Diabetic Retinopathy Explained: How Diabetes Damages the Eyes and What Stops the Damage
Updated: 6 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer
Diabetic retinopathy is eye damage caused by diabetes, in which high blood sugar weakens the retina's tiny blood vessels so they leak, and fragile new vessels can detach the retina. Early stages have no symptoms, so a dilated eye exam is essential with diabetes or prediabetes. It is not curable, but blood sugar control and timely treatment limit vision loss.
What the research says
Diabetic retinopathy is common, and the burden is still growing. A systematic review and meta-analysis of 59 population-based studies estimated that 22.27% of people with diabetes worldwide have diabetic retinopathy (95% CI 19.73%–25.03%), 6.17% have vision-threatening disease, and 4.07% have clinically significant macular edema. The number of adults with diabetic retinopathy was projected to rise from 103.12 million in 2020 to 160.50 million by 2045 (PubMed: Teo et al., Ophthalmology, 2021).
Tighter blood sugar targets lower retinopathy risk, with a trade-off. In a meta-analysis of 19 randomized trials in type 2 diabetes, intensive glucose control reduced the risk of retinopathy (risk ratio 0.75; 95% CI 0.63–0.90) but increased the risk of hypoglycemia (risk ratio 2.04; 95% CI 1.34–3.10), so the authors conclude that A1C targets should be individualized (PubMed: Aldafas et al., Expert Rev Endocrinol Metab, 2023).
Anti-VEGF injections reduce some sight-threatening complications of proliferative disease. A Cochrane review of 23 randomized trials (1,755 participants) found that anti-VEGF drugs, with or without laser (PRP), probably reduce vitreous hemorrhage compared with laser alone (risk ratio 0.72; 95% CI 0.57–0.90) and may reduce the need for vitrectomy (risk ratio 0.67; 95% CI 0.49–0.93), although the improvement in visual acuity was not clinically meaningful (PubMed: Martinez-Zapata et al., Cochrane Database Syst Rev, 2023).
What Is Diabetic Retinopathy?
Diabetic retinopathy is an eye disease that weakens the blood vessels in your retinas. The weakened blood vessels damage the retina, and that damage can cause vision loss. When the damage becomes severe enough, it can even cause permanent blindness.
This matters because diabetes is a major risk factor for vision loss, though not everyone with diabetes will develop retinopathy. Both diabetes and diabetes-related retinopathy are manageable. Combining regular medical care with your own daily efforts can go a long way toward maintaining your vision.
Living with diabetes can be challenging, and learning that you might develop retinopathy can add worry. But you are not powerless. Several things you do every day can delay the condition, and even if you develop it, there are ways to slow it and limit its severity.
The Two Stages of Diabetic Retinopathy
Stage | What happens in the eye | Why it matters |
Nonproliferative (NPDR) | Blood vessels leak into the retina; damaged vessels eventually close off as the body tries to repair them | The earlier, less severe stage — but still damaging the retina |
Proliferative (PDR) | New blood vessels grow on the retina surface to feed undersupplied areas; they leak blood and fluid into the vitreous (the gel-like liquid inside the eye) | The vitreous can stick to these vessels and detach the retina, which can lead to blindness |
Diabetic Retinopathy Symptoms: What to Watch For
You might not have any symptoms in the early stages of diabetic retinopathy. The condition does not start causing vision changes until the damage becomes more severe or widespread throughout the retina.
By the time symptoms appear, they can include the following:
Symptom | What it looks or feels like |
Blurred or distorted vision | Detail becomes soft, wavy, or unclear |
Color vision changes | New color blindness, or colors that look faded or less vivid |
Night blindness (nyctalopia) | Difficulty seeing in dim light |
Eye floaters (myodesopsias) | Spots or streaks drifting through your vision |
Blind spots (scotomas) | Patches of missing vision |
Visual field defects | Areas of your field of view that are cut off |
Low vision and vision loss | Overall decline in how well you can see |
What Causes Diabetic Retinopathy?
