Ischemic optic neuropathy, known as ION, is a sudden loss of central vision and/or side vision because of poor blood flow to the optic nerve which transmits visual signals from the eye to the brain. The most common sympttom of ION is a loss of central or side vision. Some people notice a loss of side vision in the lower half of reading vision. Vision loss is usually at its worst when first noticed and in most eyes, permenently remains at this level. In a few eyes, vision either progressively worsens or improves over days to weeks.
ION generally does not cause any other symptoms, such as pain or double vision. The risk of stroke is no greater for people with ION. People who may have temporal arteritis, one cause of ION, notice headaches and tenderness in the temples. Joint aches and pains commonly affect the shoulders and hips of people with this blood vessel disorder. Patients may also feel tired and run a fever, combined with recent weight loss.
The most common type of ION occurs in individuals over 40 years of age and is usually not related to other illness. ION may be more common in people with diabetes and high blood pressure. A less common type of ION occurring in people over 60 years of age is temporal arteritis. This disease is an inflammation of certain arteries, including those in the eye. Rarely, ION can occur after loss of large amounts of blood.
ION has no proven treatment. There is about a 50% risk that the other eye may lose vision. There is no treatment to improve vision, however, 43% of patients will experience spontaneous improvement of their vision over time. Patients with ION caused by temporal arteritis have a very high chance of the other eye being affected unless treated with corticosteroids. Treatment with corticosteroids is for prevention of ION in the fellow eye but this treatment rarely improves vision that has been lost in the affected eye.
Unfortunately, with either type of ION, vision loss is usually permanent. For those with severe vision loss in both eyes, often some side vision is preserved. This side vision generally allows the patient enough sight to function at home independently. Special visual devices are available to help patients continue many of their daily activites.
Home