Diabetic Retinopathy (DR)
A progressive microvascular complication of diabetes mellitus affecting the retina, leading to blindness if untreated. Diabetic retinopathy is caused by damage to the blood vessels in the tissue at the back of the eye (retina).
Causes & Risk Factors
- Chronic hyperglycemia (HbA1c >7%)
- Hypertension & Dyslipidemia
- Smoking & Alcohol Consumption
- Duration of Diabetes (>10 years)
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| DIABETIC RETINOPATHY |
Pathophysiology
- Microvascular changes → Capillary basement membrane thickening.
- Increased vascular permeability → Leakage of plasma proteins & lipids.
- Capillary occlusion → Retinal ischemia → VEGF release.
- Neovascularization (PDR) → Fragile vessels rupture → Vitreous hemorrhage & retinal detachment.
Stages
- Non-Proliferative DR (NPDR): Microaneurysms, dot-blot hemorrhages.
- Proliferative DR (PDR): Neovascularization, vitreous hemorrhage.
- Diabetic Macular Edema (DME): Retinal thickening at the macula.
Clinical Features
- Gradual vision loss
- Scotomas (blind spots in vision)
- Floaters (due to vitreous hemorrhage)
- Blurry & distorted vision
Diagnosis & Investigations
- Fundoscopy: Essential for DR staging.
- Optical Coherence Tomography (OCT): Detects macular edema.
- Fundus Fluorescein Angiography (FFA): Shows capillary leakage & ischemia.
- Visual Acuity Test: Determines functional vision loss.
Treatment & Management
- Target HbA1c <7%, BP <130/80 mmHg.
- Anti-VEGF Therapy: Bevacizumab, Ranibizumab, Aflibercept.
- Laser Photocoagulation: For NPDR & PDR to reduce progression.
- Vitrectomy: For persistent vitreous hemorrhage.
Hypertensive Retinopathy (HR)
A spectrum of retinal vascular changes due to persistent hypertension (>140/90 mmHg).
Causes & Risk Factors
- Chronic systemic hypertension
- Atherosclerosis & Arteriolar sclerosis
- Diabetes, Smoking, Obesity
- Renal Disease
Stages (Keith-Wagener-Barker Classification)
- Mild HR: Arteriolar narrowing, AV nicking.
- Moderate HR: Hemorrhages, cotton wool spots.
- Severe HR: Retinal edema, extensive hemorrhages.
- Malignant HR: Papilledema (Medical Emergency).
Clinical Features
- Mild Cases: Asymptomatic.
- Severe Cases: Blurred vision, headache, visual field defects.
Diagnosis & Investigations
- Fundoscopy: Identifies characteristic signs.
- OCT & FFA: Evaluates macular involvement.
- BP Monitoring: Essential for systemic evaluation.
Treatment & Management
- BP Control: ACE inhibitors (Lisinopril), ARBs (Losartan), CCBs (Amlodipine).
- Urgent Care (Malignant HR): IV Labetalol, Nitroprusside for rapid BP reduction.
- Lifestyle changes: Low-salt diet, exercise.
Comparison Table
| Feature | Diabetic Retinopathy (DR) | Hypertensive Retinopathy (HR) |
|---|---|---|
| Definition | Microvascular complication of diabetes causing retinal damage due to prolonged hyperglycemia. |
Retinal vascular damage due to systemic hypertension, leading to arteriosclerosis and ischemia. |
| Causes | Chronic hyperglycemia, uncontrolled diabetes (Type 1 & 2). |
Chronic systemic hypertension, sudden BP spikes. |
| Pathophysiology | Hyperglycemia → endothelial damage → capillary leakage & occlusion → ischemia → neovascularization. |
Increased BP → endothelial damage → arteriosclerosis → ischemia & leakage. |
| Stages | NPDR, PDR, DME | Mild, Moderate, Severe, Malignant HR |
| Symptoms | Gradual vision loss, floaters, scotomas. |
Blurred vision, headaches, sudden vision loss. |
| Treatment | Anti-VEGF (Ranibizumab, Bevacizumab), Laser photocoagulation, Vitrectomy. |
BP control (ACE inhibitors, ARBs, CCBs), Anti-VEGF in severe cases. |
Conclusion
Diabetic Retinopathy: Caused by hyperglycemia-induced retinal damage; treated with anti-VEGF, laser, and vitrectomy.
Hypertensive Retinopathy: Caused by hypertension-induced retinal changes; managed by BP control and addressing systemic conditions.