Diabetic retinopathy is an eye condition that occurs when high blood sugar levels damage the blood vessels in your retina—the light-sensitive tissue at the back of your eye that helps you to see details in your line of vision.
This eye condition affects nearly one-third of people with diabetes and is the leading cause of blindness in adults. Researchers estimate that by the year 2040, 224 million people with diabetes will develop some form of diabetic retinopathy.
Symptoms of diabetic retinopathy include having blurry vision and seeing spots or blank areas in your field of vision. Left untreated, diabetic retinopathy can lead to gradual vision loss or blindness.
Treatments like medication, laser therapy, and surgery can help prevent vision loss. If you have diabetes, annual eye exams can help with early detection and treatment of eye conditions like diabetic retinopathy.
Diabetic retinopathy is an eye condition that usually develops gradually. You may experience no symptoms in the early stages but have blurry vision or see floaters in your line of vision as your retinopathy progresses.
Symptoms of diabetic retinopathy can include:
- Difficulty seeing objects from a distance
- Blurry vision
- Floaters, which are tiny, dark spots or strings that float in your field of vision
- Obstructed vision at night or in low-light conditions
- Dark or empty patches in the center of your vision
- Colors appear faded or washed out
- Gradual vision loss
- Blindness
Diabetes is a metabolic disorder in which the pancreas has difficulty processing or producing insulin, a hormone that helps the body turn the food it eats into energy.
The pancreas is an organ in the abdomen that helps you digest food and regulate your blood sugar by releasing insulin into the bloodstream. Without enough insulin, your body cannot effectively use glucose (sugar) for energy, and it builds up in your bloodstream, causing hyperglycemia (high blood sugar).
Having chronically high blood sugar levels can cause complications over time, including diabetic retinopathy. People with type 1 or type 2 diabetes are the most likely to develop diabetic retinopathy. Over time, excess sugar can damage blood vessels throughout your body, including the tiny vessels in your retina.
Damage to blood vessels in your retina can cause them to weaken or grow at an exponential rate. When blood vessels in your eye are weakened, tiny microaneurysms (bulges) can occur. These microaneurysms leak fluid into your retina and cause swelling in the surrounding tissue. This can cause bleeding in your eyes.
The growth of too many new blood vessels is called neovascularization. Neovascularization can block blood flow to the retina. The formation of new blood vessels during this process is fragile and can lead to vision loss or blindness.
Risk Factors
Anyone with diabetes can develop diabetic retinopathy. The longer you have diabetes, the more at risk you are for diabetic retinopathy.
Your risk of diabetic retinopathy is also higher if you have other health conditions like hypertension (high blood pressure), kidney disease, and high cholesterol.
People with a family history of diabetic retinopathy are at an increased risk of developing the condition. People of African and Hispanic descent in the United States are at an increased risk because of higher rates of high blood pressure within the community.
During your annual eye exam, your healthcare provider (usually an ophthalmologist or optometrist, doctors who specialize in eye health) can typically see symptoms of diabetic retinopathy. Your healthcare provider will then review your medical history and ask if you are experiencing any symptoms, such as vision loss or pain in your eyes.
Your healthcare provider may perform a series of tests to check your retinal and overall eye health, including:
- Dilated eye exam: Your ophthalmologist or optometrist will place drops in your eye that dilate (widen) your pupils, allowing a healthcare provider to examine your retina more closely.
- Fluorescein angiography: A test that helps detect changes to your blood vessels by injecting a dye into your vein and allowing it to travel through your bloodstream and reach your eyes. Using a camera, your healthcare provider can view leaking or blocked blood vessels in your retina.
- Optical coherence tomography (OCT): You sit in front of an OCT machine and rest your head on a support to keep it still for an OCT scan. The machine uses light waves to scan your eyes and create detailed images to detect swelling and other symptoms.
There are two main stages of diabetic retinopathy, classified by the severity of damage to the blood vessels in the retina. The non-proliferative and proliferative stages help healthcare providers understand how to treat you.
Non-Proliferative Diabetic Retinopathy (NPDR)
Non-proliferative diabetic retinopathy (NPDR) is the early stage of diabetic retinopathy that occurs when blood vessels in your retina weaken and develop microaneurysms.
