The retina is tissue located in the back of your eye that transforms light into nerve signals that are then sent to the brain for interpretation. When your blood pressure is too high, the retina’s blood vessel walls may thicken. This may result in narrowing of the vessels, which then restricts blood from reaching the retina. In some cases, the retina becomes swollen.
Over time, high blood pressure can cause damage to the retina’s blood vessels and limit the retina’s function, and can also put pressure on the optic nerve, causing vision problems. This is called hypertensive retinopathy (HR).
The main cause of HR is high blood pressure. Hypertensive retinopathy generally occurs after your blood pressure has been persistently high over a prolonged period. A lack of physical activity, being overweight, and a stressful lifestyle are all factors that can negatively affect blood pressure levels.
If you have high cholesterol or diabetes, or if you smoke, your risk of vision problems increases.
According to the Harvard Heart Letter, studies show that people with hypertensive retinopathy are up to four times more likely to suffer from a stroke than people without the condition. Other studies show a link between hypertensive retinopathy and a higher risk for heart attack, and observed that women are more likely to be affected by blood vessel damage than men
In rare cases, a condition called malignant hypertension can develop. This condition causes blood pressure readings to increase suddenly, interfering with vision and causing sudden vision loss. People with hypertensive retinopathy are also at risk of developing other complications related to the retina.
Ischemic optic neuropathy can take place when high blood pressure blocks off normal blood flow in the eyes, damaging the optic nerve. The optic nerve carries images of what we see to the brain.
Retinal artery occlusion occurs when the arteries that carry blood to the retina become blocked by blood clots. When this happens, the retina does not receive enough oxygen or blood, resulting in loss of vision.
You will likely not experience symptoms until the condition has progressed extensively. Possible symptoms include:
- reduced vision
- eye swelling
- bursting of blood vessel
- double vision accompanied by headaches
If your blood pressure is high and you suddenly have changes in your vision, seek medical help immediately.
Your doctor will use a tool called an ophthalmoscope, which shines a light through the pupil to examine the back of your eye for signs of narrowing of blood vessels, or to see if any fluid is leaking from the blood vessels. This procedure is painless, and takes less than 10 minutes to complete. In some cases, a special test called fluorescein angiography is performed to examine retinal blood flow. In this procedure, your doctor will apply special eye drops to dilate your pupils and then take pictures of your eye. After the first round of pictures, your doctor will inject a dye called fluorescein into a vein (typically on the inside of the elbow), then take further pictures as the dye moves into the blood vessels of your eye.
Your doctor will determine the extent of the retinopathy, which is generally represented on a scale of one to four. On the lower end of the scale, you may not have any symptoms. At grade four, your eyes typically suffer from swelling of the optic nerve that can cause more serious vision problems. High-grade retinopathy tends to be a sign of serious blood pressure concerns. People with grade four retinopathy have a higher risk for stroke and may have kidney or heart disease.
Effective treatment for hypertensive retinopathy involves controlling and lowering high blood pressure with a combination of medication and behavioral changes.
A diet high in fruits and vegetables may help lower blood pressure. Regular physical activity, reducing salt intake, and limiting the amount of caffeine and alcoholic beverages you drink all contribute to healthy blood pressure as well. If you smoke, take steps to quit. If you are overweight, losing weight is an effective strategy to controlling high blood pressure.
Your doctor may prescribe blood pressure medications such as diuretics or ACE inhibitors.
You can control this condition by controlling your blood pressure. If your condition is severe, however, you may have irreversible eye damage that causes permanent vision problems.
To prevent hypertensive retinopathy, take precautions to avoid high blood pressure. Take your blood pressure medication regularly. Get regular exercise, eat a balanced diet, and avoid smoking. Keep up-to-date with regular medical exams to ensure that your blood pressure readings are normal.