My brother-in-law came over for Thanksgiving, wearing an eyepatch over one eye. At first, I thought he was playing a joke as he’s known for things like that. It turned out he developed nerve palsy unexpectedly. He said his doctor told him that it’s apparently normal to happen when you age. My husband shouted, “Where’s the old man manual?” We laughed, but apparently it can be serious.
Nerve palsy is a disorder that affects eye movement. It’s caused by something disrupting the blood flow or damage to the sixth cranial nerve. The function of this nerve is to send signals to the small muscle, lateral rectus located on the outer side in your eye. It helps you turn your eye away from your nose. When the muscle weakens, your eye crosses inward toward your nose. The sixth cranial nerve travels from the brainstem to the lateral rectus muscle. This means neurologic disorders may cause the nerve palsy. Various circumstances and illnesses can also cause the disorder. This includes head injuries, a skull fracture, stroke, brain tumor, a brain aneurysm, multiple sclerosis, diabetic neuropathy, meningitis, Lyme disease, and inflammation or infection.
Double vision is the most common symptom. Other symptoms include crossed eyes or poor eye alignment. Your eyes don’t look in the same direction at the same time. Treatment in some cases is unnecessary because the nerve palsy improves with time, such as when caused by a viral infection. Other times, the disorder only improves once the underlying cause has been treated. Your doctor may prescribe antibiotics if it’s caused by a bacterial infection.
If you have a brain tumor, symptoms of nerve palsy won’t improve until after surgery, chemotherapy, or other treatments to remove the tumor or kill the cancer cells. If caused by trauma, your doctor may monitor your condition over a six month period. If the double vision or cross eyes hasn’t improved or worsens, options include wearing an eye patch over the affected eye or the doctor might recommend prism glasses to provide single binocular vision and align your eyes. Another treatment is Botox injections. The doctor paralyzes the muscles on one side of the eye to correct poor alignment.