A 58-year-old man from Delhi presents to the ophthalmology clinic with blurred vision in both eyes for 2 weeks. He has a 10-year history of hypertension, poorly controlled on amlodipine monotherapy. His current blood pressure is 178/114 mmHg. On fundoscopy, you observe flame-shaped hemorrhages, cotton-wool spots, hard exudates arranged in a macular star pattern, and optic disc swelling. What is the Keith–Wagener–Barker grade of hypertensive retinopathy in this patient?

## Keith–Wagener–Barker Grading of Hypertensive Retinopathy **Key Point:** The presence of optic disc edema (papilledema) is the defining feature that elevates hypertensive retinopathy to Grade IV, indicating accelerated/malignant hypertension. ### Grading Classification | Grade | Features | Clinical Significance | |-------|----------|----------------------| | **I** | Minimal arterial narrowing, no retinal changes | Mild hypertension | | **II** | Arteriovenous nicking, flame hemorrhages, hard exudates | Moderate hypertension | | **III** | Grade II + cotton-wool spots, retinal edema, macular star exudates | Severe hypertension | | **IV** | Grade III + **optic disc edema (papilledema)** | Accelerated/malignant hypertension | **High-Yield:** Optic disc swelling in the presence of hypertensive retinopathy findings is pathognomonic for Grade IV and indicates a hypertensive emergency requiring urgent BP reduction. **Clinical Pearl:** Macular star exudates (hard exudates radiating from the fovea in a star pattern) are a hallmark of Grade III–IV disease and correlate with severity of retinal edema and lipid leakage. **Warning:** Do not confuse Grade III (cotton-wool spots + macular star without disc edema) with Grade IV (same findings + optic disc swelling). The disc edema is the critical discriminator. ### Pathophysiology Accelerated hypertension causes acute endothelial injury, fibrinoid necrosis of arterioles, and breakdown of the blood–retinal barrier, leading to: - Retinal hemorrhages (flame-shaped due to superficial location) - Cotton-wool spots (nerve fiber layer infarcts) - Hard exudates (lipid and protein leakage) - Optic disc edema (ischemic swelling from arteriolar occlusion) **Mnemonic:** **CHEMO** for Grade IV findings — **C**otton-wool spots, **H**emorrhages, **E**xudates, **M**acular star, **O**ptic disc edema. [cite:Park 26e Ch 11]