What are the treatment options for diabetic retinopathy?

Treatment Options for Diabetic Retinopathy

Anti-VEGF therapy is the first-line treatment for center-involving diabetic macular edema, while panretinal photocoagulation remains the standard treatment for proliferative diabetic retinopathy. 1

Classification of Diabetic Retinopathy

Diabetic retinopathy can be classified into two main categories:

1. Non-proliferative diabetic retinopathy (NPDR):

   • Mild
   • Moderate
   • Severe

2. Proliferative diabetic retinopathy (PDR):

   • Characterized by neovascularization, vitreous/preretinal hemorrhage

Diabetic macular edema (DME) can occur at any stage of diabetic retinopathy and is classified as:

• Without central involvement
• With central involvement

Treatment Algorithm Based on Disease Severity

1. NPDR without DME

• Optimize glycemic control (target HbA1c <7%)
• Control blood pressure and lipids
• Regular follow-up:
  • Mild NPDR: every 6-12 months
  • Moderate NPDR: every 3-6 months
  • Severe NPDR: every 3 months 1

2. NPDR with DME

• Without central involvement:

  • Focal/grid laser photocoagulation 2
  • Follow-up every 3 months 1

• With central involvement:

  • Anti-VEGF therapy (ranibizumab, aflibercept, bevacizumab) as first-line treatment 2, 1
  • Most patients require near-monthly administration during first 12 months, with fewer injections in subsequent years 2
  • Follow-up every month initially 1

3. PDR

• Panretinal photocoagulation (PRP) is the standard treatment 2

  • Reduces risk of severe vision loss from 15.9% to 6.4% in treated eyes 2
  • Most beneficial in advanced baseline disease (disc neovascularization or vitreous hemorrhage) 2

• Anti-VEGF therapy as an alternative when PRP cannot be performed 1

  • FDA approved ranibizumab for treatment of diabetic retinopathy in 2017 2
  • Ranibizumab demonstrated improvement in ETDRS-DRSS scores in clinical trials 3
  • Aflibercept showed significant improvement in ETDRS-DRSS scores compared to control groups 4

• Vitrectomy for:

  • Severe vitreous hemorrhage that doesn't clear
  • Tractional retinal detachment 1

Adjunctive Therapy

1. Glycemic Control:

   • Intensive glycemic management reduces risk of retinopathy onset and progression 2
   • Caution: Rapid implementation of intensive glycemic control in patients with existing retinopathy may cause early worsening 2

2. Blood Pressure Control:

   • Lowering blood pressure decreases retinopathy progression 2
   • ACE inhibitors and ARBs are both effective treatments 2, 1
   • Tight targets (systolic BP <120 mmHg) do not provide additional benefit 2

3. Lipid Management:

   • Fenofibrate may slow retinopathy progression, particularly in very mild NPDR 2, 1

Follow-up Recommendations

• No retinopathy: every 1-2 years
• NPDR mild: every 6-12 months
• NPDR moderate: every 3-6 months
• NPDR severe: every 3 months
• PDR: less than 1 month
• DME without central involvement: every 3 months
• DME with central involvement: every month 1

Special Considerations

Pregnancy

• Pregnancy can cause rapid progression of diabetic retinopathy 2
• Women with pre-existing diabetes who are planning pregnancy should be counseled about risk of progression 2
• Women with gestational diabetes do not require eye examinations during pregnancy 2

Common Pitfalls and Caveats

1. Delayed Treatment: Early detection and timely intervention are crucial to prevent vision loss. Many patients present too late when significant neurodegeneration has already occurred 5.

2. Underestimating Non-vascular Components: Diabetic retinopathy is now recognized as an inflammatory, neuro-vascular complication with neuronal injury preceding clinical microvascular damage 5.

3. Incomplete Treatment Response: While anti-VEGF therapy has shown remarkable benefits, many patients fail to achieve clinically significant visual improvement, highlighting the need for comprehensive management 6.

4. Inadequate Follow-up: Regular ophthalmological examinations are essential, especially in high-risk patients, to detect progression early 7.

5. Poor Interdisciplinary Coordination: Close cooperation between endocrinologists, primary care physicians, and ophthalmologists is critical for optimal management 7.

Diabetic retinopathy remains the leading cause of blindness among working-age adults in developed countries, making early detection, appropriate treatment, and regular follow-up essential components of diabetes care 8, 7.