Diabetic retinopathy can develop because of multiple types of diabetes:
Diabetes type | Included in risk? |
Type 1 diabetes | Yes |
Type 2 diabetes | Yes |
Type 3c diabetes | Yes |
Gestational diabetes | Yes |
Here is how the damage happens. Diabetes causes increased blood sugar levels, which can damage the insides of blood vessels throughout your body over time. With diabetic retinopathy, the damaged blood vessels in your retina try to repair themselves and reroute to avoid an interruption in blood supply. As a result, fragile new blood vessels grow on the surface of your retina. These new vessels can cause retinal detachments and bleeding into the vitreous.
The damaged blood vessels can also leak fluid into your retina, causing macular edema — swelling that causes blurry vision.
Risk Factors for Diabetic Retinopathy
Your odds of developing retinopathy are significantly higher if your blood sugar is unmanaged and if you have had diabetes for a longer period of time. Specific risk factors include:
Risk factor | Detail |
Difficult-to-manage diabetes | Unmanaged blood sugar strongly raises risk |
High blood pressure (hypertension) | Damages blood vessels further |
High cholesterol (hyperlipidemia) | Contributes to vessel damage |
Heart-specific cardiovascular diseases | Includes heart disease and coronary artery disease |
Chronic kidney disease and kidney failure | Signals widespread vascular damage |
Complications of Diabetic Retinopathy
Over time, retinopathy can produce serious complications:
Complication | What it means |
Diabetic macular edema | Fluid leakage causes swelling in the macula |
Retinal detachments | The retina pulls away from the back of the eye |
Vitreous hemorrhage | Bleeding into the gel-like fluid of the eye |
Glaucoma | Pressure damage to the optic nerve |
Macular ischemia | Loss of blood flow to the part of the retina responsible for color and sharp vision |
Eventually, these complications can damage the light-detecting cells (photoreceptors) so much that they stop working correctly. When enough photoreceptors fail, it causes permanent vision loss and can eventually lead to blindness.
How Is Diabetic Retinopathy Diagnosed?
Many of the key changes that happen with diabetic retinopathy do not cause symptoms until much later — but they are still visible very early to an eye care specialist who looks at the back of your eyes using special instruments during a dilated eye exam.
Diagnostic sign | What the eye doctor sees |
Cotton wool spots | Fluffy white patches on the retina |
Retinal hemorrhages | Bleeding in the retina |
Microaneurysms | Small blood vessels that bulge and burst |
Neovascularization of the eye | Growth of new, abnormal blood vessels |
Macular edema | Swelling in the central retina |
Retinal exudates | Lipid (fat) deposits |
Abnormal-looking retinal blood vessels | Vessels that no longer look healthy |
Vitreous hemorrhage | Bleeding into the gel-like fluid |
This is why a dilated exam matters: the specialist can see damage long before you have symptoms, which is exactly when treatment is most effective.
Diabetic Retinopathy Treatment: Two Approaches Work Together
Diabetic retinopathy is treatable but not curable. Some symptoms or retinal changes are treatable, but certain types of damage are not reversible once they become severe enough. The two main approaches are managing your diabetes and eye treatments, and your provider will recommend both.
Approach 1: Managing Your Diabetes
Research clearly ties higher blood sugar and hemoglobin A1C levels to diabetic retinopathy. Keeping blood sugar lower and more consistent is critical to delaying and slowing how the disease progresses and affects your retinas.
Management step | Why it helps |
Monitor blood sugar | Finger-stick testing or continuous glucose monitoring keeps you informed |
Manage what you eat | Food directly affects blood sugar and A1C |
Take prescribed medications as directed | Keeps blood sugar and A1C in or near your recommended range |
Get regular physical exams | Catches important changes before you feel symptoms |
Keep regular eye exams | Gets you treatment before changes become permanent |
Maintain a healthy weight | A big help in managing diabetes |
Approach 2: Eye Treatments
Eye treatments focus on managing vision and eye symptoms and limiting or slowing retinal damage.
Eye treatment | How it works |
Medications (anti-VEGF drugs, corticosteroids) | Target the factors driving abnormal vessel growth and swelling |
Laser surgery (e.g., laser photocoagulation) | Prevents blood vessel growth, shrinks abnormal vessels, or stops leaking; it can sometimes cause loss of night or peripheral vision |
Eye surgery (vitrectomy) | Recommended if the retina is detached, if vitreous hemorrhage will not clear, or with certain other retinal damage |
When to See a Healthcare Provider
If you have diabetes or diabetic retinopathy, it is crucial to see an eye care specialist regularly. They will recommend a schedule for follow-up visits, which makes a big difference in catching serious changes before they become severe or permanent.
