Health ... Conditions
How Hypertension Can Put Your Vision at Risk
from Johns Hopkins Health Alerts
If you have ever experienced love at first sight, you know that the heart and the eyes share an intimate connection. Unfortunately, the eyes and the heart are also linked in a less romantic way: through hypertension, or high blood pressure.
Hypertension can damage the small blood vessels that supply the retina, the layer of light-sensitive cells at the back of the eye that are essential to vision. Called hypertensive retinopathy, this condition occurs in 2 to 14 percent of people over age 40.
Hypertension is also a risk factor for other diseases of the eye, including retinal vein and retinal artery blockages, retinal emboli (blood clots), diabetic retinopathy, ischemic optic neuropathy (damage to the optic nerve because of reduced blood flow), glaucoma and age-related macular degeneration.
All of these conditions, including hypertensive retinopathy, can cause headaches, blurry vision and, if left untreated, a loss of vision. What’s more, these conditions may forebode other serious, non-eye-related conditions such as stroke, heart failure and death from cardiovascular disease. Fortunately, detecting hypertension-related eye problems sooner rather than later can help preserve your eyesight.
When your blood pressure is high, the increased pressure can cause damage to several structures in your eye: the retina, macula and optic nerve:
- Damage to the retina from hypertension. The small blood vessels in the retina are very delicate, and even slightly elevated pressure can cause them to narrow and thicken. As blood-vessel damage worsens, cotton-wool spots (small areas of damaged tissue) and hemorrhages (bleeding) begin to appear in the retina. Cotton-wool spots are the result of reduced blood flow to the retina. Bleeding occurs when blood leaks out of small tears in the blood vessels.
- Damage to the macula from hypertension. With further damage, the blood vessels lose their structural integrity and other fluids and fat leak out as well. These leaked substances form hard exudates around the macula (the central portion of the retina). This produces swelling of the macula that can lead to vision loss.
- Damage to the optic nerve from hypertension. When blood pressure is extremely high, blood flow to the optic nerve (which carries visual signals to the brain) can become blocked. This reduction in blood flow causes swelling of the optic nerve that can ultimately result in a permanent loss of vision.
The Good News -- In most cases, hypertension-related eye disease progresses slowly. While this means the condition could go undetected for some time before you notice changes in your vision, it also means that, if you have an annual dilated eye exam, you and your doctor can detect any problems early and treat them before any permanent vision changes occur.
Medical Disclaimer: This information is not intended to substitute for the advice of a physician. Click here for additional information: Johns Hopkins Health Alerts Disclaimer
