthy, and taking your medicine can help you prevent or delay vision loss^[2].

Controlling blood sugar, blood pressure, and cholesterol levels is crucial for controlling diabetes and preventing or slowing the progression of diabetic retinopathy^[18]. People with diabetes should get at least 150 minutes of moderate-intensity physical activity weekly^[18].

Foods that can promote strong overall eye health include those rich in omega-3 fatty acids like fish, chia seeds, and walnuts, as well as fresh fruits and green, leafy vegetables^[18]. These can help lower A1C levels and overall reduce the risk of developing diabetes-related complications like diabetic retinopathy^[18].

If you have diabetes, a yearly dilated eye exam with an eye care professional is recommended, even if your vision seems fine^[1]. Regular screenings increase the likelihood of detecting diabetic retinopathy in its early stages, which can lead to better vision outcomes^[18].

Living with Diabetic Retinopathy

Living with diabetic retinopathy can be physically and emotionally challenging^[17]. However, the condition can be managed effectively by employing positive coping strategies and seeking support^[16].

Educate yourself: Learning about the symptoms, progression, and treatment options of diabetic retinopathy can empower you and help you make informed choices and take effective actions^[16]. Patient education has been shown to effectively motivate action and implementation of diabetic retinopathy self-management behaviors such as diet and medication compliance^[16].

Get regular comprehensive eye exams: Regular eye exams with a retina specialist trained in diabetic eye care can detect changes in your eyes and enable early intervention if needed^[16].

Manage your blood sugar: Eating a healthy diet, exercising regularly, and staying committed to your diabetes management plan to maintain healthy blood sugar levels is a self-empowering method of coping with diabetic retinopathy^[16]. The progress of diabetic retinopathy can be slowed down by maintaining stable blood sugar levels^[16].

Control blood pressure and cholesterol: High blood pressure and elevated cholesterol levels can exacerbate diabetic retinopathy symptoms. Therefore, it’s important to monitor your blood pressure, regularly have your cholesterol levels checked, and follow your healthcare provider’s recommendations for long-term management^[17].

Make lifestyle changes: Incorporate healthy habits into your lifestyle, such as quitting smoking, managing weight, and reducing stress. These changes can positively impact both your eye health and overall well-being^[17].

Find support: Taking care of yourself includes seeking out emotional support. Look for in-person or online support groups for those with diabetic retinopathy or vision loss. For additional help, reach out to family, friends, or a mental health professional^[17].

While not everyone with diabetes will develop diabetes-related retinopathy, it’s still a major risk factor for vision loss. But diabetes and diabetes-related retinopathy are both manageable. Combining regular medical care and your own efforts can go a long way to maintaining your vision^[3].