## Hypertensive Retinopathy: Characteristic vs. Atypical Findings ### Classification of Hypertensive Retinopathy Hypertensive retinopathy is graded by severity, with findings correlating to blood pressure elevation and duration of hypertension. ### Findings Present in Hypertensive Retinopathy | Finding | Mechanism | Grade | |---------|-----------|-------| | Flame-shaped hemorrhages | Rupture of superficial retinal arterioles in nerve fiber layer | I–IV | | Cotton-wool spots (microinfarcts) | Ischemia of nerve fiber layer due to arteriolar occlusion | II–IV | | Hard exudates (macular star) | Lipid leakage from damaged capillaries; organized in radial pattern around macula | II–IV | | Arteriovenous nicking | Arteriole compresses venule at crossing (Salus sign) | I–II | | Copper-wire arterioles | Severe arteriolar narrowing and wall thickening | III–IV | | Papilledema | Optic disc swelling from increased intracranial pressure in malignant hypertension | IV | **Key Point:** Neovascularization of the disc and retina is NOT a feature of hypertensive retinopathy. Neovascularization occurs in ischemic retinopathies (diabetic retinopathy, central retinal artery occlusion, sickle cell retinopathy) where there is significant retinal ischemia and upregulation of VEGF. Hypertensive retinopathy causes acute vascular damage and leakage but does NOT trigger the chronic ischemic stimulus needed for neovascularization. ### Clinical Pearl **High-Yield:** The presence of neovascularization in a hypertensive patient should prompt investigation for an alternative diagnosis—most commonly diabetic retinopathy (if the patient is also diabetic) or other ischemic retinal diseases. Pure hypertensive retinopathy does not produce new vessel formation. ### Mnemonic for Hypertensive Retinopathy Grades **CHAFE** — Cotton-wool spots, Hard exudates, Arteriolar narrowing, Flame hemorrhages, Edema (papilledema) - Grade I: Arteriolar narrowing only - Grade II: Arteriolar narrowing + flame hemorrhages, cotton-wool spots, hard exudates - Grade III: Grade II + papilledema - Grade IV: Grade III + optic disc swelling and macular star (malignant hypertension) ### Why Neovascularization Is the Exception Neovascularization requires chronic retinal ischemia with upregulation of angiogenic factors (VEGF, FGF). Hypertensive retinopathy is primarily an acute vasculitic and vasospastic process causing hemorrhage and exudation, not chronic ischemia. Only when hypertension coexists with diabetes or other ischemic retinopathies does neovascularization occur—and that would be attributed to the ischemic disease, not hypertension alone. [cite:Harrison 21e Ch 428]
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