Ischemic optic neuropathy (ION) occurs when blood flow to your eye’s optic nerve is disrupted, resulting in long-term damage to the nerve. When you have ION, you lose vision in one or both of your eyes.
The optic nerve connects your eyes to your brain, carrying signals. These messages are subsequently translated into the visuals you see by your brain. The optic nerve does not receive adequate oxygen or nutrients when blood flow is decreased or stopped. The optic nerve eventually stops operating correctly and dies.
ION can damage either your central (detail) or peripheral (side) vision—or both. Any visual loss caused by ION is usually permanent since a damaged optic nerve cannot be repaired. People with severe ION usually retain some peripheral vision.
What Are the Signs and Symptoms of ION?
Your vision will darken for a few seconds or minutes if the blood supply to your optic nerve is decreased, then return to normal. This is referred to as a transient ischemic attack (TIA). This type of attack can occur prior to the start of ION. If you think you’re having a TIA, see your ophthalmologist or primary care physician right away. Early detection and treatment of the condition can help avoid additional ION vision loss.
Who Is at Risk of Developing ION?
Ischemic optic neuropathy (ION) can affect anyone, but you are more likely to have it if you:
- Have high blood pressure
- suffer from diabetes
- smoke cigarettes
- have arteries that are blocked
- have glaucoma
- are over the age of 50
- suffer from migraine
- arteries in the head are swollen (called temporal arteritis)
Your ophthalmologist will perform an eye exam to look for evidence of ischemic optic neuropathy (ION). He or she will use eye drops to dilate (widen) your pupils, then examine the back of your eye for enlargement of the optic nerve and blood vessels.
Your ophthalmologist may also examine your peripheral vision and take measurements of the fluid pressure inside your eye.
Your ophthalmologist may prescribe steroid (prednisone) pills if your ION is caused by the swelling of arteries in your brain (temporal arteritis). This medication may help prevent ION in your other eye from forming.
Any additional health issues that put you at risk for ION should be addressed by your doctor. He or she may prescribe medication to treat high blood pressure, diabetes, clogged arteries, migraine headaches, and other ailments.
There is no treatment for ION-related visual loss. On the other hand, your ophthalmologist may recommend valuable tools and practices to help you see with low vision.