Diabetic Retinopathy
Diabetic retinopathy is a complication of diabetes that damages the blood vessels in the retina. It is the most common cause of vision loss in working-age adults. High blood sugar levels weaken and damage these delicate vessels, potentially leading to bleeding, swelling, and blurred vision.
At a Glance
Diabetic retinopathy is a complication of diabetes in which persistently high blood sugar damages the retina's blood vessels — causing leakage, bleeding, and swelling. It is the most common cause of vision loss in working-age adults. Early stages have no symptoms, making routine screening essential for anyone with diabetes.
Key Facts
Types / Stages
- ●NPDR — Non-proliferative: early–moderate stage with leaky, weakened vessels. Most common.
- ●PDR — Proliferative: advanced stage with fragile new abnormal vessels that can bleed.
- ●DME — Diabetic macular edema: fluid in the macula, the most frequent cause of vision loss at any stage.
Common Symptoms
- •Blurry or fluctuating vision
- •Floaters (dark spots or strings)
- •Dark or empty patches in the visual field
- •Colors appear washed out
- •Poor night vision
Risk Factors
- •Long duration of diabetes (Type 1, 2, or gestational)
- •Poorly controlled blood sugar (high HbA1c)
- •High blood pressure or high cholesterol
- •Smoking, pregnancy, kidney disease
How It's Diagnosed
Annual dilated eye exam for all patients with diabetes. OCT imaging is the gold standard for detecting diabetic macular edema. Fluorescein angiography maps vessel leakage and areas of poor blood flow.
Treatment Options
Anti-VEGF injections (first-line for DME and PDR), laser photocoagulation (PRP for PDR, focal for DME), steroid implants, and vitrectomy in advanced cases. Systemic control of blood sugar, blood pressure, and cholesterol is essential.
⚠ Seek Care Promptly If You Notice
- •Sudden increase in floaters
- •Flashes of light in your vision
- •Sudden blurring or vision loss in one eye
- •A shadow or curtain spreading across your vision
What is Diabetic Retinopathy?
Diabetic retinopathy is a vision-threatening complication that arises when persistent high blood sugar injures the delicate blood vessels lining the retina. The retina is the light-sensitive tissue at the back of the eye that converts visual information into signals sent to the brain. When these vessels are damaged, they may leak fluid, bleed, or close off entirely—disrupting normal retinal function and potentially leading to blindness if left untreated.
Because the disease often begins without any noticeable change in vision, many people are unaware they have it until significant damage has occurred. Regular dilated eye exams are the only reliable way to catch the condition in its earliest and most treatable phases.
The good news is that vision loss is not inevitable. With early detection, modern therapies, and diligent control of blood sugar and blood pressure, most people can preserve their sight.
Key Facts at a Glance
Stages of Diabetic Retinopathy
The disease progresses along a spectrum. Recognizing where you are on that spectrum helps guide treatment decisions and monitoring frequency.
NPDR
Non-Proliferative Diabetic Retinopathy
This is the earlier phase of the disease. Elevated glucose levels weaken the walls of the retina's tiny vessels, causing them to bulge, leak fluid, or close down. Because these changes happen gradually, vision may remain normal even as damage accumulates.
- Mild NPDR: Small outpouchings in vessel walls (microaneurysms) appear.
- Moderate NPDR: More vessels become blocked or leaky, with dot-blot hemorrhages and hard exudates.
- Severe NPDR: Widespread vessel closure deprives large areas of the retina of oxygen, triggering signals for new vessel growth.
PDR
Proliferative Diabetic Retinopathy
This advanced stage occurs when oxygen-starved retina releases growth signals that cause fragile, abnormal blood vessels to sprout along the retinal surface and into the vitreous gel. These new vessels are structurally weak and prone to rupture.
- New vessels may rupture and bleed into the vitreous (vitreous hemorrhage), causing sudden vision loss.
- Accompanying scar tissue can contract and pull the retina away from the back of the eye (tractional retinal detachment).
- If abnormal vessels grow on the iris, they can block fluid drainage and lead to neovascular glaucoma—a painful, sight-threatening form of eye pressure.
Diabetic Macular Edema (DME)
Diabetic macular edema is a build-up of fluid in the macula—the central part of the retina responsible for sharp, straight-ahead vision. It occurs when compromised blood vessels leak fluid and protein into surrounding retinal tissue, much like a leaky pipe soaking a wall.
