High Blood Pressure and Your Eyes
High blood pressure puts a strain on all the blood vessels in your body, including the delicate blood vessels inside your eyes. Although you may not notice any symptoms for many years, this can cause permanent damage to your eyes – even resulting in blindness.
The retina is light-sensitive tissue that lines the inside of the eye. It functions like the film inside a camera. Hypertensive Retinopathy is damage to this tissue caused by high blood pressures.
How does it happen?
High blood pressure causes changes in your blood vessels. You have high blood pressure if the top number of your blood pressure is higher than 140, or if the bottom number of your blood pressure is higher than 90.
In the short term, blood vessels will try to control the blood flow by clamping down. At this stage, you are unlikely to notice any change to your vision.
Long term increases in blood pressure weakens and damages the blood vessels. High stress on vessel walls stretch out the smooth muscle layer. Eventually, the inner layer of the blood vessel breaks, and blood products leak into the vessel wall.
Vessels react by forming abnormal scar products, causing thickening of the vessel wall and narrowing of the inner space. These changes cause blood vessels to become leaky, weak, and abnormal – they may have areas of narrowing and outpouchings called aneurysms.
This can lead to blockage and bleeding of the vessels.
Who gets it?
The longer you’ve had high blood pressure, the more likely you are to develop hypertensive retinopathy.
What are the risk factors for getting Hypertensive Eye Disease?
The risk factors are same as those for getting high blood pressure. These include:
- High salt diet
- Family History
How can I prevent this?
- Maintain good blood pressure
- Stop smoking (if you do currently)
- Limit alcohol
- Eat a healthy low salt diet
- Maintain a healthy weight
- Minimize stress
What are the symptoms?
There are usually no symptoms until the very late stages, when your blood vessels may develop outpouchings (called aneurysms) or become blocked off altogether.
Aneurysms can burst and cause bleeding inside the eye – this can cause floaters or vision loss.
Blocked off vessels will cut off the blood supply to parts of the eye – this may lead to partial or complete vision loss.
- You may not notice any changes to your vision until the very late stages, when the damage is often irreversible. This is why it is important to keep your blood pressure low and get your eyes checked.
Aside from eye disease, having chronic high blood pressure also puts you at risk for heart disease, vessel disease, and stroke.
Tests your doctor might order
Dilate Fundus Exam
- Purpose: Enlarging your pupil so the doctor can take a look inside your eye.
- How it’s done: Eye drops will be used to dilate your eyes (enlarge the pupil) so that the doctor can look inside with some lights and lenses to see if there is any bleeding, swelling, or changes in the blood vessels in the back of your eyes.
- Purpose: This test tells us how the blood is moving through the blood vessels in the back of your eye.
- How it’s done: This test uses a mild dye and a camera to look at the blood vessels inside your eyes. Dye will be injected into one of your veins and pictures will be taken of the inside of your eye.
What your eye doctor can see by looking inside your eyes
- Outpouchings (aneurysms) where the vessel walls are weak
- Bleeding from the vessels
- White deposits left behind by leaking vessel
- Areas of swelling that may cause blurry vision
- Pale areas that are starving and beginning to die
Optic Nerve – the nerve that carries the information from the eye
- Swelling or bleeding caused by leaky, abnormal vessels that supply the nerve (see images below)
Left – Early Changes in Hypertension; Right – Later Changes in Hypertension
!! Malignant Hypertension !!
Very high blood pressure that comes on suddenly is called malignant hypertension. It can cause blurry vision, headaches, change in mental status, shortness of breath, chest pain, and decreased urine output. This can be a life threatening condition, and you should call 911 or go to the emergency room if you have symptoms of malignant hypertension.
What are the symptoms of malignant hypertension?
Immediate symptoms may include headache, eye pain, blurry vision, change in mental status, shortness of breath, chest pain, and decreased urine output.
What should I do?
This can be a life threatening condition, and you should call 911 or go to the emergency room if you have symptoms of malignant hypertension
How is it treated?
If you have malignant hypertension, you will most likely stay in the hospital and take medications to lower your blood pressure until it is under control. Your doctor will also order some tests to see if damage has been done to your kidneys, heart, lungs, eyes, and brain.
What are the long-term effects?
Luckily, symptoms often improve with blood pressure control. However, damage to the optic nerve and macula can cause permanent decrease in vision.
Prepared in partnership with Lily Huang, MD, Class of 2013, Case Western Reserve University School of Medicine.
For more information:
Go to the Eye and Vision Care health topic.