Pathophysiology
Acute blood pressure elevation typically causes reversible vasoconstriction in retinal blood vessels, and hypertensive crisis may cause optic disk edema. More prolonged or severe hypertension leads to exudative vascular changes, a consequence of endothelial damage and necrosis. Other changes (eg, arteriole wall thickening, arteriovenous nicking) typically require years of elevated blood pressure to develop. Smoking compounds the adverse effects of hypertensive retinopathy.
Hypertension is a major risk factor for other retinal disorders (eg, retinal artery or vein occlusion, diabetic retinopathy). Also, hypertension combined with diabetes greatly increases risk of vision loss. Patients with hypertensive retinopathy are at high risk of hypertensive damage to other end organs.
Symptoms and Signs
Symptoms usually do not develop until late in the disease and include blurred vision or visual field defects.
In the early stages, funduscopy identifies arteriolar constriction, with a decrease in the ratio of the width of the retinal arterioles to the retinal venules.
Chronic, poorly controlled hypertension causes the following:
Sometimes total vascular occlusion occurs. Arteriovenous nicking is a major predisposing factor to the development of a branch retinal vein occlusion.
If acute disease is severe, the following can develop:
Moderate hypertensive retinopathy is characterized by thinned, straight arteries, intraretinal hemorrhages, and yellow hard exudates.
This image shows retinal arteriolar narrowing due to thickening and opacification of arteriolar walls (copper wiring) caused by hypertensive arteriosclerosis.
The cardinal funduscopic feature of malignant hypertension is optic disk swelling, which appears as blurring and elevation of disk margins. The image also shows a characteristic star-shaped macular lesion caused by leaking retinal vessels.
Yellow hard exudates represent intraretinal lipid deposition from leaking retinal vessels. These exudates can develop a star shape within the macula, particularly when hypertension is severe. In severe hypertension, the optic disk becomes congested and edematous (papilledema indicating hypertensive crisis).
Diagnosis
Treatment
Hypertensive retinopathy is managed primarily by controlling hypertension. Other vision-threatening conditions should also be aggressively controlled. If vision loss occurs, treatment of the retinal edema with laser or with intravitreal injection of corticosteroids or antivascular endothelial growth factor drugs (eg, ranibizumab, pegaptanib, bevacizumab) may be useful.
Key Points
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Chronic hypertension progressively damages the retina, causing few or no symptoms until changes are advanced.
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Chronic hypertensive retinopathy is recognized by permanent arterial narrowing, arteriovenous crossing abnormalities (arteriovenous nicking), arteriosclerosis with moderate vascular wall changes (copper wiring), or more severe vascular wall hyperplasia and thickening (silver wiring).
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Hypertensive crisis can cause retinopathy with superficial flame-shaped hemorrhages; small, white, superficial foci of retinal ischemia (cotton-wool spots); yellow hard exudates; and optic disk edema.
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Diagnose patients by history and funduscopy.
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Treat primarily by controlling blood pressure, and, for retinal edema, sometimes laser or intravitreal injection of corticosteroids or antivascular endothelial growth factor drugs.
Drugs Mentioned In This Article
| Drug Name | Select Trade |
|---|---|
bevacizumab |
AVASTIN |
ranibizumab |
LUCENTIS |
pegaptanib |
MACUGEN |