DME can appear at any stage of diabetic retinopathy, from mild NPDR through advanced PDR. It is the single most common cause of reduced vision among individuals with diabetes. Swelling distorts the macula's delicate architecture, blurring detail work such as reading, driving, and recognizing faces. Optical Coherence Tomography (OCT) is the primary tool physicians use to detect this swelling, measure retinal thickness, and track how well treatment is working.
Leaking vessels deposit fluid in and under the retina, causing it to thicken and function poorly.
Unlike PDR, DME does not require advanced disease; it can develop even in mild NPDR.
Anti-VEGF injections, laser, and steroids can reduce swelling and often improve vision.
Symptoms
One of the most challenging aspects of diabetic retinopathy is that early disease frequently produces no symptoms at all. As the condition advances, vision changes may come and go or worsen gradually. Because damage can occur silently, relying on symptoms alone is risky. Everyone with diabetes should follow recommended screening schedules regardless of how well they see.
Risk Factors & Prevention
All individuals with diabetes—whether Type 1, Type 2, or gestational—face some risk of developing retinopathy. Several factors can raise that risk or cause the disease to progress more rapidly. Understanding them empowers you to take control.
The longer you have lived with diabetes, the greater your risk. After two decades, the majority of patients show some retinal changes.
Poorly controlled glucose (high HbA1c) accelerates vessel injury. Tight control significantly lowers risk.
Hypertension compounds damage to retinal vessels. Keeping pressure in a healthy range protects your eyes.
High cholesterol encourages fatty deposits (hard exudates) in the retina and worsens vascular health.
Tobacco impairs circulation and magnifies the harmful effects of diabetes on blood vessels throughout the body.
Hormonal shifts during pregnancy can speed up retinopathy changes in women with diabetes.
Diabetic nephropathy and retinopathy often travel together; kidney dysfunction signals higher eye risk.
Rates are higher among Hispanic, African American, and Native American populations.
Keep Your Health on TRACK
Leading health organizations recommend the TRACK framework as a practical way to prevent or delay vision loss from diabetic eye disease. Small, consistent lifestyle choices add up to meaningful protection for your sight.
Your medications exactly as prescribed by your physician
And maintain a healthy body weight through balanced nutrition
Regular physical activity to your daily routine
Your blood sugars, blood pressure, and cholesterol levels
The smoking habit for good
Diagnosis
Because diabetic retinopathy often advances without symptoms, routine screening is the cornerstone of protection. A comprehensive evaluation goes beyond a standard vision check to examine the retina in detail.
Dilated Eye Exam
Special drops widen the pupil so your eye doctor can inspect the retina, optic nerve, and blood vessels for leakage, bleeding, swelling, or abnormal growth. This is the foundational screening test for all patients with diabetes.
OCT Imaging
Optical Coherence Tomography uses light waves to capture high-resolution, cross-sectional pictures of the retina. It is the gold standard for detecting and quantifying diabetic macular edema.
OCT precisely measures retinal thickness, locates fluid within or beneath retinal layers, identifies structural disorganization, and allows your physician to monitor treatment response with extraordinary accuracy.
Fluorescein Angiography
A harmless yellow dye is injected into an arm vein, and rapid photographs track its path through retinal circulation. This test reveals exactly which vessels are leaking, where blood flow is compromised, and whether abnormal new vessels have formed.
Treatment Options
The right treatment depends on the stage of retinopathy and whether macular edema is present. Modern therapies have transformed outcomes, but the window of opportunity is widest when disease is caught early.
Anti-VEGF Injections
Considered first-line therapy for DME and active PDR. Medications such as aflibercept, ranibizumab, and bevacizumab block a protein that fuels abnormal vessel growth and leakage.
Administered into the eye after numbing drops, usually on a monthly or treat-and-extend schedule.
Laser Surgery
Focal or grid laser closes leaking microaneurysms to reduce macular swelling. Panretinal photocoagulation (PRP) treats widespread PDR by shrinking fragile new vessels in the peripheral retina.
Often combined with injections or used when injections alone are insufficient.
