What Are the Treatments for Ischamic Neuropathy?

Ischamic neuropathy, or AION (anterior ischemic optic neuropathy) is a disease of the eye that typically strikes those who are middle aged or elderly. Typically, ischamic neuropathy begins suddenly without warning and is local to one eye. It is considered to be a stroke of the optic nerve, and it often progresses to effect both eyes over time. Vision loss varies and may cause severe impairment in the visual field and visual acuity. There are minimal treatments available, however corrective measures may help improve vision, and new developments may help reduce the effects of ischamic neuropathy.

Symptoms

• When ischamic neuropathy is diagnosed, blood work is generally performed to diagnose or rule out giant cell arteritis (GCA). GCA is largely asymptomatic and may strike patients who are in good health. GCA, one cause of ischamic neuropathy, is dangerous and can be fatal, in addition to causing permanent vision loss. However, the permanent vision loss caused is generally preceded by a loss of vision or blurring.

  Nonarteritic ischamic neuropathy (NAAION) is more common than that caused by CGA and has a better prognosis. Approximately 90% of patients diagnosed with NAAION are over age 45 and it affects men and women equally. Its cause is acute impairment of the circulation of the arteries that supply the optic nerve. The impaired circulation causes a temporary fall in blood pressure, so the vessels supplying the optic nerve do not receive sufficient blood.

Prevention

• Although ischamic neuroapthy often can't be prevented, it is speculated that a drop in blood pressure while sleeping is one cause of nonarterial ischamic neuropathy. Because 75% of patients with vision loss report decreased vision when they wake, researchers believe ischemia must occur during sleep. If this theory is substantiated, blood pressure lowering medications may be proven to increase the risk of ischamic neuropathy. Furthermore, smoking may also help to cause blood pressure problems that lead to ischamic neuropathy.

Treatment

• Currently there are few treatment options for the optic nerve. Doctors may prescribe medications that lower intraocular pressure to protect the optic nerve and increase blood flow to prevent ischamic neuropathy. Taking baby aspirin after an episode of ischamic neuropathy that affects only one eye may also help to reduce the risk of ischemia occurring in the other eye. For patients diagnosed with GCA, steroids may help to reduce the incidents of ischamic neuropathy and save the patient's vision.

Low Vision Rehabilitation

• Because the ischemia generally can't be treated effectively, treatment for ischamic neuropathy involves rehabilitating decreased vision. There are four areas of rehabilitation: magnification, contrast, glare control and visual field loss. Special rehabilitators, including eyeglasses, magnifiers and sun filters may be recommended. Closed circuit television systems with magnifying effects may also be worn around the head to magnify objects.

Prognosis

• Approximately 40% of patients who experience ischamic neuropathy may have some improvement in vision in the weeks or months after the initial vision loss. However, approximately 20-25% of patients who are only affected in one eye will develop an ischemia in the other eye within three years.