Blood Sugar & Your Eyes: What You Should Know About Diabetic Retinopathy

Written by Dr. Kirilyuk Inna Anatolyivna on Fri, 11 November 2022

Key Highlights

  • Diabetes causes small blood vessels throughout the body, including the retina, to deteriorate over time.
  • Non-proliferative diabetic retinopathy (NPDR) is a form of diabetic retinopathy in which symptoms are mild or nonexistent.
  • Diabetic retinopathy is more common in Hispanics and African Americans.
  • Proliferative diabetic retinopathy (PDR) complications include retinal detachment caused by scar tissue formation and the development of glaucoma.
  • Diabetic macular edema (DME) occurs when the macula, or center of the retina, begins to swell, causing blurry vision.

Diabetic retinopathy is a condition that can occur in diabetics. It gradually deteriorates the retina, the light-sensitive innermost layer at the back of the eye.

Diabetic retinopathy is a potentially blinding complication of diabetes. Diabetes impairs the body's ability to utilize and store sugar (glucose). Too much sugar in the blood causes the disease, which can cause damage throughout the body, including the eyes.

Diabetes causes small blood vessels throughout the body, including the retina, to deteriorate over time. When these tiny blood vessels leak blood and other fluids, diabetic retinopathy develops. The retinal tissue swells as a result, likely to result in cloudy or hazy vision.

Diabetic retinopathy affects both eyes in most cases. Diabetic retinopathy is more likely to develop as a person's diabetes progresses. Diabetic retinopathy, if left untreated, can result in blindness.

When diabetics have high blood sugar levels for an extended period, fluid can build up in the lens of the eye, which controls focusing. This alters the curvature of the lens, causing vision to change. When blood sugar levels are under control, the lens usually returns to its original shape and vision improves.

Diabetes patients who can better control their blood sugar levels will see a reduction in the onset and progression of diabetic retinopathy.

Diabetes causes damage to the small blood vessels in the retina, which results in diabetic retinopathy. Vision loss can result from these damaged blood vessels:

  • Fluid can leak into the macula, the retinal area responsible for clear central vision. The macula is the part of the retina that allows us to see colors and fine detail, despite its small size. The fluid swells the macula, causing blurred vision.
  • New blood vessels may form on the retina's surface to improve blood circulation. These fragile, abnormal blood vessels can cause blood to leak into the back of the eye, obstructing vision.

Types of diabetic retinopathy

There are two kinds of diabetic retinopathy:

  • Non-proliferative diabetic retinopathy (NPDR) - Non-proliferative diabetic retinopathy (NPDR) is a form of diabetic retinopathy in which symptoms are mild or nonexistent.
  • Proliferative diabetic retinopathy - The more severe form of the disease is proliferative diabetic retinopathy (PDR). Circulation problems deprive the retina of oxygen at this stage. As a result, new, fragile blood vessels can form in the retina and the vitreous, the gel-like fluid that fills the back of the eye. Blood from the new blood vessels may leak into the vitreous, clouding vision.

Risk factors & causes

Risk factors & causes

  • Diabetes: Diabetics with type 1 or type 2 diabetes are at risk for diabetic retinopathy. Diabetes retinopathy is more likely to develop in people who have diabetes for a long time, especially if the diabetes is poorly controlled.
  • Race: Diabetic retinopathy is more common in Hispanics and African Americans.
  • Medical issues: People who have other medical conditions, such as high blood pressure or high cholesterol, are more vulnerable.
  • Pregnancy: Pregnant women are more likely to develop diabetes and diabetic retinopathy. If a woman develops gestational diabetes, she is more likely to develop diabetes later in life.

Symptoms of diabetic retinopathy

It is peculiar to experience symptoms in the early stages of this condition. Diabetic retinopathy symptoms frequently do not appear until significant damage has occurred within the eye. Unseen damage can be avoided by controlling your blood sugar levels and having regular eye exams to monitor your eye health.

When the symptoms do appear, they may include the following:

  • encountering floaters or dark spots
  • inability to see at night blurred vision inability to distinguish colors
  • vision impairment

Diabetic retinopathy typically affects both eyes.

Complications of diabetic retinopathy

Diabetic retinopathy, if left untreated, can lead to a variety of complications.

