What Is Diabetic Retinopathy?

More than 37 million people in the United States¹ live with diabetes. This chronic condition affects how your body turns glucose into energy and causes various complications, including kidney disease and eye problems.

Diabetic retinopathy is an eye condition due to high blood sugar levels. If left unmanaged, it could lead to partial vision loss or blindness. Like diabetes-related kidney disease, this eye problem is related to damaged blood vessels.

Let's take a closer look at diabetic retinopathy, its symptoms, causes, and treatment options.

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What is diabetic retinopathy?

Diabetic retinopathy² is an eye condition caused by diabetes. When a person with diabetes doesn't keep blood sugar levels under control, they cause damage to the blood vessels in the retina (tissue in the back of your eye responsible for converting light into images).

Damaged blood vessels in the retina can swell, leak, or close and stop the blood from passing. In some cases, new blood vessels that grow on the retina can be abnormal. Without proper blood supply to the retina, a person with diabetes could lose vision.

In the early stages of this condition, an individual may not experience any vision-related symptoms. That's why people with diabetes need to check the retina regularly.

There are two main stages of diabetic retinopathy:

Non-proliferative diabetic retinopathy (NPDR)

This early phase of diabetic retinopathy has three stages:

Early NPDR

At this stage, your vision isn't affected. However, a doctor can already detect a problem because there is balloon-like swelling in blood vessels in the retina. While you don't need treatment at this point, it's imperative to begin implementing preventive measures.

Moderate NPDR

At this stage, you experience damage to blood vessels in the retina. The blood and fluid may leak into the retinal tissue. This causes the macula (center of the retina) to swell.

Severe NPDR

If left unmanaged, more and more blood vessels in your retina become damaged, causing a bigger impact on your vision. At this point, some of the blood vessels in the retina can close off, so blood can't reach the macula. This is called macular ischemia.

Depending on the stage of NDPR, you can experience various symptoms, including blurriness and a reduced field of vision.

Proliferative diabetic retinopathy

This is the final stage of diabetic retinopathy, where you may lose your vision. The damage to blood vessels results in poor blood supply to the eye. The retina may start growing new blood vessels. However, they are likely to be abnormal and cause vision loss.

At this stage, it's imperative to consult a retina specialist since there is a big risk of blindness. Surgery may be necessary.

Diabetic retinopathy is the most common eye condition³ that affects people with diabetes. It's also the leading cause of blindness in American adults.

Diabetic retinopathy and nephropathy: Is early-stage kidney disease related to eye problems?

Both diabetic retinopathy and nephropathy (kidney disease) occur due to blood vessel damage. Around one-third of people with diabetes have diabetic retinopathy. Meanwhile, one-third of people⁴ with diabetic retinopathy are likely to have the vision-threatening stage of this condition.

Between 30% and 40% of people⁵ who live with diabetes are likely to develop kidney disease. For some of them, it will progress to end-stage nephropathy.

What is the connection between kidney disease and the eyes? Studies⁶ show that the presence and severity of diabetic retinopathy could be associated with the presence and severity of chronic kidney disease. Early identification of diabetic retinopathy could mean earlier intervention in diabetic control, which can help slow the progression of diabetic nephropathy.

Another study⁷ demonstrates that diabetic retinopathy can help diagnose and screen for diabetic nephropathy. If a person has proliferative diabetic retinopathy, they are likely to have nephropathy. Both involve damaged blood vessels from poor diabetic control.

Kidney disease and eye conditions are some of the most dreaded complications of diabetes. Together, they lead to serious consequences and substantially reduced quality of life.

Symptoms of diabetic retinopathy

Since you may not experience symptoms at the early stages, it's important to schedule regular retina exams. A comprehensive eye exam can determine whether you have early-stage retinopathy.

The symptoms of diabetic retinopathy may vary depending on the stage of your condition and include:

  • Seeing spots

  • Eye floaters (small shapes that float across your vision)

  • Blurred vision

  • The dark or empty spot in the center of your vision

  • Problems with seeing well at night

The above symptoms may also signal other conditions. That's why scheduling an appointment and getting a diagnosis is imperative. If you don't start addressing diabetes-related vision problems, they could lead to complete vision loss.

