What are the symptoms and treatment options for diabetic retinopathy?

Symptoms and Treatment of Diabetic Retinopathy

Diabetic retinopathy is often asymptomatic in its early stages, with patients developing vision-threatening complications only in advanced disease, making regular screening essential for early detection and treatment. 1, 2

Symptoms of Diabetic Retinopathy

Early Stages (Mild to Moderate NPDR)

• Often asymptomatic - patients maintain normal vision
• No visual complaints until disease progresses
• May have subtle changes only detectable through professional examination

Advanced Stages

• Blurred vision
• Fluctuating vision
• Progressive vision loss
• Floaters (from vitreous hemorrhage)
• Dark or empty areas in vision (scotomas)
• Impaired color vision
• Sudden vision loss (in cases of vitreous hemorrhage or retinal detachment)

Progression Pattern

Diabetic retinopathy progresses from mild nonproliferative abnormalities characterized by increased vascular permeability, to moderate and severe nonproliferative diabetic retinopathy (NPDR) characterized by vascular closure, and finally to proliferative diabetic retinopathy (PDR) characterized by new blood vessel growth 1.

Classification of Diabetic Retinopathy

Non-Proliferative Diabetic Retinopathy (NPDR)

• Mild NPDR: Microaneurysms only
• Moderate NPDR: More than just microaneurysms but less than severe NPDR
• Severe NPDR: Any of the following (without signs of proliferative retinopathy):
  • More than 20 intraretinal hemorrhages in each of four quadrants
  • Definite venous beading in two or more quadrants
  • Prominent intraretinal microvascular abnormalities in one or more quadrants 1

Proliferative Diabetic Retinopathy (PDR)

• Neovascularization (abnormal new blood vessel growth)
• Vitreous/preretinal hemorrhage 1

Diabetic Macular Edema (DME)

• Can occur at any stage of diabetic retinopathy
• Classified based on retinal thickening and hard exudates:
  • Mild: Retinal thickening/hard exudates distant from macula center
  • Moderate: Approaching but not involving the center
  • Severe: Involving the center of the macula 1

Treatment Options

Preventive Measures

1. Glycemic Control

   • Optimize blood glucose levels (target HbA1c <7%)
   • Reduces risk of onset and progression of retinopathy 1, 2

2. Blood Pressure Control

   • Lowering blood pressure decreases retinopathy progression
   • ACE inhibitors and ARBs are effective treatments 1

3. Lipid Management

   • Addition of fenofibrate may slow retinopathy progression, particularly in very mild NPDR 1

Treatment Based on Disease Stage

Non-Proliferative Diabetic Retinopathy (NPDR)

• Mild to Moderate NPDR without DME:

  • Regular monitoring
  • Optimization of metabolic control 1, 2

• Severe NPDR:

  • Urgent referral to ophthalmologist
  • Consider panretinal photocoagulation (PRP) 1, 2

Proliferative Diabetic Retinopathy (PDR)

• Panretinal Laser Photocoagulation (PRP):

  • Standard treatment for high-risk PDR
  • Reduces risk of severe vision loss by 50-60%
  • Most beneficial in advanced baseline disease 1, 2

• Anti-VEGF Therapy:

  • Intravitreal injections of anti-VEGF agents (ranibizumab, aflibercept, bevacizumab)
  • Alternative for patients who cannot undergo PRP
  • FDA approved ranibizumab for diabetic retinopathy treatment 2, 3

• Vitrectomy:

  • For vitreous hemorrhage or tractional retinal detachment
  • Beneficial in cases of severe proliferative retinopathy with vitreous hemorrhage 2, 4

Diabetic Macular Edema (DME)

• DME without Central Involvement:

  • Focal/grid laser photocoagulation 2

• DME with Central Involvement:

  • Intravitreal anti-VEGF agents as first-line treatment
  • Monthly injections initially, with fewer injections needed in subsequent years 1, 2

• Refractory DME:

  • Intravitreal corticosteroids as an option 1, 2

Screening Recommendations

• Type 1 Diabetes: Initial dilated eye examination within 5 years after diagnosis 1
• Type 2 Diabetes: Initial dilated eye examination at time of diagnosis 1
• Follow-up Intervals:
  • No retinopathy: Every 1-2 years
  • Mild NPDR: Every 6-12 months
  • Moderate NPDR: Every 3-6 months
  • Severe NPDR: Every 3 months
  • PDR: Less than 1 month 2

Special Considerations

Pregnancy

• Pregnancy may aggravate retinopathy, especially with poor glycemic control at conception
• More frequent monitoring required during pregnancy
• Women with gestational diabetes do not require eye examinations during pregnancy 1

Aspirin Therapy

• Retinopathy is not a contraindication to aspirin therapy for cardioprotection
• Aspirin does not increase the risk of retinal hemorrhage 1

Important Clinical Pitfalls to Avoid

1. Delayed Screening: Many patients with diabetic retinopathy remain asymptomatic until advanced disease develops. Don't wait for symptoms to appear before screening.

2. Inadequate Follow-up: Ensure appropriate follow-up intervals based on retinopathy severity.

3. Poor Glycemic Control: Failure to optimize blood glucose, blood pressure, and lipid levels significantly increases risk of progression.

4. Missing Macular Edema: DME can occur at any stage of retinopathy and requires prompt treatment if central involvement is present.

5. Delayed Referral: Prompt referral to an ophthalmologist is essential for any level of macular edema, severe NPDR, or any PDR.