Steroid Implants
Corticosteroids delivered by injection or sustained-release implant can quiet stubborn inflammation and reduce chronic macular edema, particularly when anti-VEGF therapy falls short.
Your doctor will weigh benefits against potential side effects such as cataract progression or elevated eye pressure.
Vitrectomy
A microsurgical procedure to remove blood-filled vitreous gel and scar tissue from the back of the eye. It is indicated when heavy vitreous hemorrhage fails to clear or traction threatens the retina.
May be paired with laser treatment or an intraocular gas bubble to stabilize the retina during healing.
Screening Guidelines
Regular dilated eye exams are the single most effective step you can take to prevent vision loss from diabetic retinopathy. Screening schedules differ based on the type of diabetes and life circumstances.
Type 1 Diabetes
Begin comprehensive dilated eye exams within 5 years of diagnosis, then repeat annually. Earlier or more frequent exams are needed if any retinopathy is detected.
Type 2 Diabetes
Obtain a dilated eye exam at the time of diagnosis. Because Type 2 diabetes may have been present for years before detection, retinopathy can already exist. Continue annual exams thereafter.
Pregnancy
Women with diabetes who become pregnant should schedule a dilated eye exam during the first trimester and receive close monitoring throughout pregnancy, as retinopathy can worsen rapidly.
Note: If diabetic retinopathy is discovered, your retina specialist may recommend follow-up every 3 to 6 months depending on severity. Once you have had treatment, you will likely need ongoing monitoring to guard against recurrence.
🔬 Clinical Trials
Active research for Diabetic Retinopathy — from ClinicalTrials.gov
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🔬 Clinical Trials
Active research for Diabetic Retinopathy — from ClinicalTrials.gov
Clinical Trial Landscape
Research activity for Diabetic Retinopathy — sourced live from ClinicalTrials.gov
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Status Breakdown
Trials by Phase
Filtered by phase —What do these phases mean?
First tests in a small group of people to check safety, dosage, and side effects.
Tests whether the treatment works and continues to monitor safety in a larger group.
Large trials comparing the new treatment to the current standard to confirm effectiveness.
Studies done after FDA approval to track long-term benefits and side effects in real-world use.
Currently Recruiting
Frequently Asked Questions
Can diabetic retinopathy be cured or reversed?
How often should I have a diabetic eye exam?
What is the difference between diabetic retinopathy and diabetic macular edema?
Are injections into the eye painful?
Will controlling my blood sugar prevent diabetic retinopathy?
When to Seek Help Immediately
Some symptoms signal an eye emergency. Do not wait for a scheduled appointment if you experience any of the following. Prompt evaluation by a retina specialist can mean the difference between preserved vision and permanent loss.
A rapid increase in spots, strings, or cobwebs may indicate bleeding into the vitreous.
Repeated flashes can signal traction on the retina from scar tissue or an impending tear.
A dark veil drifting across part of your visual field may indicate retinal detachment.
Any abrupt drop in sight requires same-day emergency eye care.
Diabetic retinopathy is the most common eye disease in people with diabetes and the leading cause of blindness among working-age adults. Persistently high blood sugar damages retinal blood vessels, causing them to leak, swell, or close. In advanced stages, fragile new vessels may grow and bleed into the eye. With regular screening and modern treatments, vision loss can often be prevented or reversed.
- Blurred or fluctuating vision
- Dark spots or floaters in vision
- Poor night vision or dim colors
- Blank or dark areas in the visual field
- Sudden severe vision loss in advanced cases
- Anti-VEGF eye injections (first-line for DME and active PDR)
- Laser photocoagulation to seal leaking vessels
- Steroid implants for persistent macular edema
- Vitrectomy surgery for non-clearing hemorrhage or traction
- Sudden increase in floaters or flashes of light
- A curtain or shadow over your vision
- Sudden severe vision loss
- Any rapid, unexplained change in vision
Go to the emergency room or call your retina specialist immediately.
Schedule a comprehensive dilated eye exam at least once a year if you have diabetes—more often if retinopathy is present. Keep blood sugar, blood pressure, and cholesterol well controlled, and do not smoke.
Disclaimer: This handout is for educational purposes only and does not replace personalized medical advice from your retina specialist.
Information sourced from: American Society of Retina Specialists (ASRS) · American Academy of Ophthalmology (AAO) · National Eye Institute (NEI)