A 48-year-old woman with chronic hypertension (BP 160/100 mmHg, well-controlled on medication for 3 years) undergoes routine fundoscopy. She has arteriovenous nicking, arteriolar narrowing, and scattered flame hemorrhages but no optic disc swelling. In contrast, her sister with acute hypertensive crisis (BP 210/130 mmHg) presents with the same retinal findings plus papilledema and retinal whitening. Which feature best discriminates chronic hypertensive retinopathy from acute hypertensive retinopathy?

Explanation

## Chronic vs. Acute Hypertensive Retinopathy **Key Point:** Optic disc edema (papilledema) and retinal whitening (cotton-wool spots and retinal infarcts) are the hallmark findings that distinguish acute hypertensive retinopathy (malignant hypertension, Grade IV) from chronic hypertensive retinopathy (Grades I–III). ### Grading of Hypertensive Retinopathy (Keith-Wagener-Barker Classification) | Grade | BP | Findings | Prognosis | | --- | --- | --- | --- | | **I** | Elevated | Arteriolar narrowing, AV nicking | Excellent | | **II** | Elevated | Grade I + focal arteriolar constriction | Good | | **III** | Elevated | Grade II + flame hemorrhages, cotton-wool spots, hard exudates | Fair | | **IV (Malignant)** | Very high (>180/120) | Grade III + **optic disc edema**, retinal whitening, Elschnig spots | Poor without treatment | **High-Yield:** The transition from chronic (Grade III) to acute (Grade IV) hypertensive retinopathy is marked by the **sudden appearance of papilledema and retinal whitening**. These findings indicate acute endothelial failure, blood-retinal barrier breakdown, and impending hypertensive encephalopathy. **Clinical Pearl:** Retinal whitening in acute hypertensive retinopathy includes: - Cotton-wool spots (nerve fiber layer infarcts) - Retinal infarcts (Elschnig spots) - Retinal edema (giving a "white" appearance to the posterior pole) These are NOT present in chronic hypertensive retinopathy because the retinal vasculature has adapted to chronic elevation in pressure. **Mnemonic — Acute HTN Retinopathy (PAPILLEDEMA):** - **P**apilledema (optic disc edema) - **A**cute presentation - **P**erfusion failure (retinal infarcts) - **I**schemic (cotton-wool spots) - **L**ipid exudates - **L**ayer infarcts (nerve fiber) - **E**dema (retinal) - **D**iastolic BP >120 mmHg - **E**mergency (hypertensive crisis) - **M**alignant hypertension - **A**cute kidney injury (systemic sign) [cite:Park 26e Ch 8]