Causes of diabetic retinopathy

The key cause of diabetic retinopathy is high blood sugar levels due to diabetes. People with all types of diabetes (type 1, type 2, and gestational) can develop this eye condition.

If high blood sugar levels remain unmanaged, they affect the condition of blood vessels in your retina. Sugar starts blocking retinal blood vessels and keeps them from working properly. It also prevents the retina from growing new normal blood vessels. Abnormal vessels are fragile. They leak and bleed easily.

While diabetes is the main risk factor for developing diabetic retinopathy, the risk may increase if you also have:

  • Hypertension (high blood pressure)

  • Dyslipidemia (unhealthy levels of fat in your blood)

  • Nephropathy

The risk also increases with age and the duration of your diabetes. Those who control diabetes with insulin have a higher risk of developing retinopathy than those who use other methods.

Diagnosing diabetic retinopathy

If you have diabetes, your doctor recommends regular eye disease screening. To diagnose diabetic retinopathy, the doctor needs to look at the blood vessels on your retina.

Pupil dilation test

Besides conducting a regular eye exam to check your visual acuity, muscle function, peripheral vision, and pupil response, the doctor needs to run a pupil dilation test.⁸ To widen your pupils, they will give you special eye drops. Once pupils dilate, the specialist will check for:

  • Abnormal blood vessels

  • Bleeding into retinal tissue

  • Retina swelling

The doctor may diagnose diabetic retinopathy or run additional tests depending on the results.

Optical coherence tomography (OCT)

This imaging test allows the doctor to see a picture of your retina and measure its thickness. It can also produce a good image of your blood vessels. The OCT scan isn't painful. While the special equipment scans your eye, you look at the light during the test.

Fluorescein angiography

Fluorescein angiography checks the blood flow to your retina. During the test, the doctor will:

  • Give you eye drops to dilate your pupils

  • Take pictures of your eye

  • Inject a dye into your vein

  • Take more pictures as the dye moves through your body

This test allows the doctor to see if the blood vessels in your retina are damaged or closed off.   

Treatment for diabetic retinopathy

The treatment of diabetic retinopathy depends on the stage of the disease. It begins with developing a comprehensive plan to control your blood sugar levels. This includes:

  • Taking the prescribed medication on time

  • Adjusting and watching your diet

  • Exercising regularly

  • Maintaining a healthy weight

  • Keeping blood pressure under control

  • Kicking bad habits (excessive alcohol use, smoking)

This could be enough to prevent the disease from progressing. However, at the later stages of diabetic retinopathy, you may need:

  • Laser surgery to seal leaking blood vessels

  • Injections of medication to decrease inflammation or stop the formation of abnormal blood vessels

People with proliferative diabetic retinopathy with leaking blood vessels may need surgery called vitrectomy. During this surgery, the doctor removes your blood-filled vitreous (gel-like fluid that fills your eye) and replaces it with saline. This provides an opportunity for successful laser treatment. You may also need surgery if diabetic retinopathy causes a retinal detachment.


The common complications of diabetic retinopathy are:

  • Vitreous hemorrhage: Blood leaks into your vitreous and partially or completely blocks your vision.

  • Retinal detachment: Abnormal blood vessels cause scar tissue growth that pulls the retina away from your eye and causes floaters, flashes of light, and vision loss.

  • Glaucoma: New abnormal blood vessels interfere with fluid drainage and cause eye pressure to build inside your eye. This damages the optic nerve and may cause blindness.

  • Macular edema: Damaged blood vessels in the retina leak fluid into the macula and cause blurry vision.

It's possible to avoid these complications by diagnosing the problem early and keeping diabetes under control.

The lowdown

Diabetic retinopathy is a complication of diabetes that may cause serious vision problems. Like diabetes-related kidney disease, this eye condition is caused by damaged blood vessels from high sugar levels.

By keeping your diabetes under control and getting regular eye exams, it's possible to prevent diabetic retinopathy from progressing and causing vision loss. In the later stages of diabetic retinopathy, it's still possible to improve your vision with surgery and other treatments.

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