In this stage, the retina leaks fluid, which causes swelling of the macula, the center part of your retina that helps you see colors and shapes.
Many people with NPDR do not have symptoms, though some may have mild or occasionally blurry vision.
Proliferative Diabetic Retinopathy (PDR)
Proliferative diabetic retinopathy is the most advanced stage of the condition. At this stage, damaged blood vessels in the retina close and prevent oxygen from reaching your retina. This leads to excess blood vessels growing in your retina.
The new blood vessels tend to bleed and cause you to see dark spots or floaters in your field of vision. If they leak blood into the vitreous—the gel-like fluid in the back of the eye—you may have severe vision loss or blindness. The new blood vessels can also form scar tissue and a detached retina or glaucoma, a group of eye conditions caused by excess pressure in your eyes.
There is no cure for diabetic retinopathy, but early detection and management can help prevent vision loss. Treatment options vary depending on the severity of your symptoms. Some healthcare providers may suggest corticosteroids (hormones implanted or injected into the eye) or surgery for more severe cases.
Diabetes and Blood Pressure Management
Managing your long-term blood sugar levels and your blood pressure are important to help prevent diabetic retinopathy. Steps to manage your diabetes well include taking your medications, eating a diabetic-friendly diet, and getting regular exercise. It is best to avoid smoking or drinking alcohol excessively.
Anti-VEGF Injections
Diabetic retinopathy causes your body to make too much vascular endothelial growth factor (VEGF)—a protein that can cause swelling in the retina, blood vessel leakage, and the overgrowth of blood vessels.
VEGF can also develop from other eye conditions like age-related macular degeneration (ARMD) and macular edema (swelling of the macula). Damage to the macula is one of the leading causes of vision loss.
Anti-VEGF injections block VEGF to prevent eye damage and preserve your vision. Your optometrist or ophthalmologist will numb your eye before injecting the medicine into your eye with a small needle. Common medications used to treat VEGF include Avastin (bevacizumab), Lucentis (ranibizumab), and Vabysmo (faricimab).
Most people require monthly injections of anti-VEGF therapy. You may need injections less often over time as your condition improves.
Laser Treatments
Scatter laser treatment (pan-retinal photocoagulation) is a treatment option for people with advanced diabetic retinopathy. Using a laser, your healthcare provider will shrink damaged blood vessels to prevent further damage to your eyes and vision.
During the treatment session, you may see light flashes and feel stinging in your eyes. Some people require one session, while others may need more than one session.
Surgery
If blood vessels in your retina are bleeding heavily or have severe scarring, your healthcare provider may recommend surgery. A vitrectomy is a surgical procedure that involves removing most of the vitreous gel from your eye and repairing bleeding blood vessels in your retina to preserve vision.
Your eye may be swollen and painful for a few weeks after the surgery. You may also temporarily experience blurry vision. Aqueous humor, a water-like fluid produced inside the eye, will naturally replace the vitreous over time. Most people can return to normal activities within a month following surgery.
There is no guaranteed way to prevent diabetic retinopathy when you have severe diabetes, but you can significantly reduce your risk by staying on top of your diabetes treatment.
Getting your yearly eye exam—including a comprehensive dilated eye exam—can help prevent complications. Keeping your blood pressure in a normal range can help prevent your diabetes from getting worse.
Diabetic retinopathy can increase your risk of developing other eye conditions, including:
- Neovascular glaucoma: Blood vessels grow outside your retina and block fluid from draining from your eye. This can damage your optic nerve and lead to neovascular glaucoma, increasing the risk of damage to your vision.
- Diabetic macular edema: This is characterized by swelling of your macula, the part of the retina responsible for central vision. It occurs in about 1 out of every 15 people with diabetes.
- Retinal detachment: Scars form in the back of your eye from blood vessel damage and can cause your retina to detach from the rest of your eye.
Severe diabetes can lead to eye conditions like diabetic retinopathy. This severe eye condition can cause vision changes, pain, and swelling. Speak with a healthcare provider if you notice any changes to your vision.
Maintaining healthy blood sugar levels, preventing high blood pressure, and getting annual eye exams help prevent diabetic retinopathy.