Call or see your provider if you notice gradual vision changes such as vision loss or trouble seeing as well as you used to, blurred or distorted vision, or areas of your vision that look dim, faded, or different from how you saw before.
Go to the nearest hospital or emergency room if you have sudden vision changes, including severe eye pain or complete (or severe) loss of vision.
Can Diabetic Retinopathy Be Prevented?
Yes. Managing your blood sugar levels and maintaining a low hemoglobin A1C can help you prevent diabetic retinopathy — and can even make existing retinopathy regress over time. Not everyone with diabetes gets it, but the odds rise sharply with unmanaged blood sugar and longer duration of diabetes.
If you do not have diabetes but have a high chance of developing it (such as having prediabetes), you can act long before a diabetes diagnosis. Acting earlier can prevent or delay diabetes itself, which affects whether and when retinopathy develops.
Prevention factor | What to do |
Blood sugar and A1C | Keep them low and consistent — this can even reverse early damage |
Regular dilated eye exams | Catch early signs long before symptoms appear |
Family history | First-degree biological relatives (parents, siblings, children) with diabetes mean much higher risk — exams are especially important |
Prediabetes action | Prevent or delay diabetes onset to protect your eyes early |
One honest note: no matter how well you manage your diabetes, sometimes it is not enough to prevent retinopathy entirely. Managing your diabetes, getting regular vision exams, and receiving consistent eye care remain the keys to safeguarding your vision.
Outlook: Living with Diabetic Retinopathy
Diabetic retinopathy is a permanent, lifelong condition. There is no cure, but you can take steps to manage it and limit vision loss. Having diabetes does not guarantee you will develop retinopathy, but the risk is real enough that avoiding or delaying it matters.
With early diagnosis and timely treatment, you may be able to prevent vision loss and delay the progression of diabetic retinopathy. After treatment, you have the best chance of limiting the effects of the disease if you manage your diabetes and keep your blood sugar within the ranges your providers recommend.
Unfortunately, some people will still develop more severe complications. But there are ways to delay those complications as long as possible and to manage diabetes-related vision changes. Anything you can do to limit the severity of vision changes is preferable to developing more severe issues early on.
Key Takeaways
Diabetic retinopathy weakens the blood vessels in your retinas and can cause permanent vision loss or blindness.
It has two stages — nonproliferative (leaking vessels) and proliferative (fragile new vessels that can detach the retina).
Early stages often have no symptoms; damage is visible to an eye specialist long before you feel it.
It is treatable but not curable — strict blood sugar and A1C control is the foundation of slowing it down.
Regular dilated eye exams, timely eye treatments (anti-VEGF, laser, surgery), and healthy habits protect your sight.
Take the Next Step
If you have diabetes or prediabetes, schedule a dilated eye exam at your next healthcare visit — early detection is the single most effective way to keep retinopathy from taking your vision. Share this guide with anyone managing diabetes who has not had an eye exam recently.
Frequently Asked Questions
1. What is diabetic retinopathy?
Diabetic retinopathy is an eye disease in which high blood sugar weakens the blood vessels in the retina — the light-sensitive tissue at the back of the eye. The damaged vessels leak fluid and blood, and fragile new vessels grow on the retina surface. Over time this damage causes vision loss and can lead to permanent blindness.
2. What are the two stages of diabetic retinopathy?
The two stages are nonproliferative (NPDR), in which blood vessels leak into the retina and damaged vessels close off, and proliferative (PDR), in which new fragile blood vessels grow on the retina surface, leak blood and fluid into the vitreous, and can detach the retina — a change that can lead to blindness.
3. What are the first signs of diabetic retinopathy?
In the early stages there are usually no symptoms at all — the damage does not cause vision changes until it becomes more severe or widespread. The first visible signs (such as microaneurysms, cotton wool spots, or leaking vessels) are only detectable during a dilated eye exam by an eye care specialist.
