How can diabetic retinopathy be prevented?

How to Prevent Diabetic Retinopathy

Achieve strict glycemic control with HbA1c <7%, maintain blood pressure <130/80 mmHg, optimize lipid levels, and establish regular dilated eye examinations starting at diabetes diagnosis for type 2 diabetes or within 5 years for type 1 diabetes. 1

Glycemic Control: The Foundation

Target HbA1c <7% through intensive diabetes management, which reduces retinopathy progression by approximately 33% and prevents onset by up to 67% when combined with blood pressure and lipid control. 1

• Intensive glycemic control is the single most important modifiable factor for preventing diabetic retinopathy onset and slowing progression 1
• Large prospective randomized trials demonstrate that near-normoglycemic control both prevents and delays diabetic retinopathy development 1
• Caution: Avoid rapid HbA1c reductions when intensifying glucose-lowering therapy, as this can cause early worsening of retinopathy, though this risk is minimal in newly diagnosed patients 2, 3

Blood Pressure Management: Critical Secondary Target

Maintain blood pressure below 130/80 mmHg, as hypertension is an established risk factor for macular edema and proliferative diabetic retinopathy. 1, 2

• Blood pressure control decreases retinopathy progression as demonstrated by the UKPDS trial 1
• Use ACE inhibitors or ARBs as first-line agents for patients with diabetes and hypertension, especially when retinopathy is present or suspected 1, 2
• Systolic targets below 120 mmHg do not provide additional benefits beyond the 130 mmHg target 2
• ACE inhibitors and ARBs provide dual benefit for both kidney and eye protection, particularly important since diabetic nephropathy strongly associates with retinopathy progression 1, 2

Lipid Optimization

Optimize serum lipid control, as dyslipidemia is associated with increased retinopathy risk and progression. 1, 2

• Lipid-lowering agents demonstrate a protective effect on diabetic retinopathy progression 2
• Consider fenofibrate specifically, which may slow retinopathy progression, particularly in patients with very mild nonproliferative diabetic retinopathy 2
• Dyslipidemia shares common pathophysiological mechanisms with other diabetic microvascular complications 2

Screening Protocol: Early Detection is Essential

For type 2 diabetes: Perform initial dilated comprehensive eye examination at the time of diagnosis, not years later. 1

For type 1 diabetes: Perform initial examination within 5 years after diabetes onset. 1

• If any level of retinopathy is present, repeat dilated retinal examinations at least annually 1, 2
• Screening every 1-2 years may be acceptable only if no retinopathy is found for one or more annual exams AND glycemia is well controlled 1
• More frequent examinations are required if retinopathy is progressing or sight-threatening 1, 2
• Promptly refer patients with any level of macular edema, severe nonproliferative diabetic retinopathy, or any proliferative diabetic retinopathy to an ophthalmologist experienced in managing diabetic retinopathy 2

Additional Modifiable Risk Factors

Beyond the classical triad of glucose, blood pressure, and lipids, emerging evidence identifies other modifiable factors 4:

• Obesity and abnormal adipose tissue distribution contribute to retinopathy risk 4
• Lifestyle modifications including dietary changes, vitamin intake, regular exercise, smoking cessation, and appropriate sunlight exposure may play relevant roles 4
• The inflammatory and neurodegenerative components of diabetic retinopathy suggest that neuroprotection may become a future therapeutic strategy for preventing advanced stages 4, 5

Special Population: Pregnancy

Women with type 1 or type 2 diabetes require eye examinations before pregnancy or in the first trimester, with monitoring every trimester and for 1 year postpartum. 1

• Pregnancy may aggravate retinopathy and threaten vision 1

Nephropathy Screening: Dual Benefit

Screen for microalbuminuria annually starting at diagnosis in type 2 diabetes and after 5 years in type 1 diabetes. 1

• Use ACE inhibitors or ARBs for treatment of albuminuria, providing dual benefit for both kidney and eye protection 1
• Diabetic nephropathy is a significant risk factor for diabetic retinopathy progression, and these conditions frequently coexist 2

Critical Pitfalls to Avoid

• Do not discontinue aspirin therapy due to concerns about retinal hemorrhage—retinopathy is not a contraindication to aspirin for cardioprotection 1, 2
• Do not delay screening in type 2 diabetes—examination must occur at diagnosis, not years later 1
• Do not target systolic blood pressure below 120 mmHg, as this provides no additional benefit 2
• Avoid rapid HbA1c reductions in patients with existing retinopathy 2

Algorithmic Approach to Prevention

1. At diabetes diagnosis (type 2) or within 5 years (type 1): Perform dilated comprehensive eye examination 1
2. Immediately initiate: HbA1c target <7%, blood pressure target <130/80 mmHg, lipid optimization 1, 2
3. First-line antihypertensive: ACE inhibitor or ARB 1, 2
4. Annual screening: Microalbuminuria, dilated eye examination (if no retinopathy and good control, can extend to every 1-2 years) 1
5. If retinopathy detected: Annual or more frequent eye examinations, intensify systemic risk factor control 1, 2
6. If vision-threatening retinopathy: Immediate referral to experienced ophthalmologist 2