Diabetic Retinopathy (DR)
A microangiopathy caused by prolonged hyperglycemia. It is the leading cause of preventable blindness in working-age adults.
| Stage | Key Clinical Features |
|---|---|
| Non-Proliferative (NPDR) | Microaneurysms (earliest sign), dot/blot hemorrhages, hard exudates (lipid), cotton wool spots (ischemia). |
| Proliferative (PDR) | Neovascularization (disc or elsewhere), vitreous hemorrhage, and tractional retinal detachment. |
Hypertensive Retinopathy
Reflects systemic blood pressure. Changes in the retinal arterioles (vasoconstriction, sclerosis, and leakage) correlate with organ damage.
- Keith-Wagener-Barker Classification:
- Grade 1: Mild generalized arteriolar narrowing.
- Grade 2: Focal narrowing + AV nipping (crossing changes).
- Grade 3: Grade 2 + hemorrhages, exudates, and cotton wool spots.
- Grade 4: Grade 3 + papilledema (Malignant Hypertension).
High-Yield Comparison Pearls
| Comparison Point | Diabetic Retinopathy | Hypertensive Retinopathy |
|---|---|---|
| Primary Pathogenesis | Microvascular leakage & ischemia. | Arteriolar sclerosis & constriction. |
| Exudates | Hard exudates (lipoprotein). | Star-shaped (macular star). |
Clinical Note:
Diabetic Macular Edema (DME) is the most common cause of vision loss in DR, whereas papilledema (Grade 4 hypertensive retinopathy) is a hallmark of an emergency hypertensive crisis.