Vitreous hemorrhage occurs when blood vessels bleed into the main jelly that fills the eye, known as the vitreous.

Floaters are common in mild cases, but vision loss can occur in severe cases because of the blood in the vitreous blocks lights from entering the eye.

If the retina is not damaged, the vitreous bleeding may resolve on its own. Diabetic retinopathy can result in a detached retina in some cases. This can occur if scar tissue pulls the retina away from the back of the eye. Floating spots in the individual's field of vision, flashes of light, and severe vision loss are common symptoms. If not treated, a detached retina poses a significant risk of total vision loss.

Diabetic macular edema (DME) occurs when the macula, or center of the retina, begins to swell. Diabetic macular edema causes blurry vision because the macula is important for precise vision. It's a fairly common complication among diabetics.

Glaucoma occurs when the normal flow of fluid in the eye becomes blocked due to the formation of new blood vessels. The blockage increases the risk of optic nerve damage and vision loss by causing a buildup of pressure in the eye.

Diagnosis of diabetic retinopathy

Diabetes-related retinopathy can be diagnosed during a routine eye exam by an ophthalmologist.

  • Visual Acuity Test: Acuity refers to how you can see.
  • Tonometry: The Intraocular pressure is measured to ensure there are no signs of glaucoma.
  • Eye muscle function: Muscle function refers to how well you can move your eyes.
  • Peripheral vision Analysis: It is defined as seeing from the sides of your eyes.
  • Pupil Response: This evaluation looks at how your pupils respond to light.
  • Fluorescein angiography. A test in which an organic dye is injected into the bloodstream to reveal the blood vessels in the eye. This happens as images are captured using a specialized camera, and it will let your doctor know if the blood vessels are leaking or no longer supplying certain regions of the retina.

Diagnosis of diabetic retinopathy

Your eye doctor will then place drops in your eyes. The drops dilate (widen) your pupils (centers of the eyes).

During this examination, the doctor looks for:

  • Blood vessels that aren't normal.
  • Bleeding in the center of your eye.
  • The formation of new blood vessels.
  • Swelling of the retina.

Treatment of diabetic retinopathy

When developing a plan of care, your healthcare provider will take several factors into account, including:

  • Age.
  • Medical background.
  • The degree of retinal damage.
  • The acuity of vision.
  • HbA1c.

Your doctor might take a wait-and-see approach in the early stages of the disease, especially if your vision is clear. During this stage, you have regular eye exams but no further treatment is required. Some people require eye examinations every two to four months.

Other available treatments include:

  • Injections: Your healthcare provider will inject medication into your eyes, such as anti-vascular endothelial growth factor drugs or corticosteroids. These medications help to slow the progression of the disease and improve vision.
  • Laser surgery: A laser is used by your healthcare provider to reduce swelling in your retina and the formation of new blood vessels. The lasers either shrink or stop the leaking of blood vessels.
  • Vitrectomy: If you have cloudy vision due to leaking blood vessels, your healthcare provider may recommend this outpatient eye surgery. The eye doctor performs a vitrectomy by making a small incision in the eye. The provider is capable of repairing blood vessels and removing scar tissue.

Prevention of diabetic retinopathy

Diabetes increases your risk of developing certain eye diseases such as diabetic retinopathy, glaucoma, and cataracts. The good news is that you can keep your vision and lower your risk of eye disease.

prevention of diabetic retinopathy

Follow these steps now to ensure that your vision is preserved in the future.

