Diabetic retinopathy (DR) is a common and serious complication of diabetes that affects about one in four people living with the condition in the United States. In 2021, an estimated 9.6 million Americans with diabetes had some form of diabetic retinopathy, with nearly 2 million experiencing vision-threatening stages of the disease1 2. As diabetes prevalence rises, the burden of diabetic eye disease is expected to grow, making early detection and management critical to preserving vision3 1.
Diabetes and Vision Health
Diabetes mellitus can cause damage to the small blood vessels in the eyes, leading to a range of vision problems and even blindness4 . Elevated blood sugar levels harm the retinal blood vessels, causing them to swell, leak, or become blocked. This damage disrupts the retina's ability to function properly and can lead to diabetic retinopathy, diabetic macular edema, vitreous hemorrhage, neovascular glaucoma, and cataracts4 . Over time, uncontrolled diabetes may cause retinal detachment and irreversible retinal damage, resulting in permanent vision loss4 .
Key risk factors that increase the likelihood of diabetic eye complications include:
- Duration of diabetes: longer disease duration raises risk4 .
- Poor blood sugar control over time4 .
- High blood pressure and cholesterol levels5 .
- Smoking5 .
- Certain racial and ethnic groups, including African American, Hispanic/Latino, and Native American populations5 6.
Regular eye exams and controlling systemic factors like blood sugar, blood pressure, and cholesterol are essential to reduce the risk of vision loss5 7.
Diabetic Retinopathy Overview
Diabetic retinopathy is a microvascular complication of diabetes that affects the retina, the light-sensitive tissue at the back of the eye responsible for vision8 9. It is a sensory neuropathy involving multiple retinal cell types and can impair visual functions such as contrast sensitivity and dark adaptation even before visible signs appear8 . The underlying mechanisms include oxidative stress and metabolic abnormalities caused by chronic high blood sugar levels10 .
Globally, the prevalence of diabetic retinopathy among people with diabetes ranges from about 25% to over 40%, depending on the population studied and the duration of diabetes11 1213. In the United States, approximately 26.4% of people with diabetes had diabetic retinopathy in 2021, equating to 9.6 million individuals1 2. Vision-threatening diabetic retinopathy (VTDR), which includes severe stages of the disease, affected about 5% of people with diabetes14 2.
The prevalence of diabetic retinopathy increases with age but tends to decrease in the oldest age groups, likely due to earlier mortality among those with severe diabetes1 . Additionally, VTDR prevalence is higher among Black and Hispanic individuals compared to White individuals, highlighting disparities in disease burden6 .
“Diabetic retinopathy is caused by changes in the microscopic blood vessels of the eye. In this condition, the blood vessels and nerves that go to the retina of the eye are affected. It causes the blood vessels to sometimes swell or even leak blood or fluid into the eye.”
— Gangaputra3
Forms of Diabetic Retinopathy
Diabetic retinopathy progresses through distinct stages that reflect increasing severity and risk to vision. The two major forms are:
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Non-proliferative diabetic retinopathy (NPDR): This early stage is characterized by weakening and bulging of retinal blood vessels, leading to swelling and leakage. Fluid accumulation in the macula (the central part of the retina responsible for sharp vision) causes diabetic macular edema, the most common cause of vision loss in DR4 9. NPDR may cause mild vision blurriness but is often treatable, especially if detected early4 .
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Proliferative diabetic retinopathy (PDR): This advanced stage involves the growth of new, abnormal blood vessels (neovascularization) on the retina's surface. These fragile vessels can bleed into the vitreous humor, causing floaters or severe vision loss. Scar tissue formation can lead to retinal detachment and neovascular glaucoma, both of which threaten permanent blindness4 9.
Vision-threatening diabetic retinopathy (VTDR) includes severe NPDR, PDR, and diabetic macular edema at any stage14 2. VTDR requires urgent medical attention to prevent irreversible vision loss.
| Stage | Key Features | Vision Impact | Treatment Urgency |
|---|---|---|---|
| Non-proliferative DR (NPDR) | Retinal vessel swelling, leakage, macular edema | Mild to moderate vision blurriness | Early detection critical |
| Proliferative DR (PDR) | Neovascularization, vitreous hemorrhage, scar tissue | Floaters to severe vision loss | High risk, requires prompt treatment |
Regular retinal screening is essential to detect DR early, as the disease can develop silently without symptoms while retinal neural cells sustain damage4 15. Unfortunately, adherence to recommended yearly eye exams remains low, with some populations showing screening rates below 20% 16.
Diagnosing and Treating Retinopathy
Diagnosis of diabetic retinopathy relies on a comprehensive dilated eye exam, which allows the ophthalmologist to examine the retina and retinal blood vessels closely9 4. Additional imaging tests include:
- Optical coherence tomography (OCT): Provides detailed cross-sectional images of the retina to detect swelling and fluid accumulation9 4.
- Fluorescein angiography: Involves injecting a dye to visualize blood flow and identify leaking or blocked vessels9 4.
Classification of diabetic retinopathy into NPDR and PDR stages guides treatment decisions11 4. Diabetic macular edema (DME) can occur at any stage and is a major cause of vision loss11 4.
Although the number of people with diabetes-related retinal diseases has increased, the incidence of the most severe, vision-threatening forms has decreased in recent years. This suggests improvements in diabetes care and screening access may be preventing severe vision loss. 19
Treatment options include:
- Anti-vascular endothelial growth factor (anti-VEGF) injections: Medications injected into the eye to reduce swelling and inhibit abnormal vessel growth11 4.
- Laser photocoagulation: Laser therapy to seal leaking vessels and shrink abnormal blood vessels11 4.
- Vitrectomy surgery: Removal of vitreous gel and blood in cases of vitreous hemorrhage or retinal detachment11 4.
Emerging technologies such as FDA-cleared autonomous artificial intelligence (AI) screening tools are improving early detection rates by enabling automated diabetic retinopathy screening in primary care settings7 17.
“All diabetes patients with vision abnormalities should definitely seek assessment with their eye care provider, as there are treatment options that can save the patient from losing vision.”3
Preventing Diabetes-Related Eye Damage
💡 Did You Know? More recently, the ACCORD trial demonstrated that intensive glycemic control reduced the risk of progression of diabetic retinopathy, highlighting the importance of blood sugar management18 .
Preventing or delaying diabetic retinopathy and its complications depends largely on early diagnosis, effective treatment, and good control of systemic risk factors7 5. Key prevention strategies include:
- Maintaining tight glycemic control to reduce blood sugar fluctuations18 7.
- Managing blood pressure and cholesterol levels to protect retinal vessels5 7.
- Adhering to regular annual dilated eye exams to detect early retinal changes4 7.
- Improving healthcare access and addressing social determinants of health to increase screening adherence7 .
- Utilizing AI-based screening tools to expand coverage and reduce disparities in underserved populations11 7.
Lifestyle modifications such as quitting smoking, maintaining a healthy weight, and engaging in regular physical activity also contribute to eye health5 .
