Carotid Artery Disease
When people are warned and are concerned about deposits forming in the blood vessels, most think of the arteries surrounding and supplying the heart with its oxygen and nutrients, and the possibility of heart attack or stroke.
Actually, the body has an intricate system of arteries and veins busily moving blood from the heart to the very tips of the fingers and toes and all organ systems, and they are all prone to damage from deposits of fatty tissues and calcium that can develop from genetic causes or from an unhealthy lifestyle and diet.
All the blood that brings nutrients and oxygen to the brain is transported through two arteries, the carotids, located on both sides of the neck. The jugular veins carry the oxygen-depleted blood back to the heart and lungs. The carotid arteries are the ones close to the surface of the neck and are the ones that form the pulse in the neck. Higher up, the carotid arteries branch into their interior and exterior branches.
The carotid arteries, just as others elsewhere in the body, are prone to have plaque buildup and loss of elasticity known as "hardening of the arteries." As plaques form along the artery walls from cholesterol, calcium and fats in the blood, they can even form discrete deposits that can break free from the artery walls and be carried along by the circulation; this is what is known as atherosclerosis. General narrowing of the arteries is known as stenosis.
Stenosis of the arteries can result in a general reduction of the flow of blood, which means the brain cells get less and less oxygen and nutrients as time passes. If a discrete plaque breaks free, it can clog the passage of blood down that particular artery. If the clog happens to an artery that feeds the heart, the result can be a heart attack; if it occurs in the carotid arteries it can lead to a stroke or transient ischemic attack (TIA) and cause a loss of function beyond that point.
Please see the articles about Retinal Vein Occlusion and Retinal Artery Occlusion, about more specific information on blockages that can occur in the eye.
Transient Ischemic Attacks are sometimes known as “mini-strokes,” and can be valuable as diagnostic tools for circulatory problems that could result in heart attack or full-fledged stroke. Because carotid artery disease usually doesn’t present with clear-cut symptoms or signs, sometimes the TIA can be an indicator that the person has carotid artery disease.
Signs and symptoms of a stroke or TIA include:
- Sudden numbness or weakness in the face or limbs, usually on one side of the body but not in the other
- Trouble speaking or understanding others
- Sudden vision changes such as seeing double or even loss of vision in one eye
- Dizziness and loss of balance
- Sudden, severe headache with no known cause
A quick way to tell if someone is having a stroke or a TIA is to ask the person to do three little things:
- Raise both arms
- Speak a simple sentence
- People experiencing a TIA or stroke will almost always have trouble with one or more of these simple tasks.
See your primary care physician as soon as possible if you experience these symptoms or signs; often a TIA will resolve itself in about an hour or so, but that doesn’t mean the problem is gone; it just means you have a little more time to take action before experiencing a serious heart attack or stroke.
See the list to the left; if the person has problems with even one of these tasks, call an ambulance immediately to prevent possible permanent loss of functions. Do not wait to see if the symptoms disappear, as this is a time-sensitive emergency. Don’t take the person to the hospital yourself, don’t allow the person to drive there. Call 911 immediately.
Risk factors for carotid artery disease include high blood pressure, smoking, age, abnormal fat levels in the blood, diabetes, obesity, heredity and lack of physical exercise.
Testing and Treatment
Some cases of carotid artery disease have no symptoms at all, but some have an indicator that your physician may be able to detect using a stethoscope, called a bruit. A bruit is a sound generated by turbulence in the effected artery. Pronounced “broo'-ey" this characteristic sound can be a valuable signal that the circulation has been effected.
Several specialized tests will be performed to determine if carotid artery disease or other circulatory problems exist.
The goal of treating carotid artery disease is to prevent a future stroke or heart attack. The method of treatment depends to some extent on how much narrowing of the artery wall has formed.
Treatment can include changes in diet and exercise patterns, better management of any chronic medical conditions such as high blood pressure or diabetes, adding a blood-thinner such as low-dose aspirin to decrease the chance of dangerous blood clots, or using other medications to increase circulation and decrease cholesterol.
In more severe cases, your physician may recommend carotid artery surgery to prevent more serious attacks in the future.
By now, you may be thinking, “OK, but what does this have to do with my eyes?” and the answer is: “Everything!”
Arterial stenosis and blockages can also happen in the vessels that carry blood to the eye, where they are called retinal artery occlusions (RAO). An RAO is a very serious issue for the vision as it can cause loss of vision in the effected eye. It is also a clear indication of circulatory trouble elsewhere, just like a TIA.
Yearly vision examinations are recommended for all patients over 55 years old to search for just this type of thing. There are many diseases and conditions that are painless and unnoticeable until the damage is already permanent; most eye conditions are not painful at all.
See your eyecare practitioner right away if you experience a loss of vision without pain or head injury. It is possible to be unaware of vision changes that are only happening in one eye, so it’s best to get regular checkups.
Your vision is the first concern of an eyecare practitioner, but he or she is also concerned with the more complete picture of health or disease that may be present, and if a future heart attack or stroke can be avoided, your eye doctor wants to help you do so.