  1. Get an annual eye exam: Diabetes can result in retinopathy, which is caused by damaged blood vessels in the back of your eyes. You may initially have no symptoms. If the condition worsens, you may lose your vision. Obtain a dilated eye exam from an ophthalmologist or optometrist once a year. They'll look for early signs of retinopathy and treat you if necessary to save your vision.
  2. Maintain blood sugar control: If you don't keep your blood sugar under control, you're more likely to develop diabetic retinopathy. Check your blood sugar levels frequently throughout the day, or use a continuous glucose monitor. If you're stressed or sick, you may need to check it more frequently. Maintain your blood sugar levels within healthy target ranges. This is typically 80-130 (mg/dL) before meals and less than 180 mg/dL 1-2 hours after meals.
  3. Monitor your A1c: A hemoglobin A1c test can be performed by your doctor to determine your average blood sugar levels over the previous three months. Your target A1c level should be less than 7%, but it may be higher if you're older or have other health issues. Set your A1c target with your doctor.
  4. Take note of your other numbers too: High blood pressure and cholesterol both increase your chances of developing diabetic retinopathy. Your blood pressure and cholesterol levels can be checked by your doctor. If your numbers are high, they will recommend dietary changes, weight loss, or more exercise. If that doesn't work, they can prescribe medications.
  5. Reduce your intake of salt: High blood pressure can be caused by consuming too much salt or sodium. You may not have any symptoms that indicate a problem. Instead of salt, experiment with herbs and spices for flavor. Low-salt diets also help to reduce inflammation and maintain the health of your eyes' tiny blood vessels.
  6. More colorful fruits, less fat: Consume a well-balanced diet low in fat, sugar, and sodium. To help prevent retinopathy, follow the Mediterranean diet or consume plenty of fresh fruits, vegetables, and fish. Obesity also increases your chances of developing this eye disease. The Mediterranean diet can also help you lose weight.
  7. Quit smoking: If you smoke tobacco, it is time to quit. Smoking increases your chances of developing diabetic retinopathy. Consult your doctor for assistance in quitting. To combat the urge to smoke, you may require counseling and prescription medication.
  8. Get a lot of exercise: Regular exercise keeps your eyes healthy and helps you control your diabetes by lowering blood sugar levels. Each week, aim for 150 minutes of moderate-intensity exercise. Do you enjoy walking? Put on a pedometer. Aim for 10,000 steps per day. Find enjoyable exercises to keep you motivated to complete them.
  9. Reduce your stress: High stress increases your chances of developing diabetes complications such as retinopathy. It increases hormones like cortisol and adrenaline, which cause insulin resistance and can raise blood sugar levels. Find ways to manage stress, such as getting enough exercise and rest.
  10. Limit your alcohol consumption: If you must drink, do so in moderation. Women should limit themselves to one serving per day, while men should limit themselves to two. Alcohol can interfere with diabetes medications and cause dangerous blood sugar drops. New research suggests that moderate wine consumption may even help protect against diabetic retinopathy, but don't overdo it.
  11. Keep an eye out for vision changes: Contact your eye doctor right away if you notice any sudden changes in your vision, such as spots, haze, blurring, eye pain or redness, floaters, or loss of vision. Do not put off bringing up these symptoms until your yearly eye exam. You may require treatment to slow or stop vision loss.

When should you consult a doctor?

Because diabetic retinopathy can develop without symptoms, it is critical for people with diabetes to have regular eye exams.

healthcare provider

If you have diabetes and notice changes in your vision, this could be a sign of diabetic neuropathy. Reasons to contact your doctor include:

  • Impaired vision in one or both eyes.
  • Seeing flashing lights.
  • Floaters.
  • Eye pain or pressure.
  • Blurred vision that you've noticed over time.


Diabetic retinopathy can occur in anyone with diabetes. This serious eye condition requires immediate attention. Without treatment, it can cause vision loss and even blindness. However, prompt treatment can prevent vision loss and halt disease progression.

The best way to avoid the disease is to manage your diabetes and keep your blood sugar under control. If you notice any new vision changes, make an appointment with a healthcare provider.

People living with diabetes who have diabetic retinopathy may experience vision loss or even go blind as a result of this serious eye condition. There are, thankfully, ways to avoid it or slow its progression.

If you've been diagnosed with diabetes, you should do the following:

  • Maintain regular eye and physical examinations.
  • Maintain healthy blood sugar, cholesterol, and blood pressure levels.
  • Be aware of any changes in your vision and discuss them with your doctor as soon as possible.

Some eye symptoms can indicate a medical emergency, such as:

  • The unexpected loss of vision in one or both eyes.
  • Unexpected blurry vision.
  • Unexpected vision loss.

If you have a sudden, unexplained change in your vision, call medical assistance or have someone assist you to the nearest hospital.


Dr. Kirilyuk Inna Anatolyivna

She is graduated from Vinnytsia National Medical University, in 2008.
2008-2010 resident, family practice.
2010-2015 General practitioner, family practice doctor.

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