4. Can diabetic retinopathy cause blindness?
Yes. If the disease progresses, complications such as retinal detachments, vitreous hemorrhage, and macular damage can stop photoreceptors — the eye’s light-detecting cells — from working, causing permanent vision loss and potentially blindness.
5. Is diabetic retinopathy reversible?
The condition is treatable but not curable. However, managing blood sugar and keeping a low hemoglobin A1C can help prevent retinopathy and can even make existing retinopathy regress over time. Once damage becomes severe, certain types of retinal damage are not reversible.
6. What types of diabetes cause diabetic retinopathy?
All major types can: type 1, type 2, type 3c, and gestational diabetes. Risk rises with difficult-to-manage diabetes, longer duration of diabetes, high blood pressure, high cholesterol, cardiovascular disease, and kidney disease.
7. How is diabetic retinopathy diagnosed?
Through a dilated eye exam, where a specialist uses special instruments to look at the back of the eyes. The exam can reveal cotton wool spots, retinal hemorrhages, microaneurysms, abnormal vessels, macular edema, retinal exudates, and vitreous hemorrhage — long before symptoms appear.
8. How is diabetic retinopathy treated?
Two approaches work together: managing diabetes (blood sugar monitoring, diet, medications, healthy weight, regular check-ups and eye exams) and eye treatments — anti-VEGF or corticosteroid medications, laser surgery such as photocoagulation, and surgery such as vitrectomy for retinal detachment or persistent hemorrhage.
9. How often should people with diabetes get eye exams?
Regular dilated eye exams are critical for anyone with diabetes or prediabetes, and your eye care specialist will recommend a follow-up schedule. Regular exams allow treatment before changes become permanent — this matters even more if first-degree biological relatives have diabetes.
10. When should I go to the emergency room for vision changes?
Go to the nearest hospital or emergency room for sudden vision changes, including severe eye pain or complete (or severe) loss of vision. For gradual changes like blurred or dimmed vision, call or see your provider promptly.
11. Can managing blood sugar actually slow diabetic retinopathy?
Yes. Research clearly ties higher blood sugar and hemoglobin A1C levels to the disease. Keeping blood sugar lower and more consistent is critical to delaying and slowing how diabetic retinopathy progresses and affects your retinas.
References
Cleveland Clinic. Diabetes-Related Retinopathy. Cleveland Clinic. Feb. 26, 2024. https://my.clevelandclinic.org/health/diseases/8591-diabetic-retinopathy
Kim JE, Feldman BH, Shah VA, et al. Diabetic Retinopathy. American Academy of Ophthalmology EyeWiki. Updated Aug. 31, 2026. https://eyewiki.org/Diabetic_Retinopathy
Kropp M, Golubnitschaja O, Mazurakova A, Koklesova L, Sargheini N, Vo TKS, et al. Diabetic retinopathy as the leading cause of blindness and early predictor of cascading complications—risks and mitigation. EPMA J. 2023;14(1):21-42. doi:10.1007/s13167-023-00314-8. PMID: 36866156.
Shukla UV, Tripathy K. Diabetic Retinopathy. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Updated Aug. 25, 2023. PMID: 32809640. https://www.ncbi.nlm.nih.gov/books/NBK560805/
Teo ZL, Tham YC, Yu M, Chee ML, Rim TH, Cheung N, et al. Global prevalence of diabetic retinopathy and projection of burden through 2045: systematic review and meta-analysis. Ophthalmology. 2021;128(11):1580-1591. doi:10.1016/j.ophtha.2021.04.027. PMID: 33940045.
Aldafas R, Crabtree T, Vinogradova Y, Gordon JP, Idris I. Efficacy and safety of intensive versus conventional glucose targets in people with type 2 diabetes: a systematic review and meta-analysis. Expert Rev Endocrinol Metab. 2023;18(1):95-110. doi:10.1080/17446651.2023.2166489. PMID: 36718676.
Martinez-Zapata MJ, Salvador I, Martí-Carvajal AJ, Pijoan JI, Cordero JA, Ponomarev D, et al. Anti-vascular endothelial growth factor for proliferative diabetic retinopathy. Cochrane Database Syst Rev. 2023;3(3):CD008721. doi:10.1002/14651858.CD008721.pub3. PMID: 36939655.
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read here.
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