## Distinguishing Hypertensive from Diabetic Retinopathy **Key Point:** Optic disc edema (papilledema) is the hallmark finding that separates hypertensive retinopathy from diabetic retinopathy. It indicates acute, severe hypertensive damage to the optic nerve head and is pathognomonic for hypertensive emergency. ### Comparative Table | Feature | Hypertensive Retinopathy | Diabetic Retinopathy | | --- | --- | --- | | **Optic disc edema** | Present (especially in acute/malignant HTN) | Absent | | **Cotton-wool spots** | Present | Present | | **Hard exudates** | Present (macular star pattern) | Present | | **Microaneurysms** | Absent or rare | Hallmark finding | | **Flame hemorrhages** | Common | Less common | | **Arteriovenous nicking** | Prominent | Absent | | **Arteriolar narrowing** | Marked | Mild | **High-Yield:** In hypertensive retinopathy, optic disc swelling reflects acute endothelial damage and breakdown of the blood-retinal barrier due to severe elevation in BP. Diabetic retinopathy does NOT cause optic disc edema unless there is concurrent diabetic macular edema or other comorbidity. **Clinical Pearl:** The presence of papilledema in a hypertensive patient signals **hypertensive emergency** (Grade IV hypertensive retinopathy) and mandates urgent antihypertensive therapy to prevent stroke, MI, or acute kidney injury. **Mnemonic — Hypertensive Retinopathy Features (FLAME-ADS):** - **F**lame hemorrhages - **L**ayer (cotton-wool spots = nerve fiber layer infarcts) - **A**rteriolar narrowing - **M**acular star exudates - **E**dema of optic disc ← **KEY DISCRIMINATOR** - **A**rteriovenous nicking - **D**iastolic dysfunction (systemic HTN) - **S**evere BP elevation [cite:Park 26e Ch 8] 
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.