Diabetic Retinopathy

Diabetic retinopathy is a complication of diabetes that affects the blood vessels in the retina, the light-sensitive tissue at the back of the eye. It's the leading cause of blindness in working-age adults but can often be prevented or managed with proper diabetes control and regular eye exams.

Stages of Diabetic Retinopathy

Non-Proliferative Diabetic Retinopathy (NPDR)

Mild NPDR:

• Small areas of balloon-like swelling (microaneurysms)
• Usually no vision symptoms
• No treatment typically needed

Moderate NPDR:

• Some blood vessels become blocked
• Small hemorrhages and exudates appear
• May develop macular edema

Severe NPDR:

• Many blood vessels are blocked
• Retina signals for new blood vessel growth
• High risk of progression to proliferative stage

Proliferative Diabetic Retinopathy (PDR)

• Most advanced stage
• New, abnormal blood vessels grow (neovascularization)
• These vessels are fragile and leak easily
• Can cause:
  • Vitreous hemorrhage (bleeding inside the eye)
  • Tractional retinal detachment
  • Neovascular glaucoma
  • Severe, potentially irreversible vision loss

Diabetic Macular Edema (DME)

• Can occur at any stage
• Fluid leaks into the macula (central vision area)
• Causes blurry or distorted central vision
• Most common cause of vision loss in diabetic retinopathy

Symptoms

Early Stages

• Often no symptoms
• Vision may be normal despite retinal changes
• This is why regular screening is crucial

Progressive Disease

• Blurry vision
• Floaters (spots or dark strings)
• Dark or empty areas in vision
• Fluctuating vision
• Difficulty with color perception
• Vision loss

Risk Factors

• Duration of diabetes—longer duration increases risk
• Poor blood sugar control
• High blood pressure — if you're unsure whether your eye changes are from diabetes or blood pressure, both can damage retinal blood vessels in overlapping ways
• Diabetes also frequently causes dry eye through corneal nerve damage
• High cholesterol
• Pregnancy (can accelerate retinopathy)
• Smoking
• African American, Hispanic, or Native American ancestry

How Diabetic Retinopathy Is Diagnosed

Dilated Eye Exam

• Drops to widen pupil
• Examination of retina for:
  • Microaneurysms
  • Hemorrhages
  • Exudates (fatty deposits)
  • Abnormal blood vessel growth
  • Macular swelling

Imaging Tests

Optical Coherence Tomography (OCT)

• Cross-sectional images of the retina
• Detects and measures macular edema
• Monitors treatment response

Fluorescein Angiography

• Dye injected into arm vein
• Photos show blood vessel leakage
• Maps areas of poor blood flow
• Guides laser treatment

OCT Angiography

• Non-invasive blood vessel imaging
• No dye injection needed
• Shows blood flow abnormalities

Treatment Options

Blood Sugar Control

The foundation of management:

• Tight glucose control slows progression
• HbA1c target typically below 7%
• Reduces risk of developing retinopathy by 76%
• Slows progression of existing retinopathy

Blood Pressure Control

• Target usually below 130/80 mmHg
• Reduces risk of progression
• Important even without hypertension diagnosis

Anti-VEGF Injections

For diabetic macular edema and PDR:

• Medications: aflibercept (Eylea), ranibizumab (Lucentis), bevacizumab (Avastin)
• Injected directly into the eye
• Reduce swelling and abnormal vessel growth
• Given monthly initially, then less frequently
• Can significantly improve vision

Laser Treatment

Focal/Grid Laser (for DME):

• Treats leaking blood vessels
• Stabilizes vision
• Less commonly used now with anti-VEGF

Panretinal Photocoagulation (PRP) (for PDR):

• Treats peripheral retina
• Reduces abnormal vessel growth
• May reduce peripheral and night vision
• Often combined with anti-VEGF

Vitrectomy Surgery

For advanced cases:

• Removes blood from vitreous
• Repairs retinal detachment
• Removes scar tissue
• Can restore vision in severe cases

Prevention

Primary Prevention

• Maintain good blood sugar control
• Control blood pressure and cholesterol
• Don't smoke
• Annual dilated eye exams

Screening Recommendations

Type 1 diabetes:

• First exam within 5 years of diagnosis
• Then annually

Type 2 diabetes:

• First exam at diagnosis
• Then annually (or as recommended)

During pregnancy:

• Exam in first trimester
• Monitor throughout pregnancy

Living with Diabetic Retinopathy

Lifestyle Management

• Check blood sugar regularly
• Take medications as prescribed
• Eat a balanced, healthy diet
• Exercise regularly
• Attend all eye appointments
• Monitor vision changes

When to Call Your Doctor

• New floaters or flashes
• Sudden vision changes
• Blurry or distorted vision
• Difficulty reading or driving

Frequently Asked Questions

Can diabetic retinopathy be reversed?

Early stages may improve with better diabetes control. However, significant damage cannot be reversed. Treatment focuses on preventing further vision loss. This is why early detection and prevention are so important.

How often do I need eye exams?

At minimum, annually. More frequent exams if you have retinopathy—every 6 months for moderate NPDR, every 3-4 months for severe NPDR or PDR, depending on your doctor's recommendations.

Will I go blind from diabetes?

With modern treatment and good diabetes management, most people do not go blind. However, diabetic retinopathy remains a leading cause of blindness because many people don't get regular exams or control their diabetes well.

Do eye injections hurt?

The eye is numbed with drops before injection, so most patients feel only mild pressure. The procedure is quick and any discomfort is brief.

Can I prevent diabetic retinopathy?

You can significantly reduce your risk by:

• Keeping blood sugar well controlled
• Managing blood pressure
• Not smoking
• Getting regular eye exams

Does diabetic retinopathy affect both eyes?

Usually yes, though severity may differ between eyes. Both eyes should be examined and treated as needed.

References