Overview
Diabetic retinopathy is an eye condition that occurs when chronically high blood sugar levels damage the blood vessels in the retina—the light-sensitive layer at the back of the eye. Over time, this damage can lead to vision problems and blindness, especially in people with poorly managed diabetes.

Why It’s Important
Diabetic retinopathy is the leading cause of vision loss in adults aged 20–74 in the U.S. It often has no symptoms in early stages, making routine eye exams crucial. If caught and treated early, vision loss can be slowed or prevented.

Quick Facts

• Affects nearly 1 in 3 adults over age 40 with diabetes

• Can affect both Type 1 and Type 2 diabetes

• Risk increases with duration of diabetes, poor blood sugar control, high blood pressure, and high cholesterol

• Condition is progressive and chronic

• Two main stages:

  • Non-proliferative diabetic retinopathy (NPDR) – early stage

  • Proliferative diabetic retinopathy (PDR) – advanced stage with new, fragile blood vessels that can bleed

What Happens in the Body
High blood sugar weakens and damages tiny blood vessels in the retina, causing them to leak fluid or blood, or become blocked. In advanced stages, the retina tries to grow new vessels, but these are abnormal and prone to rupture, leading to scarring, retinal detachment, or blindness.

Common Signs and Symptoms
Often no symptoms in early stages. As it progresses:

• Blurred or fluctuating vision

• Dark spots or floaters

• Impaired color vision

• Empty or dark areas in vision

• Vision loss (especially sudden in later stages)

• Symptoms often affect both eyes

Diagnosis

• Detected through comprehensive dilated eye exam by an ophthalmologist or optometrist

• Tests include:

  • Visual acuity test

  • Dilated retinal exam to check for bleeding or swelling

  • Fluorescein angiography (dye test to view blood flow)

  • Optical coherence tomography (OCT) to detect swelling in the retina

• Annual eye exams are critical for anyone with diabetes

• Red flag symptoms: sudden vision changes, dark floaters, or flashes of light

Treatment and Management

• Blood sugar, blood pressure, and cholesterol control are the foundation of prevention and treatment

• Laser therapy (photocoagulation) to seal leaking vessels

• Anti-VEGF injections (e.g., ranibizumab, aflibercept) to reduce swelling and stop abnormal vessel growth

• Vitrectomy surgery in advanced cases (removes blood and scar tissue from the eye)

• Early NPDR may not need immediate treatment but requires close monitoring

• Not curable, but progression can be slowed or halted

Risks and Complications

• Retinal detachment

• Vitreous hemorrhage (bleeding into eye)

• Macular edema (swelling in central vision)

• Blindness

• Often progresses without pain, making it more dangerous without screening

Who Is at Risk

• People with Type 1 or Type 2 diabetes, especially for >5–10 years

• Poor blood sugar control

• High blood pressure

• High cholesterol

• Pregnancy (can worsen retinopathy)

• Smoking

• African American, Hispanic, and Native American populations are at higher risk

Related Conditions

• Macular edema (often a result of retinopathy)

• Cataracts (diabetes-related risk)

• Glaucoma

• Kidney disease (microvascular complications often occur together)

When to See a Doctor

• If you’re diabetic and haven’t had a dilated eye exam in the past year

• If you notice sudden changes in vision, floaters, or blurriness

• If you are pregnant with diabetes, get an eye exam during the first trimester

• Any diabetic experiencing vision issues should be evaluated urgently

Last Updated: June 21, 2025