NAION is a disease of the optic nerve, which is the cable that connects your eye to your brain. We need this nerve to send messages from the eye to the brain about things we see. When the optic nerve is damaged, it is called an “optic neuropathy”. The word “ischemic” means that there was a loss of blood flow to the optic nerve. When the blood supply to any part of the body is cut off, then that body part becomes damaged. Damage to the optic nerve causes loss of vision. Most people with NAION notice loss of either the top half or the bottom half of their vision, or both. “Non-arteritic” means that it is not a particular kind of optic neuropathy that affects all the arteries of the body, called temporal arteritis or arteritic ischemic optic neuropathy.
Who is at risk for NAION?
NAION is a disease of blood flow, so people who have unhealthy blood vessels may be at risk. These are the same risk factors as for other diseases of blood flow like stroke or heart attack. Risk factors are poorly controlled blood pressure (too high or even too low), high cholesterol, smoking, diabetes and a personal or family history of stroke or heart attack. Not everyone who has these medical problems with get NAION. It is much more common is people who have a certain size and shape of their optic nerve. You may hear your doctor say that you have a “disc at risk”, which just means that the tip of your optic nerve (the disc) is small.
Will I get my vision back?
You may get a little improvement over the first few months, but it will not go back to normal. Most people are able to read with the affected eye, but the peripheral vision almost always stays foggy.
Can it happen again?
It is very rare to have NAION happen twice in the same eye.
Will this happen to my other eye?
Most people have similar size and shape optic nerves, so that means that NAION could happen to your other eye. But the risk is less than 15%, which means you have an 85% chance that it won’t happen to your other eye. You can work on your risk factors like blood pressure, cholesterol, diabetes and smoking to protect your other eye.